An assessment of run of river hydropower potential in Great Britain

In the UK, hydropower produces 1.65 GW of energy, only 2% of the national capacity. With most large-scale storage-based hydropower potential sites already utilised in the UK, further development is minimal due to financial, environmental and construction time concerns. However, run of river (RoR) is a type of hydropower that has the potential for further development. While there are studies that estimate different ranges of RoR hydropower potential, the last UK-wide study was undertaken in 1989, meaning it is outdated. In this study, a methodological framework was created to assess the potential of RoR hydropower in Great Britain (GB) (Northern Ireland was omitted from this study due to a lack of river flow data). The hydrological, technical, financial and realisable potentials for pico, micro, mini and small RoR hydropower were determined. The results show that the total hydrological potential is 20 GW, the technical potential is 11 GW, the financially viable potential is 320–420 MW and the realisable potential is 290–320 MW. Most realisable schemes are either mini or small, situated in the west and north-west parts of GB. This study adds to the understanding of the RoR potential in GB and offers a reliable estimate of RoR hydropower that can be produced alongside suitable RoR scheme locations.