ESB, dCarbonX to repurpose Irish gas reservoir for offshore green hydrogen storage

Ireland's ESB and energy storage developer dCarbonX have launched a project to develop large-scale storage for renewable hydrogen off the Irish coast in County Cork, the companies said on Aug. 12.

The 'Green Hydrogen at Kinsale' project is pending license and planning approvals, and could store up to 3 TWh of green hydrogen and hydrogen carriers such as ammonia, the companies said in a statement.

The project aims to repurpose the depleted Kinsale Head natural gas reservoirs for hydrogen storage.

"The Kinsale Head reservoirs hosted safe, secure and reliable offshore natural gas subsurface energy storage for many years, underpinning Ireland's security of gas supply," dCarbonX COO John O'Sullivan said.

"As subsurface lead for the original natural gas storage development, the dCarbonX and ESB partnership is optimally positioned to repurpose and develop these reservoirs for green hydrogen storage," O'Sullivan said. "Kinsale Head is the third Irish offshore location that we are assessing with ESB for green hydrogen storage and we look forward to providing further updates as appropriate."

The companies evaluated the potential of the reservoir for hydrogen storage earlier in 2021, and have since conducted work on subsurface analysis, mineralogy, capacity modelling, injection and withdrawal rates, compression, drilling evaluation, well design, retention assurance, monitoring, electrolysis and infrastructure tie-ins, the statement said.

ESB and dCarbonX signed a memorandum of understanding in May to assess and develop offshore renewable hydrogen subsurface storage offshore Ireland.

The partnership will also support the creation of a proposed "green hydrogen valley" centered around the Poolbeg peninsula in Dublin, integrating renewable hydrogen production and storage with a view to decarbonizing heavy transport, shipping, industry and power generation.

The companies said storage caverns for large quantities of renewable hydrogen could be used to balance the electricity grid, producing hydrogen for storage from surplus wind power for conversion back into the grid at times of low wind generation.

ESB also said in May that it plans to invest in a hydrogen facility as part of the redevelopment of the Moneypoint power station site into a renewable energy hub.

dCarbonX is primarily focused on developing storage for green hydrogen, and is also exploring opportunities for carbon capture, use and storage, and geothermal energy in other UK and Ireland offshore locations. It aims to build and operate a portfolio of subsurface storage facilities to store 11 TWh of hydrogen and other hydrogen carriers, such as ammonia, and 8 million mt/year of CO2.

S&P Global Platts assessed the cost of producing hydrogen via alkaline electrolysis in the UK (including capex) at GBP6.31/kg ($8.73/kg) on Aug. 11. PEM electrolysis production was assessed at GBP7.66/kg.