exist within a power grid, redundancy can reduce recovery time, as can redundancy in supply chains. This was particularly evident in Texas following Hurricane Harvey where nuclear power was able to operate at full capacity throughout the event and wind farms were curtailed during the event but most immediately came back online, covering much of the demand deficit seen from reductions in generation facilities located on the coast which were more affected by storm surge and flooding for longer time periods (Conca 2017).

# **6.0 - CONCLUSIONS**

The impact of natural hazard events on power infrastructure varies based on the asset being analyzed, the standards to which it was constructed, the hazard event, its severity and duration, as well as many other factors. Yet across geographies and hazards, some generalizations are possible. In many instances, design and planning considerations can enhance the resiliency of the asset to withstand and recover from an event. This is true for wildfires, drought, heat waves, flooding, hurricanes, earthquakes and more. As climate change continues to accelerate the pace and severity of weather-related events, quantifying the benefit to proactive adaptation and construction of the power grid requires better understanding. To this aim, this paper has identified several key vulnerabilities and adaptation considerations, including generation facility-specific considerations, supply chain differences in fuel types and the transmission grid.

This paper details three general areas of vulnerability: Supply chains for fuel and maintenance; Generation facility cooling systems and safe operating thresholds; Transmission infrastructure, particularly for above ground transmission lines. System-wide catastrophic failures due to extreme natural hazard events were also seen, especially in developing regions. Each of these findings is detailed in Section 3, including (where available) associated estimated costs and design considerations for more resilient operation of the grid.

# **6.1 – Areas for Future Work**

An important area of future work is to establish the likelihood of future disruptions to power systems from region specific threats. In particular, electrical distribution grids were found to be generally vulnerable to many natural hazards, but wind in particular. Historical wind data is available at high spatial and temporal resolution for much of the world. This can be used to identify regions where electrical grids would be at significant risk and to advise building and maintenance standards to ensure their resiliency. Climatological predictions for future rainfall and temperature also available and can be used to inform where cooling water might become limited. Similarly, historical data on wildfires can be used to identify regions at particular risk for these events. These predictive data can be used to design better systems, and to inform ‘build back better’ efforts.

Additional case studies on geography specific natural hazard events should also be undertaken. Several cities in Sub-Saharan Africa, Southeast Asia and South America cite aging, failing or inadequate energy infrastructure as ongoing considerations. Additional case study work for these locations could help inform the best techno-economic approach to increasing resilience. Appendix F contains information on some developing regions of the world that are of interest for future work. This includes a list of severe natural hazard events (Table F-1) and a list of geographic regions with regions of interest for case study work based on hazard exposure and an infrastructure gap (Table F-2). As an example, Lagos, Nigeria has over 20 million persons, lacks critical power, and other, infrastructure and is prone to natural hazard events including flooding and sea level rise (Gandhi 2018; Soleye 2015; Business Journal 2017; 100 Resilient Cities 2018b; Busari and Osman 2017). Kigali, Rwanda cites similar issues regarding infrastructure, energy shortages, and exposure to flood, droughts, and severe storms (Byumvuhore 2018; May and Kamurase 2009; 100 Resilient Cities 2018a; Al Jazeera 2018; Davis 2017).

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