Hire people who are smarter than you, and don't be afraid to work with them as partners. Make it clear that you plan to learn from them, not just the other way around. The right, smart, motivated people respond very well to that approach, particularly coming from a younger manager like I am.

Rooftop solar is the first true form of competition that utilities have ever faced, and that is why they're attacking it.

Homeowners want solar power. It's cost-effective. We invented a business model that makes it really easy for consumers to switch to solar - and that's solar-as-a-service.

I'm on the board of the Sierra Club Foundation and am myself a big environmentalist. But the way to make the biggest difference is to change mainstream behavior.

For a lot of people, one of the reasons they don't like to work for founders of startups is that they can be sensitive and protective around what they've built. You have an emotional attachment to the early marketing and technology materials, and you don't want to hear that anything's wrong with them.

We're leading a fundamental shift from centralized energy to distributed energy. Energy will go in that direction, just like mainframe computers went to client servers, then to the Internet. I believe in solar, and the macro trends are just too undeniable.

For every family in liberal San Francisco that went solar with SunRun in 2010, nearly eight families in more conservative Fresno made the switch to our solar power service.

I think, in a lot of places, the solar panels are a badge of honor; they're trendy. If you go to Hawaii or Japan, people even install fake solar panels because it's cool and it's popular. And so I think solar panels have gotten a lot more attractive. They're sleek, black, they look good on a roof.

I was an investor doing well and decided to be an entrepreneur.

You have to accept the fact that not all your decisions are going to be right - and when they are wrong, you have to own it right away. I try not to have an emotional connection or investment in the decisions I make so that when they need to change, I can quickly move on to: 'How do we fix this?'

For me, not owning a car means I may spend a little extra time on public transportation, but I can use that time to read, catch up on work projects, and make the phone calls I couldn't get to earlier. Plus, I never waste time at the mechanics or gas station.

We believe widespread adoption of home solar will significantly improve life in cities by phasing out polluting coal plants, eliminating miles of ugly new transmission lines, and ensuring cleaner, healthier lives.

With Zipcar, consumers avoid the upfront cost of buying a car, not to mention gas, insurance, and repairs. Plus, they reduce the number of polluting vehicles on the road. Suddenly the planet-smart carless option is also the convenient money-saving option.

On Sundays, I like to plan how I want to exit the week and what are the key things I need to get done that week. I list them, and then I do check-ins on them each morning.

Thanks to the social web, we can share and trade to use a whole universe of things we once had to buy ourselves. From cars to solar panels, people are realizing they can reap the benefits of ownership without the expense and hassle of buying.

As we settle into 2013, I predict this: We'll see companies that promote this shift from private ownership thrive. More people will be able to access things they simply don't need to own, and they'll save money and live better, cleaner, green lives doing it.

Innovative companies have started to realize there are not enough 'green consumers' willing to pay more for something just because it's green.

There is a huge market for products and services aimed at what I like to call the Pocketbook Environmentalist: a shopper who's savvy enough to know things don't necessarily have to cost more just because they're good for the environment.