The Anapo hydroelectric power plant

The Anapo power plant is located in the municipality of Priolo Gargallo, in the province of Syracuse, near the largest industrial hub in Sicily. Construction began in 1980 and was completed in the late 1980s.

The plant consists of the two dams of Ponte Diddino and Monte Cavallaro and their associated reservoirs, capable of storing 7.3 and 5.6 million cubic meters of water, respectively. The engine room is located in caverns within the Climiti Mountains: this is where the four reversible pump-turbine units are installed, each with a capacity of 125 MW, for a total of 500 MW.

The Anapo plant is a closed-loop, pure pumped-storage hydroelectric power plant: that is, it does not draw from natural watercourses, but instead reuses the same volumes of water by pumping them from a lower reservoir to an upper reservoir and then letting them fall back down, thus driving the turbines.

Since it is a pumped-storage power plant, it functions as an electricity storage system: it stores energy during the hours when the surplus of energy in the grid is high, and supplies it to the grid during the hours when consumer demand is highest. In this way, acting as a battery, the plant helps stabilize the Sicilian grid and compensate for the variability of new renewable sources, which are growing dramatically on the island.

In addition, the Anapo power plant has the ability – rare in Italian hydropower plants – to generate and absorb energy from the grid at the same time: an additional stabilizing element for the regional grid.