Fossil fuels allowed the human race to operate... complex systems at gigantic scales. Renewable energy sources are not compatible with those systems and scales. Renewables will not be able to take the place of oil and gas in running those systems. The systems themselves will have to go. Even many "environmentalists” and "greens” of our day seem to think that all we have to do is switch inputs. Instead of running all the air conditioners of Houston on oil- or gas-generated electricity, we'll use wind farms or massive solar arrays; we'll have super-fuel-efficient cars and keep on commuting over the interstate highway system. It isn't going to happen. The wish to keep running the same giant systems at [a] gigantic scale using renewables is the heart of our illusions about solar, wind, and waterpower.