Probably a stupid car question...

[Lissa]

Hi,

When I was working at the Georgia Tech library, we had an 'inventor' come in to search the patents (the GTL is one of the regional patent depositories). His idea was to find or make a lake up on a mountain. Then using the water from the lake, spin three turbines at the foot of the mountain. Two of them would be used to generate electricity and the other would pump the water back to the lake.

They are actually doing this. Of course not going against the laws of thermodynamics but just using the fact that electrical power is cheap at night and expensive at day time. So at night water gets pumped upwards and during the day electricity is generated.

You'd be better off storing the electricity in batteries than doing this. There's a reason why power companies have specially designed plants called "peakers" for when the power requirements peak. These power plants are typically gas turbines (basically a large scale jet engine designed to make power instead of produce propulsion).