Residential windmill sizes depend on use, weather, building codes

Dear Jim: I am tired of my high electric bills and of consuming so much fossil fuel (coal, gas and oil). I like the idea of using a small windmill to produce my own electricity. What are the options for a house? – Paul M.

Dear Paul: There are many options for using wind power to generate your own electricity. The first step is to contact your local weather service to check on the average wind speed in your area. Various wind turbine sizes and designs begin producing electricity at different minimum wind speeds.

Knowing the average and wind speed ranges, you can estimate how much electricity a given system will produce. Keep in mind, wind speeds on a specific lot can vary significantly from regional averages depending on its topography. Consider renting a wind speed meter for an extended test period.

Since the sun’s uneven heating creates the wind currents across the Earth, wind energy is actually an indirect form of solar energy.

The best wind turbine option depends upon your specific energy needs. Wind turbines can have an output as small as 400-watts to provide supplemental electricity for a specific appliance or application. Large ones, by residential standards, produce 10 kilowatts, enough for an entire house.

To give you an idea of size, a 400-watt wind turbine uses about a 4-foot-diameter rotor versus a 7-foot diameter to produce 900-watts. A 10,000-watt turbine uses a 23-foot turbine and is mounted on a tower that is often more than 100 feet tall. Before purchasing any wind turbine system, check your local building codes about the maximum allowable tower height.

When installing a small wind turbine, less than 1 kilowatt, an off-grid design is best. This means its output wiring is not connected to the grid from the utility company. It is often used to charge batteries for energy storage. An inverter converts the stored electricity to alternating 120-volt current to power an electric appliance.

Larger wind turbines (up to 2 kilowatts) with which you plan to use to power your entire house should be set up as a grid-tie system. When your house requires more electricity than the wind turbine produces, your house draws electricity from the utility company. The Windstream, by Southwest Windpower, has the grid-tie control built into the wind turbine.

If the wind turbine produces more electricity than you use, it may run your electric meter backward (net-metering) and feed the power back to the utility company. Check with your utility company to see if it offers net-metering. Also your utility company or state may offer a credit for installing a wind turbine system.

The following companies offer residential windmills: Abundant Renewable

Energy, 503-538-8298, www.abundantre.com; Bergey Windpower, 405-364-4212, www.bergey.com; Southwest Windpower, 928-779-9463, www.windenergy.com; Solar Wind Works, 877-682-4503, www.solarwindworks.com; and Wind Turbine Industries, 952-447-6064, www.windturbine.net.

Dear Jim: I installed gas logs in an old Ben Franklin wood-burning stove thinking it would be efficient. My gas bills were very high and it did not heat well. What can I do to make this stove more efficient? – Bob S.

Dear Bob: There really is not much you can do to make it energy efficient. Your old wood-burning stove was not designed for gas logs so it does not capture and transfer heat to the room air. The heat just goes up the flue pipe.

If you want to use gas to supplement the central heating for your house, select a direct-vent gas fireplace or freestanding heater. These units are designed for gas or propane, so they are efficient and safe to use.

Send inquiries to James Dulley, Bangor Daily News, 6906 Royalgreen Drive, Cincinnati, Ohio 45244 or visit

www.dulley.com.