Natural Power has successfully supported Statkraft in delivering the Cushaling Wind Farm and co-located battery energy storage system (BESS) in County Offaly, Ireland. The project, now fully energised and operational, represents a significant milestone in Ireland’s renewable energy infrastructure development.
Project Overview
The Cushaling project combines a 55.8MW wind farm with a 20MW battery energy storage system capable of four-hour duration operation. This marks Ireland’s first grid-scale battery storage system of this duration, setting a new benchmark for renewable energy integration in the country.
Under a project management agreement with Statkraft, Natural Power served as project manager, site manager, engineer, and project supervisor design process (PSDP). The company provided comprehensive management and technical oversight from the development phase through to energisation.
Technical Specifications
The wind farm features 6.2MW turbines with tip heights reaching 185 metres, making them the tallest on any wind farm in Ireland. The battery storage system, supplied by Fluence, a global leader in utility-scale energy storage solutions, is designed to store and provide 20MW of power for up to four hours.
Statkraft announced plans for the project in September 2023, with the BESS and wind farm receiving planning approval in September 2020. Construction of the battery project was initially expected to be completed by late 2024.
Operational Capabilities
The battery system enables energy from renewable sources to be stored during periods of low demand, reducing costly curtailment. The stored energy can then be dispatched during peak electricity demand periods. This capability addresses one of the key challenges in renewable energy integration: matching variable generation with fluctuating demand.
The project also supports EirGrid, Ireland’s transmission system operator, in maintaining network stability by delivering fast-acting system services as more non-synchronous renewable generation comes online. This function is crucial as Ireland increases its renewable energy capacity.
Strategic Importance
Kevin O’Donovan, Managing Director of Statkraft Ireland, stated that the longer-duration storage capability demonstrates Statkraft’s commitment to innovation and embracing advancements in battery technology. The co-location of the battery system with the wind farm on the same site maximizes the use of available infrastructure and land resources.
The Cushaling BESS secured a 10-year T-3 2024/25 capacity contract, enabling it to participate in Ireland’s capacity market. This participation helps ensure sufficient generation capacity to meet peak demand periods, typically occurring in December each year.
Grid Integration and Market Participation
As grid capacity in Ireland becomes increasingly scarce, the strategic location of storage systems helps mitigate the risk of local constraints and supports congestion management. The Cushaling battery project is positioned to store energy from renewable sources in the midlands area, addressing regional grid challenges.
The four-hour duration capability provides greater flexibility for energy trading opportunities, particularly during periods of volatile wholesale prices. Batteries can deliver their full power for 0.5-4 hours, allowing participation in multiple market mechanisms including the balancing market and capacity market.
Rory Griffin from Statkraft Ireland noted that the decision to implement a four-hour system was influenced by market conditions in Ireland, available site size, and technology maturity beyond two-hour duration systems. The team also optimized the rating of the main grid transformer to enable capacity sharing with the Cushaling wind project.
Natural Power’s Role and Expertise
Neil Mullan, Associate Director for Construction at Natural Power, emphasized the significance of the project’s completion. He stated that the project demonstrates what can be achieved through strong collaboration and technical excellence, delivering clean, reliable energy infrastructure that will support Ireland’s renewable energy ambitions.
Natural Power has established a significant presence in Ireland’s renewable energy sector since entering the market in 2013. The company opened its Dublin office initially and has since expanded with a second office in Castlebar, County Mayo. Ciaran Farrell serves as Country Director for Natural Power Ireland.
The company has worked on over 450 renewable energy projects across wind, solar, and energy storage technologies in Ireland. Notable projects include the Codling Wind Park, which is the largest Phase 1 offshore wind project currently in development in Ireland, as well as ESB’s offshore wind farm developments and various solar projects.
Natural Power provides end-to-end services across the project lifecycle, including advisory and analytics, due diligence, consenting and environmental impact assessment, project management, construction, engineering, and operations support.
Broader Context
The Cushaling Battery is the third battery project developed by Statkraft in Ireland, following two previous installations in County Kerry. Statkraft built Ireland’s first grid-scale battery at Kilathmoy—an 11MW, 5.6MWh lithium-ion system that commenced operation in April 2020.
Ireland’s Climate Action Plan 2024 sets ambitious targets including 9GW of onshore wind capacity, 8GW of solar capacity, and at least 5GW of offshore wind capacity to be connected by 2030. The plan aims for 80% of electricity demand to be supplied by renewables, requiring unprecedented levels of investment in renewable electricity generation and grid infrastructure.
Industry Partnerships
Brian Perusse, Managing Director of Fluence Energy Ireland Ltd, commented on the collaboration, noting that continuous advancements in energy storage technology position the sector well to serve both flexibility and peak capacity needs in the market. Fluence expressed satisfaction in collaborating with Statkraft on bringing the first four-hour duration battery-based energy storage system to the Irish market.
The successful completion of the Cushaling project demonstrates the viability of hybrid renewable energy systems combining wind generation with long-duration storage. This model addresses grid stability challenges while maximizing the utilization of renewable resources.
Policy and Future Development
While system constraints can last longer than four hours, the Cushaling team had confidence in delivering a four-hour system that could mitigate constraint risks. The project also creates opportunities for policy development around long-duration energy storage.
In late 2023, EirGrid issued a Call for Evidence regarding what a long-duration energy storage (LDES) specific auction would entail. Statkraft participated in this consultation process. The Department of Environment, Climate and Communications was expected to publish its Electricity Storage Policy Framework for Ireland, which would provide further guidance for the sector’s development.
The Cushaling Wind Farm and BESS project sets a precedent for future renewable energy developments in Ireland, demonstrating the technical and commercial viability of integrating wind generation with substantial battery storage capacity. This integration model is expected to become increasingly important as Ireland works toward its 2030 renewable energy targets and longer-term decarbonization goals.
