Also see Elon Musk raises the (solar) roof (SFGate), which notes "“You don’t want to put panels on a roof you’re going to replace,” Musk said. “So what if we could offer you a roof that looks way better than a normal roof? A roof that last longer than a normal roof?”"
"Musk says his goal is for SolarCity to sell solar roof and battery products that make homeowners so excited that they want to show their neighbors. SolarCity plans to launch two new products before the end of the year, and presumably the solar roof will be one of them.Elon Musk Says SolarCity Will Sell a Roof Integrated With Solar Panels - Fortune
“It’s a solar roof, as opposed to a module on a roof. . . it’s not a thing on a roof, it’s the roof,” said Musk. He added: “it’s something that will be a standout.”"