The Effect of Off Shore Wind Farms on Sea and Land Breezes

European Union energy targets require that 27 % of energy consuption be generated from renewable energy sources by 2030. A key method for meeting these targets is installing large scale off-shore wind farms, with new developments averaging 43 km from the shore in Europe. Some existing wind farms in the UK are only 20 km from the shore such as the London Array and Great Gabbard wind farms. The close proximity to the shore bring about questions as to the impact of wind farms on local meteorological phenomena such as sea and land breezes.

Sea breezes are important in coastal regions because of the impact they have on local temperatures and human comfort. The collision of sea breezes can also play an important role in the triggering of convection over islands, or over peninsulas such as the SW of the UK. There are two potential drivers for wind farm impacts on sea and land breezes: the first being increases to night time surface temperatures reducing the strength of a land breeze and secondly the additional turbulent mixing and drag affecting both sea and land breezes. It is unclear what the implications of these secondary impacts are for the strength and propagation of sea breezes.

In order to understand these effects, numerical simulations are presented using the Weather Research and Forecasting model. Both idealised simulations and case study simulations are used to analyse the dynamical changes that occur with offshore wind farms and also see how these may affect areas in the UK with strong convective activity.