This paper studies the influence of temperature change until 2100 under different scenarios, on different aspects of the power system of an island in the south-west Indian Ocean. In particular, the influence of temperature on photovoltaic (PV) production and electricity consumption is first assessed. While the impact on PV production remains negligible (up to 1.5 % decrease in annual production), the impact on electricity consumption could be significant in the long term (up to +8.4 % on annual consumption). The complete electrical system is then simulated, in order to size the necessary PV installations and quantify the consequent storage requirements. While installed capacity could reach the island's full potential (1200 MW, compared to 230 MW in 2022), storage requirements could rise to 1.8 GWh. It is therefore essential to anticipate the effects of climate change on the electricity grid.