He says: "Water released from the base of the dam through pipes into the turbines could then go via a pipeline back into the reservoir."

"There would be nowhere for the water to go but up. The pressure and the weight from the volume of water above would push it straight back round; it shouldn't even need to be pumped back up."

Gravity determines that water always finds its own level.Therefore the water in the return pipe will only rise to the level of the water in the dam.

Having found its own level and unable to defy gravity to "leap" back into the dam, it will then stop, as will the turbine.

To return the water below or at the surface of the dam would merely create a loop with zero force or circulation to turn the turbine.

To return the water into the dam and turn the turbine would require electric pumps that would consume more energy than that produced by the turbine generators because nothing is 100 per cent efficient due to friction losses.

The first law of physics is that neither matter or energy can be created nor destroyed, only exchanged from one form to another.

For the turbine generators to produce surplus energy after powering the pumps would "create" energy, thus defying the first law of physics and produce perpetual motion, which is impossible.

Ah, well back to the drawing board.

Paul Campbell