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  There is more to solar and wind than meets the eye or the article.
  My wife and I lived aboard our sailboat for almost 8 years relying on solar and wind for our energy requirements. Admittedly, we were working with a 12 VDC system, but the principle is the same for higher voltages. The panels we used were about the same size as the article and generated 51 watts each. We used 4 in parallel for a total panel output of 204 watts. But that was 12 amps @ 17.2 VDC (I know, that comes out to 206.4 watts). We had a voltage limiter installed which fed our batteries a max of 14.8 volts so we would not cook them.. So the actual usable output was about 177.6 watts. Our efficiency was therefore, 86 % based on available to actual. The rest was lost to heat.
  Our windmill put out about 70 watts @ 10 knots of wind, and supplemented our solar, especially on overcast (& windy) days. There were times when we had to supplement wind/solar with our diesel engine, but with the massive house battery bank we had aboard, we could go for 4 days before we had to run the engine. We could also charge out starting batteries at the same time, if needed.
  With the new breed of solar panels, one would have been sufficient for our daily energy requirement of 1.2 KW. We had TV, stereo, navigation instruments (GPS (2), Loran), 3 VHF radios, autopilot, inverter for small power tools, etc., but we were energy conscious, too.
  To supply energy using wind/solar for a community, it must be converted into a useable form. Most present homes rely on the good old 120 VAC, and every time you convert to a different form of the energy, you lose a minimum of 10 %. It is therefore imperative that those conversion losses be kept to a minimum.
  The major problem with energy today, is not that we don?t have enough, but the population is growing to fast and generating excessive demand. When I was born, the population in this country was about 30 % of what it is today. The huge population growth plus all the so called convenience items on the market, including computers, cell phones, IPods, whatever, all contribute to energy demands. More people, more air conditioners, more washers, dryers, rechargeable devices and on & on. And that is just this country. The same situation exists world wide.
  I wouldn?t quibble about the numbers in the article. Look further and apply some basic math and ask what the useable output is. Ask how the energy is converted to something that can be transported to where it is needed, and then, at the end of the pipeline, ask just how much of the 315 watts are available for use. I wouldn?t be surprised that it is in the neighborhood of 60 %.
  There is just a little more to it than numbers, young fellas.

  October 17, 2006

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