three minutes or longer<sup>6</sup> – and (2) resulting in consumers being out of power.<sup>7</sup> Netherlands reports all disruptions of at least 5 seconds, and Cyprus and Malta do not have a classification. Countries included in the dataset represent the EU-28 (without Hungary, Denmark, and Bulgaria) plus Serbia.

The 463 significant outages are grouped in 128 unique categories detailing the causes of the disruption. We label each of these categories as natural shocks, non-natural causes, load-shedding, or other. Nonnatural causes include technical problems on both supply and consumer sides as well as human error. Unlike in the US, vandalism on the electricity grid and fuel supply shortages play subordinate roles and thus are not reported as individual categories.

# 2.1.3. Bangladesh

The Bangladesh Rural Electrification Board (BREB) has recorded daily reports of division-level load shedding volumes since at least November 2009. Processing these daily reports is challenging as they are published as individual pdf scans of a non-harmonized form sheet with a layout that changes over the years. These scans have been converted into readable datafiles, from which daily division-level load shedding volumes were extracted through an automated text processing algorithm. The robustness of the resulting time series has been tested through manual comparison with the original form sheets. The load shedding volumes for divisions Chittagong, Rajshahi, Rangpur, Sylhet and Barisal have been found to be robust. However, given the lack of power outage data in Barisal, we exclude this division from the analysis. The remaining data is summarized in Figure 3.6 in annual aggregates.

Moreover, data on storm-induced outages are retrieved from daily records published at the district level by the Bangladesh Rural Electrification Board. The data reports outages that can be attributed to climatic shocks – in particular storms – during the period 2010-2017. The BREB publishes reports for 64 of its 79 power supply or Palli Biduyt Samity (PBS) zones<sup>8</sup> . However, due to heterogeneous reporting methods<sup>9</sup> and missing time stamps, we only used 28 PBS zones, distributed across 7 Bangladeshi divisions.<sup>10</sup> Therefore, estimates should be considered as lower bounds and conclusions taken as insights rather than a representative picture of the impact of storms on power outages in Bangladesh. A list of included districts and corresponding divisions may be found in the appendix (Appendix 4).

# 2.2. Climate data

# 2.2.1. ERA5 climate data for the US

To assess the storm exposure of Puerto Rico and all federal states of the USA, this paper uses global highfrequency climate data from the 5<sup>th</sup> global reanalysis (ERA5) conducted by the European Center for Medium-Range Weather Forecasts (ECMWF) using its Integrated Forecasting System (IFS).<sup>11</sup> As the dataset goes back as far as 1950, wind speed and temperature data could be extracted for all recorded outage events since 2000, and for all 52 centroid coordinates of the respective US states and territories.

> 6 Therefore, we only keep the outages falling within the scope of this definition. Twenty-five outages whose duration is unknown are included in the dataset.

> 7 The European Commission reports do not allow us to cross-check the number of consumers being out of power.

> 8 Details on zones can be found in maps posted by the BREB Directorate at: http://gis.brebms.com/.

> 9 Some reports only display yearly aggregates, preventing the matching of outages with climatic events.

> 10 On 14 September 2015, Mymensingh Division was added as eighth division of Bangladesh. Given the time frame of the data, Mymensingh will be considered as a part of Dhaka division in the present analysis.

> 11 Retrieved from https://www.ecmwf.int/en/forecasts/datasets/archive-datasets/reanalysis-datasets/era5.

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