Ireland’s lead role in battery storage ‘needs fine tuning’ as renewables scale up, industry expert says

Island of Ireland is ahead of much of the EU and already has 1.5 gigawatts of battery storage in planning, enough to power 750,000 homes

Ireland is a leader in deploying available renewable technologies such as battery storage and grid flexibility enhancement systems, but has to apply focus and urgency to maintain that position, according to Paul McCusker of energy storage firm Fluence.

The country’s credibility has been enhanced by the scale of renewables – notably wind – routinely accommodated on its power grid and ambitious decarbonisation targets in the Government’s latest climate plan, adds the Europe, Middle East and Africa president of Fluence.

There is 1.5 gigawatts (GW) of battery storage in planning and subject to grid connection on the island of Ireland – a gigawatt delivers enough energy to power 500,000 homes. “It’s a good number for Ireland, relative to market size,” he says, and an indication of its status among EU leaders.

During February last year, 96 per cent of island demand was covered by wind generation at its peak. Wind grabbed the headlines as a perfect combination of stormy weather and an advanced power system kicked in. “Another renewable record was only possible with the backing of battery-based energy storage,” McCusker underlines.


The technology enables renewables at scale, “while ensuring the grid remains stable and resilient”, he explains. But there are challenges to effective operation in the Irish market and a much-changed scenario in Europe because of an energy crisis exacerbated by the Ukraine war.

That was why McCusker was in Dublin this week; “to build the value case for storage in Ireland” with stakeholders and to discuss the Government’s proposed electricity storage policy framework with Minister for Climate Eamon Ryan, who has responsibility for energy. It is also why he is spending time in Brussels as the EU moves “unusually fast” to redesign Europe’s energy market.

Operators of battery storage plants could have cut some €35 million off energy bills on the island of Ireland this winter if they were allowed to sell electricity on to the wholesale market, he says

Based on the REPowerEU package, analysts forecast energy storage deployment will double by 2030, but EU policies fail to create a market environment to support rapid large-scale deployment of storage projects and other flexibility technologies, he says. “This unprecedented acceleration in renewable buildout will result in new challenges for the integration of this additional capacity.”

Operators of battery storage plants could have cut some €35 million off energy bills on the island of Ireland this winter if they were allowed to sell electricity on to the wholesale market, he says. At present, they are kept in reserve to provide emergency backup.

More capacity

Renewables do not produce power constantly amid increased electricity demands, especially from data centres. This means storage has become important for energy security. Operators are contracted to provide power at short notice if there is not enough supply to meet demand. The technology is there but requires regulators to change the rules here and at EU level, adds McCusker, an Armagh native based in Amsterdam.

“Ireland has to move to actioning now, to meet those KPIs [key performance indicators] in the climate action plan,” he says, and to accommodate buildout of renewables in a future scenario where there is more capacity than demand in the country to ensure it can become a clean-energy exporter.

Capacity to produce an abundance of wind and solar at zero marginal cost means “having the ability to flex the system” and ensure it remains stable in a cost-effective way, McCusker says. “That is where battery storage comes into its own” – especially where there is very tight capacity, as is the case in Dublin.

Subsidies to support deployment of energy storage are not critical, he believes, but market reforms recognising its critical value, while enhancing backup capacity, are needed as well as greater certainty for investors so the sector can participate properly.

Battery storage needs to be acknowledged as a different asset class, he says, requiring high capital expenditure and low operational expenditure – the opposite to gas generation – and longer contracts.

Technology advances will bring greater power density and battery performance, but their ‘sustainability and circularity’, including recyclability, will be critical

“There has been a good start with strong buildout. There is a lot of capital looking to be deployed. Ireland is an attractive market for that,” he says. EirGrid’s DS3 programme to deliver a secure, sustainable electricity system is working “but we cannot lose that leading position” amid changed circumstances across the world. “It needs fine tuning to encourage investment and moving that bit faster than two years ago.”

Fluence, a joint venture between Siemens and AES, employs more than 1,000 people and has 5.5GW of battery energy storage deployed or contracted across more than 205 projects – 11 in the Republic, four of which are with the ESB. In the Republic, it has commissioned more than 107 megawatts (MW) of battery storage and is contracted to/constructing a further 335MW.

It was the first company to deploy battery-based energy storage on the island (Kilroot, 2016) and with Statkraft was first to deploy a battery-based energy storage system for providing fast-responding frequency services under the DS3 framework (Kilathmoy, 2019).

McCusker sees Irish customers pushing for longer durability with installation of four-hour storage systems over the near term if the right policy and market conditions are present. Technology advances will bring greater power density and battery performance, but their “sustainability and circularity”, including recyclability, will be critical.

Enhancing the technology with the ultimate aim of providing cheap electricity are paramount, he says. This includes minimising curtailment of renewables when they exceed applied limits, providing enhanced cyber security and “inertia services”. The power grid is evolving to include ever-higher levels of wind and solar and less thermal generation – which do not provide inertia, historically a key source of grid reliability.

‘Building collaboration’

Increasingly, Fluence will work with grid operators to strengthen their grids, “the motorways of electricity systems”, he predicts.

It recently announced an agreement with TransnetBW GmbH, the transmission system operator in the German state of Baden-Württemberg, to deploy the world’s largest battery-based energy storage-as-transmission project. It will improve energy security and significantly support Germany’s energy transition pathway by increasing the efficiency of the existing grid infrastructure, he says.

McCusker hopes Ireland’s progressive approach to battery storage and flexibility systems will be matched by Europe as the EU states scale up the technologies, while being mindful of impacts from a much-changed US approach.

Above all, “there is a need for building collaboration and strengthening supply chains at European level. There’s definitely work to be done there.”

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times