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Wind Power

Although wind power represents less than 1% of electricity generation in the U.S., some European countries have invested more heavily in wind and generate a greater percent of electricity with that renewable resource. Denmark supplies 20% of its electricity from wind, and Germany (7%) and Spain (9%) top the world in installed wind capacity (U.S. DOE, 2007). Not surprisingly, many of the top wind turbine manufacturing firms are based in Europe. Those firms with a manufacturing presence in the U.S. may add jobs to meet growing U.S. demand.

Wind Farms, Utility-Scale Wind Power

A leader in wind power generation is FPL Energy, headquartered in Florida but with generating capacity in 25 states. This power wholesaler has an energy portfolio that includes 33% wind.

On both sides of Interstate Highway 10, this wind farm near Palm Springs in Southern California's San Gorgonio Pass takes advantage of high winds in the valley between the San Bernardino and San Jacinto Mountain Ranges.

Residential, Building-Scale Wind Power

Although cost and zoning restrictions often limit an individual's ability to install windpower, there are small-scale wind setups available for rural settings. Turbine assemblies usually are mounted on a pole, but sometimes can be mounted on the roofs of buildings. Small-scale wind turbines are even being developed to work in urban settings, where wind speeds and directions vary in complex and turbulent ways.

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.) 

Mariah Power (Reno, NV): creators of the Windspire, a propeller-free wind power appliance designed for use in residential areas. The device is just 30 feet tall, with a 2-foot radius, and costs about $5000. The Windspire, which is a vertical axis wind turbine, is elegant enough to pass for a wind sculpture, and plugs directly into your home's electric box.

Another example of "small wind" is the helical-shaped turbine from Helix Wind (San Diego, CA) that catches wind from any angle and generates direct current even with low, and turbulent, winds.

Aerotecture International (Chicago, IL) also specializes in "aeroturbines" for urban residential and commercial buildings.

Additional Information Resources

• American Wind Energy Association
• The Danish Wind Industry Association
• Annual Report on U.S. Wind Power Installation, Cost, and Performance Trends: 2006.

Bloomberg Offers Windmill Power Plan

NYC Mayor Bloomberg hopes to install small wind turbines on city bridges and buildings and just off shore as part of an alternative energy plan to help power the city. (NYTimes, Aug. 19, 2008)

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Getting Green Power For those of us who want green power, but don't want to generate it on-site, there are several options. Green Pricing Programs: in some areas, consumers can pay a price premium (in cents per kWh) to a utility for electricity made from renewable sources. In addition, Renewable Energy Certificates are evidence of green energy generation that can be used for bragging rights and/or to comply with Renewable Portfolio Standards. Purchase of a certificate is separate from purchase of actual kWh of electricity.