Invinity Selected to Design GWh-Scale VFB System

Strategic Partnership with FlexBase to Develop World's Largest Flow Battery

Invinity Energy Systems plc (AIM: IES), a leading global manufacturer of utility-grade energy storage, is delighted to note FlexBase Group's announcement that, following an in-depth competitive selection process that reviewed proposals from flow battery manufacturers from across the world, it has selected Invinity to design a GWh-scale vanadium flow battery ("VFB") for deployment at the Technology Centre Laufenburg.

Situated in the Swiss municipality of Laufenburg, which is located on the Switzerland-Germany border, the project will feature an AI datacentre and technology campus, integrated with a VFB of up to 1.5 GWh capacity - believed to be the world's largest to date. Invinity's battery solution, which FlexBase will look to expand to 2.1 GWh in subsequent phases, will be used to support the integration of renewable energy onto the site and provide stabilisation to the grid.

The project broke ground in May 2025 and is currently under construction. Invinity will now proceed with the engineering phase of the project, which is expected to take place during 2026 and into 2027 and will generate engineering revenue for the Company, subject to the achievement of various development milestones. Following the successful conclusion of the engineering design phase, a purchase order for the battery system is anticipated to be received, allowing Invinity to initiate phased manufacturing of datacentre-optimized VFB modules for integration into the project.

Further announcements will be made in due course as the project progresses.

Marcel Aumer, Group CEO, Chairman of the Board and Founder of FlexBase Group said:

"Invinity has proven to be the strongest partner by presenting the most compelling overall package with the lowest life-cycle costs (LCOS). Invinity's vanadium flow technology is perfectly suited for our project due to its safety - particularly its non-flammability - its cycle stability, and its flexibility in application."

Pascal Wyss, Chief Innovation Officer at FlexBase said:

"In Invinity, we have found a partner that not only possesses market-ready and internationally proven technology but has also impressed us with innovative, modular solutions perfectly tailored to FlexBase. We look forward to working with the Invinity team to advance the vision of a sustainable energy future."

Jonathan Marren, Chief Executive Officer at Invinity said:

"Having just delivered the biggest vanadium flow battery in the UK, Invinity now enters the engineering phase of what will be the world's largest vanadium flow battery to date. Our longstanding focus on continually building our expertise in flow battery technology has been recognized with the award of this phase of the contract and I am extremely proud of the efforts of the Invinity team in getting us to this position."

Stay up to date with news from Invinity. Join the distribution list for the Company's monthly investor newsletter here.

The report by JMK Research and Analytics and the Institute for Energy Economics and Financial Analysis (IEEFA) discusses the Indian BESS industry and particularly the viability of current tariff schemes (tariffs here mean fixed payments auctioned for energy storage developers, not the Trump kind). Of particular note are pages 17-18, which anticipate a diversification of storage technologies in the future, and isolate VRFBs as a prominent example. The same pages also discuss the push for increased domestic manufacturing. This is of course relevant to Invinity through their strategic partnership with Atri Energy Transition. You can read a summary of the report in this ESS News article:

https://www.ess-news.com/2026/05/19/india-awards-10-4-gw-of-standalone-bess-capacity-in-2025-but-tariff-viability-remains-a-concern/

Right now, Indian storage tenders are quite short-sighted, with heavy penalties for AC-AC RTE lower than 85% (which essentially excludes any technology except LIBs), contract tenures no longer than 20 years (and usually no longer than 15), and storage durations capped at 4 hours. Hopefully we will see more flexible and LDES-focused tenders coming in the near future.

The LDES Council is also pushing for increased attention to longer durations, as evident by the white paper they released last month in cooporation with various Indian stakeholders.^(1) In July and August of last year, the Council also signed MoUs with the National Solar Energy Federation of India^(2) and The Energy and Resources Institute^(3) to advance LDES deployment.

[1] https://ldescouncil.com/wp-content/uploads/2026/04/LDES-India-Policy-Paper_April-10-final.pdf

[2] https://ldescouncil.com/ldes-council-and-nsefi-partner-to-advance-long-duration-energy-storage-ldes-for-indias-clean-energy-transition-2/

[3] https://www.linkedin.com/posts/teriin_terienvisions-activity-7353042748075106305-IFZn/

A place for general discussion and events not considered as requiring a dedicated post. Quality contributions of note and depth may eventually go on to form the basis of future curated posts.

Invinity and the Hagshaw LDES Cap and Floor Proposal

 

21 flow battery projects totalling 16.7GWh met the eligibility criteria for the LDES Cap and Floor scheme (C&F).

 

Undoubtedly for Invinity, the flagship project in the LDES Cap and Floor scheme (C&F) is 3R Energy's Hagshaw LDES proposal with a massive 6GWh renewable energy (REN) storage capacity (500MW at 12 hr duration). Crucially, their proposal is designed around Invinity's, locally manufactured, vanadium flow battery (VFB), Endurium  [1].

 

Drilling into the documents included in 3R Energy's proposal reveals that the 6GWh of Invinity's Endurium VFB have a supply value of £1.25 Billion (see details on Pg. 17 of the "R013 Socio Economic Report" at [2]), or roughly £200 million/GWh (or £200/kWh).  This also ties in with the recent Canaccord broker note (5th May'26) highlighting Invinity's ongoing cost reduction programme allowing future profitable delivery of large scale Endurium installations at a very competitive $250/kWh.

 

Note that full Hagshaw LDES project application documents can be accessed at the Scottish Government Energy Consents Unit website here [3]

 

Scanning these documents reveals that this LDES development has full support of the local community and council planning, with no outstanding objections from any of the numerous environmental, utility, and transport organisations consulted.  There's also a support letter from Invinity.

 

I believe that this Hagshaw proposal has an excellent chance of getting awarded a C&F, since the site forms part of an existing significant onshore wind cluster already generating over 300MW of power (but with no long duration storage).  3R Energy also have existing plans to expand and at least double the wind generation capacity in the surrounding areas of the cluster.  Hence, adding LDES, yields a project which can offer better utilisation of existing low carbon footprint REN assets and reduced wind generation curtailment - a big win for the Government 2030 REN targets.

 

3R Energy's role is primarily to take projects through the higher risk consent and early-stage design (i.e. site identification, land agreements, planning and consenting (e.g. Section 36 applications), environmental studies and community engagement), with capital funding coming later from utilities, investors, or project companies.  There is precedent for this with 3R Energy and Scottish Power Renewables (a subsidiary of Scottish Power Group, which in turn is part of the utility behemoth, Iberdrola), where they set up a special project company for the Hagshaw Hill repowering project [4]. 

 

For this, 3R Energy developed and consented the project, with Scottish Power Renewables funding the construction and later taking ownership of the project company.  Iberdrola would certainly have the capital to fund the ~£1.5 billion Hagshaw LDES construction, so I could foresee a similar scenario here, with the significant added incentive of a guaranteed return under C&F.

Following an anticipated award of a C&F for Hagshaw LDES, Invinity is then well positioned to secure the Hagshaw contract because it combines:

Technology Fit (12-hour, grid scale, vanadium flow battery design already specified, Endurium integral to the Hagshaw proposal)

Market Validation (multiple, existing, global deployments of Invinity VFBs)

Regulatory Alignment (meets UK LDES criteria cleanly, and aligns perfectly with the Government 2030 REN strategy)

Economic Advantage (VFBs are long life, low degradation, fully recyclable - all strongly favoured in cap-and-floor modelling)

UK Manufacturing and Employment Benefits (supporting significant local employment growth and manufacturing expansion; Hagshaw is ~20 miles from Invinity's Motherwell factory)

Offers Sovereign Energy Security (provides UK VFB supply, energy security, and local control of supply chain)

Lower Risk Profile (VFB safety, technology maturity, track record of manufacture and delivery of large scale VFB installations in theUK, i.e. Copwood,Oxford)

Naturally, securing an order of this magnitude (£1.25 Billion for 6GWh LDES) would be truly transformational for  ~£125m market cap Invinity, and that's only roughly a third of the 16.7GWh eligible flow battery projects that IES could potentially supply under C&F.  A truly multi-billion pound commercial opportunity for Invinity!

Furthermore, this is before even considering the massive potential for >500MW LDES for the plethora of Hyperscale AI Data Centres that have already been given planning approval across the central belt of Scotland (where of course Invinity also have two manufacturing bases), including within Lanarkshire (Motherwell site), the, as yet, only currently designated Scottish AI Growth Zone  [5]. An immense additionalUKcommercial opportunity for LDES, again, right on Invinity's doorstep, to complement and expand upon the (I believe) inevitable award of substantial C&F LDES supply contracts to Invinity.

 

Combining Scotland's low carbon footprint, renewable energy, with long life, low degradation, fire safe, high cycling capability LDES (i.e. Invinity VFBs), will, I feel, play a significant future role in powering these AI Data Centres, whilst fully supporting the UK net zero and sovereign energy security objectives.

 

More on the AI Data Centre angle in due course, but lets wait first for the imminent Ofgem release of the list of successful projects provisionally awarded a C&F.

 

DJW

 

References:

[1]  https://tinyurl.com/muv7yxh6

[2]  https://tinyurl.com/5n8scx3j

[3]  https://tinyurl.com/4cpa24rd

[4]  https://tinyurl.com/7d3bnnxe

[5]  https://tinyurl.com/5bpb29he