R & D
Storing Wind Power in Volcanic Rock
Can volcanic rock be a lockbox for wind energy?
Researchers are studying whether they can store wind energy in basalt rock formations, like these in Idaho. (Photo By: iStockphoto)
That’s the idea behind a project in the Pacific Northwest, where researchers are trying to determine whether they can shunt excess wind energy underground, and retrieve it when it’s needed.
The technology is considered a long shot. But scientists say it’s worth a look as a way of dealing with situations when a surplus of both wind and hydropower exceed load requirements and threaten grid reliability.
“Cost-effective large-scale energy storage could transform the regional electric industry,” said Steve Knudsen, project manager for Bonneville Power Administration.
BPA and the Pacific Northwest National Laboratory are sponsoring the $800,000 project, which is also backed by Washington State University and several utilities.
The target of the investigation is the Columbia River Basalt Extent, a rock formation under Washington, Idaho and Oregon that volcanic lava flows produced millions of years ago. BPA wants to see if it can store wind energy in spaces between individual basalt flows.
The research model calls for using excess wind power to compress air to as much as 2,000 pounds per square inch and inject it into seams between the basalt, which is considered impermeable. The air would displace water in the basalt, though the water would stay underground and serve as a pressure check.
When there’s a need for power, it would be returned to the surface, heated, and used to drive a turbine.
Researchers say they will examine carbon capture and storage technology as one way of evaluating how to trap compressed air in basalt formations, and study basalt to ensure it won’t crack under the added pressure.
They’re looking at large-scale storage―as much as 110,000 megawatt-hours of power, the equivalent of all the off-hour wind energy generated on the BPA transmission system in a 10-day period. That could offset the intermittent nature of wind power, one of its principal drawbacks.
“Although the technology and low costs of rapid cycling of compressed air storage in basalt is unproven, there’s enough potential there to invest in this research,” Knudsen said.
“And at a minimum, this project will help us focus future research into the best ways to integrate large amounts of variable energy supplies into the regional power system.”
Figuring out new ways to accommodate wind energy is essential for BPA, which expects another 6,000 megawatts of wind on its system by the end of 2013.
The power marketer has tried to find a middle ground by curtailing some fossil-fuel and wind generation at times of high hydro production. But federal regulators have rejected that plan.
Researchers hope to issue their findings by the end of 2012.
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