 I remember we used to drive around when we would see someone with a solar panel. We'd go, look, they got solar over there. Now it's everywhere, at least out here in California. I don't know if you see the same thing around the country, but you certainly see it here in California. NBC continues. But as California works toward its ambitious clean energy vision, an almost counterintuitive challenge has emerged. The state is at times generating more solar energy than it can handle.