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From the article:

"All of the light from our LEDs is concentrated in a 20 degree beam, while the incandescent and compact fluorescent lights were tested without fixtures...and most of the light they produced was never measured in the test, since it sensed only light falling on the sensor. It's OK to compare different lights by how brightly they illuminate a certain size area...but put a reflector behind the compact fluorescent and incandescent bulbs in the test rig and the data would change significantly. Therefore, while the LED lights in this test may illuminate a small area as brightly as other lights, they are NOT significantly more efficient."

They take a light, shine it in a sensor at a 2.5 foot distance, and measure the light.

LED's have a built-in lens that focuses the light. so more of their light falls on the sensor. Of course this means that the LED's will test better. They get to cheat. If you redid the test with parabolic reflectors for all the lights that do not have lenses built-in, then the LED's actually measure out about the same as 100W incandesant bulbs.

OTOH, if what you want is what the article was testing (a reading lamp) LED's rock. but for general purpose lighting, LED's are not all that great. See this article for more details.

I was thinking the same thing some nine or ten months ago. It really is curious, especially with so many people doing DIY turbine-building and other people doing DIY power generation via the harnessing of rotary kinetic motion, well I guess it's just a matter of time-to-convergence, really.

I think the biggest challenge right now is mounting a turboshaft that can handle the stresses? It needs to be balanced and mounted with great precision. Also, you can't have an alternator spinning at 60,000 RPM because it'd have to be built such that it wouldn't fly apart at such speeds. The solution I've been able to come up to this issue is the idea of a worm gear reducer to turn the low-torque high-speed shaft motion into high-torque low-speed shaft motion to drive a large, slow (~2000 RPM), heavy PM generator or alternator.

Also, I think that the turbine and/or the worm gear arrangement might benefit greatly from some of this great NanoLub stuff. (although the crankcase inside a conventional piston engine is probably a much better place for it)

I have great faith in the eventual development of hybrid foil and magnetic bearings that could bear the multi-axis load of a turbine, giving us the 5million+ hour MTBF turbines we all want. Whether this sort of thing will ever be within the reach of the DIY consumer, well, remains to be seen.

I was thinking the same thing some nine or ten months ago. It really is curious, especially with so many people doing DIY turbine-building and other people doing DIY power generation via the harnessing of rotary kinetic motion, well I guess it's just a matter of time-to-convergence, really.

I think the biggest challenge right now is mounting a turboshaft that can handle the stresses? It needs to be balanced and mounted with great precision. Also, you can't have an alternator spinning at 60,000 RPM because it'd have to be built such that it wouldn't fly apart at such speeds. The solution I've been able to come up to this issue is the idea of a worm gear reducer to turn the low-torque high-speed shaft motion into high-torque low-speed shaft motion to drive a large, slow (~2000 RPM), heavy PM generator or alternator.

Also, I think that the turbine and/or the worm gear arrangement might benefit greatly from some of this great NanoLub stuff. (although the crankcase inside a conventional piston engine is probably a much better place for it)

I have great faith in the eventual development of hybrid foil and magnetic bearings that could bear the multi-axis load of a turbine, giving us the 5million+ hour MTBF turbines we all want. Whether this sort of thing will ever be within the reach of the DIY consumer, well, remains to be seen.

For those of you with the land to spare:
http://www.otherpower.com/

Do you know how much power those waste. You yanks spend twice as much on power as you should! Heck, even leaving your TV plugged-in just so you can be lazy and use a remote to turn the TV "on" wastse watts of power (now times this times your number of DVD/VCR/TV/Computers/Monitors/etc that are not on a power switch that you actually _turn off_. Over a year, it really adds up!

There's very little power available in low winds (see my recent article in the Energy Self Sufficiency Newsletter for more details), so it's critical to extract all the power possible from it.

Fortunately NdFeB magnets have dropped so much in price since the early 1980s when they were invented, that compromise is now cost-effective....not many years ago, it would've been prohibitive. Hugh Piggott's pioneering Brake Drum Windmill used big ferrite magnet blocks, and required a very small airgap and salvaged transformer cores to make good power. Hugh has also switched to a large-airgap design with big NdFeB magnets, and no longer builds or gives classes in making that older design.

DANF Otherpower.com IT director http://www.otherpower.com/contact_op.html

PS and, yeah, we are in the magnet business too! ;~)

It seems that there may be some argument for not worrying too much about steel laminates, or ferrite cores in the coils, and simply adding a few more magnets and wires and settling for a somewhat larger machine. One immediate benifit of having "air coils" is obviously the complete lack of cogging, which, if used in a windmill should result in a machine that starts very easily.

Hamster power is where the real future is!

To illustrate, here's a thought experiment: if every other source of energy quit working, and we had to restart the world economy off of solar PV power, we could round up every PV panel in the world and put them around a big factory in Arizona or the Sahara and start making more PV panels as fast as possible. However, the ring of panels around the factory would slowly and inevitably shrink away -- for each 10 panels that wore out, the factory would have only made 5 or six panels to replace them.

Somewhere a factory is burning even more natural gas or coal because you chose to buy energy-expensive PV instead of having a smaller amount of coal or natural gas burnt closer to your home.

Now, in the US at least some of the silicon and PV production is in the northwest where there is cheap hydroelectric power. So that offsets it a bit.

If you live miles from the city, it's possible that PV makes more sense because of the power lost in transmission.

However, the vast majority of those California tax breaks are being spent to burn more fossil fuel. (Figuring out why the same scientists who claim to believe that human action is causing global warming don't lobby against pointless installation of PV in residential homes is left as an exercise to the reader.)

If you care about saving energy, the best solutions are boring: carefully seal your house, and put an extra 6 inches of insulation in. Don't buy more car than you need.

If you really insist on being on the cutting edge of alternative energy with your own hands, I suggest you build a windmill.

Never underestimate the power of hamsters

About 60mW according to the builders of the Hamster powered night light.

My first hobby is a war against the MPAA / RIAA / BSA. So, if I had lived 60 years ago, I would have been fighting the NAZIs.

My hobbies in guns, reloading, and explosives probably would have put me in the Ordnance Department, but then I would have never had the privlidge of bayonetting an RIAA employee with a swastica on his uniform...that would have been a tough decision.

I'm buidling a Piggott Style Brake-Rotor Windmill (see http://www.otherpower.com/ )

Andy Out!

Seriously, solar power is ridiculously overrated. The energy density of sunlight at the earth's surface is simply too low to be practical.

oh

They only reference one study, published in "Home Power" magazine, written by two people who appear to work for solar panel manufacturers (I think its this one: http://www.ecotopia.com/apollo2/knapp/PVEPBTPaper. pdf)

Anyone got a better source? I admit my info's a bit out of date- I had a lecture a couple of years ago from one of materials science prof's and that's about it. Can't seem to find anything definative on google - seems to be a lot of debate about how you make the calculations. Chiefly that many pro solar studies ignore the fact that you need a bunch of big, deep cycle batteries (with a life time of only a couple of years) to make a practical solar system. Many of the anti-solar people tend to use older silicon refining energy figures though.

There are some execellent comments under "want more on the subject?" but what do they have to do with wave powered generation? Those comments I will be bookmarking because I do want to make my own watts and I don't want to be owned by NSTAR or help piss away fossil fuel into the sky.
But on the topic...TFA says is if ... 25% of the available wave power were used at 50% efficiency..." it would equal all current hydro electric. Well maybe...but what does that mean? does that mean lining 1/4 of our nations coast line with a flotilla of generators? That would be uglier shit than all the dams and coal-fired powerplants combined! Yes, its "green" but only if they paint all those thousands of miles/acres of wave harnessing generators with green paint. Not gonna fly! You'll get your juice this way a lot sooner.

Part of the reason that LEDs seem to be more efficient than incandescent bulbs is because LEDs are more or less "directional." The epoxy envelope is curved like a lens, focusing the light to about 20 degrees or so, compared to the full 360 of your tungsten filament. Compared to a typical bulb, a white LED is about the same efficiency.

Lighting Efficiencies:
* 32 watt T8 fluorescent--85 to 95 lumens/watt
* standard F40T12 cool white fluorescent--60-65 lumens/watt
* compact fluorescents--low 30's to low 60's lumens per watt, usually 48-60
* T3 tubular halogen--20 lumens/watt
* white LED--15-19 lumens/watt
* standard 100 watt incandescent--17 lumens/watt
* incandescent night light bulb (7w)--6 lumens/watt
* incandescent flashlight bulbs--dismal, less than 6 lumens/watt

from http://www.otherpower.com/otherpower_lighting.html

The true fantasy light of the future is those that use LDs (laser diodes.) Average LD efficiency is about 60-80%, absurdly higher than anything currently used.

Solar Panel's do not take more energy to make than they produce in their lifetimes.

I would use a beowulf cluster of these.

I don't know, You'd need to ask the G.P (Mr. Anonymous Coward. :P )

I think it's a joke, but I'm sure you could get some power. It'd be a HUGE waste of water though.

Googled, found this.

Seems like only about 75watts assuming 30psi.
I've seen 90psi around here though.

Doesn't sound worth the trouble... 75watts is about $0.20/day in California.
And everytime someone flushes the toilet, you'll have a brownout!

You can find a lot of useful information about homebuilt wind generators here. I'm also thinking of doing something similar to this someday when I get the time for it.

current "governments", "states", "regulators" etc haven't really built an even slightly more advanced society anywhere as far as I've seen. simple mechanisms to justify, legalize, formalize or otherwise protect the monopolies that their members profit from themselves. i can't recall many monopolies, big business or financial interests being broken down by new efforts the public organizes, in spite of technologies galore. It appears Microsoft might be the first one. We've seen how they keep trying to protect their interests, and it's far from over yet. The auto and oil industry, however, isn't going anywhere soon it seems, in spite of better altrenatives being around forever. All of these monopolies are going to put up real resistance when they see people organize and build their own alternative economies, as they largely did in Argentina, install their own communications infratructures, build their own vehicles and transportation systems, generate their own power, build their own electronics, plant and grow their own food, etc.

What, and you think that those "controlling interests" wouldn't love to be the ground-breakers in a massive changeover to alternative fuels and have a (temporary) monopoly?

The problem with your theory is that the newer technologies in renewable energy tend to work rather efficiently on a micro producer scale, and thus would serve to reduce the amount of control that any one company or small group of companies can have over the energy market.

Electricity from solar energy can be that are on the market today.

Biodiesel takes very little equipment to produce in your garage from waste vegatable oil (big plastic drum, litmus paper and/or phenolthalene solution, hydrometer, measuring devices, etc) for pennies. No new technology need be implemented for the use of biodiesel

Natural gas can be efficiently produced on farms and by municipalities using biological processes.

Wind can be harnessed for electric production by windmills ranging in size from small ones that will power the lights in your garage (can be home-made without too much difficulty) to giant towers that can power several city blocks.

The truth is that petrochemical and energy corps are interested in maintaining the status quo, and will shun any technological advances that threaten to decentralize the energy markets. OTOH, the same corporations are showing considerable interest in implementing large scale renewable energy projects that allow market control to remain in their hands, such as large scale wind farms and hydrocarbon fuels produced from poultry processing wastes. The problem is that many people think that these companies are somehow attached to the idea of fossil fuels, when the truth is that they do not care where the money and power come from, as long as it remains in thier own hands.

(btw, the "hydrogen energy economy" is a red herring. It takes more energy to seperate the hydrogen from water than can be gained by burning or through fuel cells. The companies know this, and stand to profit from subsidies for building hydrogen plants, and from producing the electricity that will be used to seperate the hydrogen from water.)

I'm sure it's just a total coincidence, but hamsters can provide 5.33 - 8 Hz.

math: 40-60 rpm, 8 cycles (16 magnets, alternating poles)/rev.

• you have daylight
• the river is flowing
• there is a breeze

• you have daylight
• the river is flowing
• there is a breeze

• you have daylight
• the river is flowing
• there is a breeze

Get yourself an IBM Thinkpad X30 from the authorizes IBM Ebay store. These are heavily discounted (overstock) NEW laptops with a full warranty.I recommend these for several reasons:

Very durable, small -- won't take up that much space in your cabin

12" screen, more than adequate for general purpose computing, plus the smaller backlight mean considerable power savings in the long run.

Get yourself a couple of deep cycle marine batteries. 1 to use, the other being charged.

Do you want to build your own windmill? Looks like fun project.

P.S. I don't know how remote your cabin is, but if you get yourself a Proxim/Orinoco WiFi card (these have external antenna jacks) and build/buy from a ebay a hi gain 2.4 Ghz yagi antenna, you might be able to hit someone's WiFi AP. It's worth a shot/ fun to try.

If you do by any chance get WiFI with this setup, update your journal and let us. It would be cool to know how you accomplished it.

--
3-5 hr battery life depending on usage.

I agree as this info has been available on the net for decades.

if you want REAL plans to make a wind generator... go to here

someone that has already built high power low speed power generation devices out of surplus junk and he uses MORE POWERFUL magnets to get really good results.

the story's site is just someone who doesn't know how to use www.google.com to search for the information that has been covered thousands of times by others already.

They've also got a whole alternative energy site, featuring amusing things like rustic wooden wind generators, here.

This incredible object is worth a look, too.

They've also got a whole alternative energy site, featuring amusing things like rustic wooden wind generators, here.

This incredible object is worth a look, too.

People should concentrate on using solar power, wind energy,

Solar = destroy you planet faster... The process for making silicon solar cells is very very VERY nasty and pollutes worse than dumping raw gasoline directly into a lake (Which by the way 1 gallon of gasoline will pollute 1,000,000 gallons of water to undrinkable levels) as for wind power, you need to get the idiots and morons who sit on boards of light and power, and city/county/state governments to pull their heads out of their butts long enough so that you dont have to spend a year fighting to get a tower erected to put your windmill up and THEN spend another year getting permission to tie into the electrical grid so that the excess power you create goes to benefit mankind.

until people start voting in smart politicians we will be doomed that way.... and I have never EVER met a politican that wasn't as dumb as a stump, but though he was a genius...

The only other resourse is to do gurella alternative power... you just do it and hook up without permission or permits... something that is happening quite alot lately... just pick up a copy of home power magazine.. or look at their website here

and you can make your own high efficiency wind power generation systems from crap and junk from here

but the absolute best thing to do is to figure out how to reduce consumption.. over-insulate your home.. change all lighting to compact flouresent... buy all appliances that are energy star compliant and at the very top of the efficiency graph. (Note: instead of spending $45,000.00 onm your beloved yukon that get's 4-12 miles per gallon... buy an aztek WITHOUT 4wd that get's on average 25-27 Miles per gallon if you need big for carrying things... or get a honda insight for the highest fuel efficiency.)

I agree, america = spend BIG and screw everyone else.. I live here.. I watch the masses of idiots who refuse to obey the speed limits and further reduce the MPG of their gas guzzlers, still throw trash out the windows and leave their homes with every light in the house on. It wont change until it's required, or energy gest's so expensive that it forces people to change... as they will not change willingly it must be forced.

• Slashdot : Crank Up Your Webserver (18jun2001)
• Two days ago : Slashdot : First Wind-up Phone Charger Review (25jul2002)
• mini FAQ on bicycle lights (dynamo=3W)
• How to construct a permanent magnet alternator (this one is for windpower, ~180 watts)
• other homebuilt alternators (~100 watts) (again windpower. ?efficiency)

Ok then take this for example...

efficient lighting

task lighting is a very new and rare to see concept. 99.997% of all homes still have a single bulb at the ceiling or on a lamp to light the room.

Could you please send a note to Home Power magazine, then? I'm sure they'd like to update their statistics.

If they can't be bothered to do their own research - like, say, five minutes with Google to find this, or this, or this - why should I do it for them?

But then, the last link I give above says "...a recent, very detailed study about solar panel energy payback time in the January 2001 issue of Home Power magazine...finds payback time for a standard module to be about 3.3 years, and 1.8 years on a thin-film panel." So maybe they are doing their research and you're reading back issues from the 1970s?