You know that the a fan (like the pc fan that cools the processor) needs a quantity of energy to work. The most usually are 12V to work Ok.
Some days ago, I have seen a video where a guy moves a fan to make energy. That guy used the help of a blowdryer to move the fan at a high speed. The video shows that moving the fan at high speed you can make power to run a device (in the video was a led). So, if you have a motor, you can have a generator if you inverse the process (you move the fan).
My question is, If the fan need 12V to work properly... How much energy can I obtain if I move the fan? I know that It depends of the speed that I move the fan, but I want to know what is the max power that can I obtain. Can I obtain the same 12V moving the fan? More? Less?
Thanks