Retaining existing hydropower and nuclear capacity — after accounting for planned retirements — and much of the existing natural gas capacity combined with new battery storage, is sufficient to meet U.S. electricity demand dependably with a 90% clean grid in 2035. With a 90% clean grid, all existing coal plants are retired by 2035 and no new fossil fuel plants are built.
During normal periods of generation and demand, wind, solar, and batteries provide 70% of annual generation, while hydropower and nuclear provide 20%. During rare periods of very high demand and/or very low renewable generation, existing natural gas, hydropower, and nuclear plants combined with battery storage cost-effectively meet demand. Generation from natural gas plants is reduced by about 70% compared to 2019.