How did you get the idea for Sunrun?

I was at school at the Stanford Graduate School for Business, and went to China for an internship. There was all this building happening in Shanghai, and I thought, “Oh my gosh, we need to figure out how to build things more sustainably.” When I went back to school, one of my classmates said, “Oh, I have this friend who has this solar idea.” And I was like, “Yes. Love it.”

Had you been interested in the environment before that?

Absolutely. Growing up in the woods and trees, I was a little bit of a naturalist. I love bird-watching, and my daughter and I do that every morning. We mark which birds we see. It’s good to actually listen to the birds.

How did you get Sunrun off the ground?

My husband and I both wanted to be entrepreneurs, and we were just married, and were both in business school. There was a little bit of an agreement that whoever gets their company going first gets to do it, and then the other person has to support them. So we were both pursuing entrepreneurial ideas. When my classmate said solar, I was like, “O.K., let’s do it.” And then my husband went back into private equity and supported us.

After Sunrun got up and running for a while, he left and started a company with a classmate, Tatcha. It was so stressful. There were times in 2013 when Sunrun wasn’t profitable yet, and Tatcha was needing capital. And so before we really had any real assets to our name, we were taking the money we were making from Sunrun and investing it into Tatcha. So those were some stressful times, but we earned it. We came by it honestly.

With Sunrun, our idea was to target residential customers. I went through the Stanford database and used my cold-calling skills to call pretty much anybody I could find that had energy or utility experience. One hundred percent of people said it wouldn’t work and gave me this dismissive message. “Well, there’s a lot of sophisticated people working on that stuff. Go home, little girl.” Fast forward to today: We have almost 300,000 customers and $5 billion worth of solar.

What were your various roles at the company along the way?

I’m still figuring it out. I wasn’t originally the C.E.O.; my co-founder was. In the beginning, I’d literally spend my weekends going to farmers markets and putting fliers on people’s windshields, and doing town hall meetings to explain how you can get solar. It was a hustle.

Over the years, it sort of evolved into what our roles would be. I had no ambition necessarily to be a C.E.O. I always thought I would be the chief of staff to the president or something. But I never aspired to be in the limelight.