Wind energy set to blow in a gale of U.S. power

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Percent increases in states’ installed wind capacity

Cape Wind: The power of offshore wind

Harvesting U.S. wind potential

CAPE COD, Mass. — The U.S. is churning up a gale of wind energy with those turbines visible across the countryside and soon to be anchored to the floor of the Atlantic Ocean in Nantucket Sound near Cape Cod.

One area of debate surrounding offshore wind farms in the U.S. is the cost of the turbines. Offshore turbines are much bigger, sturdier and more costly than onshore models that typically carry about a $6 million price tag for a 3 megawatt unit. The 130 Cape Wind turbines have a generating capacity of 3.6 megawatts each.

“Offshore, the price is probably going to be about 50 percent greater,” said Rick Walker of the Texas Wind Energy Institute.

A more complicated installation process is one of the factors associated with this elevated cost. The turbines that will make up the Cape Wind farm will be drilled approximately 85 feet into the ocean floor, and have foundations weighing between 250 and 350 tons to keep them in place.

The lack of offshore turbine manufacturers in the U.S. also drives the cost of these projects up. Cape Wind will be importing turbines from Siemens, located in Denmark, according to Mark Rodgers, director of communications for Cape Wind.

Despite the additional costs of offshore wind farms, onshore turbine installations are increasing at a pace that places within reach the goal to draw 20 percent of America’s electricity from wind by 2030.

Since the release of the 2008 study, “20 percent Wind Energy by 2030: Increasing Wind Energy’s Contribution to U.S. Electricity Supply,” the Department of Energy has pushed for the increased implementation of wind energy across the nation.

“If we’re going to try and make 20 percent by 2030, we’re well ahead of the pace to do that,” said Don Farris, an instructor in the Wind Energy Programs at Texas Tech University, Lubbock.

It will take 100 gigawatts of power capacity nationwide for wind to meet that goal. A gigawatt is a billion watts and enough electricity to power 10 million, 100-watt light bulbs. As of January 2011, the nation was harnessing about 41 gigawatts of installed wind capacity.

At this rate, it’s very likely for the U.S. to meet, and even exceed that 20 percent goal, Farris said.

Another existing effort headed by the Department of Energy aims to generate a whopping 80 percent of electricity from renewable energy sources by 2050. At the pace wind energy is currently expanding, it could make up a large chunk of that 80 percent.

“A couple of people I know, part of the people working on that, they think wind could be almost half of that 80 percent,” said Walker. “Maybe 40 percent of our electricity supply [from renewables] could be met by wind energy by 2050.”

That’s because wind energy in the U.S. has great potential to grow. According to the National Renewable Energy Laboratory, areas of the U.S. with a designation of three or above on the annual average wind power map are suitable for wind energy applications.

The three is close to midway on the one to seven scale of wind power density.

A good portion of the country falls into the viable category, with areas such as the Great Lakes and the Northeast coast scoring up to at least six on the seven-point scale, with winds ranging from 17.9 mph to 19.7 mph at an altitude of 164 feet.

And unlike other, more traditional sources of energy such as nuclear power plants, wind turbines are relatively low-impact.

“There are no pollutants and it produces energy with almost no side effects,” Farris said. “It does take a small amount of land to operate and…it takes up a little bit of space on the landscape, but other plants take up space on the landscape.”

And the real bonus is that wind energy doesn’t require any external fuel input to get the desired output.

“Its just a pollution-free, fuel-free way to produce energy, and it works just marvelously well,” Farris said.

But with every pro comes a con, and both Farris and Walker acknowledge the potential problems of wind turbines.

“When you hear people talk about wind, some of the most common objections are that the wind doesn’t blow all the time, so it’s somewhat intermittent,” Farris said.

But certainly turbines are most economically viable when there’s a consistent source of wind.

And while it’s technically possible to put up wind turbines wherever there’s wind, turbines need winds blowing at about 6 mph to start turning, according to Farris.

“Wind turbines are expensive,” said Farris. “If you look at the typical cost figure—the installed cost—is something like $2 million per megawatt. You have to harvest a fair amount of energy from that to make it economically pay for itself.”

Barbara Hill, former executive director of the now defunct Cape Cod organization Clean Power Now, which supported the Cape Wind Project on Nantucket Sound, agrees that offshore means a hefty investment.

“However, the winds offshore are much more robust,” Hill said. “You get essentially, more bang for your buck. The winds are more sustainable.”

Offshore winds also tend to be more robust during peak energy consumption hours—during the middle of hot, summer weekdays, according to the Deepwater Wind Energy Center’s research conducted by meteorological experts at the consulting firm AWS Truepower.

That correlation should be another addition to the list of pros for wind energy, but some people are still resistant. And that resistance could stem from perception of wind energy, Farris said.

“Perhaps to an engineer these things are a thing of beauty,” Farris said. “To someone who’s an outdoorsman, they may be pollution on an otherwise beautiful landscape. How you view wind is going to be something that depends on your background. You can’t put up wind farms in a community if the community isn’t going to accept them.”

And most community members who would be most impacted by wind turbines, especially offshore turbines, aren’t engineers or scientists, who’ve been exposed to the research that makes the case for wind energy.

“You really have to ask the question ‘What is important to you?’” said Hill. “Is your view more important than a sustainable environment? We can’t have it all. We’ve got to make some tough choices about energy.”

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