S&P Global Market Intelligence ($):

A new wave of solar farm development, pairing solar photovoltaics with battery storage, is accelerating across the United States, most notably in California, Hawaii, Florida and the Northeast.

Roughly 40 such systems were in operation in the U.S. as of late September, combining about 533 MW of storage with 1,242 MW of solar capacity. Meanwhile, companies are developing at least another 85 co-located solar and storage projects, most of which are in the near- to medium-term planning stages or under construction, according to S&P Global Market Intelligence data. The planned projects combine 4,175 MW of storage with 8,921 MW of solar.

These dynamic renewable energy assets can operate past sunset and into the hours of peak electricity demand typically served by natural gas-fired and hydroelectric generation. Adding energy storage to PV can also help reduce curtailments, or cuts of solar production during periods of midday oversupply on the grid, a growing challenge throughout California and other parts of the country, and smooth the variability of the renewable resource.

The Los Angeles Department of Water and Power, or LADWP, in September approved power purchase agreements for output from the Eland Solar and Storage Center in Kern County, a planned 400 MW solar project with 200 MW to 300 MW of batteries. Under development by 8minute Solar Energy LLC, the Eland facility is billed as “the largest solar and battery energy storage system in the United States.” The contracts, pending approval from the Los Angeles City Council, have all-in prices between $30/MWh and $40/MWh, depending on battery size. That is comparable to other recently contracted solar-plus-storage projects in the West.

But some of the biggest U.S. solar-plus-storage buyers are outside of California. Berkshire Hathaway Inc. affiliate NV Energy Inc., for instance, in June announced plans to add 1,190 MW of solar capacity paired with 590 MW of battery storage in Nevada.

Platts Analytics has identified a recent surge in solar-plus-storage projects in the deeper development pipeline. As of September 2019, for example, the California ISO’s interconnection queue showed 23,377 MW of energy storage under consideration with solar projects on the grid operator’s transmission system. That is up from 5,965 MW in June 2018.

More ($): Solar-plus-storage power plant development accelerates in the U.S.