Future impacts of river flow on hydropower generation in Great Britain

Climate change is likely to alter Great Britain's water resource availability for hydropower generation. This affects hydropower production due to uncertainty around the timing and magnitude of water availability, particularly run of river (RoR) schemes that lack the storage capacity to buffer seasonal flow variability. This study examines the likely future changes on RoR potential at locations across GB using the enhanced future flows (eFLaG) dataset. Results show that annual river flows are projected to increase in winter and spring but reduce in summer and autumn. This has an impact on RoR potential with a projected decrease in the near (2030–2059) and far future (2050–2079) for both summer (−19%, −32%) and autumn (−11%, −19%) throughout GB. Therefore, results indicate a decrease in the annual RoR potential in GB. This study underscores the importance of incorporating climate change considerations in the planning and operation of RoR schemes to ensure sustainable energy generation. This could be achieved by upgrading existing turbines to handle higher flows or designing new turbines capable of accommodating larger discharges to fully utilise the increased flows during winter. However, this should be done with consideration of the technical limitations and the opportunities for optimisations for system generation.