As corporate leaders dutifully line up for audiences with President Donald Trump, and try to outdo each other with curry-favoring announcements about the new American jobs they plan to create, it seems a bit curious that one of the more outspoken business executives assailing Trump and his Cabinet picks is a former energy-industry C.E.O. and ex–Wall Streeter. David Crane, who used to run the enormous power company NRG Energy and used to work at Lehman Brothers, recently wrote a blog post titled “Meet the Four Horsemen of the Climate Apocalypse,” in which he fretted about weakened environmental protections under Trump, citing the administration’s picks for secretary of state (former ExxonMobil C.E.O. Rex Tillerson), secretary of energy (Texas ex-governor Rick Perry); head of the Environmental Protection Agency (Scott Pruitt, Oklahoma’s attorney general); and head of the Department of Energy transition team (Thomas Pyle, president of the American Energy Alliance, an industry lobby). “It’s like the fossil-fuel industry’s nirvana,” he told me.

Of course, Crane isn’t a typical energy executive. He was, in fact, fired a little over a year ago from NRG Energy, a huge independent power producer, for trying (and failing) to turn one of America’s biggest carbon emitters into a major renewable energy provider that could have made the world a dramatically greener place. NRG generates $15 billion in annual revenue and ranks No. 193 on the Fortune 500 list. Its core business is generating electricity, which it delivers to the grid. Its customers are local utilities (some of which NRG owns), whose customers are consumers and businesses. Companies like NRG have one overriding mission, often described, quaintly, as “keeping the lights on.” The way they do that—by boiling water to generate steam to spin turbines to produce electrical current—hasn’t changed much since Thomas Edison, and it’s a filthy project. Two-thirds of the electricity that Americans consume is made by first burning coal or natural gas. Most of the remainder comes from nuclear power plants, and only some 5 percent from wind and solar.

In early 2014, Crane wrote a letter to NRG shareholders that owned up to his company’s role in climate change—think Jerry Maguire’s “mission statement” for the power business. He laid the groundwork for a sweeping transformation of NRG, and ultimately the $6 trillion global energy industry, imploring it to move away from fossil fuels, giant power plants, and far-flung transmission lines, toward what’s called “distributed generation,” built around home solar and battery backup. “The day is coming,” Crane concluded, “when our children sit us down in our dotage, look us straight in the eye, with an acute sense of betrayal and disappointment in theirs, and whisper to us, ‘You knew . . . and you didn’t do anything about it. Why?’ ”

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Under President Trump, who has promised to revitalize the coal industry and gut the Environmental Protection Agency, Crane’s pledge to turn a pollution-spewing utility into a renewable-energy company feels all the more quixotic. But its important to note that Crane’s cri de couer was supported by a clear-eyed analysis of the competitive threats to the power industry. Disrupters such as Elon Musk, chairman of SolarCity, had started selling solar panels and other clean-energy services directly to homeowners and businesses. Crane worried that these start-ups could one day make NRG obsolete. He proposed that NRG mirror what phone companies did three decades ago when they invested heavily in cellular networks even as they continued to operate traditional land lines, operations that today make up a much smaller part of the phone companies’ business. NRG would invest in clean-energy technologies such as solar, wind, and nuclear projects (the green business), even as it continued to run—and eventually shrink—its coal-burning plants, which would come to be known internally as the “brown business.”