The decarbonisation of Ireland’s energy system will bring with it the inherent bonus of significantly enhanced energy security, through indigenous supplies of renewable fuels. For the moment, however, the country remains reliant on imports for 80 per cent of its natural gas supply. Any interruption to that supply, accidental or otherwise, would have very serious consequences for the economy and indeed for society.
At present, approximately 30 per cent of Ireland’s primary energy needs are met by natural gas, of which almost 50 per cent is used for electricity generation. While the amount of renewable electricity generation in the form of wind and solar continues to increase, long-duration battery technology is only developing. Therefore, gas-fired generation will still be required to provide backup power for when the wind doesn’t blow and the sun doesn’t shine.
It is planned that over the course of the next two decades, indigenously produced biomethane and green hydrogen will completely replace natural gas. Not only will this provide a carbon-neutral or carbon-free alternative for domestic and industrial gas users, it will also be critically important for the decarbonisation of the electricity network. In the meantime, however, we remain highly dependent on imported natural gas.
The security of European energy systems came into sharp focus following the Russian invasion of Ukraine in 2022. “Europe has largely replaced Russian gas, primarily increasing flows from Norway, increased use of storage and through existing and new liquid natural gas (LNG) import terminals. In contrast, Ireland remains dependent on the two gas interconnectors with Scotland,” says Gas Networks Ireland chief operations officer Bobby Gleeson. “There is now an increasing risk of third-party interference with subsea pipelines, electrical interconnectors and data cables. We need to be mindful of this, considering the recent movements of international vessels off the Irish coastline, and the damage to subsea cables linking Sweden to Lithuania and Germany to Finland in the Baltic Sea.”
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A state-led facility could exclude fracked gas. Only 25 per cent of the global LNG supply originates from fracked sources
He also points to damage to other subsea interconnector gas pipelines as evidence of the increased risk level. “The Nordstream gas pipeline was damaged by sabotage,” he notes. “The Baltic interconnector between Estonia and Finland was damaged by a ship’s anchor and it took over six months to repair the damage. Fortunately, both had alternative supply options. Finland had just completed a floating LNG storage facility and Estonia had access to gas from the European system.
“Ireland currently does not have an alternative supply option, and so both our gas and electricity supplies would be severely impacted until a repair could be made. The Irish economy would be significantly disrupted by such an event, with key multinational export businesses being worst affected.”
The Government is aware of this vulnerability, and in 2023 the Department of the Environment, Climate and Communications (DECC) published the Energy Security in Ireland to 2030 report. This followed on from an energy resilience study published by Gas Networks Ireland in 2018.
Both studies came to the same conclusion, that Ireland needs what is known as a floating storage regasification unit (FSRU). In simple terms, this is a ship converted for the storage of LNG that can dock at a jetty which is in turn connected to the gas network. Such vessels can store vast quantities of LNG which is liquified by bringing the temperature down to minus 160 degrees Celsius. That makes it 600 times denser than the gas flowing through the network at present. Should the supply be called into use, the unit can be replenished quickly.
The solution identified by the Energy Security review had one important caveat, however. The FSRU would be State-led rather than a commercially run facility. This is not a mere ideological point, as Gleeson explains.
“While both a state-led solution and a commercial solution would address the risk identified, there are a number of important differences between the two,” he says. “A commercial solution relies on sales of gas for revenue. It would therefore try to maximise the flow of LNG into the system. In the case of the State-led solution, it would seek to minimise the flow of LNG into the system at the lowest level required to keep the vessel operational, necessary to avoid boil-off or evaporation of the stored LNG. It would not seek to earn commercial revenues through the sale of gas.
There is now an increasing risk of third-party interference with subsea pipelines, electrical interconnectors and data cables
“The fact that it would be within the control of the State would provide assurance that sufficient storage levels are maintained to meet emergency requirements, should they arise.”
Very importantly, it would be temporary in nature. “The solution would be put in place to address the risk while it exists,” says Gleeson. “When the point in time comes that the risk no longer exists – for example, due to the availability of indigenous biomethane and green hydrogen – the facility can be repurposed to service those renewable gases. The ship can literally sail away. It will be a matter for the Government and the Regulator to decide, not a commercial operator, that the risk no longer exists and that the proposed solution is no longer required.”
There is another crucial difference, and that relates to the controversial issue of fracked gas. Fracking is a highly environmentally destructive method of extracting natural gas and the Irish Government is opposed both to the method and the import of such gas.
Gleeson advises: “A state-led facility could exclude fracked gas. Only 25 per cent of the global LNG supply originates from fracked sources, and there are many sources of LNG around the world that do not include fracked gas.”
With Ireland’s energy system continuing to decarbonise, and new backup sources of electricity through the Celtic Interconnector with France and other new interconnectors with the UK due to come on stream before the end of the decade, there is a debate about whether an FSRU facility really is needed. Gas Networks Ireland has considered these various scenarios, and remains convinced that an FSRU solution is both necessary and feasible.
It is planned that over the course of the next two decades, indigenously produced biomethane and green hydrogen will completely replace natural gas
“Of course, the Government does not want to see unnecessary infrastructure investment, and wants to be sure an FSRU really is required,” says Gleeson. “We share the Government’s optimism around the rollout of renewables, with the ultimate goal of offshore wind and green hydrogen replacing natural gas but are concerned about the timelines within which Ireland will achieve these targets. Our Pathway to a Net Zero Carbon Network strategy sets out how we are going to achieve a fully decarbonised network by 2045, with the gas network playing a critical role in an integrated energy system.”
That strategy will see biomethane being carried on the network in ever-greater volumes in the coming years, while Gas Networks Ireland is already preparing the network for green hydrogen when it becomes available in commercial quantities.
Neither of those fuels will become available overnight. For biomethane, the target set by the Climate Action Plan is 5.7 terawatt hours (TWh) equivalent by the end of the decade, about 10 per cent of current needs. But supplies from Corrib will be depleting in the meantime, and hydrogen will not begin to come onstream in sufficient quantities until the mid-2030s.
“Green hydrogen’s availability is dependent on excess wind power,” Gleeson notes. “We need that to make sure the hydrogen economy can take off. We need the excess wind power to produce hydrogen, which will in turn displace natural gas in backing up wind generation.”
Pending that, we are facing a situation where demand for electricity continues to rise in line with economic and population growth, and the consequent need for backup gas generation also increases.
“Generally, in Ireland, the peak cold weather coincides with no wind,” he points out. “Gas can account for over 90 per cent of electricity generation on any given day. The failure of an interconnector through third-party interference wilful or accidental is a real risk. A gas emergency would quickly turn into an electricity emergency. It is a risk that applies equally to electrical interconnectors, so although it is a low risk, the high consequences necessitate that we do something to mitigate it.”
Gleeson concludes by pointing out that while Gas Networks Ireland is in the business of decarbonisation, its day job is security of supply. “We have been tasked with examining this issue because of our track record of serving Ireland’s gas needs for 50 years,” he says. “We built the first interconnector to Scotland around 1990 when we saw that Kinsale Head gas field would no longer meet demand. Within 10 years we built the second interconnector to meet increasing demand. We built the pipeline to the West to connect Corrib Gas to the network and also built a pipeline to Northern Ireland to support security of supply there.
“We have always delivered the infrastructure required to meet the needs of the country, on time and on budget. And we will continue to do so.”