Towns, school districts, and farms already have taken advantage of wind as a free energy resource. Maybe it's time for developers to tap it, too.
By Diane Kittower
Imagine building a community and being able to guarantee home buyers that their electric bills would never be more than $25 a month. And you could add that the power came from a renewable source using time-tested technology. Sound too good to be true? It's not. The energy source is the wind, and the basic technology goes back centuries. Towns, school districts, and farms already have taken advantage of this free resource: More than 4,100 megawatts, or 1 percent, of U.S. electricity is being churned out by the wind. Maybe it's time for developers to tap it, too.
Unlike its green sister, photovoltaics, wind power doesn't have to affect the look or siting of homes. The futuristic-looking windmills, known as turbines, could be miles away on a wind farm, generating energy that goes into the local utility's grid or directly to the homes, as state law allows. A developer could even lease a small part of his land to a wind project company, suggests Phil Dougherty, national coordinator of Wind Powering America, a Department of Energy program. "It's a creative way to secure a revenue stream without taking too much land out of production." Another possibility is to lease the land with turbines for grazing or farming use.
Depending on the site, builders may be able to pop a wind turbine on each lot. That works best for sites of an acre or more to avoid complaints from neighbors about noise or appearance, explains Mike Bergey, president and CEO of turbine manufacturer Bergey Windpower Co., in Norman, Okla. Of course, you can't put a wind turbine just anywhere and expect it to be efficient. Like any other natural resource, it's more plentiful in some places than others and varies with the seasons. Usually winds of at least 7 mph are necessary to make a wind energy project worth doing.
The states most active in wind energy development are California, Iowa, Minnesota, and Texas. They contributed to a 63 percent increase in generating capacity last year. Many highly suitable regions remain untapped ? much of the Great Plains, several mountainous regions, and parts of the Atlantic, Pacific, and Gulf coasts. According to the Earth Policy Institute, there is enough harnessable wind energy in just three states ? North Dakota, Kansas, and Texas ? to satisfy the country's electricity needs.
All wind turbines have the same basic parts, and their operation is only a little more complex than that of the traditional windmill. Modern turbines have a rotor (which rotates in the wind, capturing its energy to drive a generator), a tail to keep the turbine facing into the wind, a speed control system, and a tower. The diameter of the rotor determines the area it sweeps, and thus the amount of wind energy it can grab and convert to electricity. A large turbine for residential use might be 20 stories high and capable of generating 20,000 watts. Small units might be 30 feet tall with 8-foot rotors.
Larger turbines are more cost effective: They can work at one-fifth the cost of smaller systems, according to the American Wind Energy Association. The smaller ones, some of which mount on roofs, generate in the neighborhood of 50 watts. By contrast, the turbines used by utility companies can put forth up to 1.5 megawatts of power. Like light bulbs, turbines are measured by the wattage they produce.
No matter what the size of a wind turbine, it can't generate any electricity at all if the wind doesn't blow. So the turbines have to be wired into either the utility grid or a battery that stores electricity generated earlier. Another option might be to combine with a photovoltaic system and hope for plenty of sunshine.
On average, electricity generated by wind costs less than 5 cents per kilowatt-hour ? and generating costs likely will drop in the next 10 years, the Energy Department's Energy Efficiency and Renewable Energy Network (EREN) predicts. (The cost of generation from more traditional sources varies substantially but can run from 1.5 cents to more than 11 cents per kwh.)
Moreover, with no fuel to purchase and minimal operating expenses for annual oiling and semi-annual greasing, wind generating systems can compare favorably with fossil-fueled systems on a life-cycle cost basis, says the Energy Department's EREN. And homeowners in a number of states can have net metering, in which the utility buys wind power at the same retail rate the utility charges. Turbines, themselves, vary in cost depending on the power they produce. One Bergey 10-kilowatt turbine plus 100-foot tower and controls to link with the utility company costs about $29,000; a 1-kilowatt one with tower and link-up goes for about $3,325. Innovative Power Systems estimates that a 10-kilowatt turbine, which generates 500 to 1,500 kwh per month, costs about $3 per watt installed; a 20-kilowatt machine, which generates 1,500 to 3,000 kwh per month, costs $1.50 to $2 per watt installed.
State incentives and the federal Production Tax Credit help keep the initial cost of a wind-based system down. Some states offer tax credits; others mandate the use of renewable energy sources by utilities. In addition, some utilities offer rebates for installing wind systems. The federal tax credit just expired on Jan. 1, but wind advocates expect it to be renewed within a few months. It provided a pretax profit credit of 1.5 cents per kwh (adjusted for inflation) to installers of wind turbines.
Despite an increase in the number of wind projects, few home buyers are hunting for a wind-powered home. Because there's more awareness of solar energy, why not package the two resources in a renewable energy package and market it, suggests Joe Wiehagen, an NAHB Research Center research engineer.
The likeliest reason for a builder to consider wind energy is the ability to market the homes as using clean energy, says Dougherty. Another reason might be to help during the purchase, siting, and planning processes for developing a large tract of land. "A builder could say, 'Let me responsibly develop my land, and I'll set aside 5 percent to site wind turbines.' Such a developer would not only be creative, he would be a good neighbor and help firm up the ability to deliver reliable power." Dougherty also suggests that building a development powered by wind offers the opportunity to carve out a niche when competing with another builder.
One key focus for the future of the national program is to explore moving some of the R&D investment into technology to capture wind resources of lower speeds than are available today, Dougherty says. "If we do that, we will increase the available resource twentyfold, meaning development closer to bigger demand centers and even alleviating pressures on the national grid."
--Diane Kittower is based in Rockville, Md.
BIG BUILDER Magazine, March 2002