Elon Musk talks about the power of sunlight and the size of a solar array that could power the US. He said that nuclear power plants have an exclusion zone of a square kilometer. If that was covered in solar panels, the solar array could put out more power than the nuclear power plant.
He said the Sun shines about a kilowatt per square meter. There are a million square meters in a square kilometer. So there is a million kilowatts or 1 gigawatt of sunlight per square kilometer.
But he forgot to take into account a few things. Solar arrays are about 20% efficient. And the surface is not covered 100% with panels. And the Earth gets less than 1000 watts per square meter the farther the distance it is from the equator. So I would reduce that from 1 gigawatt to 100 megawatts per square kilometer.
But he is right that it could be done by taking some land that is not being used for much of anything and putting many square kilometers of solar arrays all over. This will replace the fossil fuel power plants. And hopefully we will do this along with wind power in the very near future.
