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February 24, 2003
Volume 81, Number 08
CENEAR 81 08 pp. 27-30
ISSN 0009-2347

After years on the sidelines, wind energy is moving center stage, but can it become more than an alternative source of 'green' energy?


MORE OF THESE As wind energy grows, U.S. sites, similar to this one off the coast of Sweden, are likely to become more common sights and will face greater government and public scrutiny. GE WIND ENERGY

Today's wind power projects are coming in all shapes and sizes--a single wind energy turbine for the town of Hull, Mass.; two turbines for a school in Spirit Lake, Iowa; and 454 turbines lining the windswept Oregon-Washington border for FPL Energy, an independent power producer.

And they are popping up in windy places, all the time.

In the past 30 days, for instance, the mayor of Los Angeles announced a plan to install by 2004 an 80-turbine, 120-MW plant in the California desert, and New York's Long Island Power Authority said it is seeking bidders to construct a 50-turbine, 140-MW wind farm off the shore of Long Island by 2007.

Over the past two decades, wind energy manufacturing and construction costs have dropped, reliability has increased, and fuel costs have stayed exactly the same--zero.

Perhaps most important, a growing number of state officials are requiring utilities that sell power in their states to include a specific percent of renewable, nonpolluting energy in their portfolios, thereby creating a comfortable and dependable climate for wind energy.

Then there is the federal production tax credit, which gives electricity producers a tax credit of roughly 1.7 cents per kWh of wind-generated electricity for the first 10 years of a turbine's life.

As a result of such incentives, last year, U.S. wind energy capacity went up 10% to 4,685 MW. The year before that, it increased by more than 40%.

In the European Union, power produced by wind energy shot up 33% to 23,056 MW in 2002. More than 70% of the world's wind energy is produced in Europe.

Germany leads with around 12,000 MW of electricity generated in 2002, says the German Wind Power Association. Wind energy capacity grew by 37% last year to provide 4.7% of Germany's electricity.

Looking at the world rankings, after Germany comes Spain, then the U.S. and Denmark. Denmark meets some 20% of its electricity needs through wind energy. The European countries give wind a big boost by requiring utilities to pay a premium to wind energy producers when their electricity is fed into the grid.

HOWEVER, it is important to put these figures in perspective. Wind still produces less than 1% of U.S. electricity, and a single nuclear power plant can generate 1,300 MW, more electricity than four of the world's largest wind farms combined and more than one-quarter of all the electricity generated by wind in the U.S.

That said, wind has a lot going for it. Its construction costs have dropped to about $1 million per MW, which works out to about 4 to 6 cents per kWh. Nuclear power advocates dream about getting their construction costs to that level (C&EN, Sept. 3, 2001, page 29).

Natural gas construction costs, however, come in at around $600,000 per MW. And gas is ready even when the wind does not blow. Unlike gas, wind is free, has no greenhouse gas emissions or air pollution, and doesn't require any nuclear waste shipments to Nevada's Yucca Mountain.

And energy developers and financiers are starting to make money on wind energy. The U.S. is going to see a lot more windmills in the future. Just how many depends on several factors.

First, it depends on the government, notes Christine Real de Azua, a spokeswoman with the American Wind Energy Association. In the end, production costs are the final driver for the energy market, but the 11 states with a requirement for utilities to purchase wind energy certainly help prime the pump, she says.

And the production tax credit has helped, too, dropping the costs of generating electricity from wind to nearly the same as natural gas. Unfortunately for wind, the credit is not a permanent part of the tax code, Real de Azua notes, and has to be renewed by Congress every other year or so. And Congress hasn't always done so.

Energy developers and financiers don't like to make financial commitments in the face of uncertainty.

When quizzed about government aid to a private wind energy provider, Real de Azua points to government-provided oil and mineral depletion allowances and subsidized nuclear energy liability insurance, and a host of other tax breaks and R&D support for fossil and nuclear energy generators.

She also says that coal and nuclear utilities don't pay a penalty for the environmental damage they incur in terms of air pollution or radioactive waste or its shipments and placement. But wind has its own environmental issues, such as dead birds, noise, and the aesthetics of a line of huge windmills in a place where they don't seem to belong.

Over the past two decades, wind energy manufacturing and construction costs have dropped, reliability has increased, and fuel costs have stayed exactly the same--zero.

STILL, DEVELOPERS expect wind energy capacity to jump by multiples in the next decade or two in the U.S., to help meet the nation's appetite for electricity. They like to talk about Europe and wonder what might happen in the U.S. if the federal government began to address global warming in its energy policy.

The U.S. has some advantages over Europe, says Sandy Butterfield, chief engineer for the wind program at the Department of Energy's National Renewable Energy Laboratory in Golden, Colo. "We have a tremendous amount of open space with copious amounts of wind. There is enough wind resource in North Dakota alone to power the U.S."

He points to energy developers that have expanded into rural communities, cutting deals with farmers to allow the installation of wind turbines, especially in west Texas and the Midwest. However, to move the electricity, they need adequate transmission lines, which are often missing in rural areas and limit wind's potential.

Butterfield predicts the U.S. will exceed a DOE goal of installing more than 80,000 MW of new wind turbine power by 2020. He describes turbine R&D as a race in size and production efficiency.

In the mid-1970s, when engineers at the National Aeronautics & Space Administration were involved, they were designing for extremes, he says, and producing beefy and inefficient turbines in the 4-MW range. As commercialization approached, however, turbines became smaller and more efficient, but they also produced less electricity.

The earliest commercial turbines were in the 50- to 200-kW range, he says, similar to those installed at Altamont Pass in Northern California in the 1980s. From there, the machines have grown in size and efficiency and shrunk in weight and cost.

"For 20 years, I've been trying to predict the optimum lowest-cost-energy machine size, and it is always just a little bigger than where we are now," Butterfield says. Today's workhorse machines are between 750 kW and 1.6 MW, but they are getting bigger, going up to the 3-MW range.

Butterfield predicts these machines might grow bigger still for offshore installations, especially in Europe where land is dear and wind energy more popular. Size matters less when a 60-plus-ton turbine can be moved by ship and assembled by ship-based crane, he notes, rather than on land where it must be hauled by truck and assembled with a huge crane.

For the U.S., which can rely on land-based units, he says, size may stay in the 1.6-MW range, and R&D will shift to production efficiencies and better materials and manufacturing techniques.

But Steven Zwolinski, president of GE Wind Energy, sees it differently. Size does matter, and wind turbines are likely to get bigger, he says. "The smaller ones are like a football field turning on top of a 100-meter-tall tower," he says.

With about $1 billion in annual revenues, GE Wind is the largest U.S. manufacturer of wind energy turbines and the fourth largest in world. The market is tight--the world's largest manufacturer, Dutch firm Vestas, has a 24% market share. GE, with about 12% of the market, is new, having bought an Enron-owned wind energy company last May.

Wind advocates applauded the purchase, hoping it would infuse new money into the wind turbine industry. So far, GE has quadrupled R&D spending, although James Lyons, GE chief engineer, won't say to how much.

Zwolinski compares today's wind mills to early cell phones: "They work, they are good, but they still have nuisance quality issues." He says the industry will benefit from "mistake proofing" and simplifying the design, and greater research to take the weight out of the turbine, especially the blades.

GE recently announced it will supply its largest machines--3.6 MW--for the proposed Cape Wind project off Cape Cod, Mass. The large turbines have allowed the energy provider to cut the number of planned turbines from 170 to 130 for the controversial project, and the developer hopes the reduction may calm some community anger over the project's location.

The machine GE plans for Cape Cod has three blades, each 50 meters long and weighing up to 16 tons, Lyons says. You can walk inside the 2-meter blade root, where the blade attaches to the turbine nose.

Lyons says machines will grow to the 5-MW size. "We know we can do that, and other companies are going to as well. There's no reason to stop there. The big offshore machines will get to 7 to 10 MW."

Butterfield says blade manufacturing has become a big business for makers of composites. Lyons notes that industry has moved from laminated wood 20 years ago to polyester glass to an epoxy glass. The next generation will incorporate carbon epoxies as part of the design, he says.

Lyons is looking at lighter blades with a shape designed to twist under high winds, allowing the blade to shed load at very high wind speeds. The design would reduce blade fatigue, he says, particularly in areas with high wind blasts.


BLADE FATIGUE is today's R&D battle. As designers learned more about wind and turbines, Butterfield says, they found they'd over-designed the machines. They're now focusing on lighter machines and the impact of stochastic and violent environment on the blades.

As the blades have stretched out, the rotor revolutions per minute have dropped from around 50 rpm on older machines to 15 rpm on the new, bigger ones. Tip speed of the blade, however, has stayed about the same at about 70 to 80 meters per second.

The result, Lyons says, is an "elegant" machine with a slow turning motion. It is quieter and far slower than the early designs that were noisy and killed birds.

At the Altamont Pass wind farm, a study by University of California researchers found some 61 radio-tagged golden eagles were killed during four years in the 1990s due to blades or electrocution. The newer designs don't kill many birds, supporters say. Butterfield adds that DOE has spent $5 million studying bird mortality problems, and the slower blades and proper locations of turbines will keep bird deaths far below what is caused by windowpanes, cars, cats, and buildings.

The turbines' impact on birds and wildlife is much discussed but hasn't blocked a project; nevertheless, Butterfield says, it has led to removal or relocation of turbines.

When siting a new wind farm, FPL Energy looks for three things, says Steven Stengel, FPL Energy spokesman, "a place with a good wind resource, nearby access to transmission lines, and a place where we are wanted."

FPL Energy is the largest owner and operator of wind energy facilities in the U.S. Its breakdown runs like this--natural gas, 44%; wind, 24%; nuclear, 14%; oil, 11%; hydropower, 5%; and some solar and coal, 2%. In all, the company generates 7,200 MW.

FPL operates the nation's--and world's--largest wind farm, located on the Oregon-Washington border, generating 300 MW.

When explaining the economics of wind power, Stengel notes that the federal tax credit makes wind competitive with other sources of energy. Still, he says the company will install 2,800 MW of power generated by natural gas this summer, compared with 700 to 1,200 MW from wind this year. They are making the additions despite the rising price of natural gas.

But, he says, it is wrong to see natural gas and wind in competition.

"Our company believes in the strength of fuel diversity," he says, "and wind makes sense economically as well as from an environmental and public policy standpoint.

"Remember," he adds, "with wind there are no emissions, no water use, you know what the cost of fuel will be forever, and wind is almost always there. And more and more, the nation is becoming concerned about greenhouse gases, and wind is one source that can alleviate that."

The wind energy economic base is stable, Stengel believes. "Our customers contract to buy power from wind for 20 and 25 years, and windmills will probably last a lot longer than that."

IF WIND ENERGY continues to grow, and if it moves beyond its status as an alternative energy source, it is likely to bring about a hard examination of so-called green energy. An indication of what may be ahead comes from the problems faced by the Cape Wind project.

Cape Wind Associates, a group of local energy developers, plans to build the first U.S. offshore wind energy facility. The 130-turbine, 400-plus-MW project is planned for Horse Shoal on a 24-sq-mile plot off Martha's Vineyard, five miles off the coast of Cape Cod.

The project is in the midst of a complicated and contentious review. Its location has created a host of unhappy and well-placed residential opponents, such as former newsman Walter Cronkite and Robert F. Kennedy Jr.

The Alliance to Protect Nantucket Sound has attacked the project for its size, visibility, cost, potential damage to marine life and birds, dependence on federal tax aid, and much more. They are being aided by some local, state, and national politicians, including the Massachusetts attorney general, who seeks a moratorium on the project.

On the other hand, Greenpeace and the Conservation Law Foundation support moving ahead on the review process, if not the entire project, and are funding cable TV public service announcements saying so.

They point to wind energy's power to curb global warming and say that a moratorium will likely kill the project.

Environmental activists have long said big wind farms could slowly displace many coal plants, noting the emissions of sulfur dioxide, carbon dioxide, mercury, and other pollutants coming from the old plants. A study funded by the Clean Air Task Force has estimated that 30,000 people die prematurely annually from particulates emitted by coal power plants.

On the other hand, groups like the New Jersey Audubon Society worry about placing wind farms on major flight paths for migratory birds along the East Coast.

"We support green energy and wind turbines," says Eric Stiles, the society's vice president for conservation, "but we are concerned about mislocation of these turbines. They are marketing themselves as green energy. Coal is not. But there are standards to be met."

He proposes new siting requirements, including mapping of bird and marine mammal migration patterns, use of mobile radar to track birds, and more. Some of these have been proposed for the Cape Cod site and embraced by the developer.

Cape Wind would be the world's largest offshore wind energy farm. So far, only one large wind facility has been placed in the sea, an 80-turbine farm off the coast of Denmark. But many more are planned in Europe and the U.S.

Zwolinski thinks community opposition to wind farms will go away as Americans become more familiar with the machines, like the Europeans have. He sees a big market for U.S. offshore turbines. "If you look at load centers for electricity, you see the cities along the East Coast, and there is not much onshore land due to population density," he says.

The debate over wind energy and the use of the ocean is likely to get hotter. Stiles points to plans by Winergy LLC, a Long Island, N.Y., ocean developer.

The company has applied to the Army Corps of Engineers for permits to install 2,600 turbines off the East Coast stretching from Massachusetts to Virginia. Bob Link, the company's permit compliance officer, calls it a "very serious proposal." He stresses, "We are ocean developers. These wind turbines pay. They are profitable."

He estimates it will take three to five years to get the permit for such a project, but Winergy has no plans to develop the energy. Instead, the company will market the permits. "We have never built any of these things--not even on land. I don't know [anything] about electricity."

The wind marketplace is certainly changing when investors with little interest in energy are willing to risk a leap on the new energy source. But how far that marketplace will advance may depend on conditions external to wind energy itself.


WHEN LOOKING at wind's potential to grow, the U.S. Energy Information Agency (EIA) predicts a 300% increase in capacity over the next 25 years, taking it to about 12,000 MW. Sounds pretty big, but for the U.S. with its huge appetite for energy, wind would still supply less than 1% of total U.S. electricity, the agency says.

EIA doesn't consider the impact of the production tax credit since it must be renewed each year or so, and it doesn't figure in an expansion of state renewable mandates. An economist who supports EIA's view notes that, for wind to grow beyond its niche, the public must be willing to pay a premium for its electricity, arguing that economics alone will not push wind beyond a single percent.

The wild card in all of this, however, is carbon, notes Grant Ferrier, editor of Environmental Business Journal, an energy and environmental research publication.

"Global warming and carbon emissions can change the whole energy marketplace," he says. "If wind is able to capture its environmental benefits in terms of its cost and build an infrastructure to transmit electricity to where it is needed, like the infrastructure established to move coal around, the U.S. could easily reach 2 or 3% of total energy use over the next 20 years."


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Copyright © 2003 American Chemical Society

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