facade of the koepchenwerk at hengsteysee. pumped storage power plant near hagen

hengsteysee koepchenwerk alternative energy balancing base load control power electric electrical electricity generation industry storage transition environment feeding flowing water generator harkortsee hydroelectric plant hydropower industrial building lake profile new peak performance line pylons pumped pumps ruhr saving basin storing technology text space reservoir facade near hagen germany szorage from night using waterfall day hengsteysee germany gradient during day