Sizing of generation and storage capacities for tidal stream energy systems in view of the temporal pattern of tidal stream power

The use of marine energies from waves and tides have been discussed since long, however sustained application is rare. Nevertheless, in recent years systems harnessing tidal streams in the MW scale have started commercial operation after a year-long test (OES 2019).

Tidal stream flows have – as compared to other renewable energy flows - a remarkably high predictability. However, this predictable flow is characterized by distinct variabilities on various time scales that have to be negotiated when designing their application in energy systems, see e.g. Robins et al. 2015, Lewis at al. 2019, Guillou et al 2020, for discussions on the the handling of fluctuations from hourly to weekly scales. The presence of multi-year fluctuations (variations in long term mean generation) gives the task of a reasonable sizing of storage and generation capacity for integrating the tidal generation into energy supply systems.

This will be analysed for the case of the isolated supply system of the Faroe Islands, for which the integration of tidal power is foreseen for a 2030 carbon neutral scheme (see Trondheim 2021). For this, a 25-year set of predicted tidal stream data using the IOS Tidal Package (IOS 2020) on a 2 month long measured timeseries of the current from the strait of Skopunarfjørður (Niclasen and Simonsen, 2009) is applied.

Under inspection are the storage capacities necessary to assure stable generation for given generation capacities.

References

IOS 2020, https://www.dfo-mpo.gc.ca/science/data-donnees/tidal-marees/index-eng.html, as of 20.04.2020

Guillou et al 2020, Guillou N. , Neill S.P., Thiébot J., Spatio-temporal variability of tidal-stream energy in north-western Europe, Phil. Trans. R. Soc. A 378: 20190493 , 2020 http://dx.doi.org/10.1098/rsta.2019.0493

Lewis at al. 2019, Lewis M, McNaughton J. , Marquez-Dominguez C., Todeschini G.,
Togneri  M.,  Masters I., Allmark M., Stallard Y., Neill S.,
Goward-Brown A., Robins P., Power variability of tidal-stream energy and implications for electricity supply, Energy 1832019

Niclasen B. A.,  and Simonsen K., Current measurements in Skopunarfjørður, 2009, Technical Report, NVDRit 2009:12, University of the Faroe Islands, 2009.

OES 2019, https://www.ocean-energy-systems.org/publications/oes-brochures/document/tidal-current-energy-developments-highlights/ as of 20,04.2020

Robins et al. 2015, Robins P.E., Neill S.P., Lewis MJ., Ward S.L. , Characterising the spatial and temporal variability of the tidal-stream energy resource over the northwest European shelf seas, Applied Energy, 147, 20

Trondheim 2021, Tróndheim H.M.,Niclasen B., Nielsen T., Faria da Silva F. Leth Bak C, 100% Sustainable Electricity in the Faroe Islands: Expansion Planning Through Economic Optimization, IEEE open access Journal Power and Energy 8, 2021