New utility-scale solar power installations increased in the United States in 2010-16 at a faster rate than any other electricity generating technology. Solar PV and thermal power facilities together grew 72% per annum on average to currently over 21.5 GW. But regardless of this rapid growth, solar's contribution to the overall US power mix remains fairly limited – the dominant fuel is natural gas.
With just under 22GW installed of utility-scale solar (plants over 1MW), these plants account for roughly 2% of the entire electric capacity, and 0.9% of output. Monthly generation from small-scale solar capacity reached 1.6 million MWh on average in 2016, according to estimates by the US Energy Information Administration (EIA).
California has by far the highest total installed capacity of any state with 9.8GW of operating capacity, followed by North Carolina with 2.3GW. Rooftop and other customer-sited PV systems are most frequent in California, New Jersey, and Massachusetts.
Gas generation dominates US power mix
Natural gas as a fuel for power plants in 2016 made the largest contribution to the US power mix.
Gas-fired generators accounted for 42% of the operating capacity in the US that year, and provided 34% of total electricity output – surpassing coal to become the leading generation source.
“The increase in natural gas generation since 2005 is primarily a result of the continued cost-competitiveness of natural gas relative to coal,” EIA analysts said.
Combined-cycle gas turbine (CCGT) units accounted for 53% of the 449 GW of total gas-fired capacity in the United States during the past year.