Invinity Energy Systems has reached an agreement to develop a 20.7MWh flow battery system, the UK’s largest.
The UK Department for Energy Security and Net Zero (DESNZ) has given the London Stock Exchange-listed technology provider and manufacturer the go-ahead on the project, which is the largest to be deployed by the company worldwide.
Invinity has begun manufacturing the VS3 batteries that will comprise the vanadium flow battery (VFB) system at its Motherwell factory in Scotland. Construction is expected to begin in the second half of 2025. Operation is expected to begin in 2026.
The project will be installed in the South East of England and will be the first commercial battery project in the UK to co-locate a long-duration battery energy storage (LDES) system with onsite generation.
Invinity expects to co-locate the project with a solar PV array that will be developed separately by a third party.
The project is being developed as part of a demonstration competition held by DESNZ. The Longer Duration Energy Storage (LODES) competition made over £69 million of capital funding available across two competition streams.
In 2023, it was announced that Invinity had been awarded £11 million through the LODES competition. The company said today that the total project cost is expected to be up to £20 million, of which £7-£10 million will be funded through DESNZ’s competition.
The funding will be recognised as grant income by Invinity, and the remaining funds will be derived from cash ringfenced on Invinity’s balance sheet as part of a £57.4 million fundraising project completed in May 2024, supported by the National Wealth Fund and institutional investors.
With full ownership and control of the project, Invinity says it will use its unrestricted access to trading and operating data from the site to fully optimise the battery to showcase its capabilities. It will also receive the ongoing revenue from the system’s grid balancing and energy trading services.
Invinity has acquired a 25-year lease over the project site through a special purpose vehicle. The lease can be extended by 15 years at its option, and the site has an existing approved 5.5MW grid connection and planning for a solar array and battery energy storage system (BESS).
A minor adjustment to the planning permission will be required, specifying it will be a VFB not a lithium-ion battery. An application to amend the planning permission has already been made, submitted alongside a letter of support from DESNZ, and Invinity said it expects approval to be forthcoming.
This is due to the technological characteristics of VFBs, which are not flammable and do not degrade with use.
The development of the VFB project is not contingent on the solar array being installed.
CEO of Invinity Energy Systems Jonathan Marren commented that, ahead of the LDES cap and floor scheme opening, the VFB project, using Britain-made batteries, “will act as an important reference site for Invinity’s prospective customers and partners and generate significant benefits to the company both in the short and long term”.
