Nevertheless, no simple generalizations can be made about the relationship between a country’s income level and the vulnerability of its electricity system to natural shocks. In fact, a wide range of factors determine the share of outages that are caused by natural shocks – several of which are analyzed in this study. For instance, hazard intensity and exposure are crucial. In the US, states in the South-east experience a high rate of outages due to natural shocks, as they lie in the path of Atlantic tropical storms. However, even within the US, storms of the same intensity can cause different levels of disruptions in different locations. The study shows that the rate of forest cover, i.e. vegetation, can explain why storms cause more damage in certain places. As trees and branches damage power lines, storms are more likely to be disruptive in forested regions. This also emphasizes the role of maintenance – in regions with high forest cover, maintenance (in the form of tree pruning) is all the more important.

Still, the quality and resilience of the power system itself is key to prevent frequent outages and thus ensure reliable service quality for end-users. As the evidence in this study shows, there are significant differences in network fragility across regions and countries. Using high-frequency climate data, this study shows that power systems in the US and Bangladesh have very different abilities to withstand storms. While the baseline level of outages is already significantly high in Bangladesh, the analysis also shows that the same storm intensity is far more likely to cause outages in Bangladesh than in the US. For instance, wind speeds above 35 km/h are found to be 12 times more likely to cause an outage in Bangladesh than in the US. Overall, these findings suggest that higher network resilience against natural shocks is also likely to result in a reduction of baseline fragility of the network, and thus higher service quality for users. Moreover, we find robust empirical evidence of adaptation effects. This implies that at given levels of baseline fragility, grid operators can exploit experience to design measures specifically effective against natural hazards.

# References

- Allcott, H., Collard-Wexler, A. and O’Connell, S. D. (2016) ‘How Do Electricity Shortages Affect Industry? Evidence from India’, _American Economic Review_ , 106(3), pp. 587–624. Available at: http://www.aeaweb.org/articles?id=10.1257/aer.20140389.

- Bangladesh Bureau of Statistics (2010) ‘Report of the Household Income & Expenditure 2010’,

- _Bangladesh Bureau of Statistics. Ministry of Planning_ , (1), pp. 1–5. doi: 10.1007/s13398-014-01737.2.

- Bartos, M. _et al._ (2016) ‘Impacts of rising air temperatures on electric transmission ampacity and peak electricity load in the United States’, _Environmental Research Letters_ . IOP Publishing, 11(11). doi: 10.1088/1748-9326/11/11/114008.

- Dewan, A. _et al._ (2017) ‘Spatial and temporal analysis of a 17-year lightning climatology over Bangladesh with LIS data’, _Theoretical and Applied Climatology_ . Theoretical and Applied Climatology, pp. 1–16. doi: 10.1007/s00704-017-2278-3.

- European Commission (2018) _Study on the quality of electricity market data of transmission system_

- _operators, electricity supply disruptions, and their impact on the European electricity markets Final report_ . Available at:

- https://ec.europa.eu/energy/sites/ener/files/documents/dg_ener_electricity_market_data__final_report_-_22032018.pdf (Accessed: 18 December 2018).

- Government of Bangladesh (2008) ‘Cyclone Sidr in Bangladesh: Damage, Loss, and Needs Assessment for Disaster Recovery and Reconstruction ’, (March), pp. 2–19. Available at:

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