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Re:Vertical farming does not save space by mytailorisrich on Thursday February 18, 2021 @04:51PM (#26186172)
That's the whole land belonging to the site, most of which is nature, not the plant itself, which looks like less than 200 acres, including the car parks.

In any case, it's not close at all either for that specific example or in general, not least considering that a nuclear plant can produce 24/7 and that solar often does not reach peak production because of the weather.

"A solar PV facility must have an installed capacity of 3,300 MW and 5,400 MW to match a 1,000-MW nuclear facility’s output, requiring between 45 and 75 square miles. For comparison, the District of Columbia’s total land area is 68 square miles." [1]

[1] Nuclear Energy Institute @ https://www.nei.org/news/2015/land-needs-for-wind-solar-dwar...

Re:Vertical farming does not save space by Retric on Thursday February 18, 2021 @05:16PM (#26186481)
Look through several nuclear locations and ~1000 acres is fairly typical. In theory they could be more compact, but security concerns etc means nobody puts 2GW of nuclear on a 200 acre site.

1,000 acres, https://en.wikipedia.org/wiki/Beaver_Valley_Nuclear_Power_St...

1,782-acre, https://en.wikipedia.org/wiki/Byron_Nuclear_Generating_Stati...

2,767 acres https://en.wikipedia.org/wiki/Callaway_Nuclear_Generating_St... for just 1,190 MW.

Some are significantly more compact for example 391-acre https://en.wikipedia.org/wiki/Catawba_Nuclear_Station, but that’s surrounded by water.

Re:Vertical farming does not save space by manfredo on Thursday February 18, 2021 @06:05PM (#26187094)
To put this in comparison, a solar farm would need 50,000 to 100,000 acres to match the net output of those nuclear plants. Plus the land used for energy storage, which would typically involve damming rivers which has its own set of ecological effects.

And it's possible to build much denser plants. The Shin-Kori facility in Korea is massive energy relative to the land it uses. Nuclear power is far more energy dense than solar or wind. This is just thermodynamic fact.

Re:Vertical farming does not save space by Retric on Thursday February 18, 2021 @06:24PM (#26187270)
Try running the numbers for actual lifespan.

Callaway is 1,190 MW on 2,767 acres at 87.70% over it’s useful lifespan, but that’s ignoring permits + construction = 10 years and decommissioning which takes ~30 year. Even a generous 55 year operating lifespan is still reduced to 87.7 * (60 / (60 * 10 + 30)) = 48% capacity factor. Using a 20% capacity factor for solar (aka non tracking in a good but not great area).

That’s 1,190 MW * 48/20 = 2856 MW. A very good modern panel is hitting 220w/m2 add spacing, equipment etc, and 110w/m2 is a safe bet. That’s 2856 * 1000 * 1000 / 110 = 26,000,000m2 or 26 km2 or ~6,424 acres solar vs 2,767 acres nuclear. Lower efficiency panels bump that by 25% or so.

Clearly a win for nuclear, but not a 100,000 acre win.

PS: That said, this is largely a moot point as even with reprocessing we would quickly run out of fuel with large scale indoor farming.

Re:Vertical farming does not save space by sir_bearington on Thursday February 18, 2021 @06:51PM (#26187521)
30 year decommissioning is a very pessimistic assumption. Also most new nuclear plants have operating lifetimes closer to 80 years than 55.

You also have to adjust for the overproduction necessary to make intermittent sources a reliable primary provider of electricity. In far north or southern latitudes, angle of inclination is such that solar panels collect ~70-50% less energy than near the equator. This gets worse with seasonal fluctuations, which are more extreme the closer to the poles you get. Add weather on top of this and it can drop even further.

This might not seem like too big an issue, but keep in mind that most of the world's electricity consumption is in North America and Europe. These places don't have as good weather for solar.

100,000 acres is roughly the ratio that the article came up with, a factor of 75.

> PS: That said, this is largely a moot point as even with reprocessing we would quickly run out of fuel with large scale indoor farming.

No, we wouldn't: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...

Re:Vertical farming does not save space by Retric on Friday February 19, 2021 @12:10AM (#26190002)
30 year decommissioning is somewhat optimistic average based on current plans.

https://en.wikipedia.org/wiki/SAFSTOR “For nuclear power plants governed by the United States Nuclear Regulatory Commission, SAFSTOR (SAFe STORage) is one of the options for nuclear decommissioning of a shut down plant. During SAFSTOR the de-fuelled plant is monitored for up to sixty years before complete decontamination and dismantling of the site, to a condition where nuclear licensing is no longer required. During the storage interval, some of the radioactive contaminants of the reactor and power plant will decay, which will reduce the quantity of radioactive material to be removed during the final decontamination phase.”

For example, Crystal River 3 (Florida) “Duke Energy announced in Feb-2013 that the Crystal River NPP would be permanently shut down.” “Systems Removal & Building Remediation(2070–2072)“ and that’s if things go well. https://en.wikipedia.org/wiki/Nuclear_decommissioning

As to indoor farming.

“It’s not just that the 4 billion tons of uranium in seawater now would fuel a thousand 1,000-MW nuclear power plants for a 100,000.”

That sounds like a lot, but of you want ~100w of power per m2 that’s 0.1GW of power per km2. So your 1,000 GW power plants are only replacing 10,000km2 of farm land. Meanwhile agriculture takes 51,000,000km2 worth of land. In other words replace 20% of global farmland and you got ~100 years worth of uranium from all the worlds oceans, it’s replaced by rocks.

But, “And those rocks contain 100 trillion tons of uranium.” gives you 2,500 years which is not bad, but that’s not going to be replaced.

PS: You might be able to beat 100w/m2 indoors, but remember this is also for 20% of farmland.

Re:Vertical farming does not save space by sir_bearington on Friday February 19, 2021 @03:03PM (#26197405)
> But, “And those rocks contain 100 trillion tons of uranium.” gives you 2,500 years which is not bad, but that’s not going to be replaced.

How did you arrive at these figures? I think you missed a conversion from pounds to tons.

Current global uranium consumption is in the hundreds of millions of pounds annually - hundreds of thousands of tons. And this is without reprocessing. Nuclear power already generates 10% electricity globally. Even if we assume a 200x increase in consumption from 200 million pounds to 20 billion pounds that still only 10 million tons of consumption annual. 100 trillion divided by 10 million is a lot more than 2,500.

Re:Vertical farming does not save space by tshaddox on Thursday February 18, 2021 @05:19PM (#26186531)
But surely they don’t just own the “nature” land for the fun of it. I assume it could not be used for other things, like housing, or another nuclear power plant!
Re:Vertical farming does not save space by mytailorisrich on Thursday February 18, 2021 @05:30PM (#26186677)
The difference with solar/wind space requirements is so big that it does not matter.

If the land is reserved and left to nature that is still a positive thing because that helps the environment and biodiversity. But I'm sure that they could put solar panels on it if they wanted.

The point is that this land is not required for production and in any case solar require much, much more land, so, no, it's not even close.

Re:Vertical farming does not save space by Retric on Thursday February 18, 2021 @05:57PM (#26187009)
Winds density is off the charts as you can use the ground around it for crops or even solar panels. https://thumbs.dreamstime.com/b/wind-turbines-corn-fields-ae...
Re:Vertical farming does not save space by mytailorisrich on Thursday February 18, 2021 @06:02PM (#26187061)
Wind still requires a huge area covered with wind turbines to match a single nuclear plant. Each of which takes space, needs to be accessible, and needs to be connected to the grid through some facility. I would not call that a density off the charts... (see link in my previous comment as well)
Re:Vertical farming does not save space by tshaddox on Thursday February 18, 2021 @05:49PM (#26186916)
It doesn't really make sense to talk about land usage that just so happens to be owned by a nuclear plant, or even certain fixed land requirements for a nuclear plant. It only makes sense to talk about the limiting behavior of land usage for various types of power plants.
Re:Vertical farming does not save space by mytailorisrich on Thursday February 18, 2021 @05:54PM (#26186971)
Solar has hugely larger requirements than nuclear however you look at it, contrary to what was suggested above.
Re:Vertical farming does not save space by tremon on Friday February 19, 2021 @11:12AM (#26194603)
How much land does rooftop solar require?