How the French islands (except Corsica) will have 100% renewable electricity

For ordinary people, they are islands. For energy stakeholders in non-interconnected zones (ZNI). Understand: territories that are 100% self-sufficient for the production of their electricity. These territories, representing 1.2 million customers, have long been dependent on their coal or oil-fired power plants to produce their electricity. Guyana can certainly count on its Petit Saut dam to produce more than 60% of the electricity it consumes, but it is an exception. The other islands are mainly dependent on fossils. They are not connected to any other, unlike the metropolis which can count on its neighbors in the event of difficulties and vice versa. Last year, while EDF's nuclear power plants were idling, France was able to import electricity from Germany, in particular.

Such a scenario is impossible for Reunion, the Antilles, the Ponant islands (Sein, Ouessant, Molène, Chausey) or even Guyana, considered “an energy island” not being connected to its neighbors. The case of Corsica is special, the island of beauty having a connection with Italy. But this dependence on hydrocarbons to produce electricity will not last. From next year, the first island territories will produce and consume 100% green electricity. “Non-interconnected areas are ahead of the metropolis in the context of the energy transition,” summarizes Antoine Jourdain, director of island energy systems (SEI) at EDF.

The difficulties encountered are inversely proportional to the size of the territories concerned. “When a power plant breaks down in mainland France, there is no shortage of alternative solutions. On an island, avoiding cuts is more complex,” adds Antoine Jourdain. EDF has deployed a budget of 15 million euros for research and development to try to solve a thorny problem: how to avoid blackouts without oversizing the network? Part of the answer has been found, in ten years the number of cuts has been divided by ten!

Better still, by 2033 the electricity produced on the islands will be almost 100% renewable. Except Corsica. This downside is linked to the fact that Corsica is connected to Sardinia and mainland Italy for a little less than a third of its electricity consumption. The greening of this part therefore depends on the Transalpines. For other territories, the challenge was twofold: responding to both the challenges of ecological transformation and strengthening energy security. The choice was made to convert thermal power plants, burning mainly coal, to liquid biomass. In Corsica and Guyana, two new power plants are under construction to complete the system.

But in sunny and often windy areas, why not focus more on wind and solar power? Projects are well under development, for around 50 megawatts of production capacity, taking into account only the part developed by EDF Renewables. But, as a precaution, there is no question of depending only on the winds or the sun. “One day of a typhoon, Martinique lost 80% of its renewable production in a quarter of an hour: too much wind to turn the wind turbines and no more sun for the panels,” summarizes Frédéric Maillard, CEO of EDF electrical production island (PEI). Hence the producer's choice to focus primarily on thermal power plants equipped with engines in which fossil fuel is replaced by liquid biomass. “Liquid biomass is a renewable and guaranteed energy. It compensates for the intermittency of wind turbines and solar panels, while dividing CO2 emissions by three,” explains Frédéric Maillard. For a power plant, 2.5 million tonnes of CO2 emissions will be avoided every year, from 2030

A green fuel therefore, but so that the remedy is not worse than the disease, EDF explains that it has been very vigilant about the origin of this liquid biomass. The group has ruled out palm oil and soybean oil, for their negative impact on the environment, ecosystems and for not competing with food uses. Rapeseed was chosen, knowing that in addition to oils, producers make rapeseed cakes intended for animal feed. In addition, the watering needs of rapeseed are limited. EDF has chosen to rely on the Saipo group, a rapeseed specialist able to guarantee the traceability of its products. The only downside: these oils must be imported from mainland France to Reunion Island or the Antilles. “Fossil fuels are also imported,” retorts Frédérique Maillard.

The energy transition of the islands is therefore on track. The 78,000 customers in Guyana will have 100% renewable energy by the end of the decade, the 419,000 customers in Reunion will be the first to have renewable electricity next year. Bourbon Island benefits from the shift by EDF but also from other local electricity producers, such as Albomia, which converted its thermal power station to bagasse - sugar cane residue. The next power plant to be converted to biomass should be that of Lucciana, in Corsica.