But even then it's not that simple. You need different wavelengths at different phenological stages, and what wavelengths you need depend on the crop (and variety, but you can at least control that for crops you can multiply vegetatively) you're growing, and then still you need to distribute that light to all leaves and not just the top ones. So now you need either LED's that can emit many different wave lengths, or you need many LED's that are only in use part of the time (killing your capital expenditure efficiency), or you need to move plants around to be under the right lights. And you need to move the light source to places where they can hit the leaves as much as possible, but you also need to keep the excess heat away from the plants (which is a problem even with today's highly efficient LED's - I mean, these are not like that IKEA nightlight you bought last week for $5.)
You’re right that they’re not like the ikea lamp I bought last week... they’re like the hydroponic lamps I bought two years ago for a shit ton of money.
Everything you said is right. It’s still more efficient to use the suns energy and then distribute the leds than to directly try to use the suns light. Modern hydroponic grow led controllers can adjust the wavelengths as the plants grow
