FAQ

The current area of interest is approximately 80km from the shore south of Cork port. We are at the early stages of development of this project. We have completed desktop studies identifying an area of the Celtic Sea that may be suitable for the development of a subsea hydrogen storage project. If successful through the development and permitting phases, it is expected that the project would be operational in the mid 2030’s.

Hydrogen is a gas. It is colourless, odourless and non-toxic. It is the cleanest gas that can be used to produce energy.

Yes, hydrogen is natural. Water is approximately 10% hydrogen and 90% oxygen.

Hydrogen can be produced by passing electricity through water by way of a proven process called electrolysis. Using green electricity produced by renewable technologies to convert water into hydrogen would produce green hydrogen i.e. no associated emissions.

The use of renewable energy to produce green hydrogen is variable and intermittent. To manage the intermittency and seasonality of green hydrogen production in Ireland, this subsea storage project will store green hydrogen to provide a reliable continuous hydrogen supply to end users.

The government has set out a commitment of net zero emissions by 2050 in the Climate Action Plan. The Department of the Environment, Climate and Communications (DECC) published the National Hydrogen Strategy in 2023 setting out the strategic vision on the role that hydrogen will play in Ireland’s energy system, looking to its long-term role as a key component of a zero-carbon economy. One of the main points in the National Hydrogen Strategy is that long duration geological storage is critical enabling infrastructure, essential to the future viability of hydrogen.

This project will provide hydrogen storage with volume capacity of approximately 1TWh of hydrogen, which is expected to be equivalent to approximately 20% of Ireland’s 2050 hydrogen economy storage (90 days) needs (reference: Table 1 page 55 of the 2023 National Hydrogen Strategy i.e. 1 TWh being approximately 20% of the ‘Low’ 90 days storage requirement scenario).

It is anticipated that a salt cavern would be over 1,000m below the seabed. It would be cylindrical or slightly pear-shaped and up to 85m wide and 150m long. This is roughly the size of a GAA pitch. On the seabed, the facilities would likely be less than 2 meters wide. On the surface of the sea, a platform would be constructed connecting to caverns beneath the seabed.

No. This project will only store hydrogen. Green hydrogen will be produced by, for example, offshore wind farms and transported to this storage project.

Yes, the rocks offshore Ireland have a long history and vary in age and type, there are areas in the Celtic Sea where geological studies have identified the presence of salt at great depths below the seabed. It is over 200 million years old and in places it is believed to be up to several hundred meters thick.

Caverns are created by circulating water in the salt until a cavern of the required size has been dissolved.