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Vertical farming does not save space

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Re: Vertical farming does not save space

#151

Post by SamBam »

dragontamer wrote: post #140
hansvm wrote: post #123

Earlier quoted context omitted.

> lot of land that isn't suitable for farming > We're talking about powering a hydroponic greenhouse. The alternative to "Solar Powered LEDs" isn't "plant things in the ground". Its "make a glass window on your roof". I think what they were getting at is that you can take land wholly unsuitable for farming or greenhouses (e.g. severe slopes), apply solar panels, and then funnel that energy to a vertical farm. Since t…

> 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 funnel into the red and orange lights that are most efficient for plant growth.

I've read a bunch on this, and haven't been able to find an authoritative source for what the efficiency conversion is -- how many acres of solar panels power how many acres of vegetables, and is it greater or less than 1:1? -- but it's certainly not as simplistic as "solar would need 3x more land because they are 30% efficient."

1. https://phys.org/news/2012-01-energy-conversion-solar-cells....

Re: Vertical farming does not save space

#152

Post by Ekaros »

dragontamer wrote: post #113
tux1968 wrote: post #74

Earlier quoted context omitted.

The other thing to remember is that there is a lot of land that isn't suitable for farming for one reason or another that can be used for solar.

> lot of land that isn't suitable for farming We're talking about powering a hydroponic greenhouse. The alternative to "Solar Powered LEDs" isn't "plant things in the ground". Its "make a glass window on your roof". -------- "Plant things in the ground" is also cheaper, though it does suffer from potentially poor soil conditions. Still, it seems to me that spreading fertilizer across soil (and conditioning the soil i…

Or the obvious solution: put hydroponics on traditional close to ground greenhouses... Potentially best of both worlds, if they are sufficiently distributed on outskirts of cities.

Re: Vertical farming does not save space

#153

Post by brohee »

throwaway894345 wrote: post #128
cbmuser wrote: post #66

Earlier quoted context omitted.

Yeah, don’t bother with reading articles that exclude the largest source of clean energy in US. Such articles have an ideological bias.

They might have an ideological bias, but if the prevailing ideology is anti-nuclear then ignoring that bias isn't going to get you very far. Biden has committed us to moving the energy sector off of carbon in the next 15 years, which means we're going to build a lot of $CleanEnergy really soon, and if the ideological landscape doesn't change it very likely will be a whole lot of solar and wind (what is 15 years minus…

> what is 15 years minus the amount of time it takes to build out a nuclear power plant?

If the last European projects are to be taken as models, it's a negative number (Olkiluoto 3 started in 2005 and not online before next year at best...). Not better for Flamanville 3, maybe Hinkley Point C will be achieved a bit faster...

Re: Vertical farming does not save space

#154

Post by Ekaros »

tux1968 wrote: post #106
xchaotic wrote: post #102

Earlier quoted context omitted.

Surely it is easier and cheaper to make the land arable or a greenhouse or whatever than equivalent vertical farm + solar. KISS

How exactly do you do that in say the desert? Solar is KISS in many situations.

Some type of semi-reflective coating to keep heat low and closed loop systems? I wonder how expensive and actually complex would it be to find nano-scale substance that would reflect most of wasted light spectrum while allowing the one needed...

Re: Vertical farming does not save space

#155

Post by ben_w »

tux1968 wrote: post #106
xchaotic wrote: post #102

Earlier quoted context omitted.

Surely it is easier and cheaper to make the land arable or a greenhouse or whatever than equivalent vertical farm + solar. KISS

How exactly do you do that in say the desert? Solar is KISS in many situations.

Are greenhouses in deserts harder to build or maintain than PV farms and power lines in the same desert?

Not a rhetorical question, I genuinely don’t know. I assume it varies by desert, but farming and power are both way out of my domain.

Re: Vertical farming does not save space

#156

Post by tux1968 »

dragontamer wrote: post #142
dathinab wrote: post #117

Earlier quoted context omitted.

> "make a glass window on your roof". Doesn't work as you can't stack plants with it nor can you grow them underground.

Where are you placing these solar panels? Why can't those locations be rooftop hydroponic farms instead?

Because rooftop hydroponic farms have to be tended to almost daily, or at least for planting/harvesting. Solar panels don't need nearly as much maintenance and allow you to concentrate the actual growing operations for the economies of scale.

Do you mind if I ask why you're so against the idea?

Re: Vertical farming does not save space

#157

Post by benjaminjackman »

skissane wrote: post #126
maxharris wrote: post #59

Artificial lighting saves land because plants can be grown above each other, but if the electricity for the lighting comes from solar panels, then the savings are canceled out by the land required to install the solar panels. The vertical farm is a paradox unless fossil fuels provide the energy. In that case, there’s not much sustainable about it. This entire piece is based on the assumption that the only sources of…

> 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 improving the efficiency of fusion. The remaining use cases for solar would probably then be on small off-grid type situations.

Re: Vertical farming does not save space

#158

Post by shagie »

novembermike wrote: post #2

This ignores nuclear power. It also ignores the fact that you can put solar panels in places that you can't put farms such as the desert.

The idea of growing something from grow lights powered by only nuclear power is intriguing to me as it is food that never got its energy from our sun. Instead, that power came from cast of atoms from merging neutron stars billions of years ago.

Re: Vertical farming does not save space

#160

Post by Andrew_nenakhov »

dale_glass wrote: post #144
Hammershaft wrote: post #89

Earlier quoted context omitted.

In the short term nuclear energy is expensive, but in the long term nuclear energy is one the cheapest sources of energy available. Source - https://www.youtube.com/watch?v=cbeJIwF1pVY (this is even more true when you consider the cost of externalities)

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…

To make nuclear energy successful you need to stop fear mongering, and invest in improving technology. With scale, it will make far cheaper and reliable energy source than anything on earth. But it will hardly happen when politicians tirelessly promote solar & wind, while increasing the regulation of nuclear energy. And politicians act this way because of said fear mongering, which affects the public deeply.
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