Natural gas is to remain the primary source of electricity generation in the US for at least the next two years.

That’s the forecast from the Energy Information Administration (EIA), which expects the share of total power supplied by natural gas-fired power plants to average 33% in 2018 and 34% in 2019.

That’s an increase from 32% last year.

It forecasts the share of coal – which has been the predominant fuel for decades – to average 30% in 2018 and 28% next year compared to 30% in 2017.

The EIA expects the cost of natural gas for electricity generation to remain “relatively competitive” with coal over the next two years.

Power plant operators are scheduled to bring 20GW of new natural gas generating capacity online this year, which if realised, would be the largest increase since 2004.