I've probably failed more often than anybody else in Silicon Valley. Those don't matter. I don't remember the failures. You remember the big successes.

I do not know what got me interested in technology. What was very clear to me very early on was that I was not interested in religion and that naturally increased my curiosity about science and technology, and I fundamentally believe the two are conflicting.

Letting the perfect be the enemy of the good is one of the reasons we have a coal-dependent infrastructure, with the resulting environmental impact that all of us can see. I suspect environmentalists, through their opposition of nuclear power, have caused more coal plants to be built than anybody. And those coal plants have emitted more radioactive material from the coal than any nuclear accident would have.

Future is not extrapolation of past

We don't need a fuel that's cleaner, we need a fuel that happens to be cleaner, but is half the price of oil.

As for companies invested in the space - I think its important to distinguish between a good investment and a material climate change technology - you can have the first without the second, even in the "clean tech" space.

Startups allow technologists and scientists to take risks and change plans in a way that would be frowned upon in a big company. Having said that, big companies will play a key role in certain areas and in partnerships with little companies. Each has its strengths.