My shed is now a proper PC case with a solar powered in-take fan to keep the shed folder cool! 
First step was make a hole in the door and put in a vent cover, a bit of roof mastic around the edges to keep it water tight:
Then add el cheapo fan to the other side and attach the solar panel, this is a £9.99 car trickle charger pannel that had some nice crocodile clips already on.
Then position the solar panel on the roof, as the panel isn't weather proof so I'm simply going to put it up when the weather is hot, which is really only when it is needed.
And it works!!! The angle of the panel is very important though, in the morning and evening sun there is not enough to power the fan as the angle of the sun is too great, but between about 11-4 it works, it's not a massive flow of air but pretty good and certainly better than nothing.
At the moment I've only got a bit of old plant pot creating the angle, but will try to shape a bit of wood or something to get a better angle, the better the angle the more air flow.
Now I just have to hope next doors cat doesn't **** on it!!

First step was make a hole in the door and put in a vent cover, a bit of roof mastic around the edges to keep it water tight:
Then add el cheapo fan to the other side and attach the solar panel, this is a £9.99 car trickle charger pannel that had some nice crocodile clips already on.
Then position the solar panel on the roof, as the panel isn't weather proof so I'm simply going to put it up when the weather is hot, which is really only when it is needed.
And it works!!! The angle of the panel is very important though, in the morning and evening sun there is not enough to power the fan as the angle of the sun is too great, but between about 11-4 it works, it's not a massive flow of air but pretty good and certainly better than nothing.

At the moment I've only got a bit of old plant pot creating the angle, but will try to shape a bit of wood or something to get a better angle, the better the angle the more air flow.
Now I just have to hope next doors cat doesn't **** on it!!

.
Unless you're meant to put it on the dash or something.