Reopening of Kinsale gas storage reservoir would require 'major investment'

Environment Minister Eamon Ryan said the independent review 'stress tests our electricity and gas energy systems to identify risks, and to provide a range of evidence-based options to address potential security of supply gaps.' Picture: Maxwells

The reopening of the Kinsale gas storage reservoir would require "major investment" to be viable, a Government report on energy security has found.

The Department of the Environment, Climate and Communications on Monday launched a consultation of a review of the energy security of Ireland's gas and electricity systems. 

In the review document, a number of options to help secure the country's power supply are discussed, include the potential for a gas storage facility. The Southwest Kinsale reservoir, Ireland's only gas storage facility at the time, ceased operation in April 2017.

Last year, the owner of the Kinsale gas fields sought Government approval to leave pipelines from the various wells in situ as part of the decommissioning of the fields, which were depleted in 2020.

The review document says since the closure of the Kinsale reservoir, Ireland has had no storage facility. It says such an idea "would only operate as a strategic back-up in the event of a supply shock to help mitigate against unserved demand". 

It would work by injecting gas into an underground reservoir when demand is low, usually during the summer, and withdrawing gas when demand is high, usually during the winter.

However, while the paper says being a non-commercial reservoir would be good for the country, the document says the idea would require a major investment.

"The fact that it would be a non-commercial strategic back-up gas storage facility means that volumes of gas would be available for use at the onset of security of supply event. Underground storage facilities are typically created in depleted hydrocarbon fields, aquifers, or salt caverns which are determined by geology. 

"It is understood that the storage facility at Kinsale could in theory be reinstated in the future but would require major infrastructure investment and a very large investment in gas stocks to bring gas levels to a minimum level [known as cushion gas]."

LNG storage facility

Another idea proposed is a floating liquefied natural gas (LNG) storage facility. LNG enables large volumes of natural gas to be stored and transported on specially designed vessels. 

The review says Ireland could invest in a floating LNG storage and regassification unit (FSRU), which could be used on a non-commercial strategic basis. FSRUs are usually moored at a jetty and can be refilled by other LNG vessels that dock alongside it. 

When the FRSU is no longer required, it can be transported to another location without leaving a large piece of stranded infrastructure behind. The cost of leasing an LNG FSRU can vary but is typically estimated in the range of €37m to €66m per year.

This review, which covers the period up to 2030, does not seek to address the expected tight margins in electricity supply over the coming winters, but looks at mitigation for the coming years.

The list of mitigation options also includes:

• A gas package — a combination of strategic storage, renewable gas (biomethane injection and hydrogen) and demand management;
• Another 700MW interconnector to France in addition to the Celtic Interconnector;
• An additional 360MW of pumped storage hydroelectricity capacity;
• A 450MW dedicated biomass plant;
• Increased secondary fuel storage beyond the current five-day storage requirement;
• Converting a CCGT (combined cycle gas turbine) to hydrogen;
• A combination of additional capacity of batteries and demand side response for electricity.

Commenting on the launch of the consultation, Environment Minister Eamon Ryan said the independent review "stress tests our electricity and gas energy systems to identify risks, and to provide a range of evidence-based options to address potential security of supply gaps".