DIY Solar Resources?

TihSon writes "I'm building a large shed out back and I want to power the lighting using a surplus solar panel. In searching for information on how to go about this, I have found a lot of rough DIY guides for various projects that are close to my goal. But none seem to explain the reasoning and theory behind using solar panels, so hacking their project to suit my own needs could be pretty much hit-and-miss. I don't want to do a hacked-up job, and future solar projects are not out of the question, so something a bit more in-depth is required. Do you have suggestions for books or Web sites you have used to learn the ins and outs of using solar panels? Something that starts with basic theory and ends with the ability to wire a house would be perfect."

Comments

Well?

[Anonymous Coward]

I someone please shed some light on this issue.

Re:Well?

[donguru]

See http://www.tinaja.com/glib/morenrgf.pdf for a tutorial the underlying math. And why today's pv panels are TOTALLY POINTLESS in that they clearly remain net energy sinks. At present, the cost of the synchronous inverter alone will often consume more than 100 percent of the value of the electricity fed through it. Assuming a panel cost of ZERO.

Re:Well?

[ehrichweiss]

I didn't read it as the pv panels were the sink but rather the synchronous power inverters were at fault. And there are companies like nanosolar that are getting 1 Kw per Kg of solar material, IIRC their technology doesn't require the "panels" to track the sun and they're working toward $1/watt pretty quickly.

But then there's thermal energy derived from the sun and there are nearly limitless possibilities there since the development of that carbon nanotube material that absorbs 99.8% of all light that hits it. I imagine that in many parts of the country that could be converted to heat water, create steam and drive turbines, or the new stirling engine technology if it's getting along, or even just store it underground for later use. Then one could combine that technology with the brilliant idea where they essentially put the solar-thermal collector in a vacuum so that the heat couldn't boil back off of the collector and it instead got passed quickly away to an insulated tank. It was viable over 10 months out of the year and even worked on cloudy days. I'm sure it was posted here a while back.

Re:Well?

[Heembo]

I'm glad to see you quote Nanosolar. That is the company to watch. A few years back most solar R&D went into 2 camps - one camp tried to advance the underlying solar technology and mostly failed. Another camp went the route of just trying to fine-tune manufacturing (to reduce cost for mass production). That's where Nanosolar comes in. The technology behind Nanosolar in terms of energy creation is old news - but the fine tuning in the manufacturing process (super cheap "plain air" facilities) is what is so stellar about the company. Their thin-film solar panel stock is currently sold out until 2009 since several large municipal solar power generation plants bought their stock already.

Re:Well?

[Score Whore]

They're not energy sinks. They're financial sinks.

The analysis makes the premise that every penny spent on energy will be spent on energy regardless of source. This is false. Some people are willing to pay extra for energy from a specific source that they value more. Think of it as a sunglasses budget: someone might spend $300 for a pair of hand made Italian sunglasses, but if they couldn't get those specific hand made Italian glasses, they won't go and buy 100 pair of the $3.00 special on the counter at Seven Eleven.

Re:Well?

[Dare nMc]

I wasn't too impressed with that document, a little light on sources, and presented in a manner to twist the math even though thats not necessary.
More importantly that math only applies to grid connect systems, this question is about a building with no grid power, and light power demands. I bought a 45 Watt system from harbor freight, for $120 only missing a battery, has 12 Volt lights, controller, etc. For a 120 V solution, I would need a $100 permit, $80 of wire, to get inside the building (next to my house with grid power.) A property with no existing grid power system to backbone off would be out thousands of dollars to connect, then a minimum monthly payment of maybe $20 for life.

Re:Well?

[Anonymous Coward]

That analysis isn't too clear. It sounds like some economics student got ahold of some numbers and a calculator, and this is what he spewed in a late night drunken bull session at the dorm, and no one called him on his bullshit.

It is probably true that the economic unviability of varous energy schemes generally points to the fact that they may use up more energy than they create. It is probably a good first-order attempt at evaluating the "carbon footprint" of a Prius, for example, to see if it saves enough gas to pay for the expensive technology in it, as expensive components usually cost more in terms of carbon released to make.

However, this guy takes it too far. He observes that it is possible to swap dollars and energy in both directions; he uses the $10 word "fungible" which seems to have the effect of short-circuiting much of his gray matter; and then he asserts that money-losing PV schemes are actually consuming energy. Does this "educated stupid" egghead believe that an interest bearing account violates the laws of thermodynamics ?

I think more carefully researched guesses are that PV panels started breaking even around 2000 or so, and they produce more energy over their lifetimes than they took up to produce, now. (This is ignoring the fact that PV panels produced with cheap hydroelectric power in the Northwest can act as sort of batteries to export that cheap power to sunny places.)

This is the best link I know of that analyzes the PV payback issue (in terms of energy, not dollars):

http://www.ecotopia.com/apollo2/pvpayback.htm

Re:Well?

[UnderCoverPenguin]

The May issue of Circuit Cellar (http://circuitcellar.com) wrapped up a 3 part series on installing a solar electric system.

Re:Well?

[rrhal]

Real goods catalog is also a good source of info. I hooked up my cabin in Alaska from them. It worked well in the months there was sunlight.

Re:Well?

[Ex-MislTech]

Converting from DC to AC wastes power, stay DC and use LED
lights because some have life spans and power usage that is
lower any other kind.

The only draw back on LED is it costs a fair bit more up front.

The good news is you could use a cheaper/smaller battery, and
don't have to pay for an inverter at all.

At some point LEDs for lighting will go mainstream and mass
produced and the cost will start to fall.

http://en.wikipedia.org/wiki/LED_lighting

For daytime lighting of the shed you might try to make
your own Solatube.

http://en.wikipedia.org/wiki/Light_tube

Re:Well?

[CopaceticOpus]

Everyone is missing the obvious here. Simply remove the roof, and the sun will light the interior directly.

Re:Well?

[Iron Condor]

Who are the nutcases that mod this kind of drivel "Informative"? That author has no clue what he's talking about. A shed without power plus a solar panel equals a shed with power - and all the whining of the anti-solar retards isn't going to change that.

IT DOES NOT MATTER what idiotic games you can play with dollars to make solar look unattractive (and the fact that have to play games in the first place proves you squarely wrong anyways) when you have a shed without power. There's simply one solution and no word-games and math-fiddling is going to make it go away. There's NO alternative. You go ahead and power your lights with fifty-packs of C-batteries that you have to replace once a week, but for reasonable people who'd just like to run a light in a shed, solar is THE solution.

Re:Well?

[Atario]

Their thin-film solar panel stock is currently sold out until 2009 since several large municipal solar power generation plants bought their stock already.

I keep hearing this, but you'd think if they had so many payments coming in already, they could afford to expand production. Get on it, guys!

Re:Well?

[Heembo]

The just began opened up a 100 million dollar manufacturing facility. It takes time to ramp up production. They are targeting municipal solar - not consumer.

Re:Well?

[CAIMLAS]

So basically, what you're saying is this: that solar power is just about image.

Whether you say that solar power costs more per watt or that solar power wattage is more expensive due to increased energy requirements at the production side, the net result is the same.

Re:Well?

[Score Whore]

No it's not about image (well for some it may be, but the same can be said about anything.) I'm saying it's about more than just getting energy. For some people, they know that their grid is supplied primarily via coal power. Which, even with all the technology available to us, is still quite dirty. I know it may come as a surprise to you, but some people prefer not to shit in their drinking water, both literally and analogously. Maybe they're willing to pay a little extra to reduce their impact.

I'm not sure what you are saying in your second paragraph. I don't think it has anything to do with Don's article. You might want to take the time to read it before you start blathering about what assume it says. (I'll give you a hint: it doesn't make the claim that it takes more energy to build a solar PV system than you get from that same system. Because, you know, that's not true either.)

The point of the linked analysis was that for a given number of dollars you can generate more power via other mechanisms than you can with solar PV. Then concludes that therefore it is a net energy loss because less is generated than could have been for the same money. Which is false. A person buying a $10,000 solar PV system isn't cutting down their energy usage because it costs more for them, they're using the same amount of energy, just paying more.

He's right in that, for a lot of people, it's not economically sensible. But he's wrong in making any kind of connection between the generating costs of various sources and a gain or loss of actual energy.

Re:Well?

[godawsgo]

Canadian Tire has a 'solar powered shed light. It is sold for $29.99.

Solar Powered Shed Light

I can't imagine spending too much time fiddling with equations without first plunking $30 to see if this junk will do the trick...

Dawson

Re:Well?

[armb]

> power your lights with fifty-packs of C-batteries that you have to replace once a week

Or you run a cable to the shed. There are applications where that just isn't practical, like data logging devices miles from the nearest power, but for a typical garden shed, it's much more feasible, even if a solar solution would be simpler (assuming you do a proper job of burying the cable in an appropriate conduit).

Re:Well?

[electronerdz]

I spend $3 on the sunglasses I buy. When they get scratched, I throw them away or give them to kids to play with. Everything thinks they are $100 glasses and freak out when I tell them to throw them out because I forget them at their place.

Re:Well?

[eugene ts wong]

Also, solar panels might allow a person/group to set up an energy source that is far away from the grid. The cost of bringing out batteries, of power cables, or of generators would be too expensive, I assume. Solar energy would have to be cheaper in those situations.

Re:Well?

[theshowmecanuck]

use "K1A 0A9" as the postal code if you are interested. It is the postal code of the Canadian parliament buildings. The web site authors of Canadian Tire are retards the way they set up the site entrance.

Re:Well?

[Zebra_X]

"one camp tried to advance the underlying solar technology and mostly failed."

That is simply not true at all. December 6, 2006 http://www.boeing.com/ids/news/2006/q4/061206b_nr.html. 40% is nothing to scoff at, and it does use a different underlying technology.

Nanosolar has done great things - but to say that advancements in underlying solar technolgy have not been made in recent years is in accurate.

Nanosolar is also the only company that I know of that has fundamentally streamlined the solar panel production process.

Re:Well?

[OrionCA]

It all depends on the power requirements of the tool shed. If all you have is a single 100W light with a pull switch your requirements are much lower than if you've mounted your sprinkler timers in the shed and these have to be plugged in somewhere, 24/7.

Size your panel(s) appropriately to the expected peak and normal, "nominal" demand. You'll lose about 30% of the power converting from AC to DC so if you can run the light/appliance off DC you're better off. If you're charging batteries you'll need a voltage regulator to prevent the batteries from being overcharged (and hence explode). If you want to tie into the grid instead there a special controller that you have to use to ensure the power generated is compatible with the local utility and rquires permits from the power company; that's outside the scope of a DIY project and you should consult a licensed contractor.

Re:Well?

[berashith]

i have a greenhouse that needs new power run to it. An aerial line would just be flat ugly, an trenching requires removing a ton of concrete and several possible code violations. Solar for me is a near perfect fix, and the extra costs of the panels are a wash with the labor that could be involved. Then there is a plus that I can run other things from the greenhouse, and depending on efficiency, I may move some battery chargers to that system for more "free" energy.

There are some applications where solar is just best.

Re:Well?

[bitspotter]

A skylight would work.

Re:Well?

[bjohnson]

Then they should license the fucking patents to someone who WILL manufacture for the consumer. The problem with their approach is that solar energy is actually MORE efficient in a decentralized production environment. Solar power stations for utility monopolies are inefficient, compared to solar panels on every roof.

Re:Well?

[dutchtommy]

I agree that while it may not be cheap in financial terms today...today is a nice sunny day with gentle breezes. there are always those times when having your electricity is beyond price. Like when you have no power due to natural disasters, brown/black outs, or if/when the cost of electricity keeps rising.

Then there is the emotional stand point of feeling safer because you are prepared for those issues. And even on some level that you are using your 'dollar vote' to vote against coal, oil and nuclear power altogether.

I just put a $10,000.00 unit on my parents house in MI. I feel safer knowing that come heck or high water they will not freeze to death in a winter black out.

Re:Well?

[spoco2]

Yeah, that'd work wonders at nighttime.

Because you _never_ do work in a shed at nighttime.

Re:Well?

[drinkypoo]

http://www.csudh.edu/oliver/smt310-handouts/solarpan/pvpayback.htm

Re:Well?

[Anonymous Coward]

i agree with this view. now white led's are available in market, 4 LED's with sufficient glowing background are doing a great job of lighting small room with the help of some reflectors

Re:Well?

[wkaszeta]

Seems simple enough. Combine a solar PV module, battery, and DC light. Works at first. You will not be happy unless the components are selected for the intended (and actual) load (such as a light), its use, and the location (sunshine varies as well as the sun position). The weak link is the battery. Batteries can be damaged by under charging (not enough charge during the day to make up for useage), over charging, and by not selecting the correct battery. To help ensure long battery life, use a battery charge controller that will prevent over charging and limit damage caused by under-charging by disconnecting the light. Even this is not enough to prevent battery damage due a light left on. That will cause the battery to cycle from low to partial statesof charge and this is damaging to a battery. Better to use some sort of timer switch. The selection of battery size and PV module size is not simple. First determine the daily energy required in watt-hours per day (lamp watts x hours of operation) or ampere-hours per day (lamp amps x hours of operation) for the time of year with the lowest available sunshine. If load varies by month, do it for each month (spreadsheets help). Add 15-205 safety factor for battery efficiency and safety of design, err on the high side. Then select a battery that has a capacity at least 5 times this amount (easier to do if calculation is in amp-hr). You can make a rough calculation of ampere-hours by dividing the watt-hours by the nominal battery voltage. Now you need PV module data in the form of rated watts or amps at maximum power voltage, and sunshine data reduced to the form of kW-hr/m^2 per day for your location. Google this, I do not have my references with me. You want the sunshine on a surface tilted towards the equator at a tilt equal to latitude for a lighting load. Available kW-hr/m^2 per day x module(s) amps at maximum power voltage = available amp-hr/day. Compare to requirements. The problem is that excessive PV on a system has no extra value, too little fails and damages the battery. One size fitts all generally fits no one well. Consult a local PV dealer if possible, or see what has worked well for others in your area.

Re:Well?

[lbgator]

Any concern about sunlight going to power instead of photosynthesis? Is that even a concern?

Re:Well?

[berashith]

Nope.

The panels can be placed out of the direct path of sunlight to the plants, and even if I had to go directly on top there are actually shades covering quite a bit of the structure in summer. There are trees blocking the best path of the sun in winter, so the panels need to be a few feet away.

No, no, no

[gnuman99]

DIY project for wiring your house? Yeah, if you wish to invalidate your insurance and burn down your house. You need to properly wire the stuff. And if you can't figure it out, you can't do it with instructions properly either.

Want to use solar that maximizes your bang for the dollar? Want a DYI project? Invest in some thermal solar cells, you can even make them yourself. Then you can heat your hot water or even heat your house if you have wanter radiant heating (geothermal heatpump augmented with solar cells - saves oodles of cash). And thermal solar panels are 95%+ efficient, not the 20% or something like that for electrical systems.

Re:No, no, no

[ScrewMaster]

Want a DYI project?

I presume you meant a "Do Yourself In" project, which is what usually happens when people who don't know what they're doing attempt to rewire their homes.

Re:No, no, no

[Anonymous Coward]

Wiring is not hard. Talk of burning your house down is pure hyperbole.

Re:No, no, no

[mrbluze]

DIY project for wiring your house? Yeah, if you wish to invalidate your insurance and burn down your house.

Nobody is saying you have to do it at AC 110V (or 240V / 220V). AFAIK running 12V or 24V cabling through your house does not require an electrician, and to achieve low resistance you can use T-bars or other large metal structures (or just some automotive copper) for return currents to avoid voltage drops, or alternatively transport the energy via AC/240V (might need professional work for that).

Just have smaller, cheaper inverters at specific locations for the high voltage/AC appliances such as fridges, computers etc.

Re:No, no, no

[Vectronic]

But he doesn't seem to want to wire his house... "I'm building a large shed out back and I want to power the lighting..." or even bother with other electrical devices, nevermind water.

I'd have to agree, and other people have mentioned this already, use LED type lighting, this negates stuff like inversion to get 115/220 volts, etc. and requires far less power in the first places, which means less solar panels, less batteries, probably less wiring, and LEDs last longer than incandescent, and provide better lighting than neon.

Re:No, no, no

[robertjw]

Wiring is not rocket science. There is no reason a person cannot get instructions, educate himself and do it properly. No one should just 'figure it out'. Electricians are trained an licensed to do their job - they aren't born with the skill.

In my community, it's perfectly legal for a homeowner to complete work to their house as long as they pull a permit and have the work inspected. If this is an option (check your local laws) it's a good way to make sure you don't burn anything down. The inspector will make sure your work is up to code and won't burn your house down.

Re:No, no, no

[Anonymous Coward]

There are lots of little things with wiring that can have serious consequences. Where to put the ground? Please not too near a metal anything especially pipe. Why? It'll accelerate corrosion. Possibly greatly. You can screw up your neighborhood's cable this way too.

There are fire risks for improperly installed wiring as well. Or just improper choice of materials. In a house there are other concerns such as fumes given off if cabling ends up in a fire irreguardless of what precipitated it. Builing codes exist for a reason. The 1 in 10 occurances are obvious enough and easily avoided, it's the non-intuitive 1 in 10,000 occurences that take a little foresight. With 100s of thousands at stake for millions of home owners, and the virtual impossibility of knowing all the minutia of one's own particular circumstance, best to go with building code safe as opposed to back of cocktail napkin sorry.

That said: A solar shed is probably pretty straight forward. You know the voltage you want, get battery configuration that will give the amount of stored current you want, and set it up for the voltage you desire, and just run the shed off a properly installed and secured stack of batteries with the solar charging them. They probably have a weekend workshop at a Home Depot or Lowes that would get one at least half way there.

As another person above states that's not the biggest bang for the buck, but it's certainly doable as a little project.

Re:No, no, no

[I'm just joshin]

Oh yay, heat from solar. Just what I want here in sunny Arizona on the first day of summer. It is 114F/45C outside today. The water coming into the house is too hot to give the kids a bath. Greater efficiency is nice but when the problem is a lack of light, efficient creation of heat is less than helpful. :)

Re:No, no, no

[ScrewMaster]

Low voltage power wiring can be more dangerous than regular 115/220 VAC. If a circuit is shorted the I2R losses will much greater. For example, I have a Hawker 6FV11 12V 105 AH battery that runs my sump pumps. It's capable of dumping tens of thousands of amperes across a dead short: if that ever happened the results would be Biblical. I took a number of precautions when building that system, one of which was to have 200 amp fuses mounted directly to the battery terminals and covered in heat-shrink tubing. Big battery arrays are dangerous, make no mistake. A neophyte is better off getting a book on home wiring and learning how to handle conduit and junction boxes rather than fooling around with a battery bank that's more dangerous than a tank full of gasoline.

Re:No, no, no

[Fjandr]

There are lots of little things with wiring that can have serious consequences.

No, there really aren't. There are a few little things and a few big things, and very few of them are arcane. Electrical systems in a typical residence are neither rocket science nor magic. A relatively good primer for residential electrical systems for a typical homeowner would be B&D Complete Guide to Home Wiring.

Where to put the ground? Please not too near a metal anything especially pipe. Why? It'll accelerate corrosion. Possibly greatly. You can screw up your neighborhood's cable this way too.

Please, please tell me you're not an electrician, nor are studying to become one. Either you WAY oversimplified to the point of making your statement meaningless or you know nothing about the ways galvanic reactions are mitigated in residential wiring. Any text on residential wiring will mention the problems and the very simple ways to avoid them ever becoming an issue.

You're right though, there are fire risks if you don't take any care with your wiring practices. Good wiring practices are amazingly simple to learn. That said, most homeowners I'm aware of who undertake electrical work for themselves do not ever bother to do so.

virtual impossibility of knowing all the minutia of one's own particular circumstance

This statement is a crock. Residential wiring is pretty straightforward for anyone willing to crack any number of simplified wiring books. Solar systems are relatively straightforward as well. I'm honestly not sure why the submitter believes that any number of other project descriptions could not be adapted to a solar shed, unless they plan on tying it into something else at a later date.

However, and it's a big one, solar intertie systems can be enormously complicated. If the submitter is planning on later tying the solar system in a shed to one in a house, said person is going about things bass-ackwards. An intertie needs to be planned from the ground up, or the likelihood of large (and costly) problems shoots through the roof.

Many things need to be answered right from the start. Am I installing a system tied to the power grid? A backup system not tied to the grid? Are there going to be batteries involved? Do I plan to convert to AC, and if so do I need clean sine-wave power? Can my charge controller handle the potential expansion of solar panels? Can additional inverters and/or charge controllers be added to the system without a great deal of hassle should the initially chosen models not handle panel additions? Am I just planning to run dedicated DC lighting circuits? These answers should take into account future plans to expand the system, as picking one particular route and then later making substantial changes to the upgrade path can dramatically increase equipment expenses.

Depending on the complexity of the situation and whether the DIYer actually intends to acquire the knowledge necessary to execute high-quality, functionally correct work, professional help may or may not be necessary.

Re:No, no, no

[mrbluze]

Low voltage power wiring can be more dangerous than regular 115/220 VAC. The return current (black) is usually a single large wire running down the axis of the circuit and is far from the active wires which by and large are thinner. So short circuits are unlikely except at the wall socket. Battery arrays, as is written pretty much everywhere, should be stored away from the building in a separate ventilated and locked enclosure.

Re:No, no, no

[BLKMGK]

With enough amperage even 12volt wiring can start a fire. Don't think so? Go short the terminals on your car battery sometime...

Re:No, no, no

[Fjandr]

DC cabling is not going to be adequate to carry residential loads. While you could hack together a cheap system, you'll get the quality that you pay for.

While I honestly couldn't care less if homeowners do so without permits, most jurisdictions do require electrical permits and inspections for installing DC systems. The "burn down your house" is hyperbole, but if you have homeowner's insurance you'll likely need to comply with permitting requirements. In the event of a fire or other damage as a result of wiring, your insurance may not pay even if the work you did played no role in the damage to the structure.

Using small, cheap inverters at point-of-use is going to introduce problems. For one thing, the power produced by cheap inverters is by no means high quality. Most cheap inverters produce modified sine-wave power, which can be problematic for certain appliances (computers, battery chargers, A/V electronics, some electrical appliance motors). You're unlikely to be able to find out whether a particular appliance is affected until after you plug it in. Another problem is that transporting DC at lower voltages means you need conductors larger than a typical AC run would require for the same distance. I'm not sure if you've checked copper prices recently, but it adds up pretty quickly.

For an AC-DC system, the best-practice route would be to install one or more inverters at the location of the mains entrance to the house. This allows for typical residential AC wiring practices to be used, which vastly simplify the situation. It'll save time, money, and headaches in the long run, though the system will initially be a fair bit more expensive. Even an on-the-cheap installation is really anything but cheap.

Re:No, no, no

[evilviper]

Nobody is saying you have to do it at AC 110V (or 240V / 220V). AFAIK running 12V or 24V cabling through your house does not require an electrician

The fact that you think low current 120/240v is dangerous, but very high current 12/24V is safe, throughly proves the point that you do NOT understand electricity, and should certainly NOT be giving advice to others.

and to achieve low resistance you can use T-bars or other large metal structures (or just some automotive copper)

With amateur-installed T-Bars, I would fully expect the frame of your house to start slowly roasting itself in short order, if you're lucky, and not using quite enough current, it might not catch fire until the next heavy rain.

Automotive cables are designed to carry the current of ONE small car battery over just a meter or perhaps two. Drawing power from multiple batteries, or over much longer distances, and those cables will be getting very hot. It won't take long for the insulation to melt off, and start cooking adjacent objects.

Re:No, no, no

[Fjandr]

Something that starts with basic theory and ends with the ability to wire a house would be perfect.

RTFS? :)

Re:No, no, no

[mrbluze]

This allows for typical residential AC wiring practices to be used, which vastly simplify the situation. It'll save time, money, and headaches in the long run, though the system will initially be a fair bit more expensive. Even an on-the-cheap installation is really anything but cheap. You're right. But we were talking about lighting (not microwave ovens, washing machines and other high-load devices). I don't know what the best solution for things like dish-washers and washing machines is, but smallish solar panel arrays tend to be a bit inadequate for it (and deep cycle batteries don't like being drawn).

Re:No, no, no

[mrbluze]

The fact that you think low current 120/240v is dangerous, but very high current 12/24V is safe

I didn't say either was safe. I just said it does not require an electrician by law (AFAIK - but of course it's as far as I know).

With amateur-installed T-Bars, I would fully expect the frame of your house to start slowly roasting itself in short order, if you're lucky, and not using quite enough current, it might not catch fire until the next heavy rain.

These are for lighting systems not ovens or dish-washers or other things.

Why are you assuming that the designer was so stupid as to design a system that could not cope with the designated load? What are fuses for?

Re:No, no, no

[wellingj]

All Americans suck because they attempt to rewire their homes.

Re:No, no, no

[BLKMGK]

Good luck finding inspectors that know anything about DC wiring. And yeah, apparently DC wiring has it's own set of tricks that need to be followed that are separate from AC wiring - circuit breakers for instance act differently on DC than AC. Heck in my area two inspectors couldn't even agree on the right way to do something when asked by my contractor! We waited till post inspection to do the work as a result these two inspectors literally had an argument on the best way to solve the problem right in front of my contractor - it was pathetic.

Re:No, no, no

[ScrewMaster]

Sure ... but this discussion is about people who install this stuff and don't know what they're doing. My point is that working with a low-voltage system doesn't necessarily make you safer.

Re:No, no, no

[Fjandr]

Well, he talked about starting with lighting. The end point was left pretty open, and he mentions wanting to get resources that culminate with whole-house wiring. Expansion past lighting is what requires planning, and it seems that he is at least interested in the possibility of expansion. That's the only reason I've brought up points of consideration that have very little bearing on wiring for DC-only lighting.

Were DC-only lighting his only goal, his mention of being unable to adapt other published projects to his goal and asking how to do it on Slashdot would put him firmly in my "You don't belong anywhere near an attempt to wire anything, ever" group. I hope that is not the case. :)

Re:No, no, no

[mrbluze]

My point is that working with a low-voltage system doesn't necessarily make you safer. Yeah, considering people don't even switch the light off before climbing a metal ladder and replacing the bulb, using the socket to help them balance.

Re:No, no, no

[mrbluze]

I hope that is not the case. :) No amount of advice and no amount of insulation can stop a determined idiot from short circuiting something. But yeah, we're assuming this guy is not a few short of a dozen.

Re:No, no, no

[evilviper]

I didn't say either was safe.

Sure you did... Suggesting you can't burn your house down with 12/24V (as opposed to 120/240V).

I just said it does not require an electrician by law (AFAIK - but of course it's as far as I know).

And for the record, you ARE wrong, BTW.

These are for lighting systems not ovens or dish-washers or other things.

A full-scale home lighting system is going to use vast amounts of electricity. In excess of a single oven, refrigerator, or the like.

Besides, you've already LISTED the large appliances you want to be power from this: "such as fridges, computers etc."

Why are you assuming that the designer was so stupid as to design a system that could not cope with the designated load?

Because it's a DIY project, requested by someone without basic electrical knowledge. And your tips are providing clearly bad advice.

What are fuses for?

Fuses are to prevent an appliance that has malfunctioned from destroying the whole works. They help avoid a fire ONLY in a few specific circumstances, like a sudden short. They will not protect you from a fundamentally under-designed wiring system... They will also not do anything when the person installing them doesn't know how they should be sized.

Re:No, no, no

[billcopc]

All Americans suck because they believe in random sigs.

Re:No, no, no

[chuckjuhl]

Don't know where you live, but in most areas of the U.S. you legally need a permit and an inspection to perform any electrical work on residential wiring. When I say "any", I mean even down to installing an outlet or changing any type of fixed fixture. Most areas require all electrical work to be in accordance with the N.E.C. and /or the I.E.C. Further, most jurisdictions require that the person doing the residential electrical work have a valid Electrician's license. Some jurisdictions allow a homeowner to do their own electrical work, but only on their own dwelling and not on properties they own that they rent to tenants. In many jurisdictions performing unauthorized and/or unlicensed electrical work is a crime, punishable by fine and/or imprisonment.

As a licensed Master Electrician and former County building inspector, I can state with great confidence that simply reading a book such as "B&D Complete Guide to Home wiring" does not render one competent to undertake even moderately complex residential wiring projects. As I have witnessed, even seemingly straightforward tasks like stripping wires and using wire nuts can have devastating consequences when performed improperly.

To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

Re:No, no, no

[russotto]

Don't know where you live, but in most areas of the U.S. you legally need a permit and an inspection to perform any electrical work on residential wiring. When I say "any", I mean even down to installing an outlet or changing any type of fixed fixture.

Only state I've ever heard of that nonsense actually being enforced is Florida. What, should we go crying to Mommy Government or her anointed and licensed representatives every time we need to change a light bulb?

To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

Of course no licensed electrician would do so; when people do their own work it means less money for licensed electricians. Never mind that if you want to do anything even slightly unusual that no licensed electrician will touch it anyway. Building codes are all about "do it the way it has always been done, that has been worked out to be safest over the years"; they may prevent injury, but they also completely kill any sort of innovation.

Re:No, no, no

[c6gunner]

As I have witnessed, even seemingly straightforward tasks like stripping wires and using wire nuts can have devastating consequences when performed improperly.

To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

Yes, and I'm sure that no licenced car mechanic would ever advocate that you do your own car repair and maintenance. Guess what - the last time I took my car to a "professional" to have new tires put on, the retard over-torqued the lugnuts so much that they warped my rotors.

What did I learn from the experience? That since there's no way for a layman to tell good professionals from bad "professionals", you may as well skip them altogether and do the work yourself. It's either that or go and pay another guy from a totally different company to check over the first guy's work.

Re:No, no, no

[hedwards]

Quite so, a lot of people don't realize that talking on a corded phone in the bath tub can be fatal. I'm not sure how many volts are used by a phone, but it's definitely considered to be low voltage, and it definitely kills people.

Probably not as many as in the past, but that's mainly because more people use cordless phones or cell phones than they used to.

Re:No, no, no

[fast turtle]

AFAIK running 12V or 24V cabling through your house does not require an electrician.... Depends on your local laws. Where I live - Solar Power is a viable alternative and yes any PV system has to meet minimum Federal Electrical Standards for DC systems. Furthermore, it's quite easy to overload standard 12volt Automotive grade wire with a PV panel if the amperage is high enough. The big question to ask is how many amps of 14-18 volts is being output by the panel or is the panel configured for 24volt operation (28-32 volt output).

Making a blanket statement as you did tends to result in severe cases of "Foot in Mouth" disease. FYI a 50watt 12v PV panel requires a minimum of 8ga wire to connect to the busbar while a 200watt panel requires at least (4)0 wire (quad aught) to handle the amperage it can easily output and most PV panels over the 150watt rating are configured for 24v output.

Now depending on what the OP wants to do with the PV system is going to determine what he needs. If it's simply lighting for a shed, then the issue is even simpler. Get a small PV powered light unit (Brinkman/Others) from the local Home Improvement Center or order it online and use it to light the shed. If it's anything more then lighting, then you need to consider appropriate wire gauge to minimize voltage drops, Purchasing of DC rated switches (standard household switches aren't safe due to arcing).

In regards to the 120/240 AC voltages, you're actually better off putting the Inverters near the batteries and running standard house wiring because of safety factors. We're damn familiar with AC power and there's plenty of standards to follow when working with it. PV systems with high amp DC circuits are very dangerous Common Automotive Batteries can output in excess of 1200A when the posts are shorted, so you damn well better protect those batteries.

Right now the best solution would be to head over to Mr Solar where you can find plenty of PV related equipment and kits for numerous projects.

Re:No, no, no

[Fjandr]

You might be surprised how many people don't give a rat's behind about permits. Or maybe not.

To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

Most of my response to this can be summed up by re-reading the last section of the post you replied to. I also noted in my post that most homeowner wiring I've had the "pleasure" to encounter showed that they clearly cared nothing for learning to perform high-quality work (at least I believe it was this post, I'm feeling lazy and am not going to go back and read it to be sure). This is a bad thing, and the only way to attempt to rectify it is through education.

I also never claimed that an inexperienced person should attempt to tackle an entire house from the start, or even a moderately complex project. Since this is ostensibly a homeowner working on their own residence, the "unlicensed" portion has no relevance. It tends to be implied. Most jurisdictions that are not in major metropolitan areas or otherwise heavily restrictive states do allow homeowners to perform their own permitted work. Providing a starting point should this person choose to not go the professional route is vastly more responsible than taking the "no sex before marriage, we won't even discuss the possibility that you might" approach. It doesn't work, and pointing someone in the direction of an informed decision has a much higher likelihood of success than refusing to even contemplate the possibility that they might choose a route you disagree with (or which is illegal). The people to be scared of are those who don't bother asking and just do it.

Your credentials may allow you to discuss with relative authority matters pertaining to electrical work, but they obviously haven't done much for insight into human nature and failings, and attempts to mitigate those failings to some extent through education.

While a pissing match regarding qualifications to speak on certain topics might be amusing to engage in for a while, it is ultimately irrelevant to the discussion at hand. Certainly, in any task where the person performing the work is not willing or able to learn proper methods, professional help is the only reasonable option. There are people who will choose to go the DIY route even if they would be better off using professional help. If they make an attempt to educate themselves first, that's at least better than going in blind. Or, perhaps the submitter decides to get professional help and still wants to learn more about the subject. In that regard, who has helped that person more? You? To beat the argument to death, abstinence-only education doesn't work. Pretending it does causes more harm than good.

Re:No, no, no

[TooMuchToDo]

The call is low-voltage. On ILEC phones that run over copper from the CO to your house, the ringing is almost 100VAC.

Re:No, no, no

[rah1420]

Oh yay, heat from solar. Just what I want here in sunny Arizona on the first day of summer. Ah, grasshopper, heat can do much more than heat your house. Heat can flash a working fluid into a vapor and push against a turbine, which, when hooked to a generator, can provide electricity.

I have been toying with the use of solar energy for awhile - mostly because I'm so pissed off that we have all this free energy lying around and nothing useful we can do with it. I was always struck by the relative inefficiency and expense of pv solar systems when it seems to me that solar thermal systems can do so much better a job at providing work output. Plus, it's easier for a D-I-Yer to deal with solar thermal than it is to deal with solar PV.

There are people building systems like this right now. Here's an example of one of the companies and the equipment that is marketed. Note there are only four fluid connections: Working fluid in/out, cooling fluid in/out - plus the electrical connection.

Note: I have no connection to this firm, I only came across them in a Google search. I'm sure there are others.

Re:No, no, no

[jamesh]

Yeah, considering people don't even switch the light off before climbing a metal ladder and replacing the bulb, using the socket to help them balance.

You don't have to be stupid to be dangerous, just careless.

I was the kid in class who always left the chuck key in the drill before turning it on. I never hurt anyone but only because I was lucky.

I used to do a lot of work on my car (Morris 850) and would routinely forget to do things up properly (eg like wheels).

Basically I'll think before I do something, but won't necessarily remember to do the things I should do.

Under no circumstances should I be allowed to do something like work on 240V electrical wiring :)

Re:No, no, no

[jacqdesign]

I have re-wired large portions of 3 houses I owned. And your mentality, and the fact that your right about many locals having governments nose in the homeowners ass way too much is annoying to me. Your rant comes across like the boss I had in a college co-op talking about how hard all the computer shit he does is, and how he has to do it. And I figured out why, he was scared as hell that someone would come along and expose his incompetence that he was probably overpaid for.

If we are talking about 220 circuits or higher, or work at the box, then sure, most people probably should call an electrician, but should the government be up my ass about it, and should you be trying to convince me that I am too incapable of changing a light switch, and expect me to value your over charged service?

Seriously man, your not that smart, and residential wiring isn't that hard. I don't get on here and bust your balls about your bad website code, or your open wifi router that I steal bandwidth from, and demand you go hire the Geek Squad cause your too incompetent.

Basically chill out and leave people to shock the shit out of themselves if they want. It's kind of a good time anyway.

Re:No, no, no

[Guru2Newbie]

Just a note: irregardless is redundant.

Yeah yeah, -1 offtopic.

Actually, the GP said "irreguardless", so it was both redundant and misspelled.

I like the redundancy surrounding "flammable" and "inflammable," especially "highly inflammable". Hmm, like saying "this steel girder is inflammable (won't burn), but that rock over there is highly inflammable (really, really won't burn)."

I think the British started using "inflammable" to mean something WOULD burn (no clue if flammable means just the opposite to them?) So inactive means something IS active? Can't figure it out.

Re:No, no, no

[Belial6]

While I definitely agree that electrical wiring just isn't that hard, I disagree that you can count on the inspector to make sure your work won't burn your house down. In my local, they are very clear on the permits that they do not provide that service. It is much better to just make sure you do the job right. There is plenty of information on how to do house wiring correctly. It isn't rocket science after all.

Re:No, no, no

[sedmonds]

In the overwhelming majority of homes the ONLY complicated element of a literate homeowner performing their own electrical wiring in compliance with the NEC is sifting through ambiguous and/or contradictory elements of the NEC. Requiring a licensed electrician to perform electrical wiring in your own home makes about as much sense are requiring a licensed nutritionist to cook your meals, or a licensed landscaper to mow your lawn.

Re:No, no, no

[Hal_Porter]

No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

That's what the surgeon at the hospital said. They wanted $20K to remove a small brain tumour. But I read up on DIY and did it myself for a couple of hundred bucks and I'm.

I'm ok man. Did I tell you I fixed my own brain? The hospital said it would cost $30K but I did it myself. Only cost.

Only cost $2000 for some second hand brain surgery tools and some anaesthetic I ordered on the Internet from some guy in China.

Re:No, no, no

[DMUTPeregrine]

"in" is a Latin prefix, meaning into, onto, or against. inflammable means capable of turning into flame. unflammable is not capable of turning into flame.
On the "with regard to/regardless/irregardless" issue, all 3 are words. The first and last have the exact same meaning. ir means without, so irregardless means without having a lack of regard to, id est "with regard to". Irregardless is both redundant and often used to mean regardless, which means the exact opposite.
That's enough time playing Latin Grammar Praetorian for today.

Re:No, no, no

[MrNaz]

"irreguardless" ?!
Seriously.
What.
The.
Fuck.

Re:No, no, no

[MrNaz]

"fixed fixture"?
What about those fixtures that are not fixed? I've got plenty of those in my house.

Re:No, no, no

[kipman725]

As somone who has lived in houses I have whitnessed the same things from so called profesionals. I would rather do it myself and know it has been done correctly than have a fancey permit for something potentialy leathal. Also I don't know how anyone in the US can talk about electrical safty with 2 pin plugs and bathroom soccets.

Re:No, no, no

[jbengt]

Only state I've ever heard of that nonsense actually being enforced is Florida.

Codes are mostly enforced by municipalities, and to a lesser extent by states, counties, fire departments, and other agencies. And most places I've been involved with do enforce such restrictions, though not always effectively.

What, should we go crying to Mommy Government or her anointed and licensed representatives every time we need to change a light bulb?

Changing a light bulb is changing a bulb, not changing a fixture. Though I will say that most codes allow a homeowner to repair or replace 'in-kind' existing electrical work, most will not allow you to make significant changes without a permit. And usually they require a licensed engineer or licensed contractor for the permit. Of course, if the work is done inside your private home, the code officials will probably never find out about it, unless a neighbor complains, or mistake causes a fire.

Building codes are all about "do it the way it has always been done, that has been worked out to be safest over the years"

Only natural, since the purpose of the codes is to protect the health and welfare of the building occupants and the surrounding community.

hey may prevent injury, but they also completely kill any sort of innovation.

Codes all have clauses in them that allow you to design any innovative system that works, if you're willing to go through the considerable trouble of getting it approved.

Re:No, no, no

[anorlunda]

That since there's no way for a layman to tell good professionals from bad "professionals", you may as well skip them altogether and do the work yourself. It's either that or go and pay another guy from a totally different company to check over the first guy's work.

Really? I suppose you did your own appendectomy with a spoon. Or perhaps you hired a second surgeon to cut open the incision from your operation to check the first surgeon's work.

Re:No, no, no

[c6gunner]

I suppose you did your own appendectomy with a spoon.

Never had it done, actually. Never got my wisdom teeth pulled either. I still have all the parts that nature gave me - I'm 100% OEM.

I get your point, though. The difference is that the medical field is a lot better regulated than car mechanics, electricians, etc. At least, they are in 1st world nations. If you happen to be living in Mexico on the other hand, you might actually be better off ripping out your own appendix.

The other difference is that if something goes wrong during surgery due to negligence, I (or the surviving members of my family) can usually sue the doctor and expect to recoup a large sum. Whereas I have no hope in hell of getting the mechanic to pay for new rotors.

Re:No, no, no

[russotto]

Codes are mostly enforced by municipalities, and to a lesser extent by states, counties, fire departments, and other agencies. And most places I've been involved with do enforce such restrictions, though not always effectively.

Nearly always ineffectively, if the electrical aisles at Home Depots everywhere are any indication. Unless all those people buying the stuff are licensed electricians pulling permits and getting inspections, which seems unlikely.

Though I will say that most codes allow a homeowner to repair or replace 'in-kind' existing electrical work, most will not allow you to make significant changes without a permit. And usually they require a licensed engineer or licensed contractor for the permit.

Do the codes also require homeowners to get an LPN to wipe their noses?

Codes all have clauses in them that allow you to design any innovative system that works, if you're willing to go through the considerable trouble of getting it approved.

Where the "considerable trouble" = an insurmountable barrier, for an individual.

Re:No, no, no

[drinkypoo]

However, and it's a big one, solar intertie systems can be enormously complicated. If the submitter is planning on later tying the solar system in a shed to one in a house, said person is going about things bass-ackwards. An intertie needs to be planned from the ground up, or the likelihood of large (and costly) problems shoots through the roof.

Well, from where I'm sitting, this statement is a crock. I'm willing to be corrected, though.

It would be even less compelling if I were sitting at my friend's house, because he's got the micro-hydro-turbine hooked up grid-tied with an outback inverter. And uh, there's really NOT very much to it. All the magic is in the inverter (aside from the little bit in the charge controller.)

It seems to me If you can't add on to the existing system, you can add on in parallel. It will cost you more, of course.

Re:No, no, no

[drinkypoo]

A 220 circuit isn't too complicated. I mean, seriously. You have three or four wires, right? A ground, a neutral, and then one or two hot wires. The two wires have opposing sine waves on them, so if you pull from both you get 220, and if you pull from one and the neutral you get 110. Just don't fuck up! That's the one thing that most people get wrong :) Seriously though, just keep which wire is which more or less straight, and keep things balanced, and you can wire up all kinds of shit.

If you don't want to burn anything down or kill yourself, follow simple rules, like assuming every circuit is live if you don't know if it's live, and testing everything before you touch if even if you "know" it's not shorted out or cross-connected or whatever. I shouldn't admit this but I've been shocked with all kinds of stuff (not including 220V, but including the signal off the CRT card on a VGA monitor, whee!) and I'm still here because when I was being stupid enough to get shocked, I was smart enough to keep one hand in my back pocket. If you're going to be stupid, be as smart as possible while you're doing it.

None of this is going to convince anyone to let me wire their house, but it's not that fun anyway. The fact is that it's really quite simple, and only the steep potential penalty for failure should scare anyone away. Use quality parts, use the boxes, follow the code when all else fails, and don't let anyone with a professional certification tell you what to do just because of a piece of paper. Remember, not that it applies directly here, but MCSE == "Moron Confused by Sun Equipment" and CNE == "Certainly No Experience". Electricians have to have experience, but they don't have to come down off their ivory tower.

Re:No, no, no

[rjason]

OK now I see wats going on ...... the wirenut and wire strippers lobby controlling the market!

Re:No, no, no

[Fjandr]

The operative word in the quotation you selected is "can." It connotes the potential for something, not a certainty. The quoted section would in fact be a crock if there is no potential for intertie systems to be enormously complicated. However, that is not the case. There are ample examples of systems unintentionally complicated, and systems that are complicated due to site or operational requirements.

Did he plan the system at the outset or just wing it? I'm guessing some planning went into the system prior to installation. There are many ways that people go about such projects in order to cut expenses, which later turn into problems. Outback systems aren't exactly cheap. You get what you pay for. If he did just jump into an Outback system without research or thought of future system requirements, he's lucky he did. One of the hallmarks of their product line is the interoperability and expansion capabilities of their hardware. Not everyone is so lucky with a shot in the dark.

So, bravo that you have a friend with a head that's screwed on right (I'll assume that's the case). It doesn't change the fact that there are many situations out there that are nowhere close to his experience. One experience does not canon create.

It seems to me If you can't add on to the existing system, you can add on in parallel. It will cost you more, of course.

Yes, I believe that was already stated in my post.

Re:No, no, no

[pla]

Don't know where you live, but in most areas of the U.S. you legally need a permit and an inspection to perform any electrical work on residential wiring.

Not for sub-50V systems, with most DIY PV installations at 12 or 48V.



As a licensed Master Electrician and former County building inspector, I can state with great confidence that simply reading a book such as "B&D Complete Guide to Home wiring" does not render one competent to undertake even moderately complex residential wiring projects.

Gimme a break... 99% of home wiring amounts to nothing more than connecting like colors. "Licensed" electricians have a hell of a scam going on, and those "laws" you refer to exist solely due to your own guild pushing to make itself relevant in the face of work that any moron can handle.

Yes, tasks exist that I wouldn't do myself - I'd never try to wire a panel to the mains myself; But I say that simply because I consider my life worth more than a few hundred dollars, not because I have any doubt that I could do it correctly (and in fact I have wired sub-panels successfully).

Re:No, no, no

[kehren77]

All Americans suck because they attempt to rewire their homes.

That reminds me, I need to pick up a new 3 way light switch, some twist-on wire connectors and some insulated outlet boxes to rewire my garage.

Don't hate the rest of us just because you need the electrician to change a light bulb.

2 words Home Power

[SubComdTaco]

Home Power is what you want to look at. http://www.homepower.com/home/

Re:2 words Home Power

[BLKMGK]

Amen! This magazine can be found at many good bookstores and subscriptions aren't too bad either. This is an invaluable source of information on ways to save money and power IMO. I do wish they would bring back their guerrilla power features though :-)

Re:2 words Home Power

[falconwolf]

Home Power is what you want to look at.

Yea, I was going to mention it but not wanting to repeat it I found your post when I searched. I've been reading "Home Power" for years, along with "Solar Today" and "Backwoods Home".

Falcon

Car and Caravan components

[MichaelSmith]

1. Dashboard solar panel intended to boost a car battery $50 AUD
2. Car Battery
3. 12V Light fittings intended for a caravan or similar

Re:Car and Caravan components

[jeiler]

You forgot "4. Profit!!!"

Seriously, there is one other thing to remember--a skylight. What good is it to run even "green" electricity in the daytime if you have sunlight available for the job?

Re:Car and Caravan components

[robertjw]

1. Dashboard solar panel intended to boost a car battery $50 AUD
2. Car Battery
3. 12V Light fittings intended for a caravan or similar

Interesting. Purchasing a car battery is expensive (both up front and every 3-5 years when you have to replace it), plus environmentally bad. The battery will likely offset any gains to be had from the solar installation itself.

Re:Car and Caravan components

[MichaelSmith]

Interesting. Purchasing a car battery is expensive (both up front and every 3-5 years when you have to replace it), plus environmentally bad. The battery will likely offset any gains to be had from the solar installation itself. He could use a battery from a car with a dead cell. Lights will still work at 10V. A new battery should last more than five years. A cheap battery where I live is about the same price as the solar cell, and the application is not particularly demanding.

You could always use a gell cell in place of the lead acid battery.

Re:Car and Caravan components

[peragrin]

but it is a requirement in any pure solar system. what happens when you want to turn the lights on at night? a Pure Solar system fails. You need a storage system for it. On the plus side with a steady charge, a small motorcycle battery will last 6-7 years powering a shed's lights.

Batteries are going to be standard in all solar systems, until Ultra Capacitors become a reality. Who ever figures out how to mass build ultra capacitors will be billionaires. Once Ultra Capacitors begin to work. you can use solar and small vertical wind turbines to recharge them and run the bulk of your house off of them.

Re:Car and Caravan components

[xaxa]

1. Dashboard solar panel intended to boost a car battery $50 AUD
2. Car Battery
3. 12V Light fittings intended for a caravan or similar

No, not a car battery. Get a caravan battery (or one with a similar intended use). Car batteries are designed for high current draws for a short period of time, and draining them reduces their lifetime significantly. Caravan batteries are designed to be drained, and to have a low current draw.

Re:Car and Caravan components

[karnal]

Is there any other technology battery-wise for a project like this that is feasable?

I have done some basic looking at solar, and everyone seems to use lead acid banks. Similar to what's in UPSs. I can vouch that these batteries usually don't last more than 5 years in my own UPS equipment, and anything after the 5 year mark if they do last, the minute you need them they'll proabably fail.

Re:Car and Caravan components

[zach_d]

If you use good deep-cycle batteries, and maintain them, lead acid batteries will last decades. I've worked on boats with 20 year old batteries that work perfectly well, and have no need to be replaced.

Re:Car and Caravan components

[maxume]

What environmental cost are you worried about?

These parts, it is illegal to dispose of batteries as waste, they are supposed to be recycled (this doesn't mean that everybody recycles them, but it does mean that it is straightforward to do it).

Re:Car and Caravan components

[BLKMGK]

Not nearly enough amperage to power anything with these - I know because I have a couple. You might get AN LED or two going but not nearly enough to be happy. You could use these to recharge a couple of 12 volt batteries that would provide you with more amps for more LEDs but I do not think those panels have much in the way of protection from overcharging nor would there be protection from drawing the batteries down too far which will damage them. The panels are really just designed to help keep a charge while the car is being transported or parked for long periods of time - things like the ECU and clock draw some power and these offset that. You can find them from VWs on eBay pretty easily and they aren't expensive - but not ideal either...

Re:Car and Caravan components

[BLKMGK]

Properly disposed of and recycled I'd argue that lead cells aren't nearly so bad. Throwing them in the trash on the other hand would NOT be a good idea....

Re:Car and Caravan components

[Fjandr]

Second this. Another option is to look around for telcos who are cycling out their backup deep cycles. Usually done every 5 years, these batteries are typically cheap, durable, and have many years of life left in them.

Re:Car and Caravan components

[o1d5ch001]

For those not from the UK, a caravan battery is probably one type of deep cycle battery. These are mostly wet batteries that use acid and water as an electrolyte. There are a number of lead acid batteries called by different names: marine, locomotive (big!!), golf cart etc. The primary difference between a car battery and a deep cycle battery is the size and perforations of the electrodes. Car batteries have lots of perforations to produce lots of amps quickly. In the deep cycle battery world, you need larger batteries to get more amps. How big? Well, 1000lb batteries for large solar installations. The leading manufacturer with a neat interactive website is Surrette Battery http://www.surrette.com/.

Golf cart batteries are very interesting for these projects. They are 6v batteries that are relatively cheap ($60-$200) each, connect them in series and you have quite a bit of energy storage.

Other types of lead acid battery uses absorbent glass mat or gel (not the same thing)to reduce the chances of an acid spill.

Lead Acid Batteries http://en.wikipedia.org/wiki/Lead-acid_battery

Absorbed Glass Mat http://en.wikipedia.org/wiki/Absorbed_Glass_Mat

CAUTION: Lead Acid batteries contain allot of stored energy. Equivalent to a stick of dynamite, and all you need to do is short it and they WILL explode. Please treat lead acid batteries with extreme care. Nothing like an exploding bomb of sulfuric acid to fuck up your day. Do not use lead acid batteries in your house, or near kids. Yes, I know people who have had batteries explode while working on their cars..

And for those who want batteries, but just use mains power to charge the batteries, here is an excellent charger that many hams use. http://www.a-aengineering.com/5smartcharger.htm

Re:Car and Caravan components

[robertjw]

He could use a battery from a car with a dead cell. Lights will still work at 10V. A new battery should last more than five years. A cheap battery where I live is about the same price as the solar cell, and the application is not particularly demanding. You could always use a gell cell in place of the lead acid battery. I'm not sure I've ever had a car battery where I knew just one cell was bad. That's a possibility, but testing for it would be tricky.

Thing is, running wiring from the house and installing a single CFL or even incandescent if temperatures are too extreme wouldn't use much electricity. If it's a shed, it probably wouldn't receive high usage and it would take a long time to use enough electricity to justify the cost of a $50 battery.

According to this site http://michaelbluejay.com/electricity/cost.html
A 100W incandescent lightbulb takes .1Kwh to burn 1 hour. Figure a price of $0.10/Kwh, the installer could use the bulb for an hour every night of the year for $3.65. In five years he would have saved $18.25 with the solar setup, not nearly enough to buy a battery. Use a 13 Watt CFL instead, and you are down around 47 cents a year.

The whole thing is a nice idea, but not economically feasible.

Re:Car and Caravan components

[robertjw]

What environmental cost are you worried about?

These parts, it is illegal to dispose of batteries as waste, they are supposed to be recycled (this doesn't mean that everybody recycles them, but it does mean that it is straightforward to do it).

Sure, but the recycling process isn't perfect. There is always some waste, and sometimes 'recycling' is just another term for environmentally safe disposal. Just because it can't be thrown in the trash doesn't mean we need the chemicals available, especially when there is a power grid available with a (in theory) lower environmental impact.

Re:Car and Caravan components

[TClevenger]

Generally speaking, a car battery that has degraded to the point that it won't reliably start the car, could still be viable for years if used to power 2-4 amps (24-48 watts) of lights. I don't think I'd buy a new battery for a project like that, but put a couple of secondhand batteries (wrecking yard?) together in parallel, and you should get good life from them.

Re:Free energy

[xaxa]

Hook up the battery to an inverter (to make 115V AC)

Plug light into inverter.

Why not skip this bit, and use a lower-voltage bulb? An LED array might be best, for the very low power needed.

The Otherpower forum

[knarf]

Try the Otherpower forum. Not just solar but other independent power generation forms as well:

• Solar
• Wind
• Steam
• Hydro
• Controls
• Storage
• Mechanical
• etcetera...

Re:The Otherpower forum

[BLKMGK]

Oh yeah! Great source for strong magnets too! Those guys do some really cool stuff but sadly I'm not located where I can do any of it myself. Their waterwheels in particular interest me since that's pretty steady power. Look into the Indian and other knockoff slow speed diesels for some really cool reading. They can be run on bio too but sadly it looks like importing them is no longer so easy due to recent emission constraints :-( One of those in the garage would ROCK for power outages!

Re:The Otherpower forum

[noidentity]

Try the Otherpower forum. Not just solar but other independent power generation forms as well:

• Solar
• Wind
• Steam
• Hydro
• Controls
• Storage
• Mechanical
• etcetera...

What about perpetual motion? That's the most promising!

Re:Free energy

[Ken_g6]

Since you're doing the lighting from scratch, and you want it exclusively powered by solar, I'd suggest looking at low-voltage DC lighting. DC bypasses the inverter, so it's more efficient for the same type of lighting. It's also probably less likely to kill you/burn down your shed if you make a mistake.

Disclaimer: IANAE - I am not an electrician

Simple, in theory

[SEWilco]

Do-it-yourself solar is pretty simple, in theory. In practice, it's not easy to gather enough hydrogen in an empty area of space. Darned stuff keeps spreading out whenever you turn your back to get another batch.

Re:Simple, in theory

[spazdor]

Cool it down. The gas coalesces better when there's no Brownian motion to fling it everywhere.

Solar is hit and miss ...

[jxliv7]

... you've got clouds and rain and much less than 12 hours of sunshine available on any given day year round.
 
Check out the wind instead. Generators can produce power in very low winds if you've got the right windmill (the ones that look like upright cylinders seem best, not the big blades).
 
Don't limit yourself to 110v, think about 12v and 24v DC lighting systems and battery storage and you'll be amazed at the inexpensive, 24/7, energy producing capabilities of the wind.
 
I'd toss a few links out except that you'll have more fun exploring on your own - you'll find exactly what you need the more you look around.

Re:Solar is hit and miss ...

[MichaelSmith]

... you've got clouds and rain and much less than 12 hours of sunshine available on any given day year round.

It depends on where you are.

At the Equator: solar

At the Poles: wind

In between: combination of the two

Re:Solar is hit and miss ...

[BLKMGK]

Sorry but axial generators are NOT an ideal solution at all - very inefficient. You will also find that your neighbors may not like you putting up a tower that sits so high above the surrounding trees - as it must in order to get clean air and be free of debris. On top of that the cost of the crane required to loft many of these is expensive. Add to that the fact that not *many* areas get enough wind to be useful and you'll find that wind isn't too great - especially for just a shed!

This isn't the best chart but perhaps this will help http://www.awea.org/faq/usresource.html

P.S. Wind isn't 24X7 in many places either. I have a wind gauge on my roof on top of a pole and can go for hours with ZERO wind, I go DAYS without useful winds for power generation too.

DIY hack = take apart consumer stuff.

[Original Replica]

I know a bit about solar from the perspective of a cruising sailboat, in that scenario you would take a 12V solar panel, some deep cycle 12v batteries (car battery would work) and a charge controller, connect solar panel thru the charge controller to the batteries and you are done. Everything on a boat is 12VDC lights, radio, etc so running straight from battery power is easy. You could get a inverter for regular 120VAC, but it consumes your battery charge fairly quickly. For learning the parts and functions on the cheap (solar stuff can be expensive) I would suggest taking apart a solar sidewalk light and extending the wires to put the light inside your shed, and the little solar panel on the roof. To make good use of a larger solar panel you will need a larger battery bank, and probably a better charge controller. What is the output of the solar panel you want to use?

Re:DIY hack = take apart consumer stuff.

[cptdondo]

Look at RV sources as well; same stuff as marine, but 1/10 the price.

One major caveat: a car battery will *not* work for this. A car battery is designed to provide very high current for a limited length of time, the exact opposite of a solar system need. A car battery will fail quickly in this application.

You want deep cycle batteries; google for trojan batteries.

Re:DIY hack = take apart consumer stuff.

[drinkypoo]

You are aware, I hope, that deep cycle batteries are often specified for automotive use, particularly in "heavy duty" scenarios, or pretty much any time you have a diesel (which has around twice the compression of a gasoline vehicle, and thus usually has about twice the starter motor?)

Anyway, what you really want is Optima batteries. I ran into this guy who has a product called "solman" which is an aluminum solar cart. It's not cheap at all at about $3000 but it provides plenty of juice from a nice mitsu panel and you can chain two more panels onto the sides. I wasn't impressed with their inverter, but it's quiet. But the meat of this is that he's getting 100 amp hours (the batteries are rated higher, but that's a bullshit automotive rating) out of three of them, real-world. They don't outgas, you can mount them in any position... They do cost substantially more, of course :)

My personal plan is to develop flywheels, something like what beacon power did. I intend to put them in short lengths of high-pressure water pipe with the end caps bolted on. I have access to a metal shop and to various metalworkers, now I just need to work out the bearing situation and the motor/generator system... heh heh

What scale?

[rthille]

Do you need 120VAC, or can you go with low-voltage? Going with low-voltage, driving LED lights directly from the battery will probably help with efficiency over incandescent driven by an inverter, but I'm not sure about direct-drive of LEDs vs inverter-driven CFLs. For 120VAC, you may have to hire an electrician to comply with local laws. Either way, you'll need a charge controller to properly manage the current flowing from the panel(s) into the battery and to the lights.

The Solar Living Institute (a couple of hours north of me here, 3 north of SF) have lots of resources: http://www.solarliving.org/

non-grid-tied?; requirements?

[bcrowell]

For your shed, presumably the reason you're thinking of solar is because you don't have AC wiring going out to it, which means you're talking about a non-grid-tied system. This raises some issues. (1) Running wiring from your house out to the shed is probably much cheaper and easier than doing solar and getting 110 V AC just in the shed. (2) A non-grid-tied system is actually a more complex, expensive, and and difficult project than a grid-tied system. You'd need a battery and a charging system. The battery is big, needs maintenance, doesn't have a long design lifetime, and can be dangerous as hell if you screw up.

You also don't state your requirements. How much power do you need? Do you need AC, or can you get by with DC? DC is safer, and also doesn't require an inverter. Getting rid of the inverter means your efficiency is higher, and it also cuts the cost of the system. A classic application for DC solar is a pool pump. Pool pumps use DC motors, so it's wasteful to use an inverter to convert to AC, and then rectify it back to DC for the pump again. I would imagine that if all you want is lighting, you can probably do 12 V DC without an inverter.

Re:Free energy

[barakn]

Heck, you can even get a 12/24 volt DC air conditioner http://www.dcbreeze.com/ There's plenty of low voltage DC appliances.

Save yourself the trouble

[iminplaya]

Cut a big hole in the roof and put in a sky light.

Re:Save yourself the trouble

[themushroom]

...which works wonders after 6pm. Try again.

Re:Save yourself the trouble

[maxume]

Obviously you just add a hole in the floor to let the light in from China.

Re:Save yourself the trouble

[jguthrie]

Would you care to point out where in the question TihSon specifies that it has to work after dark? Please? How about where he describes the activities he expects to do in this large shed that implies that he expects it to work after dark or that he has specialized lighting or power requirements? Anything? In the absence of information, one can make up any additional requirements one likes or can make up any utilization pattern one wants.

The sort of thing I would use a large shed for (storage of stuff I don't want to keep in my garage because I would kind of like to keep my cars in there some day) there would be very little requirement for lighting it after dark because I would mostly be interested in doing things in it during daylight hours. For the rest, well, I have several LED flashlights and I can acquire chemical lights, if necessary.

Of course, if TihSon wishes to use the shed as a work area, then he will probably want to do something a little more advanced. However, the best advice I can give toward that end is "don't do it". Work benches that include access to commercial power and so forth are a whole lot easier to set up and use than a shed out back. (For the record, I'm anticipating creating a hinged workbench in the garage, just as soon as I clear some of the crap out of it. That plan has been in my family for generations, so don't hold your breath waiting for it.)

Re:Free energy

[Yvan256]

Given that most of the things we have today are DC, wouldn't it make sense to develop a new electricity plug/standard? Or do we just go with the damn huge "cigarette lighter" connector?

Step #1: $pend money....

[Slugster]

Generally speaking, if you already have on-site utility power, that's going to be cheaper over the long run than solar cells.

But say you just want to do it 'cause it's nifty? One web forum is
http://www.solarpowerforum.net/forumVB/

You can set up a solar panel to charge a car battery, and run small things off that. Basically it goes like this: solar panel->battery regulator->battery->invertor-> small-wattage wall current appliance. Alternately, you can use 12-volt RV lights that can be run straight off the battery; there's LED lights now that don't draw squat for power. The battery regulator is a necessary device that prevents the batteries from overcharging.

...About that "wiring a house" business... There's not a lot of people out there who have solar+battery storage systems to run all the junk in their houses, 24 hours a day. Most of the residential systems (in the US) use solar panels with no storage batteries, the solar panels instead feed back into the electrical grid, which gets you credit off your electricity usage but usually not your total electricity bill (you still have to pay the line maintenance charge and the natural gas charge, if it exists).

The only states where these are common is southern California and Arizona, with Nevada and New Mexico being two more possible candidates. It takes a lot of sun before solar panels are even financially worth considering. Also,,, Cali and Arizona have the biggest gov't rebate programs--and if it weren't for that, NOBODY there would have a solar setup. For what they cost, it simply wouldn't make sense.

Because solar systems are so expensive, most people who want a whole-house system start by building a house that is as energy-efficient as practically possible.... So you see, there's no way to do this cheaply. Either you spend a lot of money to build a new house, or you spend a lot of money on the greater amount of solar panels to run a "typical" house off of.

...And even having done that, solar cells are generally not considered "cheaper" than utility power, even over the long-term. It will cost very close to what 30 years of utility bills would have totaled. What you get with a whole-house setup is--you're basically paying your 30 years of utility bills "up front", and you aren't dependent upon the utility company's reliability.

In certain circumstances, a solar+battery setup can be cheaper than utility power. If you buy very remote property that is literally miles from the nearest power line, the fee that the power company may charge to extend the line to your property can run into the tens of thousands of dollars.
In this rare instance, it can be cheaper to go solar.

------

When I eventually move to the desert, I'd like to play with using some solar panels to run an air-cooling setup. Using solar power to run air conditioning in the desert just makes sense, and I don't know what else I'd run every day. Will probably try Peltiers first; I know their poor efficiency but the mechanical and electrical simplicity makes them attractive for a stand-alone setup, and easy to try on a small scale. In particular--they can be run basically straight off a battery, and need no invertor. The 3-phase invertor and the amount of solar panels you'd need to run a good-sized room air conditioner would cost six or seven thousand dollars, at least.
~

Re:Step #1: $pend money....

[asackett]

"Using solar power to run air conditioning in the desert just makes sense..." is at least somewhat debatable. Be that as it may, you might want to at least think about ditching the air conditioner for a swamp cooler.

Re:Step #1: $pend money....

[russotto]

A swamp cooler works great in the desert. Thing is, they require the one resource which is by definition scarce in a desert: water.

Re:Step #1: $pend money....

[jamesh]

When I eventually move to the desert, I'd like to play with using some solar panels to run an air-cooling setup.

Build your house underground, or into an artificial hill. Deserts often see extremes of temperature so a large amount of thermal mass will even things out nicely.

I wonder what sort of obstacles you'd have in building an underground house in soil that isn't just sandy, but is just sand... if it's anything like trying to dig a hole in the dry sand at the beach it could be a bit tricky :)

Re:Step #1: $pend money....

[Slugster]

Well yea I know that--and I also am aware of swamp coolers... but I have this grand dream of solar power to run Peltier coolers (as well as other electrical stuff) and to build a way to trap the condensate off the Peltier coolers (if there is any condensate...). So then my solar system could provide electricity, air conditioning and water.

Probably not going to work, but I figure I'll have more free time anyway as a gravel lawn doesn't need mowing.
~

Re:Step #1: $pend money....

[T3Tech]

Generally speaking, if you already have on-site utility power, that's going to be cheaper over the long run than solar cells. ...And even having done that, solar cells are generally not considered "cheaper" than utility power, even over the long-term. It will cost very close to what 30 years of utility bills would have totaled. What you get with a whole-house setup is--you're basically paying your 30 years of utility bills "up front", and you aren't dependent upon the utility company's reliability. [or lack thereof :)] Generally speaking maybe. However, many cases I've seen for a whole house system are closer to a 10 year breakeven figure.

There's a house near me in Delaware (far from the desert and its associated solar insolation) that the owner spent somewhere around $10-20k on panels and related equipment. This house is tied to the grid and more often than not is putting (selling) more power going into the grid than it uses. Although the house, built in 1981, was actually designed for solar even though the panels weren't added until sometime later (around 5 years ago I believe) since the cost/efficiency didn't make much sense about 20 years ago.

For some people, not having to rely on the utility company to fix whatever caused an outage and having a generally cleaner power signal is worth quite a bit.

When I eventually move to the desert, I'd like to play with using some solar panels to run an air-cooling setup. Using solar power to run air conditioning in the desert just makes sense, and I don't know what else I'd run every day. Will probably try Peltiers first; I know their poor efficiency but the mechanical and electrical simplicity makes them attractive for a stand-alone setup, and easy to try on a small scale. In particular--they can be run basically straight off a battery, and need no invertor. The 3-phase invertor and the amount of solar panels you'd need to run a good-sized room air conditioner would cost six or seven thousand dollars, at least. ~ Why would one waste the electricity generated from solar panels on running an air conditioner when there are much better and less wasteful alternatives (design features, evaporative cooling, earth tubes, etc.) for space cooling? In the desert you typically don't have to deal with the humidity issue which A/C is relatively good at reducing, so evap actually makes more sense and also uses less electricity.

Re:Step #1: $pend money....

[Moekandu]

I actually live in Phoenix and work in a suburb, Chandler.

Our 10Ksqf warehouse uses 4 swamp coolers to cool it during the summer. Running at full blast, the temperature usually never drops below 20 degrees F of the ambient temperature outside. To get even that, we are, IIRC, running about 80 gallons an hour total through those units. The water is so hard here in the Valley, that we have to have the pads cleaned once a month because they get completely clogged up with salt and minerals. And that's after installing in-line filters.

Also, they are only effective with less than 30% humidity. Basically only the first half of summer here. As the monsoon season starts building up, the humidity rises and it hits 102-103F in the warehouse.

Also, keep in mind that for a fair chunk of the summer, it never drops below a 100 degrees. Even at night. Whether it's swamp or air-con, you're running it most of the time.

Swamp coolers are definitely cheaper than aircon, but you get what you pay for.

Re:Step #1: $pend money....

[bcrowell]

Generally speaking, if you already have on-site utility power, that's going to be cheaper over the long run than solar cells.

I know you prefaced this with "generally speaking," but this statement is way too broad to be useful. It depends on what latitude you live at; which way your roof faces; whether you have trees giving partial shade on your roof at some times of day and year; how much the government is subsidizing you; how much electricity costs today in your area (which varies a huge amount from place to place); and how much you think electricity is going to cost over the 25-year life of the system.

Re:Free energy

[peragrin]

Yes and no. it wouldn't hurt for a standard 12volt DC connector to help keep things going, the problem is in most DC system one of the leads is bonded to the car/boat/plane/train/etc to bring back the current.

Re:Free energy

[rs79]

I guess you could do that. But I'm buessing he(she?) already has lights. Chasing
down low voltage lights aint no fun either. Hard to get and not as many options...

I used led's in my solar setup. Now I use a lot of candles instead. LED lighting is damn damn ugly.

I use fluorescents if I need a lot of light.

The odd thing too is, once you stop using electric lights you tend ot go to sleep at night and wake up with the sun and I'm saying this as somebody whose been a night owl, a serious one, for decades. No longer.

Doing it the wrong way

[MichaelSmith]

It was easy enough in Utah.

Re:Free energy

[barakn]

Hang on. I just checked out the price, $2500. This looks like an emerging , unsaturated market.

Re:Free energy

[Ken_g6]

Given that most of the things we have today are DC, wouldn't it make sense to develop a new electricity plug/standard?

Or do we just go with the damn huge "cigarette lighter" connector?

No need for a new standard. There appear to be several existing choices.

garden lights

[El Puerco Loco]

just steal a bunch of those ugly little garden lights. i'm sure that with those, a roll of duct tape and some speaker wire, you could figure a way to rig something up.

Re:garden lights

[thedarknite]

Or buy a solar lighting kit from an electrical distributor. In Australia, HPM carries a number of types depending on usage requirements.

Re:DIY? Why?

[FarmerGeoff]

Why not? I am off-grid with two sets of solar panels (house and well). Did the whole thing mysef with a little help from my friends at Home Power. Not a problem unless you're totally clueless, which, being a Slashdot reader, you're obviously not. Got to homepower.com, buy the CDs.

Re:Free energy

[Anonymous Coward]

And then you need the damn huge cables to go with it. DC current has huge line losses unless you're willing to buy expensive, fine-stranded cable at #4AWG or bigger. That 1500W monster power supply you have sitting in your living room suddenly requires 125 amps of 12V power at full load. That'll melt the insulation right off a standard 14-2 solid copper AC line.

Re:Free energy

[Bill, Shooter of Bul]

Even better, just run as much stuff on dc as possible. There are dc Florescent, and led lights you can buy. Its sort of ridiculous creating dc power with the panels, converting it to ac, only to have your light bulb switch it back to dc. Some inverters also have a dc out for this purpose. They also have dc refrigerators and other small appliances as well. I'd give the questioner more advice, but I did my conversion project in a third world country where the electrical code was non existent. So we just did the best we could, following the relevant us codes we knew about.

Re:Free energy

[Yvan256]

Replying to myself.... it seems that the USB connector itself is becoming a low-power 5V connector (I remember reading something about this a few weeks ago, about asian cellphones or something).

Why *IS* this so hard?

[f2x]

Seeing this question and various responses makes me sad. I've seen this song and dance repeated time after time. Don't forget to queue the people who keep trying to cram a kitchen sink into everything. ("Why not use wind?", "Better leave this to the professionals!", "It's as easy as 1, 2, ...1536. Profit!")

Photovoltaic technology has been around for decades, and yet manufacturing a simple solar cell to trickle out a couple of watts is regarded as black magic, wrapped in ignorance, surrounded by controversy. It always begins with the assumption that you just "happen" to get hands on photovoltaic panels.

"Surplus solar panel"? Obviously these mystical artifacts either grow on trees or have to be pumped out of shale, because no one seems to know how to make them from scratch. In any event, think of it like an array of conventional self-charging batteries that only works in daylight.

Next, you'll want to take what energy you can get out of it and store it into something that has a more reliable on-demand containment... Let's call it a battery! It must be new technology because Chevron owns the patent on all of them and thus prevents us from freely whizzing around in electric cars. Oh, and disposing of them when they expire requires an act of congress to transport them to a cave inside of Yucca mountain.

The charge controller can almost be ignored. They just pop out of the ground when you need one. This gets placed between the solar panel and the battery. Pick up the wireless version if possible to keep things simple.

Finally, you'll want to go out and buy a bunch of proprietary light fixtures that are manufactured by an obscure gnome in the land of "Walmartia". In the event that one of the fixtures ever goes bad, you must then go to "Lowesia" to find a whole new set of proprietary fixtures since the "Walmartian" gnomes only live for about a year.

Good luck with your project, and be sure to purchase futures in petroleum based technologies. That bubble won't burst without your support!

Re:Why *IS* this so hard?

[f2x]

I know it's generally not in good form to post a reply to your own comments, but after I posted "Why *IS* this so hard?", 3 people thought I was being a troll (I wasn't), 2 people thought it was insightful (perhaps), and 2 thought I was funny (hurray!).

It was my intent to place my frustration in a humorous light since I saw so many posts that cited the impracticality of the proposed DIY project. No one seems to get it when it comes to solving the energy problem. There is always some trollop out there who wants to make it harder than it has to be. Let's face it; the bottom line is always politics.

I'm going to take something seemingly unrelated and use it to demonstrate my argument. I will use textile manufacturing as an example. People need to wear clothes because it is unacceptable to publicly walk around in the nude. You have climate conditions, hygiene issues, and modesty concerns as your major arguments, but I digress.

How hard would it be to make a standard western style outfit? How do you obtain the raw materials? What kind of machinery would you need to process these materials? How much labor is involved? How much energy will be required? What is the environmental impact? And let's not forget about the cost. Let's start with a laundry list... (literally.)

T-shirt
Underpants
Blouse
Trousers
Socks
Shoes

We'll leave out headgear for this discussion, but just think for a moment what a single outfit costs in terms of its production. Think about the amount of thread you need to adequately cover the human figure. Think of the complexity of what it takes to weave thread into fabric. Think about the process of dying or printing the material. Think about the source of the molding compound for the soles of the footwear, and the acquisition, tanning, and shaping of the leather. Don't forget about zippers, ties, and buttons to hold it all in place. Keep in mind it has to be transported over vast distances. Just a simple outfit that you'll likely wear maybe once a week, and you can pick it up at K-mart today!

Some of us wear more or less depending on various factors, but just look at the fabric around you. An ordinary cotton T-shirt for under $10.00 is incredible to look at under magnification. Do any of us worry so much about its environmental impact to produce such a thing?

Now let's look at the photo-voltaic solar cell. Simple ones can be produced from copper foil subjected to a high temperature on one side until an oxide layer is created on the opposite side. Unfortunately this method also produces an unwanted layer of black carbon which must carefully removed to expose the pinkish layer underneath. The pink surface is then covered by either a transparent or translucent conductor. Fine wires closely laid in parallel would work nicely. Cover with glass or plastic to protect from the cell from the elements and connect leads from the back of the foil and the surface conductors. Is this any harder than gathering cotton, spinning it into thread, then weaving it into fabric?

Granted, copper foil isn't exactly an off the shelf item, but when you look at how much aluminum foil we have laying around, it's not too much to believe the same principles couldn't be used to adapt the process from a poor metal to a transitional one. It's not that big of a problem for engineers to adapt. It's a problem of supply and demand to dictate.

So who creates the demand? Do you still harbor the illusion that "We the people" have any real grass roots control over demand? The saddest truth is that demand is created by the most successful suppliers these days. You demand things they tell you to demand. e.g.: Cheap shirts, fast-food, heavier cars, hi-def TV, more absorbent paper towels, prescription drugs, cell phones that can surf the web, and longer lasting deodorants. A glance at the Sunday ads in the paper are all too telling when it comes to realizing just how much of our society is powered by hype.

And yet the idea of covering a r

There is a very good Yahoo Group

[Aging_Newbie]

12VDC_Power is a very good Yahoo group that covers solar power and off-grid living based on 12 volt electrical systems, which are among the best alternatives for solar using current technologies.

Here's a solution for $69.99

[rharkins]

This is a solar security light with motion sensor. The solar panel is attached to the light/battery/motion sensor by 4 meters of wire. Put the panel on the roof of the shed. Put the security light inside. Whenever it senses motion, it will turn the light on for a few minutes. When you leave, it turns off. No switch, no wiring, no problems.

http://solarilluminations.com/acatalog/Security_Lighting.html

This one uses a 10W halogen bulb, so it isn't very efficient. I'm sure there are others that use LEDs, or perhaps you could convert this yourself.

Hold on...

[epp_b]

So, your goal is to get light from solar energy...

May I suggest a window? ;)

While you're at it - light tubes!

[BLKMGK]

I have three light tubes aka light pipes in my home. They consist of an acrylic dome on the roof, a mirrored rigid pipe, and a diffuser at the end facing the inside. I often do not need to turn on lights with these suckers - very nice! Some tips - do NOT put them anywhere near a ceiling fan unless you want a disco and do NOT put them in your bedroom lest a full moon have you howling all night - yes moonlight is strong enough to light the room!

Other than that yeah go compact fluorescent or MAYBE LED. I have both and find that the LED is pretty directional and very stark white with a tinge of blue. The CF stuff lasts a good while but be careful not to get the crappy ones that take forever to light up :-( I have one of these and it pisses me off but it fits the fixture, the LED lights I bought wouldn't fit in the "can" fixture.

BTW notice that many holiday lights and tube lights are LED. These actually work pretty good for lighting some areas!

Re:While you're at it - light tubes!

[kklein]

I can't find any CF bulb that doesn't take a long time to light up. I've tried every brand I've seen (major brands--Toshiba, Panasonic--I live in Japan), and the best ones are slow, and the worst are already in the trash (before I knew how toxic they are!). I have decided that, like PC fan noise, my standards are just way higher than other people's (that's not bragging--I'm open to the idea that I may just be a whiny bastard).

And don't even get me started on the color.

Oh, and I have observed exactly NO change in my monthly electricity usage. I think I have to admit that the biggest draw in my house is this Mac Pro with its kilowatt PSU, plus all the vampire appliances I have.

But lightpipes... Now that's sexy. I love natural light. Too bad I live in an apartment.

Re:While you're at it - light tubes!

[BLKMGK]

Well this won't help since you are in Japan but the best ones I've gotten have been from Costco. (lol) The worst from Walmart and they are pushing these HARD. Some hope I've seen on the horizon is a new bulb that has an incandescent bulb in the middle for fast light off and then it goes out as the CF warms up. What you'll do when that inner incandescent fails I dunno'

Light pipes are cool in that unlike skylights you can have the roof some distance away from the diffuser. My roof is a good 8 feet away from my ceilings but the light quality is excellent. You can also route them around a little bit but performance will go down. Some of them use flexible pipes too with aluminized foil but these do NOT transmit nearly the same amount of lumens - but perhaps good for tight spaces. I worried about heat loss through it in Winter but so far it seems fine, both ends are pretty well sealed and I have spray foam insulation sealing it to my ceiling so no drafts that way either. Certainly something worth considering if you ever have a chance to use them!

Re:While you're at it - light tubes!

[kklein]

Actually, there's a Costco 10 minutes from me. I was planning on going there in a few minutes anyway!

They don't, however, necessarily sell the same things. But I'll take a look!

Re:While you're at it - light tubes!

[afidel]

GE smart energy CFL's turn on instantly and have a nice close to incandescent spectrum. I've been running them almost exclusively for the last two years and have yet to replace one bulb. The last holdout was the lights in my basement which are dimmable flood type, but now Sam's Club carries even those in GE CFL so as they break they will be replaced.

Re:While you're at it - light tubes!

[rs79]

Light pipes are indeed the hot tip - during the day at least, but, one guy around here has a single solar powered 400W halide arc lamp in his attic with light pipes from there to every room. One light bulb does his whole house.

To be sure lots of people around here have halide lights in their houses. But this guy actually uses his for lighting. Cough.

Re:While you're at it - light tubes!

[BLKMGK]

Hrm, that's a damned neat idea but every single time he wants light he burns 400W. What if he only wants one room lit - that would take what maybe a couple of 75W bulbs? I guess if it's like an office or something that it would make sense but for a home I can see where it might not be perfect - especially if Halide has any warmup time. Still, a neat idea!

Re:While you're at it - light tubes!

[myopic_bingemaster]

The phrase you're looking for is CRI (color rendering index). There are a ton of low-CRI crap lighting, but if you're willing to spend it, you can do better:

http://www.handhelditems.com/5500k-color-corrected-light-fluorescent-lamp-photo-bulb-p-5711.html
[Good quality light. No manufacturer anywhere on it so...]

http://www.solux.net/cgi-bin/tlistore/infopages/index.html
[Claims. But I haven't dealt with this company]

There's others out there, but if you get a CRI in the 90+ range, it will be better than most (Walmart are ~60 last time I researched; bad enough it's hard to find out what they really were). I'll agree with the light tubes as being a good idea, but I haven't used them yet. A poster further down said something about metal halide-- the largest problem with MH bulbs is their output goes down *drastically* as they age; we're retrofitting 8xT-8 bulbs in a few factories with good results.

Re:DIY? Why?

[jamrock]

I was just wondering if the submitter had any DIY experience whatsoever. Slashdot reader or not, intelligence has nothing to do with whether someone is adept at the practical stuff. My brother is one of the most remarkable intellects I have ever encountered, and he's absolutely baffled by a screwdriver. Thanks much for the Home Power info, by the way.

Re:Free energy

[BLKMGK]

Actually this is a pretty big problem! One of the things I have consistently read in magazines like Home Power is that 12volt devices can be a problem with regard to sockets and plugs. Lighter sockets do not carry current very well and are flimsy for one thing. Using standard 120 sockets is simply asking for it because as soon as you turn your back a guest or baby sitter is going to make a mistake. Lots of things have been tried but so far I've seen nothing really good.

I DID just read the other day about some new power standard being adopted by some companies to help get rid of wall warts. You'd have some sort of power strip that could power multiple devices using a standard power and it would completely shut the device down when not being used. I didn't pay much attention to that but perhaps that is a ray of hope? Whatever plugs they use might be useful for this. Best part of it is that hopefully all of those devices will use the SAME power instead of one being 9volts, another 13, yet another 12, and so on. It's crazy to have to have an entire BOX of chargers and wall warts (seriously)...

Mini Hydro

[mrbluze]

Is there any other technology battery-wise for a project like this that is feasable?

I discussed this exact type of project (in a farm setting) with a civil engineer who did the same thing. He found that using excess energy (also from wind power) by pumping water up an incline was more efficient than batteries. He used two dams at different parts of a hill which worked well. Also shared the power storage with a neighbour since the dams were large enough and this reduced the infrastructure cost.

Re:Mini Hydro

[robertjw]

Great idea. Think I read somewhere that the next generation of hybrid cars will use some kind of hydraulic storage rather than electrical. Wonder if the same thing could be done pneumatically. Compress air with the power and release it to run a generator on demand.

Re:Free energy

[orangesquid]

DC power transmission over short distances is feasible. Over long distances, it isn't. Look up the Current Wars and AC power distribution. For DC, P=I^2*R=V^2/R. For AC, Prms=Irms^2*Z=Vrms^2/Z. Ignoring phase shift and comparing RMS AC quantities with DC quantities, the equations look the same. The longer the lines, the larger R, so the larger your power lost to heat. DC-DC power conversion is a modern solid-state technology (using charge pumps?) and still tends to be expensive, intolerant of transients (without proper filtering), and limited to small voltages and/or currents. AC-AC power conversion is simple, cheap, and can handle huge currents and voltages. Also, it's much harder to go from DC to AC than the other way around. Until modern solid state, in fact, there was no reliable, efficient way to convert DC to AC in any significant quantity.

If you had a shed and a house on two sides of a large property, and you wanted to put solar panels on one and bring some power to the other (perhaps it is in the shade), inverter + step-up transformer + step-down transformer + AC-to-DC is going to have a noticeable improvement in efficiency over trying to carry DC long distances. If you're generating any serious amount of power, you're also going to need some thick, thick cables to carry lo-volt hi-amp DC around in order to safely dissipate the heat, especially for wires running indoors. Even if you don't care about losses, converting to/from AC is much cheaper than replacing everything in a burned-down house.

Mod parent up!

[mrbluze]

Mod parent up - this comment needs discussion because it's very interesting indeed!

DIY Solar Resources?

[Codifex Maximus]

Try using a skylight. i.e. a hole or plexi-glass covered hole in the ceiling. Then, cover the rest of the shed's roof with solar panels to generate DC for charging 12V deep cycle lead acid batteries. Then use 12V droplight at night.

Re:Free energy

[Codifex Maximus]

Bill said:
"Even better, just run as much stuff on dc as possible."

Edison would be proud of you!

Re:Free energy

[Bill, Shooter of Bul]

Yeah Edison would be, but my elephant is even more grateful.

12 volt, but....

[CBob]

12 volt DC is the easiest for lighting w/o a doubt. The hard part is finding "affordable" panels of decent quality. There used to be a large number of surplus panels, but those days are long gone. Cheating & going for the obvious http://www.google.com/search?hl=en&q=DIY+Solar&btnG=Google+Search The 12 volt airco price is scary, an inverter setup for 115 would be cheaper. As long as you're not connecting to mains, it's a simple TabA-SlotB type of setup. If you're even thinking of going to connecting it up to commercial power, get a certified electrician who knows PV systems. Your local utility will usually REQUIRE you do that if you're going to touch their system & run PV.

Re:Free energy

[Codifex Maximus]

Well,

Power = Volts X Amps. AC Power is measured in Root Mean Square approx = 0.707 of total AC amplitude.

So, let's see. Using DC with a 2000W device would be:
A = P/V = 2000 / 12 = 166+ Amps. Doh! As the AC said, Amps tend to melt wires.

BTW, IWAEFAW (I was an electrician for a while.)

Here is a source

[xkr]

There is a company called "solarstick" here: http://www.solarstik.com/education.php that has a complete setup with panels, tripod, and power converter. I think can probably buy just the components you need - like the power converter. They have very detailed user manuals available for download. You might get the theory you are looking for in the manual.

I have put in $12,000 and up commercial systems. I will caution you that the correct theory and implementation is bit complicated. There is a (1) panel, a (2) battery, and a (3) load. There are complex three-way, time-dependent interactions between all three components, none of which are linear, or even consistent (often). In between the three is a "controller," a little black box that does the tricky part. They don't cost much. Make sure you have a provision to measure current with a low-cost DVM and be sure to to put fuses everywhere. You can use low-cost in-line car-type fuse holders, which you can buy at a hardware store. Unprotected overloads in solar systems are ugly.

Re:Free energy

[Codifex Maximus]

Man, that was one unlucky elephant. I guess Edison was trying to prove how dangerous AC was. See? Look! It can even kill an elephant.

Me too

[HeyLaughingBoy]

Oddly enough, I'm doing the same thing: in fact I just came back inside after a day of building.
I'm building a coop for my ducks & chickens and am going to light it with power LEDs & surplus solar cells and perhaps keep the water liquid this winter using solar heating.

Solar cells are pretty straightfoward. Just think of them as batteries and you won't be too far off.

PM me if you want to run some ideas by me. I am an EE and I've done enough design work that this should be trivial. I'm also making my first attempt at a blog: http://softwarefromthefarm.blogspot.com/

Check out some good magazines

[dnight]

I recommend you check out "Home Power". It's a magazine dedicated to off-grid power production (solar, wind etc). It's a good read, very informative, and has a lot of good printed links to various resources.

It's about $4 an issue.

I dodn't work for them, but I love to read that mag.

Re:Free energy

[sfm]

I think you mean LOW Voltage DC, the high currents force
you to use very large wire to get appreciable power to
the load. Actually, DC line losses are less than AC for
a given voltage and power transfer.

Mother Earth News - Easy DIY Solar Lighting

[Leemeng]

Mother Earth News mag ran a feature last year on exactly this topic:

Easy DIY Solar Lighting
http://www.motherearthnews.com/Do-It-Yourself/2007-04-01/Easy-DIY-Solar-Lighting.aspx

From the intro:
"Many people dream of solar-electric power for their homes, but can't afford whole-house systems. Here's an affordable, entry-level system with which you can have fun and get to know the basics of solar power. This setup, built with a small photovoltaic (PV) panel, one battery and low-power direct current (DC) lighting fixtures, can bring solar lighting into your home or remote locations. If you can turn a screwdriver, you can install it yourself."

Really does read like "Solar Power for Dummies", though the info seems US-centric.

Disclaimer: I haven't built any solar power systems yet.

Re:Free energy

[OshMan]

Yeah sometimes Edison gets some bad press about this however apparently the elephant had "squashed three handlers in three years" and was going to be put down. The ASPCA was actually involved and gave Edison the thumbs up. http://gothamist.com/2008/01/04/edison_vs_eleph.php

I have a solar power setup and it not all that.

[joecamelman123]

Ok here is my 2 cents worth. Not to discourage anyone but solar panels are incredibly complicated and hugely expensive. I have a very large 2Kw array on my house. I ended up spending over $28,000 on it. And I don't have a single battery to store power with. I use net metering. I am still tied in to the electrical grid. My array only makes power when there is enough sunlight and that is about 8-10 hours a day. I live in Florida so I get a fairly decent amount of sunlight throughout the year. Of course I also work a 9-5 job so I am not home most of the time the panels are making power but with the net metering it just spins the power meter backwards and credits me. I have electric bills anywhere between $0 - $35 dollars now. In the cooler months I have actually had a credit from not running the a/c so my bill is balancing out to $0. From start to finish it took about 3 months to design, plan, order, and have it all installed. You have to have a licensed installer install everything or you will not get the rebate here in Florida. But I was told the state rebate fund ran out of money and so I am still waiting for my refund! I still have a seperate backup generator for when the power goes out which tends to be frequently around here.

Re:I have a solar power setup and it not all that.

[Moekandu]

Here in AZ, if you generate more energy than you use in any given month, the utilities (APS and SRP) will actually pay you the difference (minus a small management/service fee, of course). Also, the big rebate comes from the utilities, not the state, which just gives a tax credit.

The rules definitely vary by locale.

Re:Free energy

[Anonymous Coward]

You may need to read a few books/web pages before you can get the total picture. But here's a quick checklist of what you need to know:

1. Learn the basics - V=I x R, P=V x I, and most importantly power lost P=I ^2 x R.

2. Best if you can show a sketch of your plan to an electrician or engineer just to make sure that you are not doing something dangerous or against local law. Make sure that each of you load have properly sized fuses (or circuit breakers).

3. For a DC solar voltaic system, you will need to know what load your setup will consume, and how it relates to the the size the following components:
a) Solar Panel
b) Charge Controller (connects the panel to the battery when the sun is shining, disconnects otherwise, and ensures that the batteries are not overcharged)
c) Low battery voltage cut off circuit (sometimes included in b)
d) Batteries
e) Wires, terminal blocks, fuses/circuit breakers

For an AC system, you will need to add an inverter.

The choice between AC or DC is important because DC systems are usually low voltage (12 or 24V) which means higher current. A rough example, if the wire to your lamp is 150ft long with a resistance of 1 ohms, powering a 12 watt lamp (12 volts at 1 amp of current), Using P=I^2 x R, one will lose 1W to heat. Compare this with a 12 watt lamp running 120VAC at 0.1 amp current, one will only lose 0.01 W. There's a tradeoff of using a more complicated AC system (using an inverter) or spend more money to get bigger cables to reduce resistance.

BTW, IAAEE: I am an Electrical Engineer

Re:Free energy

[profplump]

Of course, now that we have solid-state, fairly efficient DC-DC power converters, you don't need an inverter to get higher voltages -- you can run DC the whole way.

In fact, high-voltage DC is commonly used for power distribution in places where the additional cabling needed for 3 AC phases costs more than the conversion equipment needed to transmit as high-voltage DC.

Hyperbole?

[chuckjuhl]

"During a typical year, home electrical problems account for 67,800 fires, 485 deaths, and $868 million in property losses. Home electrical wiring causes twice as many fires as electrical appliances. In urban areas, faulty wiring accounts for 33% of residential electrical fires." http://www.usfa.dhs.gov/citizens/all_citizens/home_fire_prev/electrical.shtm Hardly seems like hyperbole.

Re:Hyperbole?

[twitch94301]

And I bet a majority of these are a result of "professional" electricians doing a crappy job. Most DIYers are going to do a better job, purely because it is their house they are working on.

Re:Hyperbole?

[hedwards]

And how many of those fires were from obsolete, should have been replaced decades ago, wiring?

I'm not saying that it can't go really bad, but considering the numbers of houses which have outdated wiring that are being used for all the modern gear, it seems a bit of a stretch to assume that's evenly distributed or is primarily caused by incompetent installation.

Re:Hyperbole?

[drinkypoo]

Actually, my mom lives in a mobile home with aluminum wiring. Yes, you heard right. I've watched sparks shooting out of an outlet because of corrosion on the tips of the wires. Almost burned down the "house", kitchen first. The fix? You cut the tips and install these copper tips that go on with some dielectric paste or epoxy or something to prevent it from happening again... You certainly don't retrofit the wiring in a mobile from the 70's. Anyway, that happened without any wiring modification, from the original equipment.

Re:How did the person that knows learn?

[Bill, Shooter of Bul]

The person that knows learned by burning down two houses, a third burned down, then sank into the swamp, but the fourth worked.

Marine battery + panel + DC lighting. Done

[seanadams.com]

Shed lighting is pretty easy because the power requirement and the duty cycle (on vs off time) will be low, and you don't need voltage regulation. That means all you need is a largeish 12V battery (preferably rated for "deep cycle"), and a modest 12V solar panel of maybe 2-3 square feet. Test with a small setup first, and then if you want more run time (from a fully charged battery) add another battery. For more duty cycle, add another panel.

Hook the panel to the battery with a diode in series, and then hook 12V lighting (eg track lighting minus the transformer) to the battery, and you're done. Solar panels are inherently quite compatible with lead-acid charging requirements, so you don't even need charge circuitry for a small setup such as this.

If you want to power a small 110V device, you can use an inverter. You won't be running a table saw on one of those though.

Treat Batteries Like they are a bomb

[o1d5ch001]

Since becoming a ham several months ago, I started learning all about batteries and 12V power and while I was at some solar energy stuff. Starting with a shed project is a great idea. I am assuming you are looking to light things, not run a planer.

• All electrical should be 12V dc if you don't have to run 120V AC for anything. (no conversions!! yeah!)
• Use a good quality deep cycle or marine battery. Car batteries are intended to give lots of amps for a short period of time.
• You will need a charger manager that can reduce the charge to nothing from the solar panels so you don't boil you battery. Well, just go to Battery University and learn all about batteries.
• http://www.batteryuniversity.com/
• Look at using 12volt lights
• 12v side of life: http://www.ccis.com/home/mnemeth/12volt/12volt.htm
• Battery FAQ http://www.windsun.com/Batteries/Battery_FAQ.htm
• 12v CFL http://www.unlimited-power.co.uk/low-voltage-lights-12v-dc-CFL.html
• Very good inverters from Astron http://www.astroncorp.com/dc2ac.shtml with modified sine, not square sine if you want to run more than just lights.

Oh yeah, treat all large batteries like they are bombs ready to go off. Store them outside, and if it gets below 0C then you might have to figure out how to keep them warm. Good luck with that.

Re:Treat Batteries Like they are a bomb

[TooMuchToDo]

To keep the batteries warm, you insulate the battery box and use the charge controller to dump excess energy into an electric resistor heater.

Re:Lots of light in the daytime. None at night

[Vectronic]

lol, well I didn't mean having like hundreds of little calculator solar panels hooked up to LEDs scattered around the shed.

Do it the same as you would for 'normal' lighting, have solar panels up on the roof.

And I didn't say you wouldn't need any batteries, but that you would need less to run the same amount of lighting.

A Single car battery could probably run your average LED light (with its 30 or so LEDs bundled together) for probably 2 or 3 nights before needing a charge, but the same battery powering a 90 watt incandescent light would drain the battery after about 4 hours, as well as some loss via the inversion which could have been used.

DYI Solar Resources

[mycin17]

Hi: At least look to the people who know. Get in touch for info. http://www.ovonic.com/

Re:Free energy

[hedwards]

The only problem with that, is that you have to make sure that there isn't a special chip required. My Razr requires special cables to charge from a wall, or a driver installed to charge from my computer.

My Motorola bluetooth though does not require any special signals to charge.

Really, it's mostly a problem because Motorola chose to provide a bluetooth cell phone with the option of a wired headset and not engineer it to default to charging.

Re:Free energy

[Retief-CDT]

Also, it's much harder to go from DC to AC than the other way around. Until modern solid state, in fact, there was no reliable, efficient way to convert DC to AC in any significant quantity. False. Have you ever seen a motor generator? Quite common years ago for taking a DC voltage and converting it to a perfect 60hz AC. You can even use a reverse AC motor/DC generator to recharge your batteries, Look up power supplies on Submarines, its been done for ages.

The bucket analogy

[wildzeke]

Imagine you have a bucket filled with water, but it has a hole at the bottom. The bigger the hole, the faster the water will drain. You can keep water in the bucket by pouring water in the top. The trick is to keep the bucket at least 1/2 full all the time. You can either try to shrink the hole or pour water in the bucket faster. In this analogy, the bucket is the battery, the hole is the appliance you are running and the pouring water is the solar panels.

In putting together a solar system you must consider how many watt hours you are consuming. How much standby power you need (will determine the size of the battery bank) and how quickly you need to replenish the energy (will determine the wattage of the solar panels).

Re:Free energy

[rachit]

Hook up the battery to an inverter (to make 115V AC)

Plug light into inverter.

Why not skip this bit, and use a lower-voltage bulb? An LED array might be best, for the very low power needed. Even better yet, skip the battery, the inverter and the panel, and install a window / skylight. :)

HomePower

[certsoft]

I would suggest HomePower Magazine as a resource.

Extremely simple today but a bit expensive.

[Jane Q. Public]

The simplest solution would be to get yourself a few good car batteries. Use a bank of 12-volt solar panels. Then install 12-volt lighting, which is commonly available today. (The batteries should be of matched type and capacity... preferably all the same brand, model, and age.)

This avoids having to mess with inverters, matching the phase with your AC power, and so on, which is quite a bit of added cost and complexity.

In addition, you can set up a 12-volt lighting system without needing an electrician's or contractor's permit, it doesn't have to be inspected, and it won't affect your insurance.

Of course, that doesn't address the issue of electrical outlets, but you said "lighting".

Re:Free energy

[Guru2Newbie]

Even better yet, skip the battery, the inverter and the panel, and install a window / skylight. :)

Yeah, umm, that only works for a few nights each month--during the full moon!

solarnetwork.net

[FriedmannSolution5]

And when you do get your DIY kit up and running, check out this open-source project:

http://www.solarnetwork.net/dataPreview.php

thanks!

Re:Free energy

[NimbleSquirrel]

Hook up the battery to an inverter (to make 115V AC)

Plug light into inverter.

Why not skip this bit, and use a lower-voltage bulb? An LED array might be best, for the very low power needed. Because DC requires much thicker copper cabling, and the losses are greater over longer distances. If you don't mind paying extra for the thicker copper (and given the international price of copper this may be quite alot), then DC is a good choice. You will need better switchgear too, since the AC voltage and current ratings for switches will always be higher than the DC voltage and current ratings. DC wiring is hugely different to AC for house wiring, and DC presents more hazards than AC does. One of the reasons AC won over DC.

Re:Marine battery + panel + DC lighting. Done

[cnaumann]

That is a good basic plan. The 'open circuit' voltage of the panel needs to be around 18V to charge a 12V battery. 12V CF lighting is available from a number of vendors, I would highly recommend it over 12V halogen track lighting:

http://store.altenergystore.com/Lighting-Fans/Compact-Fluorescent/Compact-Fluorescent-Bulb-12V-7W/p1003/?source=froogle

I don't really like these 12V bulbs that screw into a normal 120V socket, but what are you going to do...

I would also suggest skylights. There is really no point is converting light to electricity and back to light.

Honda also makes some super quiet generators that are less of a pita than solar.

Re:Free energy

[Iron Condor]

Heck, you can even get a 12/24 volt DC air conditioner http://www.dcbreeze.com/ There's plenty of low voltage DC appliances.

This is an appliance for a boat. It requires that there is a large amount of water as a heat dump. Without that water all around, it is pretty nigh worthless.

Re:Free energy

[ottawanker]

I read somewhere that some areas will allow you to use 20A NEMA 5â"20R (with the twisted pin but not a T shaped slot) or even locking NEMA 5-30 wall sockets for DC, as long as you had no actual AC circuits using those sockets in the building. This should prevent most accidents.

Simplest Solar Powered Lighting

[Anonymous Coward]

Is a skylight in the roof. Next simplest is a marketed gadget called, I think, "SolaTube". That's for when you have a ceiling as well as a roof.

Re:Simplest Solar Powered Lighting

[mrbluze]

Is a skylight in the roof. Next simplest is a marketed gadget called, I think, "SolaTube". That's for when you have a ceiling as well as a roof.

I would certainly take that approach. The fewer steps of energy conversion, the better.

If I ever get prosperous enough to afford it, I will be converting our home to renewable (off the paid electricity grid). Probably a gradual process but I have to say investing in simple things like skylights, insulation, solar hot water heating has the best long term pay-off, since there is practically zero maintenance involved.

moving to the desert ...

[reiisi]

I were barned and rezzed ona niir dessert.

Nothing better than evaporative cooling in the desert. Refrigerated just doesn't do the job. I mean, it's quiet, and it feels nice near the A/C unit, but over by the other wall, ...

Well, anyway, what I was going to say, if I end up going back to the desert, I'll run solar water heating in the roof to get a good start on cooling things down. What I'll do with all the extra hot water in the summer, I'm not sure. Since water goes bad in the desert quickly when it isn't moving, it would not be good to just store the heated water below something. (Below what, anyway? where on earth do you want heat radiating back up from the ground?)

One problem with solar water to run a steam cycle is that the rare storm often includes hail.

Re:Free energy

[MrNaz]

He did say "much harder", not "impossible". What can be done on a submarine cannot necessarily be done by Aunt Gertrude on her farm house. Converting 12v DC to 240v AC at small currents for small devices is *not* easy if you need any reasonable level of efficiency.

Those $20 inverters you can get at Walmart waste over half of the power that goes into them through heat and low quality narrow gauge internal wires.

Also, setting up a DC powered alternator (which is what it's called, not "reverse AC motor") is not really the most sensible way to charge your cell phone.

Re:Marine battery + panel + DC lighting. Done

[burni]

I have to correct some things,

1.) no voltage regulation

a.) is bad because the more current you draw from a pv-panel the less voltage you will get thus you cannot charge a battery with
(your solution is by adding a diode to prevent this)

so a pv-battery charger and monitor is highly recommend, because lead-acid batteries need to be watched carefully you can ruin them by discharging them to their least.

b.) pv-cells have no linear characteristic, not keeping this in mind will lead to a lower effeciency, they have a
MPP - Maximum Power Point[1], the characteristics are mostly supplied with the datasheets,
also the MPP is given. So using voltage regulation you can draw more power from the cells as you could otherwise.

[1] http://en.wikipedia.org/wiki/Maximum_power_point_tracker

Re:Free energy

[Anonymous Coward]

Oh dear, please don't do this. DC powerlines do exist. In fact they just installed one between Norway and the Netherlands. A distance of some 600km. DC-DC conversion comes in several flavours, depending on what you want to do precisely. But as an example, a laptop brick or a computer PS take in AC, filter and rectify to DC, turn that into high frequency AC (30-50kHz, which goes trough an AC-AC transformer (can be small and low loss because of the higher freq.) and finally is turned into the required DC voltage. Transformers are not cheap. Going from DC to AC is simple although also not cheap. take a DC electric motor and couple it to an AC generator. Both are simple rugged and reliable machines and come in various sizes. The big ones have excellent conversion efficiency. And this was how it was done before solid state.

Low voltage high amps wil have high losses unless you put in thick and therefore expensive cable. AC at the same current and voltage levels needs the same cable thickness. It just ads the blind current losses.

different solar lighting

[hayagriva]

Not to be a luddite about things, but how about a skylight or 2?

Re:different solar lighting

[Moekandu]

Ya know, I keep seeing comments like this and I have to wonder...

What make you think he's only going to be in the shed during the day? Do you assume he doesn't work during the day, like most of us?

Are you meaning to be funny? Funny comes from the unexpected, not the blatantly obvious.

I mean, come on, how productive do you think this kind of response really is?

Re:different solar lighting

[Guru2Newbie]

Ya know, I keep seeing comments like this and I have to wonder... how productive do you think this kind of response really is?

Well, I did notice the post was from a seven-digit UID: hayagriva (1260388), so we can infer from that. ;-)

Kinda like responding to a "solar flashlight" invention by saying "Well, if the sun's shining, why do you need a flashlight? Duh!"

Two words:

[Max Threshold]

Stirling engine.

Re:Two words:

[drinkypoo]

If this were Jeopardy, that would be the answer, and the question would be "This device might potentially draw more criticism than the suggestion of just using solar." However, this is more like Family Feud, and that was the answer, the host asked you the question while checking out your daughter's tits, and the response to your answer was XX.

Re:Two words:

[Max Threshold]

"Just" using solar? A Stirling engine is by far the most efficient means of converting solar energy to electricity. It can also store solar energy as heat and convert it to electricity as needed.

Re:Marine battery + panel + DC lighting. Done

[expatriot]

I sure the parent and many slashdoters understand basic electricity, but I want to warn against just connecting a marine battery and charger together.
Improper use of these can, and have, cause fires, acid explosions, and serious burns from shorting a high current supply.

DO NOT DO THIS UNLESS YOU ARE REALLY SURE YOU UNDERSTAND WHAT YOU ARE DOING.

Re:Free energy

[kipman725]

the improvement in effecaincy is due to the lower heating due to p=I^2*R. Say you wish to transmit a given amount of power. Well as power is P=IV then by increasing the voltage you decrease the current to transmit the same amopunt of power. As the earlier equation shows the less current the less heating of your transmision lines. Therefore by using higher voltages (by stepping up the voltage with transformers) and then stepping it back down at the other end the effeiciancy of the transmision line is increased. This is done with AC because ac can be easily and effeiciantly stepped up and stepped down using transformers wheras DC>DC conversion is less efficiciant and more complex.

Re:No, no, no [wiring your house is not hard]

[quaero_notitia]

Wiring your house is not hard, burning your house down is even easier.

Re:Free energy

[eugene ts wong]

LED lighting is damn damn ugly? Why is that? Is it hard on your eyes or something? Is there glare?

Re:Free energy

[mwilliamson]

I just bought a MR-16 LED assembly with 3 Cree-E LED's. It is claimed to produce the same light as a 20 watt halogen, and draws 250 ma per my measurements at 12v. One of these would light up a single room well enough to see your way around. If you actually wanted to do work, you could mount one of these on a flexible gooseneck and aim the spot where you needed it. At 250ma, a 5-watt harbor-freight cheapie panel in conjunction with a 7.2ah gell cell is probably all you'll need.

5-watt Panel: $25
LED Assembly: $30
gel cell bat: $10

Not having to run A/C from the house > $65

Re:Free energy

[jbengt]

Heck, you can even get a 12/24 volt DC air condiioner . . .

And only $6,000 per Ton!

(That's at least 5 times the price of a cheap, reliable, efficient, off-the-shelf window A/C unit from your local store.)

Re:Free energy

[jbengt]

DC doesn't have to be low voltage.

slashdot is a good site

[zogger]

Plenty of folks here have solar PV experience, several guys run whole house systems.

Steps: Determine your mount, do you want a roof mount? Most likely. They make those you can buy, or you can fabricate your own, just starting out go ahead and get the mount from the same place you buy your panel. but make it accessible enough on the roof so that a few times a year you can access it and adjust the angle relative to the sun. This is determined by your latitude, you can find maps online that address this. Seat of the pants,this works just as good, once a season (solstices and equinoxes, 4 times a year in other words) go out exactly at noon, adjust the panel so that it perpendicular/flat to the sun.

The panel itself will have a metal frame with a grounding hole indicated. You need to install a grounding rod at the shed base, big fun, you'll develop manly man muscles hammering that bad boy in. Here's a hint, dig a hole where you want the rod to go (after first determining you are *not* going to hit a waterline or some other underground man made obstruction of course, common sense rules there), soak that hole with a bucket of water (that gives you an idea on the size of the hole to dig, something that can take a few gallons and sit there and soak in) periodically for a couple days before hammering in the rod. Man it makes it much easier. Where you buy the rod, they will have grounding wire and a connector clamp. You'll need a nice maul to get it going, a normal hammer would be possible but I don't recommend it. alternatively a fence post pounder, maybe you can borrow one. Lowes/ Home Despot have all of that. At the panel frame, just a good stout bolt with lockwashers and regular washers is adequate for the ground wire. For lead wire, welding cable you can buy off the roll by the foot is good enough for your shed needs, and your run won't be that long anyway most likely. Conversely you can use exterior grade house wiring, again, by the foot. that is more resistant to sunlight/water/whatever. If you want or need by code conduit, again, cheap plastic pipe at the store and glue and a hacksaw and some clamp mount action.

Next you need to run the raw output of your panel to a charge controller (those ship with wiring diagrams as well), then the feed from there will go to your battery. If you are using a smallish panel it will nominally output 0VDC at night with no visible moon to around 17 (maybe higher) or so VDC at high noon on high summer day. The charge controller adjusts this, better quality ones monitor the charge going to the battery and adjust as it is needed for optimum charging, which is a three stage process of voltage regulation. It will shut itself off when the battery is full, indicated by the colored lights on the controller (some have a little LCD panel with interesting little things to look at ;)). If you find yourself with extra juice potential (I bet you do) by early afternoon, lucky you, you can add an additional battery in parallel if you want that juice. I am a big fan of having lager than what you think you might need battery action, more and bigger. Makes them last longer.

For battery or batteries, now your choices get varied depending on needs, but rule of thumb with batteries after all is said and done and all the marketing BS is out of the way is you are buying lead by the pound. that's it. More lead, more stored juice. Your cheapest solution is a normal 12 volt "trolling" motor battery they sell for boaters and fishermen. Those batteries are designed to run a trolling motor for hours, they should be sufficient for your modest lighting needs. You'll need ring connectors for your lead wires, attachment is straight up, positive and negative. Next step up would be two 6VDC batteries, or golf cart batteries. Those get wired in series to give you your 12, then in turn are wired from the controller output, on one battery it is the negative, on the other it is the positive. the two others are connected battery to battery, that is your series connection. To keep it sim

Re:slashdot is a good site

[drinkypoo]

Steps: Determine your mount, do you want a roof mount? Most likely. They make those you can buy, or you can fabricate your own, just starting out go ahead and get the mount from the same place you buy your panel. but make it accessible enough on the roof so that a few times a year you can access it and adjust the angle relative to the sun.

He is building the fucking shed. All he has to do is point the flat side of the roof south and he's done.

Re:Mod grandparent down!

[SETIGuy]

Mod grandparent down - that article is what we in the real world call a "pile of crap." Others could call it a "political treatise." It is based upon three greatly flawed assumptions. The first assumption is that what we pay in energy cost is somehow related to the true (monetary and environmental) cost of the energy. This is demonstrably false.

The second assumption is that the only thing that effects cost of an item is the energy used to produce the item. Also demonstrably false.

The third is the assumption that energy costs are uniform across the planet and that they do not change with time. Has he ever looked at his power bill?

Don Lancaster needs to take an Introductory Economics course. From this article I gather that the term "informally peer reviewed" means "read by people who agree with me and guess what, they still agree with me."

Re:Marine battery + panel + DC lighting. Done

[EdwinFreed]

My son and I built a very similar setup for a school project: A solar-powered kiosk for recharging portable electronic devices. It's been operating for over a year now without incident.

We used a deep-discharge AGM battery purchased locally. The panel we bought online from www.solardepot.com. We considered just using a series diode, but eventually opted for an inexpensive SCN-2 charge controller from www.allelectronics.com. We also picked up the AC inverter there. (Checking, I see the price for the controller has gone up, so you might want to shop around for one that's a little cheaper.) The various other parts, like the mechanical dial timer, fuses, outlets, conduit, and assorted mounting hardware were all purchased locally.

Frankly, the hardest part of the project was coordinating the installation (which involved getting up on the roof) with the school. The electronics went together effortlessly.

Our main worry wasn't that the setup wouldn't work, but rather that it would be vandalized. But for whatever reason that hasn't happened.

Re:Free energy

[mstrcat]

While the parent is technically true, it's pretty much hogwash for the current discussion. The amount of current even a large shed roof can produce from solar cells is too small to worry about I^2*R loses. Use standard 10 gage wire, and you won't even have to use solid copper (most is copper coated aluminum). The only place you should worry about cable thickness is between battery and first fuse/circuit breaker.

Re:Google shopping results

[reezle]

Re:Google shopping results for "solar powered shed light" gives a lot of good solutions. Anywhere from $30-$100, fluorescent or xenon, indoor outdoor...

Re:Free energy

[SydShamino]

Most of those choices don't offer retention mechanisms. No one wants power that won't stay in the socket in response to a little tug. The only one that offers decent retention is the Molex connector, and that one has too much.

A house-wide system of 12V power based on a basement fuel cell or attic solar cell would be a good thing, but I do think a new connector expressly for that purpose would be a valuable standard.

Re:Mod grandparent down!

[syphax]

The use of a 10% risk free interest rate was also interesting.

Mod parent up; grandparent is so bad it's not even wrong. The EROEI (energy returned on energy invested) for PV is demonstrably quite positive.

The economic cost = energy argument is an interesting one but is simply wrong. There are multiple ways to attack this proposition; you could show that the energy intensity of economies (energy consumed per $ GDP produced) are not constant, labor costs are significant and do not pass through linearly to energy consumption, etc.

The economics of PV aren't great now, but are improving rapidly. The experience curve of solar shows a ~20% reduction in costs with every doubling of cumulative production, and the industry is currently growing at 30+% per year. Grid-parity could be as few as 5 years away (Solar is economically competitive in some markets today, like in sunny places with high electricity prices, e.g. Hawaii).

To really awnser your question1.

[jaker29902]

If you decide you eventually want to actually do this the basic pricipal/theory/rig is this. 1. Get a solar panel, DC charge controller, large watt DC to AC inverter, and a few high amp hour deep cycle battery 2. Attach solar panel to charge controller, charge controller to the batteries, batteries to inverter 3. Plug you appliance in to the inverter and enjoy Realize this is a fairly large simplification and you should definately do some calculation involving the amount of watts hours you need to use versus the amount of watt hours the batteries can hold. Also you should do the calculations and shop around to find out how big of a panel you want, eseentially the bigger, the more expensive, the faster the batteries charge. And once again, THIS IS A SIMPLICATION OF THE WHOLE PROCESS not a definative description

Hawaii

[falconwolf]

Solar is economically competitive in some markets today, like in sunny places with high electricity prices, e.g. Hawaii

The big island of Puna in Hawaii gets 30% of it's energy from geothermal power.

Falcon

Re:Hawaii

[syphax]

Having a volcano or two to tap into is helpful, too.

Re:Hawaii

[falconwolf]

Having a volcano or two to tap into is helpful, too.

Yea, I'd imagine if they could tap into the volcanoes more more of their energy could be geothermal. Though not as much as Iceland Hawaii could generate a lot of energy that way.

Falcon

Winnar!

[Moekandu]

Mod parent up!

I've always tried to appreciate the technology I interact with in my everyday life. It gives me the insight to understand what we are capable of in the future. And how soon that future may be.

I would also suggest skylights.

[falconwolf]

Light tubes like the Solatube would come in handy here. However with a battery bank work could be done when it's dark. Last year or the year before IEEE's "Spectrum" had an article on how people in South Asia have been able to increase their income by buying a solar panel and batteries which allows them to do some work when dark. And the panels generate more income because they are made locally creating jobs. Ump, I just searched the site but didn't find anything, maybe it's only in the print edition.

Honda also makes some super quiet generators that are less of a pita than solar.

I'd only use generators as a backup, even when converted to run on alcohol or methane.

Falcon

geeez,

[reesercher]

After slogging through this thread, I figured that I've earned the right to throw in my two cents, so here it goes... Get a "solar generator". I'm a HAM and will be using one this weekend for field day. There are many to choose from, and for the record, the one we are using is a Solar Stik (solarstik.com). Expensive system, but extremely well built, no permits required for use, can handle the elements, etc. They have a fairly informative website, and they also have links to other solar generators for comparison shopping. Good luck!

power needs

[falconwolf]

A full-scale home lighting system is going to use vast amounts of electricity.

Maybe I missed it but I don't see where the person asking about DIY solar says anything about lighting a whole house, all I see is a "large shed", now what that means I don't know. And depending on what lights are used vast amounts of electricity may or may not be needed. CFLs use 1/4 the electricity of incandescent lights while providing the same amount of light.

Because it's a DIY project, requested by someone without basic electrical knowledge.

I have a problem with this too, I don't see where the person says how much electrical knowledge they have, or what type. Someone who knows AC may not know much about DC. A good example of this is with High Voltage DC transmission, I've heard licensed electricians admit they don't know much about it. That is a person may be able to design an AC system but not one that's DC. Where knowledge of both is needed is where there's an intertie.

Falcon

Re:power needs

[evilviper]

What the submitter was asking for isn't necessarily relevant. Discussions often move off-topic.

With that said, I suggest you read the submitter's words more closely:

"explain the reasoning and theory"

"future solar projects are not out of the question"

"Something that starts with basic theory and ends with the ability to wire a house would be perfect."

Finally, as for CFLs, 1/4 of a hell of a lot of electricity, is still a hell of a lot of electricity. Even with a small house, you're still almost certain to draw more power for just lighting than a large appliance would.

Re:power needs

[falconwolf]

With that said, I suggest you read the submitter's words more closely:

Okay. I did miss the part about wiring the house.

Finally, as for CFLs, 1/4 of a hell of a lot of electricity, is still a hell of a lot of electricity. Even with a small house, you're still almost certain to draw more power for just lighting than a large appliance would.

I have 6 light fixtures with 2 12 watt CFLs in each. If I turned all of them on at the same tyme, I have at most 3 on at any 1 tyme and then only for a few minutes at most, that comes to 144 watts. I just checked the power my expresso-cappuccino uses and that's 900 watts and I'm sure the refrigerator uses much more. However my scanner only used 15 watts, the TV 126, and the dvd player 23. So it really depends on what appliances are going to be used. Now if submitter wants to wire the while house then yes a pro should design and wire the system. Especially, seeing as how the person doesn't say they are Off the Grid, because it would need to be intertied.

Falcon

solar generator seems to fit your requirement

[reesercher]

Sorry, this is a duplicate post, but I am new here and accidently posted a reply to another individual's response. Here's my two cents: Some companies make "solar generators". You can do a google search to find them. They are... 1. 'self contained' & ready to operate right out of the box! 2. not required to have 'permits' for use 3. not 'application specific' and can be used for other purposes I'll be using one this coming weekend for Field Day (I'm a HAM operator). The one we are using is called a Solar Stik, and it's probably more than the average person can afford, but they have several other manufacturers of solar generators listed on their website. The solar stik website is actually a decent resource for information regarding solar power in general as well. Good luck!

Guerrilla power

[falconwolf]

I do wish they would bring back their guerrilla power features though :-)

Ah, I miss those guerrilla power articles, it's been several years or so.

Falcon

$24.99 Solar shed light

[stkpogo]

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95573

Re:Marine battery + panel + DC lighting. Done

[drinkypoo]

Amen to that. In fact the charging voltage on a car battery is only 1.5 to 2 volts over its current voltage to a maximum of 14.6 volts. (They have 2.1 volts per cell design max, for a nominal voltage of 12.6 volts. It is not unusual to find a car battery holding over 13 volts. blah blah blah) Putting 18V into a car battery for extended periods is not good for it. This is the other reason we use charge controllers...

Re:Free energy

[Retief-CDT]

I agree that it is not exactly easy to explain a generator that can become a motor. But I was a Nuclear trained Electrician (Submarine Prototype) and the concept of using a simple DC motor to power an alternator should not be ignored. You could even use a starter motor from a car with a suitable controler to prevent speed overun to hook a simple AC generator to it. Electronics are nifty but it is very difficult to reproduce a standard sine wave form.

skylights wont work?

[Uzik2]

I've heard of technophilia but... wow.

Re:Free energy

[drinkypoo]

DC power transmission over short distances is feasible. Over long distances, it isn't.

Yes it is.

In fact, it's actually more efficient over long distance than AC, but the AC/DC conversion involved makes it less so in most cases, and definitely makes it more costly.

We use AC because you can use transformers with it, plain and simple.

Re:Free energy

[drinkypoo]

The only problem with that, is that you have to make sure that there isn't a special chip required. My Razr requires special cables to charge from a wall, or a driver installed to charge from my computer.

I charge my RAZR from my laptop running linux. I guess it has a driver, but I definitely didn't have to install it...

Have you tried putting it into filesystem mode, and seeing if it will charge like that? My V3i will. Of course, that involves a driver too, but it's the mass storage driver which should work pretty much everywhere.

Re:Free energy

[BLKMGK]

It's a sharp light with a limited spectrum. The bulbs I have are "white" but they have a blue tinge like many white LED. It's also a very directional light and not terribly diffused. Just have to be careful where you use it is all...

Re:Free energy

[BLKMGK]

AC won out over DC because it could be transmitted over long distances with less loss. Using DC meant there had to be power generation stations all over the place. Not so unlike what we'll have if everyone puts up solar panels actually. DC makes some sense with local generation.

Well, I have done a number of these projects...

[beachdog]

One starting point for books and project ideas is the Whole Earth Catalog. I don't think there is a current edition but it should be in a library.

I used Farrington Daniels' book Direct Use of the Sun's Energy as a starting point for several solar energy projects.

He lays out the physics in their elegant simplicity and shows Direct Uses of it as the title says.

Some writers suggest there are fire hazards, especially if you use batteries in your project. Those warnings also indicate that as an advanced amateur you really do need access to the design and installation and safety information used by the professionals.

For solar projects, the Code Check plastic guides at least cover solar electric inverter and wiring in outline.

It irritates me that Building Codes are copyright and building permit texts generally not available online.

It is too bad that example building permits and guides to drafting and writing a project are not available online. As an advanced amateur, what I need is a couple of well thought out example projects.

Even the Building Code used by San Mateo County is copyright and can not be reproduced on the Internet, which would be very helpful for people who want to build a solar energy project.

adjusting

[zogger]

The vertical angle of the panel needs to change periodically to take advantage of maximum gain if this is to be a low buck simple easy first solar PV install. Ya, he can use one angle, probably a midwinter angle and get a lot of juice, but it isn't all that optimal either. Really, there is a reason they make adjustable mounts (and even active x and y trackers), it is a lot cheaper to add some cheap framing than to add more solar panels for the same amount of amps to the batteries. You really will notice it with just one panel. Active east west tracking along with it is even spiffier for efficiency gains, but that is still costly and usually only done on real high end installs, but manually adjusted vertical frameworks are by far the most common, because it just works and adds not that much to the total cost. I mean it's a little aluminum L or square bracket action and some bolts and wingnuts usually and a few minutes work once in awhile. And it really depends on where you live, too, how important this is, the further north the more critical (and it-geolocation- was not specified in original topic by submitter so I made a generic reply)

Re:Marine battery + panel + DC lighting. Done

[inasity_rules]

I have to correct some things, 1.) no voltage regulation a.) is bad because the more current you draw from a pv-panel the less voltage you will get thus you cannot charge a battery with (your solution is by adding a diode to prevent this)

Uh... No. Batteries charge by drawing current. This will naturally cause a voltage drop on your supply. The voltage of the battery will be a compromize between the battery's (uncharged) voltage and the voltage rise due to the amount of current the panel is able to supply. The diode prevents the battery reverse "charging" the solar panel in the dark. This system works well in practise. The company that makes the systems here is Zimbabwean (so no URL - just take my word for it) uses relays to "regulate" the charging. The actually problem is with overcharging (and thus damaging) the battery by forcing the voltage above 14V if the system is left unused and charging for too long.

Your second point is probably correct though.

Re:Wasting power

[Technician]

Converting from DC to AC wastes power, stay DC and use LED
lights because some have life spans and power usage that is
lower any other kind.

This is a common trap by newbies to solar power who have not bothered to do the math. For the shed, the math works. For my home, it doesn't.

The assumption is wire will transport power from one place to another effeciently regardless of the source voltage. Low voltage is OK for very low power applications and very short runs, such as in an automobile and less than 100 watts.

For the shed, 12 volts may be OK as all the runs are very short and the application is for low power and short durations. The power miser looks at an inverter with 90% effeciency and go Oh! No!, that power waster has to go!

Let's make the shed a little larger, like a small shop. In the shed you want to work on the lawnmower and the LEDs are not bright enough and you would like to use the drill press. A single solar panel is about 60 watts. figure an average production of about 5-8 hours/day depending on location. In a week, you will have collected 60 Watts X 5 to 8 X 7 or about 2-3 KWH. For the weekend, you can run 2 42 Watt CF lamps for 4 hours each evening and still use the drill press on an inverter. The cost of converting the drill press and using 12 volt CF lamps would far exceed the cost of a 1KW inverter. 2 evenings of light is 42 X 2 X 4 = 2/3 KWH. Running a 500 Watt 1/2 hp Drill press for an hour won't kill the battery as it uses another 1/4 KWH. If we lost 10% of our power to the inverter, so what?

With the inverter we can run more than basic stumble in the dark flashlight brightness and get work done.

Now the math. The drill press uses 3X it's full run power for start-up. For grins try it on 12 volts. 1500 Watts at 12 volts draws 125 Amps. How long is your power cord? At 120 volts the draw is 12.5 Amps. Now for power loss. 10% of 1500 watts is 150 Watts to the inverter. How about a power cord to the battery 30 feet long?

1 It must handle 125 Amps safely
2 It must not drop the voltage to the motor by more than 1%.

For 120 volts the permitted drop is 1.2 volts. 1.2 Volts X 12.5 Amps is 15 Watts lost in the cord. (why vac cords get warm) At 10X the wire size permitted for 120 Volts (think 10 power cords in parallel) the 1.2 volt drop from 12 volts would be a very serious brown-out of 10%. Even worse is the power lost in the 10X larger cord. Instead of 15 watts, you now lost 150 Watts in the cord. You need someting much bigger than 10 X the wire size you needed for 120 Volts. Care to hit the wire tables to calculate the wire size needed to start the drill press with only a 1% voltage drop from the 12 volt system? Don't forget, a 30 foot power cord has 2 condutors, it's a 60 foot total length.

So what is the better way to get power to the drill press and lights? Mine runs fine on a 12AWG extension cord. The Xantrex pro-watt inverter was on sale at Costco for under $50. A 30 foot cord and 1/2 HP 12 volt motor would cost way more than that. On sunny days, I lug out the drill press and use it outside. A standard extension cord works fine.

In short, an inverter permits the use of high power short runtime tools at distances more than 5 feet from the battery. Without it, these uses are impractical.

The above is not based on a shed installation, but a motorhome with 8 panels and a pair of deep cycle batteries. The fridge, microwave, computer, monitor, and printer are all solar powered. Electric power tools are used from time to time and are the basis for the calculations.

Do you want just a few lights, or do you want to do more?

Re:Free energy

[eugene ts wong]

Does the sharp spectrum and blue tinge remind you of some head lights on cars? I was walking home just the other day, and a car's lights at an intersection looked completely different. Is that what you are writing about?

Ack!

[rholland356]

OMG, all my expensive solar panels blocked the light from my skylights! Oh, it's the Greener's Lament...

Uh, you DID plan skylights, didn't you?

Say, assuming here that your large workshop will be filled with high-current electric motors on all that woodworking equipment you have, and that you'll need a significant electric panel to power the place (loaded with 30-amp circuits). Why isn't high-efficiency fluorescent lighting and skylights the solution you seek?

If it is just a storage shed, why do you need more than battery-powered LED lights or an LED flashlight or lantern? It's not like you are going out there each day to fondle your possessions.

Which brings up the final point--why build a shed for storage? Just get rid of that junk and live frugally.

Re:Wasting power

[Dare nMc]

I would add couple things (that will out cost AC, currently):
      1) DC has the advantage of a simple capacitor can handle startup surges, they can be spread around easily (don't need the wire sized for the surge then.)
      2) You can run higher voltages of DC, split up your battery banks/solar cells to stack appropriately. 85% efficient 96Volt to 12 Volt @ 30 amp are available. They waste no energy during no/low load situations (AC inverters that shut off are becoming available, but can be a pain) If 96Volt DC devices became high volume, all the arguments you post disappear (except I am back to needing a permit for "high voltage" wiring.)

I would add, that although their efficiency is horrible, using air powered drills is the convenient way to go. IE my 3/4 Hp 1/2" air drill, weighs less than any 1/2 HP AC drill, has more torque, and the hose is not that much different than the AC extension cord. The expanding air, cools the drill keeping it much cooler. Except that it takes a 5HP motor at the compressor to run a 3/4 HP motor. (If I can just figure out how to solar power enough stored air, then their will be little need for AC in the shop.)

Re:Wasting power

[Technician]

(AC inverters that shut off are becoming available, but can be a pain)

Inverters with low standby (full voltage output) are also common. My 1KW inverter has a 4 Watt idle. In a day it wastes 42 Watt hours, or 0.042 KWH. Since I collect about 1.5 KWH/day, I leave the thing on 24/7 and don't worry about resetting clocks, starting the inverter to turn on lights, etc. For a loss of .35% is isn't worth saving.

Look for inverters with less than 50 mA no load current. (not the sine wave units). Most stuff runs fine on modified sine wave inverters. Some stuff runs better as the peak currents on power supply recifiers is greatly reduced. Computers, monitors, and printers fall into this catagory, and these items are the first salesmen try to sell sine wave inverters to. Other items to run off sine wave include induction motors and lighg dimmers. Refrigerators run more effeciently off sine waves. I haven't yet bought a sine wave unit to run the freezer as most of the time it runs off the utility and the inverter is just back-up power for outages. For extended outages, I plug into the hybrid car.

Stuff that works fine on modified sine wave is basicaly anything that has a switching power supply.

Save the sine wave stuff for high end audio where a little buzz is a problem. For the rest of the stuff, a quality stepped modified sine wave is very effecient.

I wish you luck with your brain surgery

[unassimilatible]

Be sure to get enough mirrors.

Short Answer

[johnnyjet]

Short question, short answer:

http://knowledgepublications.com/

They have a substantial collection of books covering everything from alternative fuel sources to solar.

ja