[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.