Table 4.08.C. Usage Factors for Utility Scale Storage Generators

  Battery Pumped Storage
Year/Month Time Adjusted Capacity Usage Factor Time Adjusted Capacity Usage Factor
Annual Data
2013 126.7 0.7% 22,389.3 9.8%
2014 155.1 1.7% 22,477.9 10.2%
2015 206.8 3.6% 22,568.9 10.2%
2016 423.0 3.8% 22,752.7 11.2%
2017 632.8 6.8% 22,791.7 11.4%
2018 713.6 5.2% 22,815.4 10.8%
2019 949.8 5.4% 22,754.7 10.4%
2020 1,210.3 5.2% 22,939.6 10.5%
2021 2,627.6 6.1% 23,007.7 10.2%
Year 2019
January 864.8 5.5% 22,721.3 9.3%
February 877.1 5.7% 22,721.3 9.2%
March 901.9 6.3% 22,721.3 8.3%
April 931.0 5.9% 22,721.3 10.2%
May 934.7 5.9% 22,721.3 11.8%
June 939.7 5.2% 22,778.3 11.7%
July 962.9 5.2% 22,778.3 15.1%
August 983.9 5.0% 22,778.3 13.7%
September 990.8 5.8% 22,778.3 12.4%
October 998.7 4.5% 22,778.3 8.3%
November 1,001.2 5.2% 22,778.3 7.2%
December 1,006.2 5.0% 22,778.3 7.8%
Year 2020
January 1,023.4 5.3% 22,917.9 9.0%
February 1,038.8 5.7% 22,917.9 9.1%
March 1,052.5 6.3% 22,917.9 7.9%
April 1,077.2 5.6% 22,917.9 8.2%
May 1,093.1 5.3% 22,917.9 10.8%
June 1,106.9 5.4% 22,917.9 13.4%
July 1,110.5 5.3% 22,917.9 15.9%
August 1,363.8 4.7% 22,917.9 15.0%
September 1,395.5 5.0% 22,917.9 11.6%
October 1,395.5 4.8% 22,997.9 8.4%
November 1,419.8 5.0% 22,997.9 7.6%
December 1,440.6 4.6% 23,016.2 8.6%
Year 2021
January 1,505.6 4.2% 23,007.7 8.1%
February 1,640.0 5.6% 23,007.7 9.0%
March 1,653.0 5.5% 23,007.7 7.4%
April 1,780.4 5.1% 23,007.7 7.2%
May 1,958.8 6.1% 23,007.7 8.7%
June 2,499.4 6.4% 23,007.7 12.4%
July 2,777.0 6.5% 23,007.7 15.2%
August 3,043.5 7.4% 23,007.7 15.9%
September 3,110.9 7.1% 23,007.7 12.8%
October 3,304.5 6.0% 23,007.7 9.7%
November 3,765.6 6.2% 23,007.7 7.7%
December 4,418.2 5.8% 23,007.7 8.6%

Values are final.
Time adjusted capacity for month rows is the summer capacity of generators in operation for the entire month; units that began operation during the month or that retired during the month are excluded. Time adjusted capacity for year rows is a time weighted average of the month rows.
Usage factors are a comparison of gross generation with available capacity. See the technical note for an explanation of how usage factors are calculated.
Sources: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report; U.S. Energy Information Administration, Form EIA-860, 'Annual Electric Generator Report' and Form EIA-860M, 'Monthly Update to the Annual Electric Generator Report.'