- Published: 11 May 2015 11 May 2015
In the coming decades, additions to U.S. electricity generation capacity are expected to be lower than in the recent past. In EIA's Annual Energy Outlook 2015 Reference case total generating capacity (including end-use generators like rooftop solar panels) increases from 1,065GW in 2013 to 1,261GW in 2040.
Capacity additions through 2017, much of which are under construction, average about 17GW per year and about half are nonhydro renewable plants (mainly wind and solar) prompted by federal tax incentives and renewable portfolio standards. From 2018 to 2024, projected capacity additions average less than 4GW per year, as earlier planned additions are sufficient to meet most growth in electricity demand. From 2025 to 2040, average annual capacity additions, primarily natural gas-fired and renewable technologies, average 12GW per year. By comparison, annual additions from 2000 to 2013 averaged 26GW per year. Natural gas-fired plants account for 58% of the capacity additions through 2040, while renewables provide 38% of the additions, and nuclear 3%. Renewable additions are aided in the near term by federal tax credits, and in the longer term by rising natural gas prices and state renewable targets. The 109GW of renewable capacity additions in the Reference case are primarily wind (49GW) and solar (48GW) technologies, including 31GW of solar photovoltaic installations from rooftop and other distributed generation installations. The analysis in the AEO2015 includes several cases that examine different assumptions of macroeconomic growth, world oil prices, and higher oil and natural gas resource availability, which yield a range of projected capacity additions. Policies such as the proposed Clean Power Plan, or the continuation of tax credits for certain renewable energy technologies that are scheduled to expire under current law can also have a significant effect on projected capacity additions and retirements.