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Vertical farming does not save space

lowtechmagazine.com

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Re: Vertical farming does not save space

#221

Post by dale_glass »

manfredo wrote: post #207
dale_glass wrote: post #144

Earlier quoted context omitted.

I don't see how nuclear can win over the long term. Solar and wind are simple and very amenable to mass production. Many parts of them are usable for other purposes -- we need generators for things other than windmills, inverters for things other than solar powerplants, etc. This means we're not making things as a one off, but doing mass manufacturing, and the different users all reap benefits. They're easy to produc…

Nuclear's non-intermittency is why it wind in the long run. Once intermittent sources fulfill demand during peak production hours, the actual cost of adding each usable watt goes up dramatically. If your goal is to run a primarily fossil fuel grid, supplemented by renewables that's fine. That's what Germany is doing. But if your goal is to actually eliminate carbon emissions, you need to factor in the cost of storage…

Nuclear's cost is almost entirely in the infrastructure, and it's paid over a very long time period. The business plan for nuclear is to spend a decade or two paying back your loans, after which you make big $$$ because the plant costs relatively little to run.

The ideal plan for nuclear is to pump out power at 100% 24/7. You save nothing by being idle, and you want to pay off your loan as soon as possible.

All that goes to hell once cheap renewables show up, because the moment wind or solar can sell power cheaper, a rational person would buy it from renewables. Which means that if the sun is shining, you're either not selling at all, or selling much less or cheaper than you'd like to. And so your loans now get repaid much later.

At some point a bank looks at that and figures that the proposition of maybe making a profit 30 years in the future isn't that great of a deal. That's a long time, for all the bank knows, solar might be dirt cheap by then and kill nuclear for good before it gets to making a profit. Probably better to put billions to some safer use.

Politically it's not a lot better -- nuclear costs $$$, and takes a long time to build, which means that if you're the one who got the country into nuclear on a large scale you can't really expect to see a benefit within your term. Worst case it goes wrong and is an expensive boondoggle, which doesn't bode well for reelection.

Nuclear may make sense if you think "emissions are paramount, screw money". But there's not a lot of people who'd be willing or even able to risk billions in such a manner.

Re: Vertical farming does not save space

#222

Post by bigiain »

SamBam wrote: post #151
dragontamer wrote: post #140

Earlier quoted context omitted.

> Since the vertical farm does save space in the abstract (just not necessarily once accounting for space needed for electricity generation) I severely doubt that. Solar panels are maybe 30% efficient. So 10-acres of glass-roofs need to be replaced by 30-acres of solar panels just to account for this inefficiency (let alone other inefficiencies: such as wiring, inverter, batteries, and LEDs). Maybe 50-acres of solar…

> Solar panels are maybe 30% efficient. So 10-acres of glass-roofs need to be replaced by 30-acres of solar panels Not remotely. Plants are also extremely inefficient, converting only about 1% of the solar energy that falls for their use. [1] Most of this inefficiency is from solar energy being in the form of frequencies that the plants can't use, but solar panels can. So the panels can capture this energy, then funn…

The article's numbers are that 1m^2 of wheat needed 20m^2 of solar panels.

That implies a 5% efficiency in the "total solar captured area" of the solar panel + LED lights compared to just sticking the plats out in the sun, which is totally independent of the plants own efficiency in photosynthesis.

(I guess coming from a site about Low Tech, their slant on the numbers might be questioned, but they certainly hold up to initial scrutiny from here...)

Re: Vertical farming does not save space

#223

Post by tohmasu »

Retric wrote: post #185
tohmasu wrote: post #168

Earlier quoted context omitted.

You're saying that a couple of 50 year old reactors when including a safety zone and adjusting for lifetime capacity outputs about twice the maximum power of commercial solar panels before adjusting for capacity factor. When you adjust PV for capacity factor the difference ends up at over an order of magnitude.

You’re skipping permits +construction ~10 years and decommissioning which seems to take 30+ years on average though few have actually finished the process. https://en.wikipedia.org/wiki/Nuclear_decommissioning 75% capacity factor * 50y / (50y + 10y construction + ~30y decommissioning) = 42% capacity factor which is higher than solar but not by that much. But let’s assume you’re at a 1.5x capacity factor advantage. So…

>"So 1.5 GW of solar = 1.0 GW of nuclear."

That's not how it works. PV capacity factor is 11-12% to the 90-95% of nuclear meaning you need to install about an order of magnitude more PV effect not 1.5x.

Re: Vertical farming does not save space

#224

Post by bigdollopenergy »

Ugh. This is really shallow analysis.

* Solar is the only form of renewable energy where this is a potential problem and there are already solutions that actually exist. Solar farms can also be vertical (look up 3D solar farms) or even on water (look up floating solar farms), which avoids this supposed land problem altogether.

* Even if we use traditional "2D" solar farms on land, space is not all equal and most of it isn't arable. With vertical farming, all that previously non-arable land is now usable for farming indirectly via solar panels. We still get desired effect of increasing our capacity to grow food in the face of shrinking available arable land, which is the whole point.

While I think this is an early technology that will be pretty niche for a long time, i'm glad it's being developed and has potential applications today. It's my view that vertical closed system farming and fusion power (for desalinization in particular) becoming practical on an industrial scale is vital for our survival as a species in the coming centuries. If the predictions on topsoil erosion and climate change are even partially correct we're going to need this technology figured out.

Re: Vertical farming does not save space

#225

Post by Retric »

manfredo wrote: post #211
Retric wrote: post #167

Earlier quoted context omitted.

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...…

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 t…

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

#226

Post by exporectomy »

benjaminjackman wrote: post #157
skissane wrote: post #126

Earlier quoted context omitted.

> If we look into the relatively near future, fusion energy is going to account for a rapidly increasing share of energy production by the end of this decade. I really don't think by the end of this decade there will be any commercial fusion production. I'm sure we will be closer but it is still some decades away. ITER proposes to follow up their current research reactor with a successor (DEMO) which they plan to sta…

I don't know about commercial by 2030 but leap frogging ITER doesn't seem far fetched at all because of the all signficant advances in superconductors achieved after ITER was planned out. Also, if the new superconductors do work out, it's very likely that all other forms of energy generation and grid level storage will become almost immediately obsolete and any additional focus moving forward would be only on improvi…

What makes you think fusion power will be cheaper than solar, wind, fossil fuels or fission?

Efficiency isn't really a good metric when the fuel is free. We see that in solar power where expensive high efficiency devices lose out to cheaper less efficient ones. It's more about capital cost and operating cost per unit of energy.

Re: Vertical farming does not save space

#227

Post by manfredo »

pfdietz wrote: post #214
manfredo wrote: post #207

Earlier quoted context omitted.

Nuclear's non-intermittency is why it wind in the long run. Once intermittent sources fulfill demand during peak production hours, the actual cost of adding each usable watt goes up dramatically. If your goal is to run a primarily fossil fuel grid, supplemented by renewables that's fine. That's what Germany is doing. But if your goal is to actually eliminate carbon emissions, you need to factor in the cost of storage…

Storage solutions are advancing fast enough that your argument cannot succeed. What you are saying used to be sort of plausible, but the sell by date on it passed long ago.

Right, as evidenced by the extensive storage infrastructure being deployed /s.

The US has 25 GWh of storage, as compared to an hourly electricity consumption of 500 GWh. Literally less than ten minutes of storage. Almost all of it hydroelectric, which is a big infrastructure project on par with building nuclear power plants

I'm sure you're eager to talk about how thermal storage, or concret weights with pulleys, or compressed air is going to be 100x better than current solutions. But until those things move out to prototypes and I to mass production, they represent potential solutions not actual solutions. Like fusion. If the next attempt at fusion works, great! But building out infrastructure assuming it's going to work is extremely unwise.

Re: Vertical farming does not save space

#228

Post by tohmasu »

tohmasu wrote: post #223
Retric wrote: post #185

Earlier quoted context omitted.

You’re skipping permits +construction ~10 years and decommissioning which seems to take 30+ years on average though few have actually finished the process. https://en.wikipedia.org/wiki/Nuclear_decommissioning 75% capacity factor * 50y / (50y + 10y construction + ~30y decommissioning) = 42% capacity factor which is higher than solar but not by that much. But let’s assume you’re at a 1.5x capacity factor advantage. So…

>"So 1.5 GW of solar = 1.0 GW of nuclear." That's not how it works. PV capacity factor is 11-12% to the 90-95% of nuclear meaning you need to install about an order of magnitude more PV effect not 1.5x.

Also one batch of PV panels equivalent to a reactor cost 6x as much and with a lifetime of 20 years to the 60 for a nuclear reactor so you will need to replace these at least twice. All 32.5 Million of them.

Re: Vertical farming does not save space

#229

Post by charlesju »

marshray wrote: post #147
throwaway894345 wrote: post #138

Earlier quoted context omitted.

The sunk cost fallacy is about continuing to incur additional sunk costs. The parent is arguing that we're going to have to pay $X/year to manage the nuclear waste we've already incurred and that the cost is fixed--adding more nuclear waste isn't going to increase the cost. Whether those claims are true may be up for debate, but it's certainly not a sunk cost fallacy.

He's arguing (to paraphrase) "Because we've already incurred such costs we should continue or even expand the policy which caused them." Claiming that hazardous nuclear waste represents a fixed cost no matter how much you generate is simply absurd.

Do you have any data that says the cost (ie. money or security) is materially increased from this point forward given the space to store is truly small.

Re: Vertical farming does not save space

#230

Post by JamesBarney »

kapp_in_life wrote: post #70
farisjarrah wrote: post #62

Earlier quoted context omitted.

If a vertical farm scales up and sells their produce to a super market, dont they still have to package up all the food and ship it on trucks before it gets to the end user?

Yes but the idea is you are now shipping it 5 miles instead of 500 miles.

Isn't using an electric truck powered on solar or nuclear a far easier and more cost effective solution than vertical farming?
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