Oh, yeah, I looked at that. I can get a couple hundred watts of panels that will realistically generate about 300 watt hours of power on my balcony on the sunniest days, given that they won't be mounted at a very good angle. I can have it charge a battery pack that'll last a few years. Then I get about 90% efficiency if I'm lucky with the inverter. Even at $0.50/kWh, that's $0.15/day I'm saving or about $50/year if we just assume a cloudless year-round summer. That'll save me just enough money to buy a new battery when the first one gets old.

Solar power will get there one day. Its great for many purposes but its still not practical for most apartment dwellers.