British Solar Renewables (BSR) has completed the construction of the UK’s largest battery energy storage facility, it has announced.

BSR says that the 49.99 MW Stocking Pelham battery is capable of delivering more than 60 MVA of power and will provide grid balancing services to National Grid under a two-year contract.

The project is located near Bishop’s Stortford, south-east England, and was originally conceived by Statera Energy, a developer of flexible electricity generation and storage capacity, who own and operate the site. The project was recently re-financed, making it not only the largest constructed battery storage facility in the UK but also a first for UK large-scale battery storage re-financing.

SMA Sunbelt Energy GmbH (SMA), a fully owned subsidiary of SMA Solar Technology AG, was selected to provide the battery installation. The 4500 m2 facility uses SMA’s proprietary E-house design, which houses batteries and other equipment in custom-built prefabricated buildings. This method reduced the site’s footprint by up to 50 per cent when compared with designs using shipping containers.

The site comprises seven E-houses, 27 inverters, 12 km of cable and 150 000 lithium-ion battery cells and is connected to a nearby 400 kV substation via a 132 kV grid connection.

In addition to the two-year contract with National Grid, the project has also secured a 15-year Capacity Market contract commencing in 2020/21, committing the unit to providing grid capacity during periods of system stress.