The use of wind to do work is hardly new…think of sailing ships and wind mills. However, use of wind to generate electricity is just coming of age, with refined turbine technologies and advanced composite materials. To date, American consumers have had few opportunities to purchase wind-generated electricity. Although installed wind power rose 45% in 2007 over 2006, wind still accounts for just a few percent of total electricity generation in the U.S.
Even where the winds are “made in USA,” the turbines are mostly made in Denmark or other European countries. Driven by their commitments to reduce carbon dioxide emissions associated with fossil fuel burning, European countries have pushed ahead on development of wind and other alternative energy technologies.
The fun part of this story is that there are a few companies in the US that make small, residential-scale wind turbines that can be purchased and installed at reasonable prices.
Southwest Windpower (West Flagstaff, AZ): since 1987, this company has specialized in small wind-driven generators, including wind turbine assemblies suited for residential or farm use. The Skystream 3.7 is a 3-bladed turbine that comes complete with built-in alternator, inverter, and noise isolator. Optional remote monitoring system allows users to receive real-time data on power generation on a home computer. The Skystream is mounted on a pole or tower, purchased separately, and the company recommends that it be about 20 feet above surrounding objects (e.g., roofline or trees). The entire unit is designed to be maintenance-free for 20 years.
The Skystream is connected to the house, via a 220 volt line with a safety disconnect switch, to a dedicated breaker on the main electrical panel. When the wind is blowing, electric power is generated, and used by the home. (Excess power flows into the electric grid, and depending on the utility’s policies, may generate a credit.). The Southwest Windpower website includes helpful information about working with your local utility and zoning officials when installing the wind turbine. (The Skystream also can be used for homes that use battery backup, as a complement to solar panels or other off-grid technology.)
The turbine operates with wind speeds as low as 8 mph, and has a safety feature that shuts down the turbine at wind speeds of 56 mph. In order to generate electricity of appropriate frequency and voltage, the unit is designed to maintain 330 rpm blade revolution speed even at higher wind speeds. (That means that only a portion of wind energy can be captured at wind speeds greater than about 20 mph.)
I noticed that Southwest Windpower products are available at NorthernTool, as well as from regional distributors that can also help with installation.
To learn more about wind power, check out these links:
Bergey WindPower Co. (Norman, OK) also manufactures small wind turbines for home or farm applications
Green Pricing Programs, where utilities allow consumers to pay a premium (in cents per kWh) for electricity from renewables
American Wind Energy Association gathers data on growth of wind power capacity in the U.s.
Energy Information Agency provides data on renewables as a percentage of overall electricity generation in the U.S.
The Danish Wind Industry Association runs a very nice, informative website on wind power