Climate change impact on Northwestern African offshore wind energy resources

Offshore wind is one of the most important sources of renewable energy. Therefore, it is crucial to assess how this resource will evolve over the 21st century in the context of a changing climate. The North African Coastal Low-Level Jet (CLLJ) region, which encompasses offshore areas from Northwest Morocco to Senegal, has an enormous wind-harvesting potential, as it provides a strong, persistent alongshore flow. In the current study, the present climate wind energy potential is featured for two heights (100 and 250 m). More importantly, the climate change impact on the wind energy density in the region is also depicted. For this purpose, the newest and highest-resolution regional climate simulations available are used, which include two ROM simulations (uncoupled and coupled) at 25 km resolution and 19 CORDEX-Africa runs at 50 km resolution. Historical and future (under the RCP4.5 and RCP8.5 scenarios) simulations are used for the periods 1976-2005 and 2070-2099, respectively. Overall, the results show that the annual wind energy density is projected to increase slightly in the northern offshore areas (<+10%) and decrease in the southern ones (>-10%). In close connection to the projected changes for the seasonal changes of the CLLJ system, in the further north regions (downwind Cap Ghir), the spring season shows the largest increases of wind energy, up to +20%, while in the offshore western Sahara, an increase of wind energy is projected in all seasons. A decrease of wind energy is expected for the southern areas.