"I'm not a fan of people who are not passionate. I think it's important to be passionate about what you do."

"I think the most important thing is to make sure that we have a path to a sustainable energy future, and to become a multi-planet species."

"I think that the future is going to be very exciting, and I'm very optimistic about it."

"I think it's important to have a good sense of direction. You need to know where you're going."

"You know, I'm not a fan of subsidies generally. I think the right answer is to have a carbon tax."