Or low energy yield per square meter required. e.g. solar is like 200W/m^2 (and doesn't run all day, so the watt-hour rating gets kneecapped), wind isn't fantas

Or low energy yield per square meter required. e.g. solar is like 200W/m^2 (and doesn't run all day, so the watt-hour rating gets kneecapped), wind isn't fantastic either. This won't scale well with anticipated energy needs. It would be a real struggle to cover our current energy needs with wind and solar (with other renewables like hydro and geothermal being geographically limited, subject to environmental issues and more or less already maximized where they can be used)...and we need more. We're heading toward electric cars with batteries that hold 3x what the average household uses in a day (which drain in a few hundred miles), and will need more energy for carbon capture and desalination as time goes on...