Coal began firing US homes and factories in the 1880s. A century later, the cheap, plentiful fuel was America’s primary one (pdf) for electricity generation. But its long reign is slowly coming to an end.

In April, renewables eclipsed coal generation in the US for the first time. The Energy Information Administration estimates renewables outperformed coal by 16% in April and will generate 1.4% more in May.

The seasonal nature of the business means electricity generation from coal will again exceed that of hydro, biomass, wind, solar, and geothermal sources later this year. But the trend is clear. In 2020, annual coal and renewable generation will approach parity.

“Coal’s proponents may dismiss these monthly and quarterly ups and downs in generation share as unimportant, but we believe they are indicative of the fundamental disruption happening across the electric generation sector,” writes the energy-and-environment nonprofit Institute for Energy Economics and Financial Analysis. “Renewable generation is catching up to coal, and faster than forecast.”