How much land would we have to cover with solar panels in order to meet all our electricity needs? In a way, it’s a thought experiment, since (a) there are plenty of clean energy options in addition to solar that we can use, so we don’t need to get all our electricity from the sun; and (b) we’re going to need other sources of energy because, after all, the sun goes down at night.
But while the idea of fully electrifying the planet with solar is kind of silly, a study pointing out the relatively small amount of land it would take to pull it off does emphasize how easily PV could become a substantial power contributor – despite the fact it now accounts for just 0.1 percent of global electricity generation.
The report, with the properly green title, “Solar PV Atlas: solar power in harmony with nature,” was put together by WWF with First Solar, 3TIER and Fresh Generation. It zeroed in on Indonesia, Madagascar, Mexico, Morocco, South Africa, Turkey, and the Indian state of Madhya Pradesh – places that “represent diverse geographies, demographics, natural environments, economies and political structures” – and concluded that it would take less than 1 percent of Earth’s land mass to meet 100 percent of projected electricity demand in 2050 exclusively through PV.
And some of those panels could go on ground that humans have already built upon, the report noted:
(W)e shouldn’t forget that other human activity and conventional energy also require land. The built environment–buildings and roads–has already claimed much land that now has roofs, awnings, and other potential for shade structures that could host PV. No additional land is required for such co-location of PV with these existing structures. New ground-mounted PV systems often offer remarkable economy of land for the value of electricity they produce. As comparison, ground-mounted PV systems in areas of high insolation require less land than the coal-fuel cycle coupled with surface mining to produce the same amount of electricity.
To put the land required in perspective, let’s look at Mexico. There, the report said, if all the solar required to meet the country’s electricity needs in 2050 was put in one square, the square would be about 29 miles on each side. That’s a lot of land, but it’s also less than one third the size of the Mexico City Metropolitan Area.
The report said its estimates for PV output were “conservative,” using an assumption of PV efficiency of 15 percent, despite the fact that “(a)lready manufacturers are showing viable modules at efficiencies of around 20 per cent, and it is reasonable to assume that technology will further improve between now and 2050.”
A PDF of the full report is available online here.