Ireland's first hybrid grid-stabilisation plant opens at Shannonbridge

What happened

Taoiseach Micheál Martin cut the ribbon on 6 March 2026 at Shannonbridge B, Ireland's first hybridised grid-stabilisation system, in Shannonbridge, Co Offaly. The plant, developed by the Irish company Lumcloon Energy with Hanwha Energy of South Korea, sits beside the 220kV Shannonbridge transmission station. Construction began in 2023 and completed in the second half of 2025.

The facility pairs two normally separate technologies. A 4,000 MVA synchronous condenser, linked to a flywheel, provides inertia and stability services; alongside it, a 180MWh battery energy storage system can export up to 20MW to the national grid for nine hours at a stretch.

The Irish Times reported the investment at €100m. Lumcloon, founded in 2008, has worked with Hanwha before: Hanwha previously developed and operated 200MW of grid-scale battery storage for EirGrid's DS3 system services programme.

The technology

The synchronous condenser is, in essence, a large spinning generator that consumes and produces no net energy but keeps a heavy rotating mass synchronised to the grid. That mass supplies what conventional coal, gas and peat plants used to provide as a by-product: inertia, which slows the rate at which grid frequency changes when a generator or interconnector trips, and short-circuit strength that keeps protection systems working. The attached flywheel adds stored rotational energy, extending the machine's ability to ride through and damp frequency disturbances.

The hybridisation is the novel part. Co-locating a 180MWh battery with the condenser on one site means the plant can both steady the grid instant-to-instant (spinning mass) and shift energy in bulk across hours (storage) — absorbing surplus wind at night, for instance, and exporting 20MW across a full evening peak.

Nigel Reams, Lumcloon's chief executive, said the plant "delivers both grid stability and energy flexibility, providing essential services to the electricity system". No other Irish installation combines the two functions in a single hybridised system.

Why it matters for UK & Ireland

Ireland's power system leans heavily on wind and solar, and as conventional thermal plant retires, the rotating mass the grid was designed around goes with it. Inverter-based wind and solar provide energy but, without intervention, neither inertia nor fault current. EirGrid's system-services programmes, under which Hanwha already ran 200MW of battery storage, exist precisely to buy those properties back; Shannonbridge B is purpose-built to sell them.

The Taoiseach called the project "exactly the kind of infrastructure required to accelerate the decarbonisation of Ireland's power system" — replacing the grid-stabilising role of fossil plant on a strong transmission node, without the fuel.

For Great Britain the relevance is direct. The same physics applies as fossil plant closes there, and the Irish plant demonstrates the next step of hybridising condensers with long-duration batteries so that one site can earn across stability and energy services.

For the all-island Single Electricity Market, more stability assets mean fewer hours in which wind output must be curtailed to keep enough conventional plant running — one of the quieter but larger costs of the transition. It is also an export story: Enterprise Ireland promotes the project as a demonstration of Irish capability in a growing global market for grid-stabilisation plant.

What to watch

Operational performance through the high-wind winter months, when inertia scarcity bites hardest, and how the plant is remunerated under EirGrid's system-services arrangements. Watch whether Lumcloon and Hanwha follow with further hybrid sites — the pairing is replicable at other retired thermal nodes with strong transmission connections, in Ireland and beyond. And watch the nine-hour battery duration: at 20MW over nine hours, Shannonbridge B is a rare European example of long-duration storage in commercial service, and its dispatch pattern will be studied by developers weighing duration against power rating elsewhere.