The Department of Energy’s Energy Information Administration (EIA) recently revealed findings indicating the U.S. electric power sector’s consumption of fossil fuels in 2017 was at the lowest level since 1994.
According to EIA, fossil fuel consumption in the electric power sector declined to 22.5 quadrillion British thermal units -- or quads -- in 2017, the lowest level since 1994. The declining trend in fossil fuel consumption by the power sector has been driven by a decrease in the use of coal and petroleum with a slightly offsetting increase in the use of natural gas. Changes in the fuel mix and improvements in electricity generating technology have also led the power sector to produce electricity while consuming fewer fossil fuels, noted EIA.
EIA in its May 29 “Today in Energy” report, also notes that in 2017, coal consumption by the electric power sector reached its lowest level since 1982, and petroleum consumption in the power sector was the lowest on record, based on data since 1949. Recent natural gas consumption in the power sector has generally been increasing, but 2017 consumption was slightly lower than the record-high 2016 level.
In energy-equivalent terms, more coal was consumed in the power sector than natural gas in 2017, at 12.7 quads and 9.5 quads, respectively. However, in terms of electricity generation, natural gas-fired power plants in the electric power sector produced more electricity than coal-fired plants, at 31% and 30% of the U.S. total, respectively, in 2017, said EIA.
The report also clarifies that as the natural gas-fired generation fleet has grown and become more efficient, the generation-weighted average efficiency of fossil fuel-fired electricity generation has improved. In 1994, fossil fuel power plants required 10,400 British thermal units of primary energy to produce each kilowatt hour . By 2017 that rate had fallen to 9,400 Btu/kWh.
These changes in energy consumption and efficiency have also affected carbon dioxide emissions from the electric power sector, which in 2017 were the lowest since 1987. “Because coal combustion is much more carbon intensive than natural gas combustion, CO2 emissions from coal were more than double those from natural gas in 2017, even though natural gas provided more electricity generation,” said EIA.
The report also noted that as recently as 2000, natural gas-fired power plants were on average about as efficient as coal-fired plants. “Since then, new natural gas-fired power plants have tended to use combined-cycle generators, which are more efficient because the waste heat from the gas turbine is routed to a nearby steam turbine that generates additional power,” EIA said.
According to the federal agency, combined-cycle units now make up most of the natural gas-fired electricity generation capacity and by the end of 2018, natural gas combined-cycle units may overtake conventional coal-fired power plants to become the most prevalent technology for generating electricity in the U.S., it noted.