Utility scale solar developers are increasingly co-locating battery storage with new solar photovoltaic capacity, the Energy Information Administration reported on Friday. As of September 2026, over 16 percent of new utility scale solar capacity added this year is co-located with operable battery storage, compared with 2 percent in 2017, according to data reported to the EIA by operators.
Reported plans for solar additions scheduled to come online in the last three months of this year show that the share with co-located battery storage could increase to 19 percent this year. Longer term plans indicate the trend will continue, with the portion increasing to more than 30 percent in plans submitted for 2027 and 2028.
When operators co-locate storage with solar, they can direct output to the grid or to the battery depending on wholesale prices. Wholesale prices in regions with large solar participation tend to fall when solar contributions are high and rise as they decrease, so plants with both can manage their combined output to maximise value.
Southwest states have higher than average solar shares and higher levels of co-location. As of September, 13 percent of total United States utility scale generating capacity is solar photovoltaic, and 18 percent of that is co-located with battery storage. The share in California, Arizona, New Mexico and Nevada is more than double the national average.