Hi there, I'm renting, so can't add power sockets and wires to my flat. My bathroom is windowless and passively vented. I'm going to put a solar panel on the roof and drop a wire down the chimney. I was thinking about getting a 7.5v 2.5w solar panel and a fan and directly connect them - that way at least during the day the air is being actively changed. I live in a reasonably sunny country, but would like the fan to work during the day even on cloudy days. My questions are: In order to easily mount the fan in the hole I'd like to use a PC fan, can a 7.5v 2.5w (Max) provide enough power to get the fan going? Would it be okay to use a 5v/6v fan or am I just going to fry it? What kind of fan: i.e voltage, draw etc would work with such a varying input power? Thanks!