As the world moves toward cleaner power in the face of climate change, there’s a need for ways to park energy until it’s needed. Wood Mackenzie’s latest U.S. Energy Storage Monitor report found that the first-quarter 2021 energy storage performance was up more than 250% over the same quarter a year ago.

Energy storage is a key factor in the U.S. weaning itself off fossil fuels. Many storage platforms allow energy generated by wind turbines and solar panels to be stockpiled for use when demand is high.

As more utilities invested in wind and solar, storage was bound to boom, even during the pandemic, said Chloe Holden, an energy storage research analyst at Wood Mackenzie. “The 2021 growth — I wouldn’t say it was because 2020 was suppressed, but rather because storage is really becoming a mature industry.”

But more than anything, the reason for the jump in storage emerging right now is that it’s getting cheaper, said Will Frazier at the National Renewable Energy Lab.