Thursday, June 23, 2011

The Futility of Rooftop Solar Panels

Q: Lithium and other batteries are some of the great 21st-century technologies, and China as made them a priority in a way the US hasn't. Do you think the US can compete?

A: The current lithium technology was invented by a guy at the University of Texas; innovative battery companies are overwhelmingly here in the US. There are several that venture capitalist Vinod Khosla backs. There are people like Donald Sado way at MIT, whom I back directly. I think if you want a leading indicator that you can feel good about, look at the amount of IQ working on energy today and the kinds of tools those smart people have to communicate and to create simulations. Compared to 20 years ago, it's night and day. In terms of innovation IQ and risk taking and starting up new companies, the US blows everybody else away.

You could have the government throw money at the most politically favored guy in the country to go build a battery factory. And there are billions of dollars that have been assigned to that waste. Or you could actually back people who have better battery ideas.

You have to think of two types of batteries. One is a battery for a car, and it has to be light and crash-proof, but the total amount of energy it has to store is not all that large. Now, that doesn't give you an environmental benefit unless your grid has somehow changed. But at least it gives you a security benefit, because you're sourcing your coal for your grid locally. The harder battery problem is the second type-the battery. If you're getting, say, 50 percent of your energy from solar, and the sun only shines during the day, then you have to be storing enough energy for the night. And that is a mind-blowing problem. I mean, that's more demanding by a factor of a hundred than any other battery challenge we have today.

I think people deeply underestimate what a huge problem this day-night issue is if you're trying to design an energy system involving solar technology that's more than just a hobby. You know, the sun shines during the day, and people turn their air conditioners on during the day, so you can catch some of that peaking load, particularly if you get enough subsidies. It's cute, you know; it's nice. But the economics are so, so far from making sense. And yet that's where subsidies are going now. We're putting 90 percent of the subsidies in deployment- this is true in Europe and the United States-not in R&D. And so unfortunately you get technologies that, no matter how much of them you buy, there's no path to being economical. You need fundamental breakthroughs, which come more out of basic research.

Interview with Bill Gates by Wired Editor in Chief, Chris Anderson
Wired, July 2011, p.108

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