Most of these sound reasonable, but I've never bought into the "grow vertically" idea. It seems to ignore physics.
Sunlight is delivered as electromagnetic power (watts) proportional to surface area. Plants naturally grow on the surface of the earth, and therefore receive a small proportion of that power which they use to convert CO2 into sugars and eventually plant mass which we eat. Stacking a bunch of plants on top of each other cannot change that the lower plants must receive less power, and therefore cannot grow as much. And that's ignoring the added complexity and logistics (read: overhead) of maintaining a system that stacks plants on top of each other, which would surely obliterate whatever 2-digit% efficiency bonus you can eke out of stacking. The universe doesn't work like Minecraft.
Chemical and water use reduction seem to be a pretty good outcome, as well as being able to ignore seasonality.
I would like to see some numbers on farm equipment (in?)efficiency before throwing that out as a fact. Color me skeptical but it doesn't seem obvious at all that rebuilding a 10000-acre greenhouse every 20 years will necessarily produce less greenhouse emissions than running a few tractors. Or even that harvesting food in a greenhouse takes less energy than doing it with a tractor.
Every once in a while you see some high school science fair project where a kid has the brilliant idea of making 3D solar cells... maybe little pyramids or ridges instead if a flat plane, to capture light from all angles.
The kid gets patted on the head. Those who know better, immediately recognize there is no great increase in power obtained as the 'shadows' caused by the raises structure invariably decrease the efficiency down to that of a plane.
Anyway, vertical farming reminds me of this. You would defintyl need artifical lights.
Akyway, it's amusing watching amateur would-be tomatoe growers get excited about a technology that has been around as long as Cheech and Chong.
Using these systems for decorative purposes, on the other hand, is a cool idea. It's a fast and cheap way to make an 'instant' hedge. I have a 'wall' of pole beans planted in this manner which thrive and create a solid mass of greenery within a month of planting.
It's been a few years since I've followed vertical farming, but I have recalled an argument being made that an artificial light source can be made efficiently by using a single-wavelength, super-efficient LED with a specific color that stimulates photosynthesis.
On the other hand, I've also read (old, long-lost) sources that state that the energy cost per loaf of bread is about $10 for indoor farming, vs $5 for outdoor farming.
These specialized lights won't save vertical farming today, but I will keep following the progress. If nothing else brings value to vertical farming, the fact remains that local food independence is valuable; growing food in a dense apartment or a dense city will pay dividends in the event of large-scale famine or civil unrest.
“Stacking a bunch of plants on top of each other cannot change that the lower plants must receive less power, and therefore cannot grow as much“
That assumes all light comes from straight up. That isn’t even true if the sun is straight overhead, and definitely not true close to the poles.
I don’t know whether it’s profitable, but I would think the economics of vertical farming on Iceland (sun lower in the sky, greenhouse heating cheap, imports expensive) are different from those in Equatorial Guinea.
No, it assumes that power is delivered based on surface area with respect to the sun. Vertical/3d farming can't work more than ~2 plants deep, where "depth" is measured as the number of plants between a given plant and the sun. Sure, build it vertically on the north pole, but it's still gonna be essentially "flat". You can't magically get power deep into a 3D farm when there 20 other plants on every side that would get the light first.
I have never heard anyone suggesting that vertical farms enabled 3d planting. It simply removes the linear relationship between square foot of land and number of plants.
> Stacking a bunch of plants on top of each other cannot change that the lower plants must receive less power, and therefore cannot grow as much.
I thought the common idea (and implementation) of indoor vertical farming used artificial lighting at each level. Possibly only using light in the wavelengths actually used by the plant, not "wasting" power at other wavelengths like the sun does.
Sunlight is delivered as electromagnetic power (watts) proportional to surface area. Plants naturally grow on the surface of the earth, and therefore receive a small proportion of that power which they use to convert CO2 into sugars and eventually plant mass which we eat. Stacking a bunch of plants on top of each other cannot change that the lower plants must receive less power, and therefore cannot grow as much. And that's ignoring the added complexity and logistics (read: overhead) of maintaining a system that stacks plants on top of each other, which would surely obliterate whatever 2-digit% efficiency bonus you can eke out of stacking. The universe doesn't work like Minecraft.
Chemical and water use reduction seem to be a pretty good outcome, as well as being able to ignore seasonality.
I would like to see some numbers on farm equipment (in?)efficiency before throwing that out as a fact. Color me skeptical but it doesn't seem obvious at all that rebuilding a 10000-acre greenhouse every 20 years will necessarily produce less greenhouse emissions than running a few tractors. Or even that harvesting food in a greenhouse takes less energy than doing it with a tractor.