Author, inventor and futurist Ray Kurzweil famously and accurately predicted that a computer would beat a man at chess by 1998, that technologies that help spread information would accelerate the collapse of the Soviet Union, and that a worldwide communications network would emerge in the mid 1990s (i.e. the Internet).

Most of Kurzweil’s prognostications are derived from his law of accelerating returns — the idea that information technologies progress exponentially, in part because each iteration is used to help build the next, better, faster, cheaper one. In the case of computers, this is not just a theory but an observable trend — computer processing power has doubled every two years for nearly half a century.

Kurzweil also believes this theory can be applied to solar energy. As part of a panel convened by the National Association of Engineers, Kurzweil, together with Google co-founder Larry Page, concluded that solar energy technology is improving at such a rate that it will soon be able to compete with fossil fuels. I caught up with Kurzweil when he was in New York promoting a new documentary about his life to ask him about his optimistic views on the usually gloomy subject of energy and climate change.

Lauren Feeney: You have made a prediction about the future of solar energy.

Ray Kurzweil: One of my primary theses is that information technologies grow exponentially in capability and power and bandwidth and so on. If you buy an iPhone today, it’s twice as good as two years ago for half that cost. That is happening with solar energy — it is doubling every two years. And it didn’t start two years ago, it started 20 years ago. Every two years we have twice as much solar energy in the world.

Today, solar is still more expensive than fossil fuels, and in most situations it still needs subsidies or special circumstances, but the costs are coming down rapidly — we are only a few years away from parity. And then it’s going to keep coming down, and people will be gravitating towards solar, even if they don’t care at all about the environment, because of the economics.

So right now it’s at half a percent of the world’s energy. People tend to dismiss technologies when they are half a percent of the solution. But doubling every two years means it’s only eight more doublings before it meets a hundred percent of the world’s energy needs. So that’s 16 years. We will increase our use of electricity during that period, so add another couple of doublings: In 20 years we’ll be meeting all of our energy needs with solar, based on this trend which has already been under way for 20 years. People say we’re running out of energy. That’s only true if we stick with these old 19th century technologies. We are awash in energy from the sunlight.

Feeney: In his recent State of the Union address, President Obama set a goal of running the country on 80 percent renewable energy by 2035, which is a little bit less ambitious than what you’ve suggested. Are you satisfied with the goal set by the president? […]