In Switzerland today, a pumped hydro facility started operation

[Finishline42]

10. As much energy that is created in a nuclear power plant

Lets talk about how much is wasted? What is the typical efficiency of a current nuclear power plant? Google says about 35%

Co-generation gas plants can have thermal efficiencies above 60% according to google.

The Hydro Storage facility in the OP is at 80%. For every Kwh used to pump water up, they get 0.8 Kwh in return. They say they can change from pumping water to making electricity in 15 min. Sure beats having some fossil fueled plant on standby, burning fuel to keep the boiler hot just in case it's needed...

BTW, I thought the Swiss stance was reasonable once they decided to not to build any more new nuclear plants - keep the existing plants operational through their useful life, one Germany should adopt.