The Alchymiste Project, led by Corsica Sole, is an innovative energy initiative aimed at achieving energy autonomy and decarbonization for island territories. Given the unique energy challenges of islands—high costs, fossil fuel dependence, and grid stability concerns—the project seeks to integrate large-scale renewable energy using hydrogen technology.

The Need for Hydrogen in Islands
Island grids face severe carbon intensity compared to mainland networks, with Corsica’s grid emitting seven times more CO₂ per MWh than mainland France. While ambitious renewable energy targets are set for 2050, their integration faces structural limitations due to:

• Mismatched production and consumption – Solar PV generate power during the day, but peak demand occurs in the morning and evening, leading to energy curtailment.
• Grid stability risks – Disruptions, such as disconnections from mainland links, can trigger frequency fluctuations and potential blackouts.

To address these challenges, storage solutions are essential, serving two primary functions:
1. Massive energy storage to balance supply and demand (hydropower, batteries, hydrogen).
2.Inertial storage to stabilize the grid in case of sudden outages, a role traditionally held by fossil fuel plants.
The Alchymiste Solution: Power-to-Power Hydrogen Loop
The Alchymiste Project leverages excess renewable electricity to produce hydrogen through electrolysis at the scale of a territory, which is then:

• Stored and used in thermal power plants via hydrogen-diesel co-combustion to maintain grid inertia.
• Allocated for other uses, including maritime and land transport, industrial applications, and future hydrogen-based sectors.

Hydrogen production does not compete with battery storage; instead, it captures excess renewable energy that would otherwise be wasted due to economic and grid constraints.

First Results: A 2040 Energy Scenario for Corsica
Initial simulations indicate that, with a 60 MW electrolyzer, Alchymiste could:

• Utilize 35% of excess wind and solar power in Corsica
• Produce 1,900 tons of hydrogen per year at 5€/kg.
• Contribute to increasing renewable electricity in Corsica from 38% today to 70% by 2040 while ensuring grid stability.

The Folell’Hy Pilot: A Real-World Demonstration
A key step towards full-scale implementation, the Folell’Hy project, launching in July 2025, will:

• Use solar energy (curtailed power + dedicated 500 kWp plant) to produce hydrogen.
• Supply hydrogen to the ALBA, a hydrogen-powered boat in Bastia.
• Prepare for a full power-to-power hydrogen cycle test in 2026 with a hydrogen engine.

Impacts and Future Deployment
By 2028, the project will deliver: Proven results in hydrogen-diesel co-combustion and grid modeling

• A successful Folell’Hy pilot in Corsica
• An operational roadmap for converting thermal plants to hydrogen

Beyond Corsica, the Alchymiste model is replicable across other island grids, offering a scalable path to energy independence while preserving existing grid infrastructure and local jobs.
With Alchymiste, Corsica Sole demonstrates that hydrogen can bridge the gap between renewable energy expansion and grid stability, unlocking a sustainable and autonomous energy future for island territories.