Assessment of tidal stream power’s ability to enhance energy system resilience

Abstract

Results are presented from energy system modelling of the GB grid that investigates the impacts of tidal stream turbine deployment within a future energy scenario. The energy system is stress tested using 2021 as a case study year, when wind resource was lower than average, and gas prices were relatively high. Results show that the inclusion of up to 5 GW of tidal stream capacity, in place of the equivalent offshore wind capacity, results in a 20% reduction in the dispatch of combined cycle gas turbine (CCGT) generation. This is approximately equivalent to a 1 TWh reduction in CCGT dispatch per 1 GW of tidal stream capacity installed. This reduced reliance on CCGT reduces both the total dispatch cost, as well as emissions, by 6.5%. The inclusion of up to 5 GW of tidal stream in place of offshore wind exhibits a reduction in the curtailment of solar PV, offshore wind and tidal stream by 12.5%, 9% and 12.7% respectively. There is also a small but not insignificant uplift in the load factor of all battery storage capacity, of up to 3.5%. These positive system impacts should be balanced against the significant cost premium that tidal stream exhibits relative to offshore wind. Further work is needed to establish the significance of these results in the context of all relevant costs.