Energy & Environment

Tilting Toward Windmills

Of all the renewable-energy sources, wind is emerging as the most competitive alternative for expanding the nation's power-generating capacity.
by | June 2001
 

Since the homestead era, people who brave the Great Plains have been cursing the relentless wind. In Spirit Lake, Iowa, however, they aren't cursing it as much as they used to.

Since 1993, the Spirit Lake School District has been powering the town's elementary school with a new-fangled windmill that generates 325,000 kilowatts of electricity every year. Mounted on a 140-foot- high tower 800 feet from the school, the turbine's 87-foot propeller spins with the prairie wind to supply almost all the building's electrical demand. On some days, the turbine produces more electricity than the school can use; so the district sells surplus power to the local utility for 6.02 cents per kilowatt-hour.

Since it went into operation, the turbine has saved the district close to $25,000 on its electric bills. "We clearly ended up to the good side," says Jim Tirevold, the district's buildings and grounds director. School officials built the windmill with a $119,000 federal grant, coupled with a matching low-interest state loan. The state loan was paid off in 1995, and the Spirit Lake school board in April approved plans to install a bigger 750-watt turbine to power the high school, middle school, administrative offices and even the football and softball fields. The 1,300-student district still will have to buy power whenever the wind stops blowing, but Tirevold notes that "the lowest winds come in May through August, when school is not in session."

At a time when California's electric power problems are raising fears about high bills and power outages, many local governments may now be envying Spirit Lake's success in harvesting energy from the wind. For the past 30 years, visionaries and scientists have touted the possibility that the country could convert the sun, the wind, the earth's internal heat, plant material and animal waste into perpetual, pollution-free power resources. Most innovative "green" technologies are still a considerable way from turning into cost-competitive components of the conventional power grid. But in communities from Minnesota to Texas, the long-awaited era of renewable energy is arriving.

Small towns are generating a good chunk of their own power for schools, hospitals and other facilities from wind turbines they've installed themselves. Of more significance, though, are the large windmill farms cropping up across the Great Plains, supplementing the country's overloaded electric power system with renewable--and now competitively priced--power for Dallas, Denver, Minneapolis and other big-city markets. In Iowa, a newly built generating station burning natural gas probably would sell electricity for 4 to 6 cents per kilowatt-hour, "and wind is competitive with that," says Sharon A. Tahtinen, the state energy bureau's chief.

That's partly because growing demand has pushed natural gas prices skyward. But it also reflects technological improvements. Just in the past few years, new blade designs, lighter materials and computerized controls have made windmills cheaper, more durable, easier to run and more proficient at converting the wind's natural energy into electric power. Larger turbines are being designed and built, and the cost of generating electricity from the wind has fallen to less than 6 cents for each kilowatt-hour, down from 38 cents 20 years ago.

Manufacturers of solar photovoltaic panels and other alternative- energy devices also have been making technical strides that are enhancing their products' performance--at least on a limited scale. But "of all the renewables, wind has been the one that's able to compete. It's just closer to commercialization," says Sue Hock, a researcher at the U.S. Department of Energy's National Renewable Energy Laboratory. With economics now in its favor, the country's wind-generating capacity is expected to double in this year alone.

Alternative energy research and development got under way in earnest after the oil shortages in the 1970s. Encouraged by federal incentives, municipal governments around the country built trash- burning waste-to-energy plants. Public opposition has now stalled a number of planned incinerators, however, and the most common form of biomass conversion has been on-site industrial generating facilities, for instance at pulp and paper mills that burn waste wood and process byproducts.

Geothermal power-generating plants operate at a few sites in California, and several Iowa communities have also begun tapping below-ground hot water to heat and power school buildings. Some states are considering the prospect of generating electricity from small- scale hydropower projects that would capture energy from falling water on tributaries and upstream stretches. In the Pacific Northwest, engineers are exploring the energy-producing potential of strong ocean currents.

Meanwhile, the U.S. Department of Energy continues sponsoring co- firing experiments that burn vegetation material along with coal in conventional power stations. Proposals also are being studied to produce power by burning switchgrass from idle Midwestern farmlands, animal waste from hog and chicken feedlots, or small timber that officials want to cull from Rocky Mountain forests to prevent major forest fires.

In recent months, alarm over the double threats of rising electricity bills and looming power blackouts has prompted state and local governments around the country to take another look at all kinds of alternative energy ideas. Unfortunately, though, most of these technologies are still too experimental or expensive to make much of a dent in supplying America's enormous energy needs.

Despite its mass appeal, even solar generating technology is still too costly to provide a practical alternative to burning fossil fuels to provide power for the electrical grid system. Two solar-thermal plants are currently operating in California, using mirrors that focus solar heat to generate electricity in combination with gas-fired boilers. However, when Pacific Gas & Electric sold off its generating assets as California deregulated its electricity markets, the utility found no takers for a Northern California plant that produced power with photovoltaic panels that convert sunlight directly into electricity. So the company dismantled the plant and sold the panels separately to other users.

"Solar really hasn't caught on as a bulk power resource," says Blair Swezey, a policy adviser at the federal NREL. Depending on how much battery storage capacity is required, it costs between 25 and 40 cents a kilowatt-hour to generate photovoltaic power. But the solar industry is developing cheaper and more dependable techniques for manufacturing thin films that convert sunlight into electricity. In fact, worldwide sales of solar panels doubled between 1998 and 2000, with U.S. firms exporting much of their production to third-world regions.

In this country, Sun Belt communities have begun taking advantage of the technology's improving capability to produce electricity in remote locations without relying on centralized distribution systems. Around the desert Southwest, government agencies have found it costs less to install solar panels to power data-gathering stations and highway signs than to run power lines to remote locations.

And in California, as the price of gas-fired electricity has shot up and rolling power blackouts have become a reality, solar technology is starting to look more attractive. A growing number of California homeowners and business managers are deciding that it's worthwhile to install rooftop panels to give themselves a hedge against disruptive power interruptions. The state's energy commission, which offers rebates on qualifying solar systems, received 450 applications in the first two months of this year--as many as in the previous three years combined. What's suddenly spurring interest in solar "is not so much the cost of electricity. It's how much it costs you when you don't have it," says John Thornton, a DOE laboratory solar expert. But even with the unexpected boost from deregulation's shaky start, Thornton adds that "the optimal use of photovoltaics is as a decentralized source of power close to where it's being used."

Wind turbines can be employed in a similar fashion--and at a lower cost--as Spirit Lake and other wind-swept towns are proving. Instead of donating a new library, a wealthy benefactor gave the town of Nevada, Iowa, three wind turbines to supply two schools and the local hospital. Five years ago, Forest City High School student Paul Smith mounted an anemometer on the town's water tower as part of his senior research project. Smith then convinced school board officials that it would pay to build a 600-kilowatt turbine that's now generating two- thirds of the power system's five-building complex. Last year, the Forest City schools saved $60,000 on their electricity bill, and officials look forward to a continuing payoff. "We were told our turbine will last 30 years, but there's no reason to think they can't last 40, 50, or 60 years if you take care of them," Superintendent Dwight Pearson says.

Wind turbines are now cheap and reliable enough that power companies also are building concentrated windmill arrays that generate large amounts of electricity and transmit it hundreds of miles at competitive rates to industrial and residential customers. Thirty minutes or so down the highway from Spirit Lake, Enron Wind Corp. operates what's now the world's largest wind farm, a complex of 262 turbines spread across farmlands with nearly 200 megawatts of capacity. FPL Energy, a subsidiary of Florida Power & Light, has installed 56 turbines at another Iowa facility that sell 42 megawatts of power to electric utilities. Wind-powered generating facilities are "getting to the order of utility-plant size," notes Swezey.

Earlier this year, FPL Energy and Portland, Oregon-based PacifiCorp agreed to jointly build 450 turbines capable of generating 300 megawatts at a new windmill farm on the Oregon-Washington border. Even Texas, a state that has prospered for decades by pumping oil and gas, now is counting on huge wind power installations to supply 3 percent of the state's electric power by the end of the decade.

Two years ago, the Texas legislature recognized that potential when it deregulated the state's electricity market. Under pressure to clean up Dallas' and Houston's dirty air, legislators ordered power- generating firms to build enough renewable projects to generate 2,000 megawatts by 2009. This spring, Green Mountain Energy Co., a leading purveyor of clean-energy supplies, began marketing "100 percent Texas wind power" to environmentally conscious customers in Austin and other cities. Just as oil companies pay royalties, wind generators may pay rural landowners $1,500 or more a year to erect towers amid their fields. Like the pump jacks that bob up and down drawing crude from beneath fields and rangelands, wind turbines supplement landowners' incomes without taking more than a few acres out of production. "Farmers can farm around it, and they will tell you they make a lot more money," says Roya Stanley, a former Iowa natural resources commissioner who now manages state and local initiatives at the NREL.

Local governments also stand to benefit from jobs and property taxes One big Texas facility pays $400,000 a year in local taxes and another $100,000 for state school funding. In wind-swept Carbon County, Wyoming, the county government took in $480,000 from property taxes the first year that a big Foote Creek Rim wind farm began exporting green power to customers in Colorado and Utah cities. Power-generating firms are tempting city and county governments all over the West with ambitious schemes for big wind developments. Wind farms also are now being planned in New York, Pennsylvania and West Virginia.

On the other hand, windmills may never be practical in some places. North Dakota, the nation's windiest state, lacks transmission lines to connect windmill arrays with big-city customers in other regions. Even at the best wind sites, production inevitably ebbs and flows with daily and seasonal shifts in wind speed, so utilities can't count on the wind for a steady supply they need to serve customers every day. That drawback conceivably can be overcome by connecting networks of turbines across wide regions with offsetting prevailing winds, but power suppliers now must manage wind-generated power in tandem with electricity from conventional plants that can be fired up as needed.

But if the wind is unpredictable, at least it's free and inexhaustible. Operating costs for efficient turbines are more stable than for conventional plants, which are at the mercy of up-and-down prices for fossil fuels and may also be forced to install expensive pollution controls as governments tighten air quality standards. And governments have given wind power some critical boosts that have helped make it a competitive component of the country's power generating system. In Minnesota, for instance, Northern States Power Co. began developing a large facility at wind-swept Buffalo Ridge as part of a deal that legislative leaders cut when the state gave the company permission to store spent nuclear fuel at a power plant near Minneapolis. What's more, since 1992, the federal government has let wind turbine operators claim a "production tax credit" of 1.5 cents for every kilowatt-hour of energy they generate.

The credit expires at the end of this year, but Congress may well renew it. Legislatures and public utility commissions in a number of states have incorporated new incentives to make renewable energy projects financially attractive in deregulated energy markets. More than 20 states offer incentives for wind equipment, and Maine, Montana, Pennsylvania and Rhode Island levy "systems benefit charges" that subsidize renewable-energy projects. Texas and a number of other states have adopted renewable-energy portfolio standards that require electricity suppliers to buy specified percentages of power from alternative generating facilities. To encourage residents and business to install on-site systems, some regulatory commissions order utilities to offer "net metering" that gives customers credit on electricity bills for the excess power they generate.

Wind industry officials say the Bush administration is acting prematurely by proposing to cut federal research and development support for renewable technologies in half. To take full advantage of renewable energy's potential, especially from remote solar devices, some advocates say governments need to rethink whether the country should rely so heavily as now on centralized power grids that require massive generating stations and lengthy transmission systems.

But even as the system currently works, wind turbines are now efficient and durable enough to make sense as an alternative supply for communities that are coming to grips with the fact that they no longer can count on costly, hard-to-maintain power plants to provide uninterrupted power from cheap fossil fuels. Conventional energy markets are expected to remain volatile for years, but the incessant winds can now deliver practical supplies of power from a source that really will last forever.

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