Cheap Savonius Wind Turbine

From Wired

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A group of volunteer engineers are finishing the design for a home-brewed wind turbine that will bring electricity to off-the-grid Guatemalan villages by this summer.

After the U.S. engineers finish the design, local workers in the town of Quetzaltenango will manufacture the small-scale turbine. It will produce 10-15 watts of electricity, enough to charge a 12-volt battery that can power simple devices like LED lights.

"They're replacing kerosene lamps, if anything at all," said Matt McLean, a mechanical engineer by day and leader of the wind-turbine project by night. "The biggest driver is just keeping the cost way down. We're shooting for under $100, which is a challenge, but we're in that range."

The effort comes amidst recent efforts to bring new light and power to small towns in the developing world. An estimated 1.6 billion people worldwide are without electricity, and many of them are forced to light their homes with kerosene. Using one of these lamps is like smoking two packs of cigarettes a day, says the World Bank, and the lamps present a significant fire risk. That's why many startup companies, such as d.Light, are trying to bring cheaper LED lights to homes, but they still need a solution for producing power locally.

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And from wikipedia

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Savonius wind turbines are a type of vertical-axis wind turbine (VAWT), used for converting the power of the wind into torque on a rotating shaft. They were invented by the Finnish engineer Sigurd J Savonius in 1922. Savonius turbines are one of the simplest turbines. Aerodynamically, they are drag-type devices, consisting of two or three scoops. Looking down on the rotor from above, a two-scoop machine would look like an "S" shape in cross section. Because of the curvature, the scoops experience less drag when moving against the wind than when moving with the wind. The differential drag causes the Savonius turbine to spin. Because they are drag-type devices, Savonius turbines extract much less of the wind's power than other similarly-sized lift-type turbines. Much of the swept area of a Savonius rotor is near the ground, making the overall energy extraction less effective due to lower wind speed at lower heights.

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I think I will do this with my 17 year old daughter this summer as a project.

120mm,

Here is a kit that may be of interest. There are also plans out on the internet and Edmunds has some rare earth magnets that you will need. Keep them away from your electronics and watch your fingers though...

From the July 7th 2008 ENR

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The U.S. is the second-largest wind-energy market and is posted to overtake Germany by the end of next year, according to the Brussels, Belgium-based Global Wind Energy Council

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Engineering News Record notes in this article that the US had 15,616 installed MW of wind power in 2007.

A gigawatt equals a thousand megawatts (MW).

As reference points the EIA notes that Iraq had a 3.8 gigawatt capacity in a June 2008 update (#76 world ranking in this arena), Germany had a 120.4 gigawatt capacity in a June 2008 update (#6 world ranking in this arena) and that the US had a 956.7 gigawatt capacity in a June 2008 update (#1 world ranking in this arena).


From the July 7th 2008 Business Week

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Wind power, while still just a speck in America's total energy mix, is no longer some fantasy of the Birkenstock set. In the U.S., more than 25,000 turbines produce 17 gigawatts of electricity-generating capacity, enough to power 4.5 million homes. Total capacity rose 45% last year and is forecast to nearly triple by 2012. Right now, only 1% of the country's electricity comes from wind, but government and industry leaders want to see that share hit 20% by 2030, both to boost the supply of carbon-free energy and to create green-collar jobs.

Such a transformation won't come easily. While much of America's wind energy is in the Midwest, demand for electricity is on the coasts. And the electrical grid, designed decades ago, can't move large quantities of electricity thousands of miles. There's plenty of wind off the coasts, but it's both expensive to harness and controversial; not-in-my-backyard sentiment has slowed some of the most high-profile projects

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It costs roughly $225 million to build a 150-megawatt wind plant. Horizon, the big wind developer, has 11,000 megawatts of projects in the works...

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Wikipedia has an interesting entry on electric power transmission

This is good stuff - lets not forget solar cooking boxes either , essentially a box lined with tin foil set in the sun - the literature says they really work. 3rd world women spend alot of time scrounging fire wood and alot of trees are taken down too. a couple hours away from scrounging fire wood = a bigger garden and more food for the family.

This is pretty cool. It's also cheap enough they could build a series-parallel array and generate some respectable voltage and current.

Along those lines, here's a link for a scratch built solar power system: How To Build a Solar Generator

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Originally Posted by goesh

This is good stuff - lets not forget solar cooking boxes either , essentially a box lined with tin foil set in the sun - the literature says they really work. 3rd world women spend alot of time scrounging fire wood and alot of trees are taken down too. a couple hours away from scrounging fire wood = a bigger garden and more food for the family.

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Does anyone have more information related to this solar cooking box?

Jon,

Not solar boxes, although I have read something about them; uodate, the BBC had this 2009 item: http://news.bbc.co.uk/1/hi/sci/tech/7991654.stm.

Try this UK-based alternative technology charity: www.PracticalAction.org

I think they are the leaders in the field of low-tech answers.

I worked with solar cookers once upon a time and it was difficult to get people to adopt. There's a huge cultural conservatism attached to cooking ad food; it's hard to get people to use different cooking techniques. I suppose that would vary according to the existing cooking culture and scarcity of fuel in any given environment.

This one really works:

http://www.fogquest.org/

Not the single sole solution for everywhere (nothing is) but where conditions are right it's brilliant.

This one:

http://www.biosandfilter.org/biosandfilter/

is another really useful water technology with potential for application in disaster relief or refugee situations. I've built some of these, it's not hard to do and people catch on really fast; they actually get used. That's key... if you track down glorious appropriate tech projects a few years later, a distressingly large number have been discarded.

I admit to a bias toward water supply as an intervention point: it's basic, it's obvious, the payoff is immediate and dramatic, and people get it... if Nelson would have had "want of frigates" stamped on his heart in the event of his demise, anyone who's been in the relief business would have "want of clean water" stamped on theirs. The combination of cheap wind or solar power, batteries, and LED lights is pretty cool, though...

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Originally Posted by Dayuhan

I worked with solar cookers once upon a time and it was difficult to get people to adopt. There's a huge cultural conservatism attached to cooking ad food; it's hard to get people to use different cooking techniques. I suppose that would vary according to the existing cooking culture and scarcity of fuel in any given environment.

This one really works:

http://www.fogquest.org/

Not the single sole solution for everywhere (nothing is) but where conditions are right it's brilliant.

This one:

http://www.biosandfilter.org/biosandfilter/

is another really useful water technology with potential for application in disaster relief or refugee situations. I've built some of these, it's not hard to do and people catch on really fast; they actually get used. That's key... if you track down glorious appropriate tech projects a few years later, a distressingly large number have been discarded.

I admit to a bias toward water supply as an intervention point: it's basic, it's obvious, the payoff is immediate and dramatic, and people get it... if Nelson would have had "want of frigates" stamped on his heart in the event of his demise, anyone who's been in the relief business would have "want of clean water" stamped on theirs. The combination of cheap wind or solar power, batteries, and LED lights is pretty cool, though...

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Not sure how many here follow the action on TED.com but I saw this presentation there on water purification and was impressed. It seems to be a bit of a commercial plug for the product but it certainly has a military application.

Water filter

I am not connected in any way to this product.

Well, I did work with solar cooking too in Chad. Chad seems to be the best place in the world to develop solar energy (360 of sun/year, average 48 degree celcius...).
Unfortunately we came to the same conclusion than Dayuhan.
One of the difficulties we faced was that it was changing women habits and children integration into the family.
I know, sound pretty much like a stupid scholar stuff but in fact, now I see it as obvious.
Coocking activity is not restricted to the act of preparation and putting stuff in the pot. It is also an exchange and learning time between mother and daughter, between women... Coocking activity starts with collecting water, fire wood and end up with women gathering together in a non men accessible space to exchange about their life, their difficulties...
In Somalia I had the same experience. The coocks in our camp, 2 young women, were taking the advantage of the kitchen men exclusion to listen to hardcore gangsta rap, comment on young men... Basically doing all what their families, elders and religious leaders forbide them to do.
What we did in the Chadian refugees camps was to provide special firedevice with estremely small entry to fuel them with wood. This had the advantage to reduce wood consuption (like divide it by 5 to 10) and as it was just a way to prepare the fire pit, it was sustainable (Was mostly working with nomads from Dafur stuck in a refugee camp).

For the wind mills in South america, I am less doubtful. And it looks like a good idea. But be carefull of the effect on small trade like charcoal and firewood. But I must say that I have no experience of South America, not even put a feet their for vacations.:D

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Originally Posted by JMA

Not sure how many here follow the action on TED.com but I saw this presentation there on water purification and was impressed. It seems to be a bit of a commercial plug for the product but it certainly has a military application.

Water filter

I am not connected in any way to this product.

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Pakistan: Well if someone had acted and got some of this stuff into the emergency equipment warehouses...

Lifesaver bottle

Again: I am not connected with this product in any way.