The scientists found that curtailing wind power reduces the energy return on investment by 10 percent. But storing surplus wind-generated electricity in batteries results in even greater reductions – from about 20 percent for lithium-ion batteries to more than 50 percent for lead-acid.
“Ideally, the energetic cost of curtailing a resource should at least equal the amount of energy it cost to store it,” Dale said. “That’s the case for photovoltaics, but for wind farms, the energetic cost of curtailment is much lower than for battery storage. Therefore, it would actually be more energetically efficient to shut down a wind turbine than to store the surplus electricity it generates.”
He compared it to buying a safe. “You wouldn’t spend a $100 on a safe to store a $10 watch,” he said.