A Tool for Assessing Acute and Long-term Climate Risks for Electric Power Distribution Utilities
Authors: Gkika Aikaterini , Lymperi Ourania-Anna , Varouchakis Emmanouil , Pavlides Andreas , Zacharis Efstratios , Lekkas Efthymios 
Published: March 2024

Modern electric power systems are critical and highly complex infrastructures that are designed to ensure a reliable electricity supply to consumers under normal operating conditions and common failures or expected disturbances. Although these infrastructures have achieved high degrees of reliability, they are however not capable of effectively dealing with unpredictable extreme situations with low-frequency rates but severe impacts, usually caused as a result of extreme weather events. In parallel, electricity grids are aging and were designed for climate bands that are now obsolete because of the changing climate and the subsequent weather extremes; this has left infrastructure operating outside of its tolerance levels. Consequently, the adverse effects of climate change on networks and their associated financial costs make it essential to establish long-term action plans and adaptation strategies to enhance network resilience.
In this paper, a methodological framework is developed to support decision-making for enhancing the climate resilience of the Hellenic Electricity Distribution Network Operator (HEDNO), allowing for the promotion of risk knowledge, and the evaluation and prioritization of the required technical interventions. The selected hazards are divided into acute climate risks (i.e., wildfire, flood, rainfall, high wind, lightning strike, snowfall, heatwave) and long-term climate risks (i.e., drought, humidity, ambient temperature rise, sea level rise, ground instability/ landslide, coastal erosion). The approach includes the performance of a comprehensive and systematic assessment of vulnerability and risk for all HEDNO&#8217;s administrative regions, following international best practices and in particular the European Commission&#8217;s technical guidance on the climate proofing of infrastructure.
The process followed consists of 2 separate phases:

Climate vulnerability assessment: This phase includes an initial screening for identifying potential climate risks through sensitivity, exposure, and vulnerability analysis based on scientific evidence and geographical considerations.
Climate risk assessment: A more detailed analysis is performed to assess the impact of climate risks and determine the adaptation solutions required. The purpose is to examine the longer cause-effect chains linking climate risks to how a network infrastructure project performs across several dimensions (technical, health and safety, environmental, social, financial, etc.) and to investigate interactions between different factors. During this analysis, issues that might not have been picked up by the vulnerability assessment can be identified.

This methodology has led to the development of vulnerability and risk maps per hazard for each HEDNO&#8217;s region, highlighting climate change hotspots. Moreover, a more advanced approach has been adopted by conducting Monte Carlo simulations to estimate the spread of the risk for various areas in Greece because of three hazard groups: acute climate risks, long-term climate risks, and major risks for the electricity distribution network. The investigated areas include the geographical regions corresponding to the 5 HEDNO&#8217;s Regional Departments, i.e., Attica, Central Greece, Peloponnese-Epirus, Macedonia-Thrace, and Islands. More than 10,000 simulations have been conducted on each of the investigated regions for the above hazard groups and the results are provided as histograms.
The proposed framework aims to provide a methodology resource for power utilities to implement targeted climate change adaptations and improve network resilience.