Electricity consumption is poised to grow steadily through 2050, with average kilowatt-hour prices remaining relatively flat, federal energy officials said. And renewables will be an ever-increasing factor.

In its Annual Energy Outlook 2018, released Feb. 6, the Energy Information Administration projects 0.9 percent average annual growth in electricity demand in what it calls the "Reference case." This scenario uses trends reflecting the current views of leading economic forecasters and demographers. It also assumes no changes to current laws and regulations affecting the energy sector, and this year does not include the Clean Power Plan.

EIA said the electricity demand growth figure could deviate by about 0.3 percent either way, were there to be high or low economic growth, which are other scenarios EIA runs as side cases.

What will it cost to generate electricity and get it to users?

"The generation cost represents the largest share of the price of electricity, and it is projected to decrease by 10 percent from 2017 to 2050 in the Reference case in response to continued low natural gas prices and increased generation from renewables," the report said.

"The transmission cost component is projected to increase by 24 percent over the forecast period, and the distribution cost component is expected to increase by 25 percent-reflecting the need to replace aging infrastructure and upgrade the grid to accommodate changing reliability standards," it added.

At the same time, EIA projects average electricity prices will "remain relatively flat-ranging between 10.6 and 11.8 cents per kilowatt-hour" in the Reference case.

As for what will be used to generate electricity, EIA notes there are many variables.

In one scenario-the High Oil and Gas Resource and Technology case, where there's a lot of natural gas supply and prices are lower-the outlook sees "significantly higher" natural gas generation with less growth in renewables and coal generation. Coal plant retirements would increase by 19 gigawatts in 2030, leaving the nation with 157 GW of coal capacity by 2050.

Conversely, higher natural gas prices would slow that pace of retirements by about 20 GW in 2030 while increasing the use of renewables, which the EIA found in its Low Oil and Gas Resource and Technology case.

Either way, EIA believes renewables will gain ground, led by wind and solar. In the Reference case it sees a 139 percent increase in renewable generation by 2050.

The natural gas price question would also have an impact on nuclear plant retirements. Under the Reference case, EIA projects a 20 percent decline in nuclear generating capacity by 2050, to 79 GW. Lower gas prices could hasten nuclear plant closures, while higher prices could mean fewer retirements.