Solar Power’s Great, If We Ignore Its Problems

The following graphic was recently making the rounds on social media:

The total area of solar panels it would take to power the world, Europe, and Germany: 


The purpose of the graphic, of course, is to show what a “no brainer” it is for humans to switch to solar-powered electricity plants. Many people presumably saw that graphic and were pleasantly surprised to see how little it would take, in order to provide for all of Earth’s electricity needs using solar. But in this post I want to walk through the issue a bit more thoroughly, to see why this graphic—though at first quite interesting—actually doesn’t prove anything at all about whether solar is good or bad, or whether governments should enact policies to promote solar power.

In the first place, consider a different graphic: How big would the square have to be, to contain enough coal-fired power plants to provide electricity for the planet? Why, the square would be tiny—you couldn’t even see it. That’s because coal-fired electricity generation doesn’t take nearly as much surface area as solar. So did I just prove that we should embrace coal-fired generation, since it wouldn’t take up much space in the desert?

Presumably the people who dreamt up the above image would retort that coal-fired plants are inadmissible because of concerns over climate change and air pollution; the point of the graphic is to show that a “clean” technology like solar can provide us with all we need.

Yet this mentality completely ignores the economic realities. Specifically, why don’t the fans of the above image go invest in solar panels and erect them in a square grid in Algeria?  The answer is obvious: They would lose a lot of money doing so. For one thing, you have to somehow transmit the electricity from Algeria to the rest of the world.

Continuing with this train of light, it soon becomes clear that the above image isn’t an actual proposal, but is rather a provocative way of illustrating facts about physics and engineering. Namely, given current solar technology, and given the amount of global electricity consumption, a simple math problem shows how much surface area in solar panels it would take to generate that much electricity.

But so what? By the same token, we could run through some back-of-the-envelope calculations and “prove” that we could provide for the entire annual energy needs—not just electricity—of the planet with a single elephant…so long as it was made of antimatter. Now I suppose one might object that my antimatter elephant solution for energy is a bit impractical. Well, the same is true for filling Algeria with solar panels.

All things considered, coal- and natural gas-fired power plants are the most economical ways to provide households and businesses with large amounts of electricity. (Depending on the specific circumstances and liability rules, nuclear plants might also do the job economically.) This is why free markets gravitate to these technologies. Currently, solar and other favored “green” technologies can serve niche roles, but they are not yet profitable for widespread adoption without government support. Mere arguments from physics and chemistry are not sufficient to pick an energy source. The choice involves economic considerations as well—an area where government intrusion will only lead to waste.

IER Senior Economist Robert Murphy authored this post.

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