Are you big on solar energy. How many solar panels do you have on your roof ?

I live in an apartment building, but my parents had two of them on their roof. There was not enough sun, so they had to be propped up on a metal "scaffolding", and angled toward the only constant sun. The only thing 2 panels can operate is the hot water heater. And once the day's hot water is used up, my parents used to run out.