The Shannon Scheme
Early Proposals
The Liffey, Shannon, Erne and Bann were mentioned as possible of hydroelectric power resources. A company was formed which sought to generate hydroelectricity from the Liffey.
Dublin Corporation had itself undertaken a feasibility study into the use of the Liffey for this purpose. It recommended a storage reservoir above Poulaphouca by constructing a dam 100 feet high with the building of a power station above Ballymore Eustace with a smaller storage reservoir and power station at Leixlip.
During this period, other towns developed their own electricity supplies on a limited basis. This includes Bray, Galway, Cork and Limerick between 1890 and 1900. Derry Corporation opened a coal-fired station to provide for street lighting in 1892. Belfast Corporation introduced electric street lighting.
Electricity at Independence
By 1922 there were 160 power undertakings in the Irish Free State, most were privately owned with the bigger undertakings in public ownership run by local authorities. In most smaller towns those undertakers consisted of small power station with direct current generators worked by gas or oil.
The average number of customers was 280. The Dublin and Cork Corporations had over a thousand customers each. Some small suppliers had a handful of customers only. Some local authorities produced electricity for lighting and did not sell to the public.
Shannon Proposal
The young Irish engineer Dr T.J. McLaughlin, who worked with Siemens Berlin, was very influential in the preference for the development of the Shannon over the Liffey with the involvement of Siemens, by whom he was employed as the ultimate contractor.
Siemens made proposals to the government in late 1923 and early 1924 for the hydroelectric scheme on the Shannon. It was proposed that Siemens work out details on a specific scheme to develop electrical power for distribution over the Irish Free State.
The final scheme was to be submitted to experts nominated by the government of European standing if the scheme could be modified, but if objections were raised by experts which would not be adequately dealt with, the proposal would lapse. The White Paper favoured the promotion of the scheme as a state enterprise.
The government decided that the construction and supply contracts would go to Siemens on certain conditions governing price and quality control. As much Irish labour as possible was to be used.
Siemens’ detailed proposals were presented and were seen as very comprehensive. It reviewed previous schemes and was clear that the Shannon was the most suitable river for development. It anticipated that the State’s needs could be met by the Shannon for up to 10 years. The report dealt with drainage, navigation and fishing issues.
Report & Alternatives Considered
The report was examined by four experts with international expertise in electricity who undertook a detailed three-month examination which reviewed the totality of options for electricity supply in Ireland. It favoured a single centralised national plan and favoured water on grounds of cost and national independence.
It looked at a number of different schemes, including a Liffey scheme, but agreed that the Shannon was the most suitable location in terms of delivering the requisite capacity. It was of the view that the Liffey could be developed at a later date but that the Shannon represented the most useful first step.
The experts considered an alternative proposal drawn up by an Irish firm based on the Liffey with a modest partial development of the Shannon. Ultimately, the initial exploitation of the Shannon was recommended. The experts reported in December 1924. The proposal was opposed by certain existing electricity undertakings and those with interest in the Liffey scheme.
State Developed
Despite the challenge that the financing of the scheme presented to the State’s finances, there was the determination that it was to be undertaken by the public sector. It was criticised on the basis of being state socialism and involving extensive expenditure. However, the opposition was relatively minimal.
The Shannon Electricity Act 1925 provided for the production by the State of electricity generated from the Shannon. A major issue was the accommodation of fishing interests on the Shannon. The legislation authorised the compulsory acquisition of land for the purpose of the scheme. It authorised steps to improve navigation and drainage. There was provision for protection of fisheries and local monuments.
The contract between the Irish Free State government and Siemens was signed on 13th August 1925. It provided for the construction of the scheme at a cost of £5.2Ms, to be in operation within 3.5 years.
Development
The scheme was one of the largest public works projects to date in the world. It required the construction of railway lines, extensive preparation and infrastructure. The scheme was constructed at Ardnacrusha.
The scheme involved the construction of a headrace, tailrace and weir intake, sluice house and power station. The 100 feet fall from Lough Derg to the sea was used to generate electrical power.
This fall was procured by drawing water from Shannon above O’Briensbridge and conducting it through a head-race canal approximately 7 1/2 miles long across the country to Ardnacrusha, where the power plant was constructed. The tailrace met the Shannon at Parteen A Lax. Above O’Briensbridge a weir was constructed in the river to raise the level of the water to the level of Lough Derg. Embankments were built to prevent flooding on adjoining land.
The scheme was to be developed in three phases. When completed, it was designed to distribute electricity over the country by high-tension 110 KV lines through the main population centres. The distribution was by 110 KV lines to Dublin and Cork, with 38 KV lines to a network of the major towns in Ireland from those lines or directly from Ardnacrusha. The works were officially opened on 29th July 1929.
Electricity Supply Board
The government did not want to entrust the enterprise directly to a government department or civil servant. The government opted for a state company with an independent board with sole control over its staff with the possibility of Executive Council consent for senior appointments. The Department of Finance opposed the idea of a private board spending public money without detailed control from the Department of Finance and the Oireachtas.
The existing undertakers and local authorities stood to lose their role as electricity-generating and distribution entities. There were 90 such undertakings in the country at that time. 20 were statutory and almost 15 were owned by local authorities.
The view was that the existing undertaking had been poorly run in terms of public service and it was doubted whether they might run the Shannon scheme in a competent manner.  It was decided that the Board would be given the power to acquire these undertakings compulsorily so that it would not have to face competition in the sale of electricity. It was not obliged to acquire those undertakings immediately but could do so over a number of years.
Local government was a relatively low ebb in the 1920s and there was little public support for the retention by local authorities of their electricity undertakings. Provision was made for compensation for the acquisition of electricity enterprises.  Private business interests, many of which were profitable, strongly criticised the proposals for compulsory acquisition.