Arverne announces a total exploration potential of up to 43 million tons of lithium carbonate equivalent (LCE), strengthening the outlook for its Lithium de France project in Alsace

Pau, September 14, 2026 - Arverne (FR001400JWR8 - ARVEN), the leading French supplier of geothermal solutions, announces the results of the independent lithium resource assessment of its Exclusive Exploration Permits (PERs) portfolio in Alsace, conducted by Sproule ERCE.

Sproule ERCE Confirms the Scale of Arverne’s Geothermal Lithium Resources

Sproule ERCE, a leading international consultancy specializing in resource evaluation and certification, has estimated[1] Indicated and Inferred[2] Resources of 26 million tons of lithium carbonate equivalent (LCE), together with a total exploration potential[3] of up to 43 million tons of LCE across Arverne’s Exclusive Exploration Permits (PERs) in Alsace. The assessment was carried out by a multidisciplinary team of geoscience and reservoir engineering experts specializing in the evaluation and modelling of geothermal resources and their lithium content. It follows the acquisition of significant new data, including the 3D seismic exploration campaign and the drilling of the first two wells at Schwabwiller. Covering the Les Sources Alcalines, Plaine du Rhin, Les Poteries Minérales, and Les Coteaux Minéraux[4] exploration permits, the report confirms the robustness of the initial assessments carried out in 2022 and 2023.

A total exploration potential significantly exceeding the Lithium de France project’s requirements

The total exploration potential significantly exceeds the requirements of Lithium de France’s development plan and confirms the long-term potential of Arverne’s geothermal and lithium-bearing asset portfolio in Alsace.

A Key Step Toward Reserve Certification

This independent assessment marks a new milestone in the valuation of Arverne’s geothermal lithium assets and further demonstrates the robustness of its subsurface modelling. The next certification phase, focused on reserves, is expected in the first quarter of 2027 and will represent a key milestone in the development of the Lithium de France project.

Pierre Brossollet, Founder and Chief Executive Officer of Arverne, commented:

“The results of the independent assessment conducted by Sproule ERCE are extremely encouraging. The estimate of a total exploration potential of up to 43 million tons of lithium carbonate equivalent confirms the scale of the lithium potential across Arverne’s permit portfolio in Alsace and highlights the significant resources available in France. These findings also demonstrate that Europe possesses, beneath its feet, part of the solution: the resources needed to strengthen its strategic and industrial independence. Against a backdrop of rapidly growing lithium demand, they further reinforce the fundamentals of the Lithium de France project, which has the potential to support production for 30 years and meet the annual needs of approximately 800,000 electric vehicles. True to our mission-driven company status, we are developing this project with the ambition of combining industrial sovereignty, sustainable value creation for local communities, and environmental stewardship.”

About ARVERNE

ARVERNE is the leading French supplier of geothermal solutions. It specialises in harnessing natural ground resources to transform them into local energy sources for heating and cooling systems and to extract lithium. A mission-driven company listed on Euronext Paris, Arverne works for local authorities and industrial companies with a focus on energy sovereignty and short supply chains.

www.arverne.earth/en

Press relations: Enora Budet enora.budet@seitosei-actifin.com +33 (0)6 72 17 84 60

Investor relations: Mathilde Guillemot investor.relations@arverne.earth +33 (0)6 64 18 35 55

[1] This independent study was conducted in accordance with the internationally recognized mining standard NI 43-101.

[2] Indicated and Inferred Resources are estimates of mineral resources based on the available geological information, with Indicated Resources benefiting from a higher level of confidence than Inferred Resources.

[3] The total exploration potential represents the estimated quantity of mineral resources that could potentially be delineated through continued exploration activities.

[4] The Plaine du Rhin and Les Coteaux Minéraux exploration permits are currently under review by the relevant authorities.