This paper analyses 2,169 power outage events recorded by the US Department of Energy (2018), 463 outages recorded by the European Network of Transmission System Operators for Electricity<sup>4</sup> (European Commission, 2018), and 562 outage events recorded by the Bangladesh Rural Electrification Board<sup>5</sup> .The US outages are recorded for all federal states of the USA and Puerto Rico, and they cover the years 2000 to 2017. In Europe, reports are issued in 26 countries and cover the period 2010 to 2016. In Bangladesh, the recorded outages are limited to those that were caused by storms in the period from 2000 to 2017, since no complete index of all outages exists.

The rest of this study is structured as follows. Section 2 provides an overview of power outage data in the US, in Europe and in Bangladesh as well as details on climate data. Section 3 describes power outage patterns in the three considered regions, with a focus on their frequency, regional distribution, and type of causes (Section 3.1), as well as the duration of different types of outages (Section 3.2). Section 4 provides an analysis of the drivers of outages and compares the vulnerability of the US and Bangladeshi networks to climatic events (Section 4.3).

# 2. Data

## 2.1. Power outages

## 2.1.1. USA

Detailed data on power outage events in the US are provided by the Office of Cyber-security, Energy Security, and Emergency Response at the US Department of Energy (2018). These electric emergency incidents and disturbances are recorded since the years 2000 and cover all federal states of the US, in addition to Puerto Rico and cross-border outages affecting Canada. Furthermore, the dataset details the location, the start and end date and time, as well as the cause of the power outage. In addition, the number of affected customers is reported, though unknown in about a third of the cases. The database records a total of 2,169 power outage events between 2000 and 2017. In cases when the start and/or end date of an outage event is not recorded the outage duration cannot be inferred – thus these observations are dropped from the sample for all analyses pertaining to outage durations.

The US dataset identifies 130 unique causes of power outages, and a majority of outages record combinations of multiple causes. These causes can be categorized into natural shocks and non-natural causes. For 19 outage events the causes are unknown. Natural shocks fall into six main categories: Storms, severe weather, extreme temperature, wild fire, flooding, and other. Non-natural causes include operational and technical disruptions, including planned load-shedding and un-planned technical failures, as well as external shocks such as vandalism or fuel supply shortages.

## 2.1.2. Europe

The European Network of Transmission System Operators for Electricity reports significant outages that occurred during the period 2000-2016 in the 26 countries of the Council of European Energy Regulators (European Commission, 2018). A _significant disruption_ is defined as (1) causing a long disruption –typically

> 4 The data was retrieved from https://www.entsoe.eu/data/power-stats/ 5 Data was collected by the Bangladesh Rural Electrification Board (http://www.reb.gov.bd/).

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