http://www.nytimes.com/2010/07/28/business/energy-environment/28storage.html?_r=1&src=meThe rapid growth of wind farms, whose output is hard to schedule reliably or even predict, has the nation’s electricity providers scrambling to develop energy storage to ensure stability and improve profits.
A battery system in Presidio, Tex., is intended to improve reliability in the town, served by only one major transmission line.
As the wind installations multiply, companies have found themselves dumping energy late at night, adjusting the blades so they do not catch the wind, because there is no demand for the power. And grid operators, accustomed to meeting demand by adjusting supplies, are now struggling to maintain stability as supplies fluctuate.
On the cutting edge of a potential solution is Hawaii, where state officials want 70 percent of energy needs to be met by renewable sources like the wind, sun or biomass by 2030. A major problem is that it is impossible for generators on the islands to export surpluses to neighboring companies or to import power when the wind towers are becalmed.
On Maui, for example, wind generating capacity over all will soon be equal to one-fourth of the island’s peak demand. But peak wind and peak demand times do not coincide, raising questions about how Hawaii can reach its 70 percent goal. For now, the best option seems to be storage batteries.
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