That new reality is most evident in Texas. So far this year, wind generated 23% of the state's power, up from 17% in 2017, according to grid operator Electric Reliability Council of Texas. Over the same period, coal-fired generation in Texas fell to 22% from 32%. Next year, the roughly 700-megawatt Oklaunion power plant in the state will close because it no longer can make a profit, joining a handful of other recently shuttered Texas coal-fired facilities.
Coal-fired plants have another problem: They cannot produce power quickly enough for 21st century needs. Coal plants take hours to start up from cold, making them remarkably inflexible.
As renewables make up more of the energy mix, what's needed is base load power — electricity generation that is supplied around the clock — that can also be quickly ramped up or down to make up for fluctuations in wind and sun. Coal (and nuclear power, too) is terrible at that, taking hours to supply electricity from a cold start. Natural gas, which is much cleaner than coal, can easily turn up or down to produce base-load power in a matter of minutes, making it the perfect partner for utility-scale wind and solar.
Another boost for renewables is that states are planning to add 110 gigawatts of battery storage capacity by 2040, enough energy storage to power about 77 million homes, according to BloombergNEF. That advance is possible thanks to technological breakthroughs in recent years.
Demand for renewables is coming from both states and corporations. In June, New York announced a road map to get all of its electricity from emission-free sources, matching the ambition of California, Hawaii, Nevada, Washington and New Mexico. Facebook Inc. is building one of the largest solar arrays in the U.S., a $416 million project in West Texas that will take up seven square miles, an area more than five times the size of New York's Central Park. The facility will help power the firm's data centers, producing sufficient electricity that, if it were not being used to run computer servers storing pictures, videos and social media posts, could power 72,000 homes. Snack food giant Mondelez International Inc. signed a deal in June to buy enough Texas renewable energy to produce 10 billion Oreo cookies annually.