Friday 12 June 2026

Plans to develop a 600MW Long Duration Energy Storage (LDES) facility which will use excess renewable energy to generate green hydrogen to provide electricity have today been unveiled.

Known as Rathrush Green Energy Park, the proposed site is located outside Rathoe in Co Carlow and is being developed by Irish firm, Net Zero Energy (NZE). It will save an estimated 180,000 tonnes of CO₂ emissions per annum which equates to taking approximately 40,000 cars off the road.

Surplus renewable energy generated off-site

With a development cost of approximately €2bn, the project will use surplus renewable energy generated off-site – which is currently being lost as a result of lack of demand at certain times and inadequate grid capacity to absorb power.

This surplus wind and solar energy will be used to generate green hydrogen which will then be stored deep underground on-site in lined rock caverns and later converted to electricity. This can then be delivered into the national grid providing crucial back-up when the need arises and delivering a timely solution to the issue of renewable energy intermittency when compared with fossil fuel generation.  

NZE chief executive Peter Harte said: “The project presents an important as well as timely solution to the current pressing and complex energy dilemma facing the country, both in terms of security of supply and decarbonising our grid.

“Moreover, by harnessing an energy source which was heretofore being wasted, we can insulate consumers from future fossil fuel crises and price shocks such as we saw in the aftermath of the Russian invasion of Ukraine in 2022 and more recently, in the Middle East. By delivering a national solution helping Ireland on its journey to energy independence, it simultaneously provides reassurance and confidence for high-end electricity users seeking to locate here in Ireland.” 

'Satisfy as much as 10% of Ireland’s peak energy requirement'

NZE chairman Tim Cowhig said: “By making available 600MW of renewable energy at the flick of a switch, this project can satisfy as much as 10% of Ireland’s peak energy requirement. Rathrush Green Energy Park provides significant, secure, sustainable long duration energy storage for the Irish grid.

“Ireland has never been in such a precarious position in terms of our energy security. We spend €10bn annually importing fossil fuels. This project is particularly timely with widespread debate and focus on Ireland's climate change targets and the enormous, subsequent fines which would result if we fail to meet them.” 

At peak, there will be up to 1,500 workers on-site during the construction phase with some 70 long-term, highly skilled jobs created once complete.

Rathrush Green Energy Park will store thirty times more green energy than Turlough Hill and have seven times the generation capacity of Ardnacrusha. Following a community consultation programme, the developer hopes to be in a position to lodge a planning application by the end of this year.