A Favourable Energy Equation for the Indian Ocean Islands
The Indian Ocean benefits from one of the best solar resources in the world: with 5.5 to 6.5 kWh/m²/day of global horizontal irradiation (compared to 3.5 to 4 in mainland France), the islands of the region have a considerable comparative advantage for photovoltaic production. Coupled with the strong dependence on fuel imports (80% of Mauritian energy is imported), solar photovoltaics is not just an ecological option: it is also an economic necessity.
The Solar-Charging Model: Principles and Configurations
Direct solar charging (stations powered by PV panels without intermediate storage) is the simplest but also the most constraining configuration: charging is only available during sunlight hours. For professional and reliable use, three architectures stand out:
- PV + battery storage + grid: the most flexible configuration, allowing charging at any time while optimising self-consumption. Stationary storage (LFP batteries) has seen its cost decrease by 40% between 2022 and 2025.
- PV + grid (without storage): less expensive in terms of investment, this solution benefits from grid balancing and remains the most common for medium-sized installations (10 to 50 kW).
- Autonomous solar island: for areas not connected to the grid (isolated tourist sites, rural areas), an autonomous installation with substantial storage allows complete independence from the public grid.
ROI Analysis: An Economic Model That Delivers on Its Promises
Based on projects completed in Mauritius and Réunion between 2023 and 2025, we observe the following economic parameters for a typical installation (100 kWp PV + 200 kWh storage + 4 x 22 kW AC charging stations):
- Initial investment: 180,000 to 220,000 euros (depending on local labour and equipment costs)
- Cost of solar energy produced: 0.07 to 0.09 €/kWh over 25 years (including amortisation)
- Charging rate applied: 0.25 to 0.40 €/kWh depending on the segment (residential, hotel, public)
- Return on investment: 7 to 9 years without grants, 5 to 6 years with available subsidies (ADEME for Réunion, Green Fund for Mauritius)
Emerging Business Models
In 2025, two business models dominate the island solar charging market:
The integrated CPO (Charge Point Operator) model: the operator owns and operates both the solar infrastructure and the charging stations, monetising the energy produced from end users. This model is adopted by players such as Engie Réunion or Corolis Energie.
The B2B energy-as-a-service model: the operator finances and installs the infrastructure on behalf of a client (hotel, company, co-ownership) and invoices the energy consumed at a fixed rate over 10 to 15 years, with no initial investment for the client. This model, inspired by solar leasing, is rapidly gaining ground in the hotel sector.
Outlook 2025-2030
The growing integration of V2G (vehicle-to-grid) electric vehicles into the equation opens new prospects: in 2025-2026, the first V2G deployments in the islands of the region will allow EV batteries to act as distributed storage, stabilising the island electricity grid and further reducing the effective cost of charging. The island territories of the Indian Ocean, often regarded as peripheral markets, could thus become advanced laboratories for the energy transition.