I never understood the economics of these. Say a balcony panel would generate $X worth of electricity for me over the next 5 years. Surely someone who can place

I never understood the economics of these. Say a balcony panel would generate $X worth of electricity for me over the next 5 years. Surely someone who can place the panel on a roof or something, where it is not shaded by a giant building half the day, can generate like $3X from it. It can be part of a bigger installation too, so labor is better amortized. Given that the supply of people with roofs is far from exhausted why would the price of panels be at a level where $X instead of $3X is a reasonable return? Basically you are bidding for panels against an unlimited supply of people for whom the panels are much more valuable than to you, no?