So assuming a 100% efficiency in the conversion of the products of the photosynthesis to light, a 12h+12h light/dark cicle, 100% canopy coverage, ignoring the branches, ignoring that plants need energy for other activities and ignoring that the plant will release 1/2 of the light to the sky instead of to the floor, we get 2W/m^2 for illumination at night.
For a 3mx3m room (10ftx10ft), I'm happy with a 18W LED lamp, and streets are usually darker. (I can't find the official recommendation.)
I'm ignoring a lot of inefficiency sources, so assuming a 100% efficiency after photosynthesis is too optimistic. Organic reactions are usually far from 100% efficiency. I think that a 10% is still optimistic, but it's difficult to give an accurate estimation.
So I think it's not ruled out by the laws of physics, but I don't expect it to be viable as a street illumination method. (On the scale from 1 to Nessie, I'd rate it as Yeti.)
Re:Living Plants That Glow Like a Lamp (2018)
by ianai on Friday May 10, 2019 @06:38PM
(#19882933)
That sounds like a figure that reflects how little energy a plant needs. Becoming an active light source requires more energy than the evolved requirements of plant life. So you have to engineer the whole cycle into the plant.
So assuming a 100% efficiency in the conversion of the products of the photosynthesis to light, a 12h+12h light/dark cicle, 100% canopy coverage, ignoring the branches, ignoring that plants need energy for other activities and ignoring that the plant will release 1/2 of the light to the sky instead of to the floor, we get 2W/m^2 for illumination at night.
For a 3mx3m room (10ftx10ft), I'm happy with a 18W LED lamp, and streets are usually darker. (I can't find the official recommendation.)
I'm ignoring a lot of inefficiency sources, so assuming a 100% efficiency after photosynthesis is too optimistic. Organic reactions are usually far from 100% efficiency. I think that a 10% is still optimistic, but it's difficult to give an accurate estimation.
So I think it's not ruled out by the laws of physics, but I don't expect it to be viable as a street illumination method. (On the scale from 1 to Nessie, I'd rate it as Yeti.)