Lower electricity demand in 2017 led to a 1.5 percent drop in total U.S. electricity generation. Natural gas and coal generation fell by 7.7 percent and 2.5 percent from 2016, respectively, as generation from several renewable fuels, particularly hydro, wind and solar, increased from 2016 levels.

The U.S. Energy Department's Energy Information Administration (EIA) says that although natural gas continued to be most-used fuel for electricity generation for the third consecutive year, natural gas-fired electricity generation fell by 105 billion kilowatthours in 2017. That was the largest annual decline on record. Coal-fired electricity generation also fell, but to a lesser extent.

The declines marked the first year since 2008 that both natural gas- and coal-fired electricity generation fell in the same year, EIA says.

Credit: EIACoal-fired generation accounted for more than half of the electric capacity retired in 2017, with 6.3 gigawatts (GW) of the 11.2 GW total. For the first year in at least a decade, no new coal-fired generators were added.

EIA says that about 4.0 GW of natural gas-fired capacity was retired in 2017, most of it steam turbine units. However, more natural gas capacity was added than retired, widening natural gas’s lead as the largest source of generating capacity in the United States. About 9.3 GW of new natural gas-fired generating capacity came online during 2017. Some 8.2 GW of the capacity was from combined-cycle units.

Credit: EIAElectricity from renewable sources, especially wind and solar, rose in 2017. Wind made up 6.3 percent of total net generation. Utility-scale solar made up 1.3 percent, representing record shares for both sources.

In part as a result of record precipitation in California, hydroelectricity increased in 2017, accounting for 7.5 percent of total net generation. EIA expects hydro to continue to exceed wind in 2018, but wind is projected to become the predominant renewable electricity generation source in 2019.

Nearly 6.3 GW of wind turbines and 4.7 GW of utility-scale solar photovoltaic systems were added in 2017. For each technology, about a third of the year’s capacity additions came online in the last month of the year. Another 3.5 GW of small-scale solar capacity came online in 2017, increasing total small-scale solar capacity to 16.2 GW.