Energy storage is heralded as the critical technology that will make widespread adoption of renewable energy possible. Storage bottles sunlight, addressing a key drawback to solar energy — that it can’t provide electricity when the sun isn’t shining. Energy storage also cures additional utility ailments from grid resiliency to power smoothing.

Due to a rise in incentives and a drop in storage costs, the market for this storage is heating up in the U.S. The market is expected to grow 250 percent just this year.

California is leading the energy storage market thanks to Assembly Bill 2514, which requires state utilities to procure 1.3 GW of storage by 2020. Now California’s three largest investor-owned utilities, Southern California Edison (SCE), Pacific Gas and Electric (PG&E) and San Diego Gas & Electric, are installing cost-effective storage solutions. SCE, for example, invested in a wind farm in the Mojave Desert equipped with giant lithium-ion batteries. The East Coast is following California’s example. New York recently budgeted $25 million to promote storage development.

While the utility-scale market gets most of the attention, a quietly growing storage market segment with a lot of potential is residential solar. After all, residential solar is a fast growing solar market segment — increasing 49 percent in 2014. Unsurprisingly it offers immense opportunity for storage.

Read more: Renewable Energy World