Hybrid wind-solar energy resources mapping in the European Atlantic

The complementarity of offshore wind and solar resources can enhance the energy output of a hybrid farm and reduce its variability relative to a stand-alone, conventional offshore wind farm. In this work offshore wind and solar resources are characterised and mapped in a large study area covering the European Atlantic, the North and Baltic Seas, and the Canary Islands. The intra-annual and overall variabilities of wind power density and solar irradiance are investigated, and their complementarity is evaluated on the basis of their correlation. Negatively correlated regions include the seas around Ireland and Great Britain, with vast wind resources (mean wind power density ~1500 Wm^-2 off W Ireland) and comparatively limited solar resources (mean solar irradiance ~100 Wm^-2). Positively correlated regions include notably the Canary Islands, with the highest values of solar irradiance in the study area (mean values of ~280 Wm^-2). Two study sites are chosen for more detailed investigation - one with a negative correlation, off W Ireland; the other with a positive correlation, off the Canary Islands. Even in the positively correlated regions, it is found that the correlation coefficient is never large (always under 0.2), which signals an opportunity for reducing power output variability through hybrid or co-located wind-solar farms. This, along with the other advantages of hybrid or co-located wind-solar farms (optimised use of scarce marine space, shared electrical infrastructure, shared O&M crews and vessels, etc.), attests to their potential in the European Atlantic. This potential could be realised through new hybrid or co-located wind-solar farms, or by retrofitting floating solar PV into existing offshore wind farms.