Visionaries like Elon Musk know how underrated solar power is.

In an interview on December 15 at the American Geophysical Union meeting, Musk mentioned that if we covered just a corner of Utah or Nevada with solar panels, we could power the entire US, as Nature News' Lauren Morello reported.

This incredible fact also came up during Musk's talk at the Université de Paris Panthéon Sorbonne during the climate talks on December 2:

The important thing to appreciate is if let's say the only thing we had was solar energy, that that was the only power source, if you just took a small section of Spain, you could power all of Europe. It's a very small amount of area that's actually needed to generate the electricity we need to power civilization, or in the case of the US, a little corner of Nevada or Utah, power the entire United States.

But that's so little space! So is he right?

More power from the sun hits the Earth in a single hour than humanity uses in an entire year, yet solar only provided 0.39% of the energy used in the US last year.

This is why Musk thinks that solar will become the biggest energy source by 2031, as he told Tim Urban from Wait But Why.

If solar is 20% efficient at turning solar energy into power, as it has been in lab tests, we'd only need to cover a land area about the size of Spain to power the entire Earth renewably in 2030 — just like Musk said.

This map, from the Land Art Generator Initiative, shows just how little space that really is:

Land Art Generator Initiative

And while it's useful in the map to show the solar installations as squares bunched together, this area could actually be spread over more space, with solar panels tucked away on rooftops and spread across deserts.

Finding all of the squares. Land Art Generator Initiative

To figure this out, the folks at Land Art Generator did the following math:

678 quadrillion Btu (the US Energy Information Administration's estimation of global energy consumption by 2030) = 198,721,800,000,000 kilowatt-hours (simple conversion) divided by 400 kilowatt-hours of solar energy production per square meter of land (based on 20% efficiency, 70% sunshine days per year and the fact that 1,000 watts of solar energy strikes each square meter of land on Earth) = 496,805 square kilometers of solar panels (191,817 square miles)

All of the squares are about the size of Spain. Land Art Generator Initiative

Remember, that's if we only relied on solar — no fossil fuel-guzzling oil, coal, or natural gas. Now we just have to work on making that happen.

Watch Musk's full talk in Paris: