When opened on 22 July 1929 the Ardnacrusha hydroelectric power station was the largest in the world and supplied almost the total electricity demand of the Irish state.
Ardnacrusha hydroelectric power station image by the ESB.
The hydroelectric power station at Ardnacrusha, Co. Clare was built between 1925-1929 by the German company Siemens Schuckertwerke. The power station required the construction of a weir on the River Shannon at Parteen Villa that diverted the water into excavated head- and tail-race canals constructed alongside the River Shannon, spanned by four new bridges. The Power station itself consists of an intake sluice house built on a mass-concrete gravity dam across the head-race that regulates water to the turbines through four penstock tubes. The turbine building is a steel-framed twelve-bay six-floor structure with a gabled roof built out over the tail-race. Designed to accommodate six turbines three vertical-shaft Francis turbine generators and one vertical-shaft Kaplan turbine generator was installed.
The construction of the power station was the single most important development carried out in Ireland in the twentieth century. The total cost of the scheme was one fifth of the total annual revenue of the Irish Free State at that time and when completed it provided almost the entire electricity demand of the state making Ireland largely self-sufficient in energy for a number of years.