Irish developer Net Zero Energy (NZE) plans to build a 600MW long-duration energy storage (LDES) facility that will convert surplus renewable power into hydrogen, store it underground, and dispatch electricity during periods of peak demand.
The Rathrush Green Energy Park, in Carlow county, would cost around €2bn ($2.31bn) to develop. The plant is designed to generate up to 600MW for 70 hours — enough to cover 10pc of Ireland's peak electricity demand, NZE said.
The LDES site will use surplus wind and solar electricity to power electrolysers to produce renewable hydrogen, which will be compressed and stored in lined rock caverns. Gas turbines will then burn the hydrogen to generate power for grid dispatch.
The plant will connect to the grid through a 220kV substation, and draw process water from a nearby wastewater treatment facility.
NZE is running a public consultation and plans to file a planning application by the end of 2026.
NZE previously developed a 4.6MW battery energy storage system (BESS) and assisted in permitting and grid connection for the Kelwin 26MW BESS site.
Separately, Ireland's department of climate, energy and environment has opened a call for evidence on geological hydrogen storage to inform future regulatory frameworks for underground storage. The consultation, which covers salt caverns, depleted gas fields, aquifers and lined rock caverns, closes on 17 July.
