“If you wanted to power the entire United States with solar panels, it would take a fairly small corner of Nevada or Texas or Utah; you only need about 100 miles by 100 miles of solar panels to power the entire United States,” he said.
“The batteries you need to store the energy, so you have 24/7 power, is 1 mile by 1 mile. One square-mile.”
Solar just makes sense when you’re talking about powering a whole country, he adds, because it simply scales up really well. The sun is essentially a giant fusion reactor floating above our heads, churning out more free energy than we’d know what to do with. He plans to use both rooftop solar — like the ones Tesla is producing — dispersed around cities throughout the US, as well as concentrated utility-scale solar panels to tap into all that energy.
It will take work and time to set up all the installations and develop the necessary infrastructure, Musk says, and in the meantime, we’ll likely need to rely on transitional power (wind, hydro, geothermal and nuclear) to keep the lights on while we make the transition. Musk also believes we should encourage local solar power as much as possible, to limit the number of power lines that will need to be laid.
Watch the entire speech below. Musk comes in at ~26:00.