The U.S. Department of Energy has set an ambitious goal to achieve in just 16 years: by the year 2020, 5 percent of America’s electricity should come from wind power. Today less than 1 percent is generated by wind.
The American Wind Energy Association estimates current installed capacity at about 4,700 megawatts. Projects under way could bring that total to about 6,000 megawatts by the end of this year—enough to provide electricity to about 1.5 million homes.
An old-fashioned farm windmill, that familiar silhouette of independent country living standing tall against a vast skyline, is a simple mechanical device that uses the wind’s push on its slanted blades to pump water, but harnessing that mechanical power to generate electricity adds many more steps.
Advocates of using wind power to make electricity point out several favorable features of wind power: it’s free, much easier to find than buried fossil fuels, and leaves no byproducts.
But using wind to provide electricity when and where consumers want it is a lot more complicated than pumping water in a single location. While wind is free, costs such as construction and maintenance of the equipment must be considered, as well as a whole set of issues surrounding the location of a wind-power facility.
Individual wind-power electric generating units, with airplane propeller-like spinning rotor blades, typically only produce between 400 watts and 50 kilowatts of electricity. That’s about enough for one home or farm.
In a recent National Rural Electric Cooperative Association (NRECA) study, the initial construction and installation costs for a small home wind-power system (9.5-15 kilowatts) were calculated as $2,500-$3,000 a kilowatt. At an average cost of $27,000, such individual home systems are unlikely to become common in the near future.
However, the basic construction costs for a large, utility-scale wind-power generating station, whose clusters of rotor towers can generate more than 500 kilowatts, produce that electricity at a cost of about $1,000 per kilowatt, which is comparable to more conventional generation methods.
Even more encouraging, the regular operating costs to produce electricity on large wind-power farms have dropped steadily due to improvements in technology, from a high in 1980 of about 25 cents a kilowatt-hour, to less than 6 cents by 2002. Within the next two years, that figure is expected to be cut in half to just 2 or 3 cents. That’s bringing it well within range of the operating costs for electricity from fossil fuels and hydro power plants.
But as Ed Torrero, senior program manager for NRECA’s Cooperative Research Network in Arlington, Virginia, points out, “The distance of a wind farm from where the power will be used and the cost to construct transmission lines to connect them, as well as the maintenance on the system that will transport the electricity to where it’s wanted, must be considered.”
The problem is matching supply in one place with demand in another. In some cases, the distance from a windy mountaintop to the community below might be measured in hundreds of feet—but the distance between a wind-swept plain and the nearest town might be measured in several miles, and could even cross state lines. Building transmission lines adds substantial amounts to the final cost of the “free” wind-generated electricity.
Electric co-ops provide power in 47 states, yet only about 40 percent of those co-ops are in states with vast wind potential. Kentucky’s highly variable inland continental climate is generally not favorable for wind-power installations.
Nationally, only two generation and transmission co-ops, Basin Electric Power Co-op in North Dakota and Great River Energy in Minnesota, provide their member distribution co-ops with substantial amounts of electricity from wind power.
Conventional solid fuel and hydropower generating units are often called “base load” installations because they provide continuous, uninterrupted electricity in predictable amounts—and that’s where wind power falls short. Even in the best locations, wind doesn’t blow at a steady speed—and sometimes it stops altogether.
“The intermittent nature of wind power is an issue that must be resolved on a case-by-case basis at each potential site,” says NRECA’s Torrero. “There’s a big debate in the electric utility industry right now as engineers try to figure out how big the steadier supply of electricity from backup systems needs to be to go along with the more variable output of wind-powered generating systems.”
Other debates must still be resolved within communities near potential wind-power installations. Initial concerns about noise pollution from the spinning blades have died down, only to be replaced with questions about the visual impact of wind farms.
Rows of propellers on stilts just don’t have the same eye-appeal as a single old-fashioned farm windmill. Many communities have local ordinances and zoning restrictions limiting the size of freestanding structures to sizes so short as to make wind-power installations a practical impossibility without rewriting the rules.
Possible dangers to birds also spark heated discussions as proposed locations for wind-power plants appear on more and more maps.
Yet, at the same time, federal and state governments continue to encourage experimentation with wind power through favorable tax laws and other financial incentives. Continued progress toward meeting the goal of generating 5 percent of the nation’s electricity from wind by the year 2020 will depend on how individual electric consumers resolve these issues.
Next month: The aftermath of the Northeast power blackout