MERCURY MOBILE
MARAETAI I Opened: 1952 Number of generating units: 5 Francis turbines Total Output: 180MW MARAETAI II Opened: 1970 Number of generating units: 5 Francis turbines Total Output: 180MW Average Annual Output (combined across Maraetai I & II): 880GWh Maraetai is a variable radius concrete arch dam, which when constructed, was the largest purely hydroelectric dam in the Southern Hemisphere. The dam serves both the Maraetai I and II. The spillway is a separate structure situated adjacent to the intake channel to Maraetai II with a concrete-lined tunnel that exits in between the stations. Operationally, Maraetai I and II are considered to be a single station.