Ballynahone project

Executive Overview

The Ballynahone Energy Storage project is a 10 MW / 1 GWh iron-air battery storage facility under development near Buncrana, County Donegal, Ireland — the first iron-air battery project to receive planning permission in Europe, and Form Energy's first international deployment. The project is being developed by FuturEnergy Ireland, a joint venture between state-owned Irish forestry company Coillte and state electricity utility ESB, using Form Energy's iron-air battery technology. Donegal County Council granted planning permission in December 2024, with a 10-year permit for a facility designed to operate for 30 years. A formal partnership agreement between FuturEnergy Ireland and Form Energy was announced on March 17, 2026, targeting commercial operation in 2029.

How It Works & Differentiation

The system uses Form Energy's iron-air electrochemistry: the battery discharges by drawing in oxygen from ambient air and oxidising iron pellets to iron oxide — effectively rusting — and recharges by reversing the reaction using electricity, restoring the iron. The storage medium consists entirely of iron, water, and air, with no lithium, cobalt, or other critical minerals, and the aqueous electrolyte is non-flammable. The 10 MW facility can discharge continuously at full rated power for up to 100 hours, giving it 1 GWh of total energy capacity — more than half the capacity of Turlough Hill, Ireland's only pumped hydro facility, in a seven-acre footprint. The system comprises 248 battery units housed in standard-sized containers on a site adjacent to the Trillick electricity substation, minimising new transmission infrastructure requirements.

Commercialization & Traction

Donegal was deliberately selected for the project because wind energy curtailment rates in the county are among the highest in Ireland, driven by local grid constraints that prevent surplus renewable output from reaching demand centres. Form Energy's own modelling projects that integrating multi-day iron-air storage could reduce Ireland's annual renewable curtailment and system costs by more than 25%. The site's direct connection to the Trillick substation allows the battery to absorb stranded generation without requiring new overhead lines. The project is structured as a first phase of up to 8 GWh of capacity at the same site in subsequent phases, with each phase following the same technology and permitting template. No electricity offtake agreement has been publicly disclosed at this stage.

Scalability & Strategic Context

Ireland's 2024 Electricity Storage Policy Framework specifically identified long-duration energy storage as essential for grid reliability given the country's island status and dependence on weather-dependent renewables. The Irish government's target of 80% renewable electricity by 2030 creates structural demand for multi-day storage capable of managing Dunkelflaute periods — extended windows of low wind and solar output — that shorter storage technologies cannot address. For Form Energy, Ballynahone is the company's first deployment outside the United States and the proof-of-concept for a broader European market entry strategy. FuturEnergy Ireland's ownership by two state entities provides institutional support for the technology demonstration and reduces counterparty risk for the development phase.