Investigating the impact of climate change on the UK wave power climate

Abstract

We explore the impact of climate change, and its uncertainty, on the prospects for wave power generation at two sites off the south-west and north-west coasts of Britain. We compare the distributions of annual mean significant wave height, mean wave energy period and wave power density in a present-day (1981–2010) and future (2040–2069) period, using a high resolution (~8km$\sim 8\,{\text{km}}$) wave model driven by a perturbed physics ensemble of dynamically downscaled regional climate model simulations. The five ensemble members were chosen (from a pool of 11) to sample the range of uncertainty in climate sensitivity, under an A1B emissions scenario. The present-day wave climate simulations were found to systematically overestimate wave energy periods when compared to an observation-based wave hindcast. There was more similarity in the wave heights, although some members still differed significantly.We tested for changes in the annual-mean wave parameters in the 2050s period. The ensemble member with the highest climate sensitivity showed a statistically significant reduction in mean significant wave height, but this was not seen in the other members. No member showed a significant change in wave energy period or wave power density.The climate change-induced differences in the wave parameters are smaller than the uncertainty of the wave climate projections, and the interannual variability of the wave climate itself, in both periods. Therefore characterising the interannual variability at these sites remains at least as important as the impact of climate change for assessing wave power output around Britain out to the 2050s.

Keywords

• Wave energy
• wave climate
• hindcast
• ensemble climate projection