Enlarge / In Texas, solar facilities compete for space with a whole lot of nothing.

Earlier this week, the US' Energy Information Agency (EIA) gave a preview of the changes the nation's electrical grid is likely to see over the coming year. The data is based on information submitted to the Department of Energy by utilities and power plant owners, who are asked to estimate when generating facilities that are planned or under construction will come online. Using that information, the EIA estimates the total new capacity expected to be activated over the coming year.

Obviously, not everything will go as planned, and the capacity estimates represent the production that would result if a plant ran non-stop at full power—something no form of power is able to do. Still, the data tends to indicate what utilities are spending their money on and helps highlight trends in energy economics. And this year, those trends are looking very sunny.

Big changes

Last year, the equivalent report highlighted that solar power would provide nearly half of the 46 gigawatts of new capacity added to the US grid. This year, the grid will add more power (just under 55 GW), and solar will be over half of it, at 54 percent. In most areas of the country, solar is now the cheapest way to generate power, and the grid additions reflect that. The EIA also indicates that at least some of these are projects that were delayed due to pandemic-induced supply chain disruptions.

Enlarge / A train carrying cars loaded with coal leaving a nearby coal mine is seen in front of Dry Fork Station, a coal-fired power plant operated by Basin Electric Power Cooperative, on Monday May 8, 2017, in Gillette, Wyoming. (credit: Matt McClain/The Washington Post via Getty Images)

A coal-fired plant near Gillette, Wyoming, stands alone in the nation on one measure of economic viability—a positive distinction for that plant, but a damning one for coal-fired electricity in general.

Dry Fork Station, with generating capacity of 405 megawatts, is the only coal plant in the country that costs less to operate than it would take to replace the plant’s output by building new wind or solar plants in the same communities or regions, according to a new report issued today by the think tank Energy Innovation.

The report joins prior editions in 2019 and 2021 that, when viewed together, show how the economics of coal power are deteriorating. In 2019, the authors found that more than 70 percent of coal plants were more expensive to operate compared to the alternative of building new wind or solar. That share has now grown to 99 percent, with only the plant in Wyoming stopping it from being 100 percent.