Some Wind Farms Need Controls to Minimize Risk of Instability on the Grid, Study Says
The location of a wind farm can play a key role in the potential for wind energy to add or detract from stability on the electric grid, according to researchers at North Carolina State University and Johns Hopkins University. The paper, released this month, notes that some wind farms, because of their location and the fact that wind generators differ from conventional generator systems, might actually worsen instability when there are disturbances on the grid, increasing the risk of power outages; others, in turn, could bolster the grid if sited in favorable locations. (See related quiz: “What You Don’t Know About Wind Energy.”)
The paper’s authors detail a technique employing controllers to moderate the flow of wind power coming onto the grid by matching control efforts between wind farms and energy storage facilities. “By matching the behavior of the two controllers, we can produce the desired damping effect on the power flow and restore stable grid behavior,” said senior author Aranya Chakrabortty in a release about the paper. (See related story: “New ‘Flexible’ Power Plants Sway to Keep Up With Renewables.”)
The researchers point out that their system can be put to use regardless of where the turbines and batteries are located, making it applicable in decentralized systems over large geographical areas.
Though wind energy accounts for just a small percentage of U.S. electricity generation as a whole (3.4 percent in 2012), it is growing by leaps and bounds: the added electricity generation capacity for wind in 2012 was larger than for any other source, and is expected to grow by nearly 50 percent between 2015 and 2040, according to the Energy Information Administration.
Meanwhile, creative minds around the world are exploring ways to store surplus wind energy when the breeze generates more than the grid can handle. Ideas for storage vessels range from rock reservoirs to frozen fish. (See related stories: “Too Much Wind Energy? Save It in Underground Volcanic Rock Reservoirs” and “Frozen Fish Help Reel In Germany’s Wind Power.”)
Note: This post has been modified to reflect that wind farm location and equipment, not wind variability, were the key factors in the destabilizing effect researchers sought to correct.