Wind Power For the American Yeoman

I grabbed this off Jerry Pournelle’s site and the link provided gives us a good update as to what is accruing at the small operator level. It is all quite encouraging. This will never be a major component of the energy equation but it can be very important on almost any farm operation.

The farm industry has a long history of using windmills to operate water wells in particular. When I grew up, they were ubiquous.

Technology has now advanced to make a number of strategies profitable. A simple efficient offset to grid power is a good start. It does not have to be running perfectly, it just needs to take over the farm load as often as possible. Because it is linked to the farm load directly, the incentive is in place to closely mange it.

The advent of grid acceptance of surplus power could eliminate the need for battery support, although it is simply not that easy. The industry is going there though. Ideally the farm will have a matching load like water pumping that makes it all easy.

It is clear that many designs are been experimented with and that modern fabrication methods are been deployed. Small vanes using foam core technology is many times stronger and lighter than historic methods. Combined with electronic control systems it becomes possible to have a very efficient system that is very robust and easily repaired.

This technology is not pushing the limits of material strength as the major systems are.

I am sure that there is now a market for fabricated wind vanes by themselves. The hardware and generator could also be almost off the shelf. All of this can be quite cheap and Mark is quite right. The Chinese have a huge internal market to feed and cannot be far behind on this.

This requires a low capital cost basis for it to be broadly adopted and likely the Chinese can meet that. After all, the water pumps were displaced by rural electrification.

At least this time around we are producing electric power. That also opens the market for many other applications. Fifty windmills mounted on the roof of a factory is a good idea if the cost is within a range similar to grid power. The space is clearly available and the load is also available to maximize efficiency.

The fact that so many amateurs are now doing it tells me that it is only a matter of time until such operations spring up almost everywhere that a wind can be found.

The farm that I grew up on was in Midwest Ontario. As the full heat of summer hit, we got a steady and persistent wind blowing from the west that likely was clipping along at fifteen miles an hour. It was the only reason that it was possible to do field work in the afternoon at the time of maximum heat. Using that particular energy source to carry the local residential air conditioning load would be a very good idea. A case of the best source of temporary energy surplus been paired with temporary maximum demand.

This must be largely true in the whole Midwest and just about other any area of continental weather.

This suggests that towns need to take advantage of local diurnal wind conditions in order to offset diurnal peak loads associated with air conditioning in particular. A city that practically goes off grid when the temperature is warmest is never going to have to apologize for their air conditioning load and the place will become very attractive to builders and new owners. It is also something that a town can implement.

Wind Power For The American Yeoman

Dear Jerry,

Here's a starting point for those too impatient to wait for Sam's Club to stock Chinese-made import wind turbines:

There's a wealth of information about it and examples of small'uns and middlin' size ones up to 5 Kw, all built with widely available materials and construction equipment.

Want something more aerodynamically efficient than hand carved wood blades, and more durable than injection molded plastic? Foam core composites aren't just for Stealth bombers any more. Burt Rutan pioneered the use of do it yourself composites in the early 1970s with his homebuilt experimental aircraft designs. Time marched on, techniques improved and costs dropped. Scaled Composites itself graduated to using multi-axis CNC machines to cut their foam.

The determined American Yeoman can follow Burt's lead in both places with suitable low cost equipment:

Best Wishes,


Wind power can be an excellent complement to a solar power system. Here in Colorado, when the sun isn't shining, the wind is usually blowing. Wind power is especially helpful here in the winter to capture both the ferocious and gentle mountain winds during the times of least sunlight and highest power use. In most locations (including here) wind is not suitable as the ONLY source of power--it simply fills in the gaps left by solar power quite nicely.


Build your own!

Building a wind generator from scratch is not THAT difficult of a project. You will need a shop with basic power and hand tools, and some degree of dedication. Large wind generators of 2000 Watts and up are a major project needing very strong construction, but smaller ones in the 700-1000 Watt, 8-11 foot range can be built fairly easily! In fact, we highly recommend that you tackle a smaller wind turbine before even thinking about building a large one. You'll need to be able to cut and weld steel, and a metal lathe can be handy (though you could hire a machine shop that turns brake rotors do do some small steps for you).

In most locations, GENTLE winds (5-15 mph) are the most common, and strong winds are much more rare. As you'll see by examining our latest machines, our philosophy about designing wind turbines is to make large, sturdy machines that produce good power in low wind speeds, and are able to survive high wind events while still producing maximum power. The power available in the wind goes up by a factor of 8 as the windspeed doubles.

Other critical factors are rotor size and tower height. The power a wind turbine can harvest goes up by at least a factor of 4 as you double the rotor size. And making a tower higher gets you above turbulence for better performance and substially increased power output. Putting a wind turbine on a short tower is like mounting solar panels in the shade!

Before you jump into building your own wind turbine or buying a commercial one, do your homework!
There are certain things that work and certain things that don't, and you can save hours and dollars by learning from other people's successes and mistakes. Some recommended reading:

DanF's series on Small Wind Turbine Basics, published in the
Energy Self Sufficiency Newsletter:

Part 1 -- How wind turbines work, power available in the wind, swept area, average wind speed and what it really means. The basic essentials!

Part 2 -- High wind survival mechanisms, wind turbine types, drag vs. lift machines, HAWTs vs. VAWTs, tip speed ratio, blade design, and lots of cool pictures and diagrams.

Part 3 -- Choosing a site, good and bad site examples, anemometers, tower types, lightning protection, power regulaton, birds and bats.

Our article
The Bottom Line About Wind Turbines is an essential introduction to wind power. It covers the basics of how wind comes to us, how much power different size wind turbines can make in different wind regimes, and has a very handy section on detecting wind turbine scams.'s
Wind Turbine User's Manual should also be considered essential reading, especially BEFORE you take the plunge and buy or build a wind turbine. It will fill you in on exactly what you are getting yourself into with wind power, including towers, installation, controllers, and troubleshooting. It can be downloaded for free from that page, and is available in printed form through our Online Store.

Wind power information from homebrew wind power guru
Hugh Piggott's website. We've learned a BUNCH from Hugh.

Hugh Piggott's book
Windpower Workshop is an indispensable reference for anyone that's thinking about building a wind turbine. His Axial Flux Alternator Windmill Plans are very detailed and highly recommended.

Homebrew wind power infomation from Ed Lenz's, a highly informative website.

Read the
Renewable energy FAQs on the Otherpower discussion board, and Search the discussion board. It's highly active and populated by windpower experts and hobbyists worldwide. If you still can't find and answer, by all means please join the board and ask your question there!
Join the
AWEA mailing list for more discussion with wind power experts worldwide.
Explore other wind power websites from worldwide on our
Links page.

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