First the Model 3 electric car. Now the solar roof. In just one week, Tesla has challenged two distinct industries with radically new products.

Tesla has completed its first solar roof installations, the company reported Wednesday as part of a second-quarter earnings report. Just like the first Model 3 customers, who took their keys last week, the first solar roof customers are Tesla employees. By selling to them first, Tesla says it hopes to work out any kinks in the sales and installation process before taking it to a wider public audience.

“I have them on my house, JB has them on his house,” Musk said, referring to Tesla’s Chief Technology Officer J.B. Straubel. “This is version one. I think this roof is going to look really knock-out as we just keep iterating.”