What area would it take to produce several GW that a few reactors would produce?

In clear weather, a surface perpendicular to the sunlight gets about 1 kW / m². So 1 GW would take a square kilometer. If our solar cells are top-notch 25% efficient cells, 1 GW will take 4 km² at best weather. And we need many multiples of that.

Verily, Sahara must be the best place for such an oil factory. Maybe some of the US Midwest and West, with many sunny days. And, unlike the cute pictures on the side, they will need to be massive, all the way to the horizon.

Maybe with a few nuclear plants thrown in if we learn to build them efficiently again.

> What area would it take to produce several GW that a few reactors would produce?

Out of curiosity, I tried some napkin math on this. If Nevada went whole hog, used say, 1% of their total land for solar, they could produce almost half the electrical needs of the US, if I haven't mucked up the math too much.

Sounds plausible, but 1% of Nevada's land for solar would indeed be 'all the way to the horizon' in many places.

That number is a bit low, but area for solar panels will never be in short supply, because the same land can be used as is used for other things.

I looked at a 2GW nuclear facility, and it's about 1 square Km. The reactors aren't too big, but there a lot of auxiliary buildings as well as parking for many employees. I know one building is a training facility that replicates much of the primary facilities, and there is a lot of space dedicated to security either with actual structures or buffer zones. There are also PR/education facilities on site, presumably so the local municipality doesn't eventually vote them out. Somewhere they store fissile material.

It's also on the coast for access to coolant water.

It seems very difficult to place huge facilities like this with all the staff and security requirements on waterfront property when you can stick a solar panel on or next to just about anything.

let's assume we can scale renewables+nuclear fast enough so that our civilisation is not damaged too much by climate change.

let's also assume we stabilised biodiversity and avoided a mass extinction.

should we continue to produce massive amounts of energy so that some can commute by plane daily and others can stream cute kitten video in 8k?

If we can continue producing them in a renewable or at least sustainable way, why not?

If the only way to keep that up is burning oil, then no.

Please also note that some of the most intense producers of CO2 are poor(er) countries which burn coal because it's cheap. Even natural gas can be too expensive for them, let alone solar or wind installations.

I wonder when the West would consider buying and converting such plants. It's likely feasible in Africa, hardly so in China.

If all that were true, I'd say definitely, we earned it. Make it a 80k kitten!

I don't even want to think about how much surface area you'd need for solar panels intended to replace 6 megawatt-scale nuclear reactors, but I'm guessing football fields is the wrong unit to use...

Last time I checked, land wasn't cheap and they weren't making any more of it.

Regarding land use, just yesterday I was pondering about what technology it would take to create survivable off shore solar. Some loose grid of floating collectors happily bouncing on the waves like a flock of resting seabirds, perhaps cleverly reeling in and out link and anchor lines to match the geometry of the waves? Or just the right amount of springyness, dynamically tuned to the wave situation?

Then it occurred to me that even nature hasn't really solved ocean surface plants, what could be a more clear indicator that it's a really hard problem...

We have plenty of calm freshwater sites for solar, so there will be no need for ocean solar.

Land isn't cheap, but there's a lot of land that can have a solar panel on top of it without causing problems. A good place to start is every building roof.

Land is, in fact, cheap in very many places. If one were making fuel with the solar energy you wouldn't put the solar in places where land was expensive, since the fuel would be highly transportable.

> I don't even want to think about...

I'd call that an argument from laziness.

> Last time I checked, land wasn't cheap and they weren't making any more of it.

Land that is remote, not fertile and that doesn't harbor any natural resources is actually rather cheap. Moreover, "they" are making more land in certain coastal areas where land is expensive.

(I assume you mean GW not MW, because MW is very little for a proper power plant). Solar panels produce about 200Wp/sqm. In Germany they average to about 12% of peak production over a year, so say 22W/sqm averaged. 6GW continuous is then about 51k football fields[1]. I assume that the US has lots of land that is much sunnier than Germany, so you can probably get away with fewer football fields.

[1] https://www.wolframalpha.com/input?i=%286GW%2F%2820W+per+squ...

The correct unit to use is parking lots. If you base this unit on the current area used for parking in the USA, you can even use centi-parkinglots ;-)

Yes, you didn't think about how much surface area, since if you did you'd realize it wasn't a big problem.

SF Reservoir has 12 football fields worth of solar panels and generates 4.5 megawatts.

It generates zero megawatts far more often than 4.5 megawatts. 4.5 is peak on the best days. 0 is assured for several hours every day.

Thanks for added details. I was wondering if this project was efficient considering the amount of "fog" in this area.

When algee biofuels were first proposed someone calculated that Arizona could produce all the fuel we use on currently unused land.

The limit is our ability to scale algee, but the lab results also show that the numbers are right.

yeah and there's crop failure coming decades in advance compared to IPCC's predictions, so better not using crop space.

Some of that crop failure is due to heat, which could be mitigated by using solar panels to provide shade. That doesn't work for all crops, some of which require direct sun, but it works for more than I expected.

No crops require 100% direct sun.

Maize and wheat yield is reduced a bit, without, but the year-round revenue from solar panels easily exceeds the difference.

If you reframe it with solar panels it is just as troubling. Because then you need a massive amount of area for the panels.