he Linthal facility is a so-called pumped-storage power plant. It generates or stores electricity by moving water between two teal-coloured mountain lakes separated by a 630-meter cliff twice the height of the Eiffel Tower. When the operator, the Swiss utility Axpo, wants to generate electricity, it opens massive steel valves that can withstand titanic pressures and lets the water run down from Lake Mutt, located at 2,490 meters above sea level, to Lake Limmern, filling up a deep, dammed valley below with nearly 23 billion gallons of water. The water runs through four GE pump turbines that turn GE variable-speed motor generators, converting the potential energy in all that falling water into electricity.
