More on windfarms. This was mostly taken from a recent article in Tech Review.

A Bountiful Supply

Currently, the U.S. generates about 0.1 percent of its power using wind—a minuscule contribution, especially compared to Denmark's 10 percent. The Department of Energy wants to increase wind's contribution to U.S. energy production to 5 percent by 2020.

The problem won't be one of raw supply. According to the National Renewable Energy Laboratory's National Wind Technology Center, North Dakota alone, sometimes called the Saudi Arabia of wind power, has enough wind to generate electricity for about one third of the continental U.S. "There's no shortage," says center director Robert Thresher.

Cost, however, is an obstacle. "It currently costs three to five cents per kilowatt-hour to produce electricity using wind," says Thresher. "If we could reduce cost below three cents per kilowatt-hour, at sites with an average windspeed of 13 mph the cost would be competitive" with conventional power generating technologies.

Small boosts in wind speed can go a long way. Power output increases in proportion to the cube of the wind speed. So a windmill at a site where the wind averages 25 kilometers per hour will yield twice as much power as one sited amidst 20 kilometer-per-hour winds. Windmills with rotors that can turn and actually hunt for wind increase efficiency. So does smarter placement of the windmills. Recently researchers have recommended staggering windmills rather than placing them in rows, which create a shadowing effect.

Barriers to Adoption

The wind power generated today isn't stored, but instead flows directly into the grid. That's a big drawback: if there's no wind, there's no juice. While most researchers aren't currently focusing on storage, some are investigating various options like fuel cells, hydrogen and battery storage.

More Uses?

David Sears is vice president of Aeromax, a Prescott Valley, AZ, company that develops small and medium-sized wind turbine generators. Sears's company is testing a design that would use wind power to compress air, which could then be stored. When power was needed, the compressed air could run an air motor. "You could set up compressed air to pump water, or run a sewage treatment, or an offshore desalination facility," says Sears.

Sears says his company is talking with the U.S. Air Force as well as IT companies to replace some of their generators with wind turbines, coupled with compressed air motors to replace diesel units.

Finally

Proponents of wind energy argue that the technology is still effective despite the lack of a steady supply. When wind power isn't available, they maintain, electricity can be produced using conventional means such as hydropower. Conversely, these conventional forms of power can be cut back as wind power increases.

"The more wind farms you build in an area, the more you can reduce the fluctuations," says Brian KillKelley, a senior energy analyst at Green Mountain Energy Company. "It may stop blowing at your one location, but 200 or 500 miles downstate it's still blowing."

Large-scale expansion of wind technology will depend in large part on federal largess. Subsidies and tax credits "can change the economics dramatically," says Steve Fetter, professor at University of Maryland's School of Public Affairs and board member of the Washington, D.C.-based Sustainable Energy Institute. "Several countries in Europe are experiencing booms in wind power, largely because of price supports for wind electricity," says Fetter. "A significant carbon tax would greatly benefit wind."

Something radical is happening in the staid world of electricity production. While most people give little thought to where their electricity comes from, the deregulation of the power industry now under way in a number of states means that, for the first time, consumers will have a choice of how the electricity that they pay for is produced. And in states that have already deregulated their electricity monopolies, consumers are increasingly choosing renewable energy sources, such as wind power, over cheaper but more highly polluting coal and other fossil fuels.

A startup called GreenMountain.com is the company moving most aggressively to take advantage of this “green” preference in what the U.S. Department of Energy estimates is a $217 billion electricity market. Indeed, by making the choice of renewable energy just a mouse click away, Vermont-based GreenMountain hopes to establish itself as the green brand of energy. “I want to be the Starbucks, the Coca-Cola, and the Ben & Jerry’s of electricity all rolled up into one,” says Dennis Kelly, GreenMountain’s president and CEO.

More than half of the states have or are starting to dismantle their electricity monopolies. GreenMountain has already begun business in two—California (where 66 percent of electricity comes from coal, oil and nuclear power) and Pennsylvania (which generates 98 percent of its electricity from fossil fuels and nuclear power). This year, the company will enter Connecticut and New Jersey, with New York and Massachusetts not far behind, according to Kelly. So far, more than 100,000 households, plus businesses such as Kinko’s and Birkenstock, have switched to GreenMountain.com, even though it costs a typical household between $6 and $12.50 more per month.

Customers sign up for the service on the company’s Web site, then have their power delivered through the same municipal power grids and electrical lines they’ve always used. The difference is that GreenMountain.com offers an environmentally cleaner mix of energy than conventional power producers, who rely heavily on fossil fuels and nuclear power. The startup produces or buys all its energy from renewable sources, including windmill farms in three states. And it recently broke ground on a $10 million windmill farm in rural Pennsylvania that it says will produce enough electricity to power 2,500 homes.

But the business of green energy has not been all clean sailing. While the company claims that 100 percent of its energy comes from renewable sources, Kelly acknowledges that a large part of it is derived from older hydroelectric dams—facilities that can have a negative impact on fish and local wildlife. In addition, the company has had financial woes. After losing $65 million prior to an aborted attempt at an initial public offering in 1999, the company scaled back its plans to create a “green portal” for the Web. Currently, it is attempting to raise $100 million more in venture capital funding.

And the more customers GreenMountain signs up, the more big-time rivals it will attract. “If they are at all successful, they will encourage competitors, including the big utilities in the power-generating business to match their environmental performance,” says Francis Cummings, a principal at Xenergy, a Burlington, Mass. consulting firm. “Now it’s just a segment of the market. But as the availability of environmentally sustainable power becomes known, it could become the mainstream.”