Despite the buzz this week from Interior Secretary Ken Salazar approving the controversial Cape Wind project off Cape Cod, the United States has yet to construct any offshore wind farms despite a slew of ideas blowing around and 11 specific proposals on the table.
While those U.S. projects inch forward, researchers see a wealth of wind being wasted.
Willett Kempton, a marine policy professor and offshore wind expert at the University of Delaware, calls the wind off the Mid-Atlantic coast "a huge resource. It's enough to run the whole East Coast."
He points to a 2007 study (he was the lead author), which showed that two-thirds of the power available from wind off the East Coast could provide enough energy to completely satisfy the demand for electricity, light vehicle fuel, and heating fuel for the region from Massachusetts to North Carolina.
But Kempton noted that study left an important question unanswered: What happens when the wind lets up?
In a paper published this month in the Proceedings of the National Academy of Sciences, Kempton suggested that if you look at it the right way, the wind never lets up. When it dies down in one spot off the Atlantic coast, it's invariably kicking up in another.
The research demonstrates, he said, that a fleet of offshore wind farms strung together along a 1,500-mile high-voltage cable could, from their combined output, provide more than enough electricity for the East Coast without interruption. And, he told Miller-McCune.com, this could happen using everyday technology and a few institutional changes.
"If you assume new technology, we could run the whole United States," he added.
It's all in the balance
Even though the power supply and customer demand vary constantly, the power grid must maintain consistent voltage at all times. To avoid power failures when circumstances change, utilities generally "load balance" — firing up highly responsive gas-fired turbines to adjust to fluctuating demand for power. In effect, these generators are what keep the lights across town from flickering whenever the stadium powers up for a big game.
Because variability is inherent in wind, Kempton says utilities use the same equipment to accommodate fluctuations in power levels introduced by the small volume of wind generation currently feeding into the grid.
"If you have 20 percent wind, that's fine, no problem. We'll just ramp the generators up and down as the wind fluctuates." So it works — up to a point.
"It keeps the managers busy; it's not that they let the fluctuations go out and let your lights bulbs flicker, but it adds maybe 5 percent to the cost of wind power to do that management."
However, "If you want to run 50 percent or 80 percent of your electricity from wind, then that fluctuation becomes more problematic." This calls for either massive power storage systems to warehouse energy for a rainy (or not so rainy) day, or major investments for more gas-fired generators.
Kempton believes that wind farms up and down the coast, under the power of local weather conditions, could perform the same load balancing function for one another that gas turbines provide onshore.
He and his co-authors Dana Veron and Felipe Pimenta from University of Delaware and Stony Brook University associate professor Brian Colle tracked coastal winds over five years using hour-by-hour data from 11 offshore weather buoys and meteorological stations.
Then they put together a computer simulation that substituted wind farms for weather stations and included the proposed interlinking cable. They generated data simulating five years' worth of power feeds from the hypothetical wind farms.
While the researchers found that output from individual wind farms varied widely over time, the power output of the network as a whole held steady. Fluctuations, when they did occur, were gradual, but at no time during the study period did power output on the simulated grid drop to zero.
Other wind energy researchers see potential in other U.S. coastal areas. For example, Stanford's Mike Dvorak and Mark Jacobsen looked at the California coas