The Entracque Power Plant, also known as The Upper Gesso Plant, is a pumped-storage hydroelectric power station located in Valle Gesso just south of Entracque, Italy. The power station contains pump-generators for two co-located but hydraulically separated power schemes; the Chiotas-Piastra Plant and Rovina-Piastra Plant. Both plants use separate upper reservoirs but use Lago della Piastra as their common lower reservoir. To produce power, water is released from the upper reservoirs to the power station located at the lower reservoir. The pump-generators re-fill the reservoirs and the process repeats as needed. The Chiotas' upper reservoir, Lago del Chiotas, is located much higher in the valley and larger than Rovina's Lago della Rovina which affords it the ability to produce more electricity. The installed capacity of Chiotas is 1,184 MW with a hydraulic head (water drop in elevation) of 1,048 m (3,438 ft) while Rovina has an installed capacity of 133.67 MW and a head of 598 m (1,962 ft). Construction on the plant began in 1962 and operations started in 1982.

Open-loop Pumped Hydro Storage