A cheap and accessible form of energy lies in a large ball of burning gas around 93 million miles up in the sky: the sun. So why haven’t we adopted solar energy more widely? “How We Survive” host Amy Scott recently talked with longtime climate writer and activist Bill McKibben about his upcoming book “Here Comes the Sun: A Last Chance for the Climate and a Fresh Chance for Civilization.” 

“Some point in the last five years or so, we crossed an invisible line where it became cheaper to generate power from the sun and the wind than it did from setting coal and gas and oil on fire. That's an epochal moment in human history,” McKibben said. 

So why isn’t solar energy being used everywhere in the U.S.? Well, one obstacle is that there is not much money in it for investors. “The paradox of solar power economics, [is that] it's almost too cheap,” McKibben explained, “So the CEO of Exxon said quite bluntly last year, Exxon was never going to invest in renewable energy because it wouldn't return above average returns for its investors. It's good news economically for everybody else, but not for people who are used to making the kind of profits that the oil industry makes.”

But, McKibben said, there’s plenty of things states, communities and individuals can do to make progress. “You know what state in America is putting up renewable energy far faster than any other? The Lone Star State of Texas,” he said, “and it's because they understand the economics of it. That's what's keeping their rapidly expanding grid affordable and probably just as importantly, reliable. They've gotten through a bunch of bad heat waves in the last year or two without brownouts and things, and the electric regulators say that's because they've put so much dependable solar and battery storage on the grid, it's really remarkable to see it when it happens.”

You might expect that reporting on and writing about solar energy and some of its setbacks would be a grim experience, but McKibben said it has actually made him feel exhilarated. There’s some hope, he said, “at the prospect that there's finally something we can do that can scale. We finally have something that if we decided to do it at the pace that it's possible to do it at, would get us somewhere. And that's the first time we've had this in the climate fight.”

To hear the full, extended interview with Bill McKibben, click the player above.