More Power, Scotty!

[Karlos]

We get a lot of rainfall in Manchester but there's a lack of streams for the most part ;-)

As for the various canals, they seem pretty sluggish...

[Karlos]

Vincent wrote:
If it can generate enough electricity to powre a house from an 8 inch waterfall, then why not make your own waterfall and use it to power the waterpump of the waterfall itself aswell as the rest of the house?

That'd solve the problem.

That would essentially be perpetual motion, which contravenes the basic laws of thermodynamics. In other words, it wouldn't work ;-)

[Karlos]

And when it is depleted?

Basically you are suggesting using a motor to turn a dynamo which in turn powers the motor (substitute motor for water pump).

If the dynamo is 70% efficient, the whole system loses energy regardless of the motor efficiency, and that's before you take mechanical loss (vibration, sound, frictional heating etc)

[Karlos]

The currents running through superconducting magnets come the closest to perpetual motion as you'll realistically get. Even they need to be "topped up" and you have to expend energy to maintain the conditions required for the superconductivity...