I was mostly making the infinite energy joke.

Assuming indoor lighting is modern, there shouldnt be much UV or IR to grab. So its taking visible light. will this grey out those frequencies/colors from the visual scene when looking thru as a window?

Absorbing frequencies of indoor light that indoor lights produce would up efficency of course, and you’d be capturing energy that would just become light polution.

But you would probably save money using reflective window cover and turning down the emitted power.

Im sure some applications would likely make sense tho.