Reducing energy inputs to battery manufacturing is also needed, he said.
Over the years, consumers have learned to expect electricity on demand from power plants that run on coal, natural gas or oil. But these fossil fuels, which provide reliable, around-the-clock energy, also emit megatons of greenhouse gas that contribute to global warming.
Wind and solar farms provide emissions-free energy, but only generate electricity when the wind blows or the sun shines. Surplus energy can be stored for later use, but today's electrical grid has little storage capacity, so other measures are used to balance electricity supply and demand.
In the study, the Stanford team considered a variety of storage technologies for the grid, including batteries and geologic systems, such as pumped hydroelectric storage. For the wind industry, the findings were very favorable.
"Wind technologies generate far more energy than they consume," Dale said. "Our study showed that wind actually produces enough surplus electricity to support up to 72 hours of either battery or geologic storage. This suggests that the industry could deploy enough storage to cope with three-day lulls in wind, common to many weather systems, and still provide net electricity to society."
The results were especially good for onshore wind turbines. "We found that onshore wind backed by three days of geologic storage can support annual growth rates of 100 percent in other words, double in size each year and still maintain an energy surplus," he said.
"These results are very encouraging," said study co-author Sally Benson, a professor of energy resources engineering and director of the
|Contact: Mark Shwartz|