Battery Storage Ireland – Grid Projects, Market Changes and the Push for Longer Duration

Battery storage in Ireland is at an inflection point. With around 800 MW of grid-scale batteries now operational, a planning pipeline of over 10 GW, and the country’s first four-hour battery system launched in early 2026, the technology is moving from a niche grid service to a central pillar of Ireland’s electricity system. As wind energy and solar generation grow, the ability to store excess electricity and release it when needed is becoming essential to keeping the lights on and bringing down costs.

This guide examines the current state of battery storage in Ireland, the landmark Cushaling project, the changing DS3 revenue landscape, the government’s long-duration storage targets, home battery economics, and what needs to happen for storage to fulfil its potential in the Irish electricity market.

⚡ Why Battery Storage Matters for Ireland

Ireland’s electricity system faces a fundamental challenge. Wind and solar generation are variable – they produce power when the wind blows and the sun shines, not necessarily when consumers need it most. In 2025, around 13% of available wind energy was wasted because the grid could not absorb it all, a problem that grows worse as more renewable capacity is added.

Battery storage addresses this by absorbing excess renewable generation during periods of high production and discharging it back to the grid when demand is high or renewable output drops. At a system level, batteries also provide critical grid stability services – responding almost instantly to frequency changes that would otherwise require conventional gas-fired power stations to remain running.

EirGrid, the transmission system operator, has set a target of at least 2 GW of energy storage by 2030, with the government’s Climate Action Plan calling for a minimum of 500 MW of long-duration energy storage. Ireland’s total energy storage capacity currently stands at just over 1 GW, comprising approximately 800 MW of battery projects (mostly short-duration systems of 0.5 to 2 hours) and the 292 MW Turlough Hill pumped hydro station in County Wicklow, which has been operating for 50 years.

🔋 Major Grid-Scale Projects

The landmark development in Irish battery storage is Statkraft’s Cushaling project in County Offaly – Ireland’s first four-hour grid-scale battery energy storage system (BESS). The 22.8 MW system, supplied by Fluence, was completed in 2025 and officially launched in February 2026. Co-located with Statkraft’s 55.8 MW Cushaling Wind Farm, the battery can store enough power to supply 10,000 homes with renewable electricity for a full four-hour period after the wind stops blowing.

The system’s response time is remarkable – the entire battery can be switched on by EirGrid in less than one tenth of a second, faster than the blink of an eye. This kind of rapid response is invaluable for maintaining grid frequency stability as the system accommodates larger volumes of variable renewable generation.

Before Cushaling, most grid-scale battery systems in Ireland ranged from 30 minutes to two hours of capacity. Statkraft, which entered the Irish renewable electricity market in 2018 and has invested over one billion euro across onshore wind, offshore wind, solar and storage, built Ireland’s first grid-scale battery at Kilathmoy in County Kerry – an 11 MW lithium-ion system that commenced operation in 2020.

Other significant players include ESB Networks, one of Ireland’s biggest BESS operators, and Gore Street Capital, a UK energy investment firm that owns two 50 MW projects in Northern Ireland (Drumkee and Mullavilly) and plans to add a further 180 MW of storage by the end of 2026. Siemens Energy has also announced the first hybrid grid stabilisation and large-scale battery storage plant at Shannonbridge, combining a 160 MWh battery with synchronous compensation technology.

📈 The Changing Revenue Landscape

The economics of battery storage in Ireland are in a period of significant transition. The majority of operational batteries were built under the DS3 system services framework, which provided contracted revenue for delivering grid stability services like frequency response. This framework gave developers sufficient certainty to invest, and Ireland’s DS3 revenues have at times been among the most attractive in Europe – Gore Street’s Irish portfolio generated average estimated revenue of 25.8 pounds per MW per hour during one quarter, compared to just 6.1 pounds in Great Britain.

However, the DS3 market has become saturated, with too many batteries competing for the same services, pushing tariff rates down. The scheme is due to expire at the end of 2026 and will be replaced by a new competitive auction mechanism called Future Arrangements for System Services (FASS), similar to systems used in Great Britain and continental Europe.

This transition has created significant uncertainty. Bobby Smith, CEO of Energy Storage Ireland, has noted that the majority of the planning pipeline is “holding fire until the market becomes a bit clearer.” While projects can secure planning permission relatively easily, the route to market – meaning the certainty of revenue needed to make an investment decision – remains the primary challenge.

🔄 Full Market Integration From November 2025

A significant step forward came in November 2025, when Ireland updated its scheduling and dispatch programme to allow battery energy storage systems to be fully integrated into the real-time electricity market. Before this change, grid-scale batteries mainly supported stability on the power system. Now they can actively trade energy – charging when renewable generation is abundant or prices are low, and discharging to supply power when demand is high.

EirGrid reported that within just three months of this change, reliance on conventional fossil fuel generation was reducing by almost 400 MW on some high-demand days. The grid operator also observed record battery discharge levels, reaching 502 MW on December 15, 2025. This demonstrates the immediate impact that properly integrated storage can have on both system efficiency and carbon emissions.

🔋 Long-Duration Energy Storage

The push toward longer-duration storage is a defining trend. While most of Ireland’s existing battery fleet provides 30 minutes to two hours of capacity, the industry and government recognise that longer-duration systems of four, six or even eight hours are needed to capture more of the value from renewable energy curtailment and provide energy security during extended calm periods.

Statkraft’s four-hour Cushaling system represents the beginning of this transition. Many developers in the planning pipeline are now targeting longer durations to capture more energy arbitrage revenue and improve their business cases under the post-DS3 market structure.

EirGrid opened a consultation for long-duration energy storage (LDES) procurement in late 2025 but set the proposed minimum procurement at 201 MW, well below the government’s 500 MW target. Energy Storage Ireland called for greater ambition and longer contract lengths to reflect international standards, arguing that LDES is essential for reducing renewable curtailment, maintaining system stability, and delivering energy security.

🏠 Home Battery Systems

While grid-scale storage dominates the headlines, home battery systems are a growing market in Ireland. A home battery works alongside a rooftop solar PV system, storing excess solar electricity generated during the day for use in the evening when the household’s demand is typically highest. Without a battery, surplus solar generation is exported to the grid at a relatively low feed-in rate; with a battery, more of the free solar electricity can be used within the home.

Home battery costs in Ireland typically range from 4,000 to 8,000 euro for a standard lithium-ion system with a capacity of 5 to 13 kWh. There is currently no dedicated SEAI grant for home battery installation, although batteries can be included as part of a comprehensive home energy upgrade through a One Stop Shop. The economics of home batteries depend heavily on the household’s electricity consumption patterns, the size of the solar PV system, and the available export tariff.

For homeowners with heat pumps and electric vehicles, a home battery combined with solar panels can significantly reduce electricity costs and provide a degree of energy independence. As smart home energy management systems become more sophisticated, the ability to optimise when a battery charges and discharges – for example, responding to time-of-use tariffs – will improve the financial case further.

The most common home battery brands available in Ireland include Tesla Powerwall, Huawei Luna, GivEnergy and BYD. Most systems use lithium-ion technology and are wall-mounted in a garage, utility room or on an external wall. Installation typically takes one to two days and should be carried out by a qualified electrician with experience in battery storage systems. Safety standards require that installations comply with current electrical regulations and that the battery management system prevents overcharging and deep discharge.

While the current lack of a standalone SEAI grant for batteries limits uptake, the growing installed base of solar PV panels – over 2,345 MW by the end of 2025 – is creating a natural market for retrofit battery installations. As electricity tariffs increasingly move to time-of-use pricing, with different rates for peak, off-peak and daytime periods, the financial logic of home storage will strengthen. Some electricity suppliers already offer tariffs specifically designed for customers with batteries and solar systems.

🔌 EirGrid’s Role and Grid Constraints

EirGrid plays a central role in the development of battery storage through its management of the transmission system, the design of system services markets, and the administration of grid connection processes. The grid connection queue has been a persistent bottleneck, with over 2.2 GW of storage projects either holding a connection offer or in the process of obtaining one.

The sharing of Maximum Export Capacity (MEC) – allowing a battery to share a grid connection with a co-located wind or solar farm – is not currently permitted in Ireland, something that Statkraft and others have urged regulators to change. Allowing connection sharing would reduce infrastructure costs, speed up deployment and make better use of existing grid capacity, particularly in areas where the network is congested.

The 700 MW Celtic Interconnector to France, due online at the end of 2026, will add flexibility to the system but also increases the complexity of managing flows between interconnected markets. Battery storage will be important in optimising these cross-border energy exchanges.

🔮 The Road to 2 GW and Beyond

Ireland has demonstrated that battery storage can work – the 800 MW of operational capacity and the record-breaking performance of newly integrated systems prove the technology delivers. The challenge now is creating the market conditions that unlock the much larger pipeline of projects waiting in the wings.

The planning pipeline of over 10 GW is enormous relative to Ireland’s electricity system, which has a peak demand of around 5,000 to 6,000 MW. Not all of these projects will be built, but even delivering a fraction of the pipeline would transform Ireland’s ability to manage a renewable-heavy system. The key constraint is not planning permission or technology readiness – it is revenue certainty. Developers need to know that if they invest tens of millions of euro in a battery project, there will be a clear and stable revenue stream to repay that investment.

Clarity on the post-2026 revenue framework under FASS, a more ambitious LDES procurement mechanism, reforms to grid connection processes, and enabling connection sharing for co-located assets would collectively release significant investment. The offshore wind pipeline will create enormous additional demand for storage as multi-GW projects come online later in the decade.

As the renewable energy share of Ireland’s electricity system continues to grow, battery storage will shift from a supporting technology to an essential one. The decisions made in 2026 on market design and procurement will largely determine whether Ireland has the storage infrastructure it needs to make the most of its world-class wind and growing solar resources.