> Worried about how we'll produce all that power? When getting stuff into orbit is sufficiently cheap it'll become economic to put solar collectors in orbit and

> Worried about how we'll produce all that power? When getting stuff into orbit is sufficiently cheap it'll become economic to put solar collectors in orbit and beam energy back to Earth. I used to be a big believer in this. But, from a pure waste heat standpoint, if we ever have to worry about having enough area in Earth's surface for solar panels, we have much bigger problems. We are nowhere near that point now, but given a small but steady exponential growth in the energy supply, we'll get there in a couple hundred years. However, space based solar power could help with intermittently of solar/wind if battery tech doesn't outpace enonomic orbital launches.