The other thing that hasn't been mentioned is conversion efficiencies. Nothing is 100% efficient, and if you are doing 90% you are doing well.

It's probably MUCH less than 90% total...

I hope I can convince my friend of what I'm thinking... He is one of these conspiracy/free-energy-device-inventors-are-being-oppressed-people.

I wonder why they don't buy this stuff, if they are so convinced?

It drives me crazy how these fraud-inventors are able to manipulate so many people.

 

It's probably MUCH less than 90% total...

I agree. The Betz limit on a submerged turbine is 59%, and even a high performance Pelton impeller wheel will bring you down to 90% right at the start. Then there is the electrical losses (copper resistance, hysteresis, eddy currents etc) in the electrically powered water pumps and the electrical generator on the turbine. Then there is friction and turbulence in the water. What about the cable losses trying to hook up pumps and generators stretched over 2 km?!

The whole thing seems silly because there are already existing water sources for hydro power. Norway is nearly 100% powered by hydro, and many countries have significant percentages of hydro power. Even our slow moving USA has 5% to 10% hydro power.

Hydro power is very practical stuff that taps naturally available energy and this guy wants to go off into fantasy land and dig useless 2 km holes in the ground.

There is a reason why people build hydro dams rather than 2 km holes in the ground, and it's not to create a market for concrete.

Interestingly, there is a real application for pumping water back up to the head, but it has nothing to do with overunity. It provides an effective means of energy storage if you have a limited reservoir to hold the water. You pay an efficiency price, but if you pump up during off peak times, you can provide power during peak times. You recover some money in the price difference and you have power capability when you need it.

That idea is also used for load balancing, which becomes more important for stability as wind and solar power is added to the GRID, due to variability in the energy.

http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity