IN Brief:
- Island Green Power has secured consent for the 125MW Broadclyst battery energy storage project in East Devon.
- The project is planned close to National Grid’s Exeter 400kV substation.
- Battery storage development is increasingly shaped by grid proximity, planning risk, flexibility value, and local network constraints.
Island Green Power has secured planning consent for its 125MW Broadclyst Energy Storage project in East Devon, adding another utility-scale battery scheme to the UK’s expanding storage pipeline.
The project is planned on agricultural land around 1.5km east of Broadclyst village. The site has been selected partly because of its proximity to National Grid’s Exeter 400kV substation, with the battery designed to store renewable electricity from the grid and discharge power when needed.
Broadclyst is listed by Island Green Power as a battery storage project of up to 125MW. The developer’s project information identifies annual carbon savings of around 2,100 tonnes, with average annual power output equivalent to the electricity use of 946 homes.
Battery energy storage systems are moving through planning in greater numbers across the UK as the electricity system adjusts to higher renewable penetration. Storage assets can absorb electricity when generation is high or demand is low, release power during tighter periods, and provide flexibility services that support the balancing of an increasingly weather-dependent grid.
Grid proximity is now one of the main factors determining storage project viability. A scheme close to suitable transmission or distribution infrastructure can avoid some of the cost, delay, and engineering complexity associated with long connection routes. Even well-positioned projects still depend on local planning approval, network studies, transformer availability, fire-safety design, noise assessment, drainage, construction access, and a workable route to market.
Battery planning applications are also becoming more detailed as projects move into communities already familiar with solar, wind, and grid-connection development. Containerised battery units, inverters, transformers, substations, underground cabling, acoustic treatment, perimeter fencing, landscaping, and fire-water management all need to be assessed before a project can move from paper consent to construction.
The UK storage market has shifted well beyond the early focus on frequency-response revenue. Newer projects are being developed against a broader commercial stack that can include wholesale price arbitrage, balancing mechanism participation, ancillary services, capacity market revenue, constraint management, renewable co-location, and local network support. Installed megawatts are only part of the asset case; duration, control software, cycling strategy, degradation management, connection capacity, and optimisation route all shape performance.
Across Europe, battery projects totalling several gigawatt-hours are moving forward as developers respond to similar pressures around flexibility, renewable curtailment, industrial electrification, and grid reinforcement delays. That wider pipeline reflects a system problem that is becoming common across markets: generation can often be consented and built faster than networks can be reinforced.
Broadclyst also sits within the UK’s wider connection challenge. Storage can help relieve parts of the system, but the asset itself still requires grid access, protection equipment, civil works, electrical installation, commissioning, and specialist operational controls. Transformers, switchgear, high-voltage equipment, control systems, and experienced delivery teams remain under pressure across the power sector.
The project’s development route will now depend on the practical stages that follow consent. Procurement, detailed design, grid interface works, construction, commissioning, and market integration will determine when the battery becomes an operational flexibility asset rather than a consented scheme.
As more battery projects move from development pipelines into delivery, attention is shifting from headline capacity to performance in real network conditions. The most useful storage assets will be those that connect without excessive delay, operate safely over long service lives, and respond effectively to the grid conditions they are being built to manage.
