I think the commenter was implying that rather than putting it on the roof of people's homes, the focus should be on utility-scale solar power stations.

Which doesn't make too much sense outside of the US, where land isn't nearly as cheap.

It makes sense in any country that has agriculture.

Solar produces 10x as much power per area than energy crops.

And other than with crops, you can have sheep grazing and have a functioning meadow ecosystem develop below the panels.

What are the upfront & maintenance costs of solar vs crops on that kind of scale? I'd hazard a guess it's a little more than 10x.

Also, how are you planning to grow meadows under solar panels without any sunlight?

I’m honestly super excited about you asking because I think I’ll be able to change your mind with a single picture:

https://cdn.arstechnica.net/wp-content/uploads/2021/10/Getty...

The sun moves, and therefore the shadows move. And you need some space between the panels anyways, so they don’t shade each other. Also, grass can grow in the shadow!

The cost of installation is not a problem, because the ROI is greater than the interest on a loan. That’s what banks are for!

You are correct, this has changed my mind as it is a lovely weird photo that I have enjoyed.

Here in Germany we waste about 2.4 million hectares on „energy crops“. That’s enough to cover a large fraction of Germany’s primary energy consumption if it were used for solar instead.

The foolish move by the German government to close down all the nuclear reactors. The German government is weird.

Or history is more complex than a sound bite.

Getting Germany off nuclear has been in the making since the 1980s, and a big factor was fighting corruption.

We still have a glowing mess from those days, waiting another 80 years until it can be cleaned up.

It would have been nice to turn off coal first, but it doesn’t change what we need to do for renewables.

you say 'If you want private panels in pretty much any country outside of America, they're going to have to go on the roof as we don't exactly have the land to waste elsewhere.'

https://www.worldometers.info/geography/7-continents/ says the population density of north america is 28 people/km², and south america is 25. meanwhile, europe is 33, africa is 49, asia is 153, "australia/oceania" (???) is 5, and antarctica is 0. so basically the population density of europe is the same as america, africa is just a little bit higher, asia is much higher, and australia is much lower

possibly by 'pretty much any country outside of america' you meant either nigeria or singapore

but let's consider the worst case continent, asia. 153 people per square kilometer means 6500 square meters per person. hopefully you are aware that the average home size in asia is not 6500 square meters or even 65 square meters, and that a substantial fraction of people live in apartment buildings which share a roof. so the vast majority of land even in asia is not roofed. this is also obvious from looking at any satellite photo. but enormous numbers of people live in houses with gardens or even farms attached

if we assume a 15% average solar capacity factor and 21% efficient solar panels, 6500 square meters per person is 200 kilowatts per person. current world marketed energy consumption is something like 2, 2½ kilowatts per person. that's still too much to put on the average roof but it's not exactly a major fraction of the total land area either

even nigeria is only 250 people per square km

you're right about singapore tho