Forget conventional hydroelectric installations – if you want to have fun generating electricity in the lab then the completely static tin can and bucket generator is for you. They are all the rage at the moment – at least in our lab here, where we’ve sidetracked a student from his summer project into making one to wheel out on Open Day. (It is, actually, vaguely related to what the student is doing for his project, so it’s not a complete sidetrack.)
Anyway, there are lots of clips on YouTube of these devices. Walter Lewin does a good job (of course) of demonstrating one. Basically, you have two dripping water streams (from the same ultimate source – e.g. a bucket) Each stream falls through a metal ring and into a metal bucket. But – the bit that makes it work is that you electrically-connect the left hand ring to the righ-hand bucket, and vice versa. This leads to a nice build up of charge in the buckets and sparks can fly between them.