The share of renewables in U.S. electric generation has been rapidly rising, and federal energy officials are projecting that growth to continue, eclipsing even natural gas after 2045.

Renewables are the fastest-growing source of electricity generation as cost declines make them economically competitive beyond the expiration of existing federal and state policy supports,”  said Lisa Capuano, head of the Energy Information Administration, at a Jan. 29 briefing in Washington, D.C., detailing the EIA’s“Annual Energy Outlook 2020.”

The report projects that renewables’ share will double from 19% in 2019 to 38% in 2050, led mostly by solar and wind. Meanwhile, natural gas is expected to remain flat at 36% in 2050 from 37% in 2019. Last year, EIA projected renewables at 31% of total generation and natural gas at 39% in 2050.

Renewables, including hydropower, will surpass nuclear and coal’s shares of generation by next year, according to the EIA’s “reference case,” a baseline projection that assumes current laws and regulations affecting the energy sector will remain the same until 2050.

The report also contains several “side cases,” alternative scenarios that assume changes in factors such as capital costs, oil and gas supplies and prices, and economic growth rates. This year, two new side cases apply low and high capital cost projections for renewable technologies.

Over the next three decades, the share of coal generation is expected to fall to 13%, down from 24% in 2019. Plant retirements will be the main driver of coal’s slide through the mid-2020s, but those losses will stabilize over the longer term “as the more economically viable plants remain in service,” EIA said.

Other takeaways from the report:

• The 2020 reference case projects U.S. electricity demand to grow by about 1% per year on average through 2050. That’s below the average annual growth of 1.9% in U.S. gross domestic product due to increasing energy efficiency of electric devices, equipment and processes.

• After falling during the first half of the projection period, total carbon dioxide emissions will resume “modest” growth in the 2030s, mostly because of increases in energy demand in the transportation and industrial sectors. However, the 2050 CO2 emissions are projected to be 4% lower than in 2019.

• Wind generation will see the most growth in the West and Midwest, while solar generation will see the most growth in the Southeast.