They crunch the numbers here: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/ http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor...

They crunch the numbers here: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/ http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-stor... The energy in one gallon of gasoline is equivalent to the potential energy stored in 13 tons of water one kilometer up