The information contained within this Announcement is deemed by Invinity Energy Systems plc to constitute inside information as stipulated under the Market Abuse Regulation (EU) No. 596/2014 as it forms part of UK law by virtue of the European Union (Withdrawal) Act 2018 ("MAR").

29 December 2025

Invinity Energy Systems plc

("Invinity" or the "Company")

First Endurium Enterprise Order

3.5 MWh Endurium Enterprise system to be collocated with onsite PV at customer site in France

Invinity Energy Systems plc (AIM: IES) (OTCQX: IESVF), a leading global manufacturer of utility-grade energy storage, is pleased to announce the first sale of its Endurium Enterprise product, which was launched earlier this year.

This project will see a 3.5 MWh Endurium Enterprise system, collocated with an existing onsite PV array, deployed at Charles Murgat, an aquaculture business in France. Chosen for its safety and durability characteristics, Invinity's battery system will enable the facility to maximise its use of self-generated solar power, improve resilience and perform other services such as peak load management as required. The installation of vanadium flow batteries is expected to deliver a significant reduction in energy costs for the site whilst improving resiliency and enabling the facility to operate with a reduced carbon footprint, supporting their commitment to environmental and ecological responsibility.

Endurium Enterprise is the latest addition to Invinity's product line and is specifically designed for commercial and industrial ("C&I") businesses looking to deploy proven, safe and cost-effective on-site energy storage to deliver low-cost, low-carbon electricity on demand.

Commencement of the project remains subject to the receipt of relevant construction permits, which are expected to be received soon, with delivery of the batteries therefore expected during H2 2026.

Jonathan Marren, Chief Executive Officer at Invinity said:

"We launched Endurium Enterprise in September this year and this announcement marks our first such sale. Endurium Enterprise is designed for C&I businesses often using the system "behind-the-meter" and the use case by Charles Murgat is exactly the sort that we envisaged.

"The efforts during 2025 by Invinity to reduce the product cost of Endurium are now starting to be rewarded. This sale, which is not reliant on subsidy or grant funding but is justified on a purely commercial basis, is an incredibly exciting milestone and provides an excellent reference case for other businesses looking to reduce their energy supply costs by deploying our vanadium flow batteries.

"Our Enterprise product delivers low-cost, low-carbon energy on demand for C&I customers who look for market-leading safety, sustainability and durability from their energy storage solution. We're looking forward to delivering this project and many more like it in the future."

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Notes to Editors

Invinity Energy Systems plc (AIM: IES) (OTCQX: IESVF) manufactures vanadium flow batteries for large-scale, high-throughput energy storage requirements of business, industry and electrical networks.

Invinity's factory-built flow batteries run continually with no degradation for over 30 years, making them suitable for the most demanding applications in renewable energy production. Energy storage systems based on Invinity's batteries are safe, reliable, and economical, and range in size from 1 to hundreds of megawatt-hours.

Invinity was created in April 2020 through the merger of two flow battery industry leaders: redT energy plc and Avalon Battery Corporation. With more than 190 MWh of systems deployed, contracted for delivery or awarded for projects across more than 90 sites in 17 countries, Invinity is active in all major global energy storage markets and has operations in the UK, Canada, USA and China. Invinity Energy Systems plc is quoted in the UK on AIM and trades in the USA on OTCQX.

To find out more, visit invinity.com, sign up to our monthly Investor Newsletter here or contact Investor Relations on via +44 (0)20 4551 0361 or [email protected].