solar desertChris Carlson/APThis solar farm is a good start.

Solar energy is a seriously underrated resource.

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.

Visionaries like Elon Musk think that solar will become the biggest energy source by 2031, according to an interview with Tim Urban on Wait But Why.

But what would a world powered by solar look like?

The Earth would probably be littered with solar panels, right?

Wrong.

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

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

solar panels world mapLand 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.

solar panels map skitch arrowsLand Art Generator InitiativeFinding all of the squares.

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)

solar panel map skitch squareLand Art Generator InitiativeAll of the squares are about the size of Spain.

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.

Editor's note: In an earlier version of this story, we miscalculated the percent of US energy that came from solar last year. It was 0.39%