by kragen | 2025-10-07 20:17:01+00:00
The cost of land is usually omitted in casual discussions because it's not a significant driver of cost for solar. Quantitative cost breakdowns do include it. See for example https://www.eia.gov/analysis/studies/powerplants/capitalcost..., where the cost estimate for a US$200 million 150-megawatt-AC solar plant in 02019 (six years ago) included US$133,000 per year in land leasing costs, one fourth the cost of "module cleaning" and one sixth the cost of "preventative maintenance".

However, not every single discussion does omit it. For example, we were discussing this yesterday at https://news.ycombinator.com/item?id=45487268 and https://news.ycombinator.com/item?id=45487197, where my calculation was that even in solar-unfavorable places like the northern extreme of Germany, the cost of land barely reaches the same order of magnitude as the cost of the solar modules, even at today's record-low module prices. US$72 million of the US$200 million of the estimate mentioned above was the modules themselves, but today that would be closer to US$15 million.

The atom of truth in your confused assertion is that solar farms do take up enormous amounts of land compared to other kinds of power plants. But, at current human energy consumption levels, it's still only a tiny amount of overall land.

I'm assuming from your past submission history that you're in the US, because you mostly only post US politics stuff. The US generates about 4200 TWh electric per year, which is 480 gigawatts (https://en.wikipedia.org/wiki/Electricity_sector_of_the_Unit...). Under the 2000kWh/year/kWp conditions prevailing in the Californian Mojave Desert, parts of Arizona, and parts of New Mexico, according to https://solargis.com/resources/free-maps-and-gis-data?locali..., this would require about 2.1 terawatts (peak) of solar panels. A square meter of 22%-efficient solar panel produces 220 watts, peak, so this is about 9600 square kilometers, a 110-kilometer-diameter circle. (Although, if you don't leave spaces between the panels, you have to make them horizontal so they don't shade each other; in practice people set them further apart to use more land but less panels.)

How big is that?

It's almost 0.1% of the US, not counting the space between the panels. It's a little over twice the diameter of the VLA radio telescope in western New Mexico, a facility you might remember from the movie Contact. It's slightly larger than White Sands Missile Range (8300km²). It's 15 times the size of Lake Mead, which was created by Hoover Dam to generate electricity. It's about two thirds the size of California's Death Valley National Park (13'793km²). It would take up one eighth of the Navajo Reservation.

Almost everywhere in the US has at least half that much sunlight. Suppose you wanted to site the panels near Springport, Michigan, for some reason. You only have 1200 kWh/year/kWp there, so you need 16000km². The panels would cover a ten-county area centered on Jackson County; they would reach Lansing, and might reach from Ann Arbor to Kalamazoo.

In real life, it wouldn't be a good idea to put it all in one place like that, both because it's fragile and because it creates higher transmission-line losses; it's better to put the panels closer to where they're used, which implies spreading them apart. So probably 0.2% of every state. In an average-sized state like Iowa (145'746km²) it might be 300km², 20% of the size of an average-sized county like Hamilton County. To power the whole state.

But try to keep perspective on the total amount of land we're talking about here: White Sands Missile Range, two thirds of Death Valley, or a small part of the Navajo Reservation to power the whole country.