[the_gastropod]

I understood the point to be more about the energy inputs. The gist of it is: plants are more efficient at capturing energy from the sun directly than indirectly via solar panels -> light bulbs -> plants (which seems obvious, when you state it that way).

The only thing that makes vertical farming make any financial sense, today, is the access to cheap (subsidized) fossil fuels.

[kibwen]

> plants are more efficient at capturing energy from the sun than solar panels -> light bulbs -> plants are

This is a counterintuitive misconception that I mention elsewhere in this thread. Plants aren't optimized for raw sunlight utilization, because that's not the bottleneck for growth or survival. Plants deliberately reflect away 90% of the sun's energy (https://en.wikipedia.org/wiki/Photosynthetic_efficiency) because other factors are more important: https://www.quantamagazine.org/why-are-plants-green-to-reduc...

[falcolas]

> deliberately reflect away 90% of the sun's energy

They'll have that same efficiency with artificial lighting too… At least until our grow lights stop emitting light in the green spectrum (not something I expect to see anytime soon).

[kibwen]

Grow lights are quite good at only emitting light in certain parts of the spectrum, and have been for some time now.

[falcolas]

Just looking at some spectrum charts for grow lights... They certainly vary, but not in any uniform fashion.

There is an exception to this: there is a standard LED graph which shows up quite frequently, identified by it's peeks in the deep reds, yellow, and dark blue, with a marked trough at cyan.

[bee_rider]

The cost of transporting the conventionally grown plants would have to be accounted for as well, but I'd be pretty surprised if that got anywhere near tipping the scale over to vertical farming.

[Ekaros]

I wonder if that could be solved more easily. Build sufficient rail network and hydrogen/electric/other zero-carbon trucks to move produce from production to there and then train it in. And this is really a sector we could fully automated almost already.

[trickstra]

Switch hydrogen for methane and produce that methane in a bioreactor from the food scraps. These technologies are already here, no need to wait for a future hydrogen car.

[bee_rider]

Also, building a zero-carbon transport system would be generally useful for transporting things other lettuce. And that's probably like 80% of the way toward a zero-carbon transit system. I think you have a good point.