China switched on what's billed as the world’s largest pumped-hydro storage facility at 3.6GW that is set to play a key role in delivering its pledge for a green Winter Olympics.

The 19.2bn yuan ($3bn) Fenging Pumped-Storage Station will help ensure smooth supplies of renewable power to the games next month and help flexible regulation of the North China grid as it moves to incorporate massive wind and solar projects into its supply mix, said operator State Grid.