Gas turbines answer the need for energy storage

Since the wind doesn’t always blow and the sun doesn’t always shine at the time that energy is needed, many assume that bulk storage technologies are essential in order for wind turbines and solar farms to contribute a larger share of the nation’s electricity demand.

A new Harvard study pokes holes in that conventional wisdom. The analysis published in the journal Energy & Environmental Science finds that the supply of wind and solar power could be increased tenfold without additional storage.

Storage “is not the only strategy to achieve a low-carbon electricity grid,” according to coauthor Hossein Safaei. “Low capital cost in addition to good emissions performance make gas turbines cost-effective carbon mitigation candidates. Moreover, dispatchable zero-carbon generation technologies such as hydropower, nuclear, and biomass can be deployed instead of, or in conjunction with, the intermittent renewables.”

These alternatives will give researchers enough time to develop ways to decrease the cost and bulk of energy storage.

“There’s no question that it would be better to have more and better storage and a sensible long-term strategy for the grid will have much more storage than today,” said coauthor David Keith, Gordon McKay Professor of Applied Physics at Harvard John and Paulson School of Engineering and Applied Sciences (SEAS) and Professor of Public Policy at the Harvard Kennedy School. “But you don’t have to wait for that before deploying more variable renewables.”

“We’re trying to knock out a salient policy meme that says that you can’t grow variable renewables without a proportionate increase in storage,” Keith said. “We could cut electric-sector carbon emissions to less than a third their current levels using variable renewables with natural gas to manage the intermittency, but this will requires us to keep growing the electricity transmission infrastructure.” Keith added, “There is a saw-off between transmission and storage, if siting battles stop new transmission then we must increase storage.”