Roncovalgrande Hydroelectric Plant

The Roncovalgrande Hydroelectric Plant, also known as the Delio Hydroelectric Plant, is located 3 kilometres (1.9 mi) north of Maccagno in the Province of Varese, Lombardy, Italy. Using the pumped-storage hydroelectric method, the power plant has an installed capacity of 1,016 megawatts (1,362,000 hp). The power plant was complete in 1971 and the last generator operational in 1973. The lower reservoir, Lago Maggiore, already existed. The power plant itself is located underground in between Delio and Maggiore. To produce electricity, water is released from the upper reservoir to the power plant via two 1,100 metres (3,600 ft) long penstocks.