Renewable energy impact assessment

Tidal and wave energy devices remove energy from the tidal current and wave fields, respectively, and this disturbance may alter the hydrodynamics, both near- and far-field. Offshore wind structures are obstructions to the flow and any change in the near sea surface wind field could also change the low flow fields and water column structure. Any significant disturbance to the hydrodynamics within a region may alter the levels of mixing and could have an effect on the local density structure, including the levels of stratification, potentially affecting the whole ecosystem. Numerical hydrodynamic models, such as the Scottish Shelf Model (SSM), are the best tools we have to assess the potential impacts of new large developments before they are implemented.

This information page is part of the theme: 
The Scottish Shelf Model
Predicted changes from the PFOW to semi-diurnal tidal amplitude resulting from two tidal stream turbine layouts which both extract a mean power of 1.4 GW (adapted from O'Hara Murray and Gallego, 2017).

The SSM has been used for a number of studies of the potential impact of large tidal stream arrays around Scotland. O'Hara Murray and Gallego (2017) used the Pentland Firth and Orkney Waters (PFOW) sub-model to examine how large tidal stream developments in the Pentland Firth could impact tidal processes in the region. It was found that smaller developments, totalling around 1 GW mean extracted power, are unlikely to lead to significant changes in the physical marine environment, whereas larger developments, > 1.5 GW mean extracted power, could significantly change the flow. This work also highlighted that thought needs to be put into where large tidal stream developments take place, in order to maximise the power outputs as well as minimise the environmental consequences. This was further discussed in a paper by Waldman et al. (2019) on the future policy implications of tidal energy array interactions. The wider SSM has been used for extensive studies of the impact of potential large tidal stream arrays around Scotland on physical processes, including stratification (De Dominicis et al., 2017) for present day and future climate change scenarios (De Dominicis et al., 2018).

References

De Dominicis, M., O’Hara Murray, R., & Wolf, J. (2017). Multi-scale ocean response to a large tidal stream turbine. Renewable Energy, 114, 1160–1179. https://doi.org/10.1016/j.renene.2017.07.058

De Dominicis, M., Wolf, J., & O’Hara Murray, R. (2018). Comparative Effects of Climate Change and Tidal Stream Energy Extraction in a Shelf Sea. Journal of Geophysical Research: Oceans, 123(7), 5041–5067. https://doi.org/10.1029/2018JC013832

O’Hara Murray, R. B., & Gallego, A. (2017). A modelling study of the tidal stream resource of the Pentland Firth, Scotland. Renewable Energy, 102(B), 326–340. https://doi.org/10.1016/j.renene.2016.10.053

Waldman, S., Weir, S., O’Hara Murray, R. B., Woolf, D. K., & Kerr, S. (2019). Future policy implications of tidal energy array interactions. Marine Policy, 108, 103611. https://doi.org/10.1016/J.MARPOL.2019.103611

Monday, October 4, 2021 - 15:30