In France, le Réseau de Transport d’Électricité (RTE) forecasts an offshore wind capacity of 22 to 62 GW by 2050. By then, the existing nuclear fleet will see its capacity fall from around 60 GW to 16 GW as older plants close.
More specifically, the International Energy Agency (IEA) estimates that offshore wind power could produce 420,000 TWh of electricity each year, or 11 times the global electricity demand in 2040.
Thanks to these advantages, the offshore wind sector is expanding rapidly. The global installed capacity has increased from 3 GW in 2010 to 23 GW in 2018. Europe dominates the market, accounting for 80% of installed capacity.
The call for tenders for the Dunkirk wind farm in 2019 revealed that production costs are falling faster than expected: the price per MWh is €44, compared with around €65 for onshore wind power and €40-70 for ground-based solar photovoltaic power.
CNRS Research Engineer in hydrodynamics at École centrale de Nantes
Floating wind turbines hold promise for energy production worldwide: 330,000 TWh per year, or 79% of the total theoretical potential of offshore wind power.
Land-based, or onshore, wind power has shown that offshore wind power could be interesting for a country's energy balance. Offshore turbines, which are technologically less advanced at present, are the logical next step.
The challenges to overcome are not only technical, but also economic: the costs of floating wind turbines are 1.5 to 4 times higher than those of their land-based counterparts. This can be explained by the fact that they are not as technologically advanced.
Offshore wind turbines have higher load factors than land-based ones and therefore suffer from less intermittent energy production. Farther from the coast, they benefit from stronger winds for a greater production capacity.
CNRS Research Director at the Laboratory of Biology of Aquatic Organisms and Ecosystems
One of the best-known effects on marine biodiversity during wind turbine operation is the artificial reef effect. If the wind farm is closed to fishing, or less visited, a nature reserve-effect can occur.
Species such as algae, mussels and anemones fix themselves onto the hard structures of the turbine and their presence attracts other species.
However, the construction stage is the one that most affects marine species negatively. Driving piles into the seabed is extremely noisy and the effects of this noise remain significant even 10 years later.
Degradation of turbine components also has an effect on the biomass present on-site. Corrosion of metal structures or electromagnetic fields caused by energy flow from the cables seem to have little impact though.
Anaïs Marechal has a PhD in Geoscience. She first became interested in earthquakes, which she studied in research laboratories and in the field for several years. In 2017, she decided to train in science journalism at ESJ Lille. Since then, she has been working as a freelance journalist for various general, specialised and professional print media where she covers climate, health and new technologies.