Power disruption risk analysis in Portugal associated with extratropical cyclones

The growing increase in frequency and intensity of extreme weather events (EWEs) has a wide impact on energy systems and consumers, such as energy transmission infrastructures - namely overhead power lines (OPL). The main objective of this work is to assess recent high-impact storms and to present the methodology of risk analysis of the extreme weather events on power outages in Portugal. The considered events are windstorms, snowstorms and heavy precipitation associated with extratropical cyclones. In this study, a comprehensive assessment of these events, synoptic conditions and large-scale dynamics are investigated using the ERA5 reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF). Furthermore, the level of risk associated with each of the identified events is classified according to the probability of occurrence and consequences, in a risk matrix, and through the cause-and-effect analysis. It is shown that, in Portugal, the extreme wind – corresponding to level 11 of the Beaufort Wind Force Scale, that is, values equal to or higher than 105 km h-1 – is the main factor that provoked the OPL disruption, between 28% and 40% of analyzed events associated with windstorms. Considering the occurrence of compound events - wind and rain - the probability of damage to OPL is between 21% and 30%; for wind and ice, it is 3%–5%. EWEs represent increasing serious risk for electrical systems, and thus this study highlights the need to develop effective solutions to minimize the associated impacts, such as the modification and upgrade of the current design and engineering standards, and electrical network monitoring.

 

References:

Gonçalves, Ana, Margarida Correia Marques, Sílvia Loureiro, Raquel Nieto, and Margarida L.R. Liberato (2023) "Disruption Risk Analysis of the Overhead Power Lines in Portugal", Energy, 263, 125583. https://doi.org/10.1016/j.energy.2022.125583

Gonçalves, A.C.R., Nieto R., Liberato M.L.R. (2023) "Synoptic and Dynamical Characteristics of High-Impact Storms Affecting the Iberian Peninsula during the 2018–2021 Extended Winters", Atmosphere, 14, 1353. https://doi.org/10.3390/atmos14091353

 

Acknowledgements:
This work is supported by the Portuguese Science and Technology Foundation through the projects WEx-Atlantic (PTDC/CTAMET/29233/2017, LISBOA-01-0145-FEDER-029233, NORTE-01-0145-FEDER-029233) and UID/GEO/50019/2019. FCT is providing for Ana Gonçalves doctoral grant (2021.04927.BD). This work is supported by national funds by FCT - Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020
(https://doi.org/10.54499/UIDB/04033/2020). The EPhysLab group is also funded by Xunta de Galicia, Consellería de Cultura, Educación e Universidade, under project ED431C 2021/44 “Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas.