THE WIND POWER BOOK

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Wind furnaces require that you calculate the amount of heat needed. In some cases, you need to calculate only the heat required to replace the heat lost from your house when it's windy. Such a system works only when it's needed. Your energy budget will now be in heat units, probably British Thermal Units (BTU) ...which can easily be converted to horsepower-hours (HPH) or to kilowatt-hours (KWH): energy units more familiar to wind machine designers.

Your utility bills and the equipment you already own will help define your energy needs. For example, average electrical energy consumption in U.S. residences is around 750 KWH per month, or about one kilowatt-hour per hour. Or, more specifically, most residential well pumps are rated at one to three horsepower. You can easily determine how long your pump runs and arrive at the total energy required per day, per week, or per month. In short, you really need to get a handle on your energy needs before you can proceed to the design of a windpower system.

WIND RESOURCES

You will also need to determine your energy paycheck. There are two possible approaches: [1] Go to the site where you intend to install the wind machine and analyze the wind resource, or [2] go searching for the best wind site you can find. The former approach is more direct. You own some property, there is only one clear spot, and that's where the tower will be planted ... along with your hopes for a successful project. The latter approach offers more avenues for refinements and better chances for success. In any event, the larger the paycheck, the less strain on your energy budget ...and the smaller and less efficient a windmill needs to be.

In either approach you need to measure, estimate, or predict how much wind you can expect at your chosen site. I've talked with folks who claimed to be wind witchers, possessing the ability to use a wet index finger and predict the windspeed with great accuracy. I've talked with people who installed wind generators back in the days before rural electrification. Most of these machines were installed in areas now known to be quite windy, with average windspeeds of 14 to 16 miles per hour (MPH). When asked, these folks almost always guessed that the wind averaged 30 MPH or more. Those old wind chargers were installed haphazardly. "Heck, anywhere you stick one, it will work just fine."

Once you have established an energy budget, you have effectively established a standard for the performance of your windpower system. That puts you in a different league from the pre-REA folks. Your system will be good if it meets the energy budget. Theirs was good because it was all they had. Your site analysis should be careful and conservative. If it is, the wind system you plan will probably serve its purpose. If not, you'll have to be happy with what you get, just like the folks be fore the REA. As you gain familiarity with your system, you might learn how to save a little power for later. Or maybe you'll build a larger wind machine because you like wind power so much.

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