Key facts about the Shannon Scheme

Before the foundation of ESB, just over 40,000 Irish homes had electricity, supplied by local authorities and private companies. The country had the second lowest consumption of electricity in Europe.

The River Shannon had long been the focus of various plans to bring electricity to Ireland. Early iterations of the project were deemed unfeasible, and were delayed by political unrest in Ireland and abroad.

In 1923, a young engineer from Drogheda called Thomas McLaughlin returned to Ireland after a period working abroad with Siemens in Berlin and studying hydroelectric schemes in Europe.


In 1925, together with Siemens and Patrick McGilligan TD, McLaughlin succeeded in getting a ‘White Paper’ on the scheme accepted by the newly formed Free State government. Read more about these key figures here.

A budget of £5.1 million was allocated to the ambitious project – 20% of Ireland’s national revenue for that time.

The Electricity Supply Bill was passed in 1925, and work began on the Shannon Scheme in August of that year.

The scheme involved work at two major locations in Co Clare – a generating station at Ardnacrusha and a weir at Parteen.

During construction, 4,000 Irish and 1,000 German men worked and lived on-site at Ardnacrusha, Co Clare.

The station was officially opened in July 1929, and began to generate power on the national network in October 1929.

The Shannon Scheme led to the establishment of ESB in 1927 and was the first national electricity system in the world to integrate all the components of the electricity supply chain i.e. the generation, distribution, marketing, transmission and sale of electricity.

The scheme was a huge success, bringing ‘cheap and abundant’ electricity en masse to the Irish people for the first time, and paving the way for the similarly innovative Rural Electrification Scheme which followed 20 years later.

In 2002, the scheme received both the IEEE International Milestone Award from the Institute of Electrical and Electronic Engineers, and the ASCE International Landmark Award from the American Society of Civil Engineers.