An integrated framework for evaluating tidal stream generation potential and its power system benefits: evidence from Great Britain

This paper presents an integrated framework that combines geospatial analysis with power system modelling to evaluate the optimal deployment and system-level value of tidal stream generation in Great Britain (GB). High-resolution geospatial screening – based on tidal maximum current velocity (≥ 2.5 m/s), mean tidal speeds (≥ 1.5 m/s) water depth (35–45 m and 30–50 m), and distance to shore (≤ 50 km) – is coupled with a multi-objective NSGA-II optimisation to identify Pareto-optimal sites for tidal stream development. The results indicate that promising locations are concentrated in a limited number of high-resource coastal regions, notably around the Orkney Islands and Pentland Firth, the Anglesey and North Wales coastline, and the Bristol Channel. These sites are subsequently incorporated into a 17-zone representation of the 2030 GB electricity system using the PyPSA model. Simulation results show that deploying 1.5 GW of tidal stream capacity – on an energy-equivalent basis in place of wind and solar PV – reduces variable renewable curtailment by 0.6 TWh, displaces a comparable volume of gas-fired generation, and lowers total system operating costs by £65 million per year. Furthermore, analysis of electricity market impacts indicates reductions in average generation costs of up to £1.0/MWh in high-cost zones, alongside relatively stable technology-specific market capture prices for tidal stream generation compared to wind and solar. The proposed framework is modular and scalable, making it applicable to other coastal regions and power systems using location-specific datasets and scenarios.