In the 1920s, after WWI which killed nearly 50,000 Irishmen; the Spanish 'flu which killed half-as-much-again and a guerilla War of Independence and a devastating Civil War whose numbers there is no will to enumerate, Ireland was a bankrupt state: 3% of the able-bodied workforce was dead and many more were disabled by wounds or PTSD. A nation of small farmers with no ready money to pay the small shop-keepers in town was not in a position to pay taxes to boost the infrastucture to promote economic growth. The mighty Shannon has been in the news this Winter as a succession of Winter storms have dumped so much rain in the catchment area [17,000 sq,km = 20% of the land area of the island] that the river burst its banks at numerous places along the main channel. It was ever thus, the river can't drain quickly because it is flat: it falls only 15m from source to Parteen Weir - a distance of more than 200km. The standard cycle is that the main channel spreads out on the riverine meadows - called callows in Ireland - and the excess drains away over the days after the spike in rainfall ends. It's an equilibrium.
The equilibrium was shifted when the nascent Free State was persuaded to exploit the mass of water and the fact that for the last 30km of its length, the Shannon falls 30m. Hydro-electricity! The principle had been on the cards for the previous couple of generations but the project gained momentum in the early 1920s. One of the early boosters was Sean Wall, the Chairman of Limerick Council, but he was also the local IRA commandant and was killed in an independence war shootout in May 1921. A couple of years later, the running was taken up by Thomas McLaughlin, an engineer who was working for German megacorp Siemens. He managed to by-pass British business and engineering interests and Siemens got the contract. It took the rest of the 1920s to bring the plan to fruition. It was the biggest hydro-electric plant on Earth; although quickly surpassed by the Hoover Dam across the Colorado River in America. It was wildly expensive: sucking up 20% of the annual tax-take for several years. 9 million cu.m of spoil had to be shifted to construct the head-race between the afore-mentioned Parteen Weir (another part of the engineering infrastructure) and the dam and turbines at Ardnacrusha 15km downstream.
The initial installation in 1929 had three turbines that could generate a staggering 35MW at full power: that was more than the entire electricity usage for the country. Demand soon rose to meet supply . . . and over top it. After 3 years, another mega-turbine was installed to add another 30MW of power. In the mid 1930s, Ardnacrusha provided 80% of the nation's electrical power and lines snaked out across the country. Initially to Dublin, Cork and other cities and centres. My father was living in Dunmore East at the time and this significant fishing port was ear-marked for early access to the grid. The Emergency, as Irish government termed WWII, put a damper on propagation of the wires but Rural Electrification extended via 1.5 million poles into every farmhouse and cottage on the mainland by 1973.
Now, Ardnacrusha supplies rather less than 2% of the electricity in the country. It's still humming at full capacity but now everyone has a kettle, a microwave, electric carving knife, waffle pan; desktop laptop, tablet and smart-phone; every house is lit up like a Christmas tree and not just at Christmas; astronomy is no longer a spectator sport because of the street lights in every hamlet and cross-roads; cyclotrons, MRIs, CAT scans, centrifuges; ice-plants, assembly lines; oh yes, and the trains. We're all wired up and Siemens, Parteen and Ardnacrusha midwifed the country to a richer, and the planet to a poorer, place.