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Wireless Internet In An Off-Grid House
matt20 writes "This is an interesting article of a family living off-grid using solar panels. In such a setting, every watt adds up. The typical home computer and monitor use almost 150 watts. What is the best computer arrangement in such a setting? Here is what worked best for them. Anyone know what percent of our national power is used on computers? Should we be thinking wireless on laptops?" Even on-grid, this article raises some good points about power consumption and convenience.
With the number of devices in the home that now use DC power, I always thought it might save energy to have one large AC to DC transformer for the house, rather than having "wall wart" adapters for each device. Even when the device is off that wall wart is using energy(feel it, it's always warm). Why not have a more advanced transformer that could adjust for load, and run DC through wires to the whole house. Plus, no more problems trying to plug 2 wall warts into adjacent spots on a power strip!
recently my local news had a story about a household that used solar. they actually sell their excess to the electric company, to the tune of something like $300 a month. apparently it paid off the equipment in about two years, and now they just collect as profit!
The One Rule Of Chess You'll Ever Need: Don't play someone who carries a kit in their bookbag.
Hardly. Buying your energy from a nuclear power plant will never net YOU, a homeowner, a net profit. Maybe if you live in the town that houses one you'll see something from their tax money.
;) But it does frequently exist, and a net zero or close to it for energy manufactured from a clean and renewable resource, for many, is maybe worth forgoing marble countertops.
If you aren't actually OFF the grid, most areas have a net metering program where you can sell excess power to the grid during the day and buy back power at night. This eliminates all the battery banks, a substantial chunk of the cost. If you furthermore design a home to be energy efficient to begin with, you can have an "affordable' solar system. I use quotes as it is undeniably a greater up front cost, but there is a return, though admittedly not much and it takes awhile to accrue.
If you ARE off the grid, then many people go with solar simply based on the economics of having a power line run to your home, if one doesn't already exist, can very quickly outstrip the cost of an entire solar electric system.
And for $1000 US or less, you can get solar hot water collection to at least augment your domestic hot water needs as well, with a definite payback period of less than ten years.
Not that payback is currently the best reason to go with solar. If someone hits a baseball into your panels, there goes your chance of payback for awhile
Interesting that I routinely deal with homes that will think nothing of spending thousands upon thousands of dollars to use Antique Jerusalem Stone on the floors, but mention Solar and the first question is, "what's the payback".
We did a study for one of my engineering classes recently about the power required to produce a solar panel as compared with the amount of power produced over the panel's lifetime. Turns out that manufacturing requires nearly 40% of the power the cell will produce over its lifetime. Kinda makes you want to look elsewhere, eh?
Photovoltaic cells have moved along from the 3 to 5 percent efficiencies of years past, although not by a large amount. A student made a presentation at my college's undergraduate symposium in the spring, and I believe he reported current efficiency standards of around 18%, with experimental (i.e. costly) cells being able to achieve rates of around 30%. I didn't get the chance to ask the student why the rates were so low, but I would assume it has to do with the design, materials, etc. I think the big jump from the ~5% range to the +10% range was due to the use of a different material (or combination of materials) - involving silicon I believe. Another thing to remember when looking at statistic on solar energy received by Earth is that although an extremely large amount of energy comes from the Sun and hits Earth, only a small amount filters through the atmosphere to a level where we can harness (i.e. near the Earth's surface to be used by photovoltaic cells). I think I recall a theoretical physicist talking about humans placing energy collectors near the Sun, in the future, that could provide all the energy we need, and that the collectors would actually be fairly small - somewhere on the order of several thousand square kilometers or something. Anyhoo, I'm sure you can find a lot more exact info with a few google searches, just adding what I recall.
my parents recently wired their home to use solar panels
the house itself didn't actually get converted over, however
all that was needed to allow normal function was an inverter
it converts the dc to normal line voltage
the excess power is pushed back onto the grid and due to recent legislation, they get paid for it
needless to say, the electric bill is down tremendously...
Base 2 yields only ARTIFICIAL Intelligence
Actually, they are developing hydrogen producing bacteria. Check it out. More accurately, people are working on using existing bacteria to produce hydrogen. But eventually genetic engineering will probably be used to up the efficency of the process. Once you have the hydrogen, producing electricity from it is pretty trival (burn it in a turbine or fuel cell).
The trick is that you have to remember that when dealing with living organisms, there is a certain amount of energy required to support life and growth (if nothing else but to replace those organisms which die.) You would have to overcome that hurdle to efficiency.
Another thing that many people don't realize is that the photosynthesis process begins with the movement of electrons. An incoming photon essentially excites an electron above the ground state, and the rest of the system acts to capture that energy. In photosynthetic systems, that energy is used to synthesize glucose. Using chlorophyll directly in photovoltaics may be possible, but would likely be more complex and perhaps even less efficient than traditional silicon PVs.
And of course, you conveniently neglect the more "traditional" approach - why don't you raise algae, collect it, burn it, and use the heat to generate electricity? It's possible, although it may not offset the cost of the fertilizers needed to grow algae in those quantities.
The real draw to a biophotovoltaic system would be cost-effectiveness, since it's likely that such a system would be much less efficient than a silicon-based system. However, it's hard to expect that you could somehow stick electrodes into a vat of algae and get electricity... although not impossible. To achieve this, however, would take some leaps in the current state-of-the-art in bioengineering and is not likely to happen for another 10 or so years.
[root@kgutwin
msdos.sys: fsav (linux) virus (17518-87)
I grew up in a 12v DC household.
We had a bank of half a dozen (or more, it varied) old automotive batteries in parallel which were charged by an old (1919) DelcoLite generator whose original 36v coil had been rewired to produce 18v. We ran it below optimal RPM's to get about 14v. It had sat in a field for 30 years used for target practice before we got it and rebuilt it with an air-compressor piston (connecting rod cut and extended with a pair of bolts welded onto it), an aluminum pot with the bottom bashed out of it as an air duct for the head, a Land Rover instrument panel, and an old motorcycle carburetor. We primed it with gas but it actually ran off kerosene.
We could run for about a week between charges until we got solar and then we only cranked up the generator about every 6 months or so when the cloud-cover had been too heavy.
All lights were ordinary 60w bulbs but anything with a motor was either designed for RV's or rewired. (Fridge was kerosene then butane).
All computer equipment was laptops and portable printers (12v or less).
I made a few bucks on the side for quite some time designing 12v adaptors for laptops that took more or less than 12v and making them fit inside in whatever space the manufacturer had left over!
The soldering iron I used for this was a piece of broomstick and a twist of coat-hanger wire holding a real soldering-iron tip which was wrapped in a heating element salvaged from an incubator.
And I really did have to walk/hitch-hike 20 miles to school every day in the pouring rain (or boiling sun)!
But that's another story...
---you can get solar install to work out to the *same* as a "normal" grid supplied house if you do some common sense budgeting things. One, live a little more remote, sometimes just a mile or two away from where the powerlines reach. The cost savings on the land per-acre makes up for the initial install. Save thousands an acre-put savings into energy independence. Net extra cost equals zero then. Two, build your own house (think of it as case modding that pays you folding green per square foot), use super insulation techniques, the over all energy savings add up immediately. Three, make use of local grown and harvested firewood instead of fossil fuels for the bulk of the heating, and the cooking in the winter. Four, skip the extra bathroom and the decorative foyer in construction if you don't really need them. Five, tie in the solar install directly into the 20 year home note, you'll hardly notice it then. Quite a few banks and lenders are willing to do this now, GMAC is the largest one I am aware of. Six, use 'solar energy" in the form of a really big garden and save thousands on food bills every year. this is all doable stuff, millions of folks are doing it now. sort of little house on the prarie with technology. I run a boatload of weird radios and gizmos and pooterz and all kinza jazz, all electrons I post start out here with a lot of PV panels.
We live all solar here. I have laptops, desktops, refridges, well pumps, fans, color tv's-you name it, wer got it, we run it. It ain't a pipe dream anymore. People who say you can't do it and it's too expensive are unwilling to actually DO it, that's the real bottom line, they are intellectually lazy and procrastinators and have sucked down the rush limbeau "being an energy hog is good for america" mindset to an extreme. usually the same people who complain that solar is too expensive think nothing of sucking down tax money for nuke plants, or signing an open ended no cost guarantee contract with your local electrico. think about it, can you ANYPLACE in the US get a carved in stone pricing contract for ten or twenty years from the electrico? Anyone here got any idea what their electric is gonna cost ten or twenty years from now?
If you WANT solar or any other on site home electrical generation, you CAN do it. My first rig was total under 500$. That was a single decent panel, a cheap charge controller, and a single big storage batt. Got more now, but that was the first rig, and it was TOO DANG COOL when I got it up and running and kicked back and ran a small tv the first night with electricity I made on site. Just slicker than owl squeeze. Instant addiction and a feeling of independence from the global energy monopolies, and doing my part to make the country energy independent. You can start there at that sort of small bucks level and work your way up. of course you can always buy gaming machines and concet tickets and cd's and bassboats and stuff like that, just dependnes what you want to show for what you blow your cash on at the end of every year. Everyone has choices, but unless you are street level poverty and dumpster diving, you CAN afford to at least start on alternate energy, call it "investing" in durable goods instead of the rigged and shilled stock market. You're always gonna want juice, right? so......
You don't have to go either grid OR solar, you can just start on grid like most people and gradually add-on alternate energy and gradually reduce reliance on the grid, and change as you can afford it as well. Certainly beats dropping a lot of cash on dot bomb stocks, which I never did, I got paid-off electricity for the next 20 years now or more probably, done deal, finished, working as advertised. I even make my own solar distilled water for the storage batts. I plan on adding a little bit every year. Just picked up a small wind charger, throw that in soon when I got the scratch and scrounge some stuff for a small tower. Just keep chipping away at it.
As to lowest useage, any old laptop that has a direct dc cord is about the least energy hog deal. I use an old 280c maccer when I'm being really frugal on watts and especially during lightning storms, but usually I'm on a later model powerbook or a linux desktop.
Have fun, hope ya check it out and get started on it, you or anyone. There's not a whole lotta ways you can thumb your nose at the enronesque energy monopolists and politicians and rampaging foreign weirdo energy producers, unless you "do it yourself". Certainly beats just bitching about stuff. Drive your old clunker an extra two years, that'll pay for the downpayment on a real nice home sized rig.
Indeed you could... the hard part is storing enough energy for a few hours with small enough loss/expense to to profitable.
:)
There's a plant at the twin lakes resivoir which pumps water uphill at night and generates power during the day.
They have much nicer bathrooms than are avaliable at the nearby national forest campsite, too
--
Benjamin Coates
I live off the grid full time and have done so for the past 12 years (24 Solarex MSX-64 panels, Trace 2524 inverter, etc.)
I bought a Cobalt Qube, because of its low power consumption, only 25 watts max - the only machine I have enough power to run 24/7.
You don't really need to have a hot water heater on all the time. In the last place I lived where I had my own heater (as opposed to the building having an unmetered boiler) I would only turn it on in the morning, about 5-10 minutes before I had a shower. By then, it was perfectly fine. After I was done, I'd turn it off again.
It can save quite a lot of money. Sadly, it's much harder to manage the same feat with the fridge.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
Some rough figures:
Some other fiures:
Industrial sheet metal shear: 3000 watts
Hydraulic press: 6000 watts
Industrial arc welder: 8000 watts
Commercial HVAC compressor (10 ton): 14,000 watts
A small, light industrial machine shop will have multiple of each of these. There are hundreds of these shops in almost every city in the US. Residential electricity usage doesn't even begin to come close to commercial usage. Computer usage doesn't even come close to the electricity used by these big tools. The last study that was done estimated that computers are using about 2% of the power consumed nation wide. That figure included networking equipment for backbones, and other office equipment like copy machines, too!
Ignore time value of money?
Interesting. I'd never thought of this... comparing (a) a $20,000 investment put into a financial instrument(s) vs. (b) an annuity based on the savings of electrical power. The general rule about the accumulationg from such things being greater the bigger the initial principal is would seem to indicate that (a) would win out.
Of course, that leaves aside the complexity of calculating costs to the environment and taxing of resources. That's the problem with these things... we can shove costs onto the commons, and we get all sorts of problems...
Libertarianism is rich wolves and poor sheep playing gambler's ruin for dinner.
Enron inspired my wife and I to have a 2.3kW grid-tied solar system installed on our San Jose,CA roof in Feb 2002. We entered a Net Metering contract with PG&E, such that we are only billed once a year, and our electric meter is a time-of-use meter that permits us to be charged less for off-peak usage. Our excess energy is fed onto the grid, thereby running our meter backwards most days during peak billing hours. Most of our consumption is off-peak, therefore we mostly sell energy at a higher billing rate than that at which we buy it back.
We had already installed a setback thermostat, replaced incandescent bulbs with CFL's, replaced a desktop CRT with LCD display and do most food reheating in a microwave. Our desktop is a Mac G4, which uses less energy than an equivalent desktop Pentium due to the nature of the Pentium chip set, and our other computers are Mac laptops, which are very efficient. No wall warts or other gear are left on when unused in our house. [ Note also that with any type of computer gear, all else being equal, the faster the clock rate, the higher the energy consumption, and the more waste heat that has to be dissipated somehow. If you don't like throwing your money away, for any given task use the slowest "suitable" system. No one should ever need 1.4GHz clock and DDR RAM to compose a text message! ]
The net result is that we will likely generate >100% of our electric needs in an average year, despite our electric stove, and using one or more computers and a TV or Stereo every evening. The installation has a 20 year warranty and will pay itself back in 15-20 years, unlike *any* other toy that I've ever purchased. No, it's not for everyone, and you have to take a long view to justify the expense, but it is quite practical in a reasonable climate, particularly if you have a more or less south facing roof.
Art