Grid resilience to natural disasters
If EU citizens are to have reliable power in instances of natural disasters, the grid needs to be designed to be more resilient, rather than just reinforcing existing assets.
If EU citizens are to have reliable power in instances of natural disasters, the grid needs to be designed to be more resilient, rather than just reinforcing existing assets. That is one of the findings revealed in a study by Joint Research Centre (JRC) scientists, who also claim that collaboration and harmonisation - whether it’s across borders or policy lines - are key to ensuring the EU’s power grid can stand up to natural hazards.
The report ‘Power grid recovery after natural hazard impact’ analyses the characteristics of different natural hazards, how they influence power grid recovery time and what the most effective mitigation strategies are. Factors affecting the power grid recovery time in the aftermath of natural disasters include the resilience of electric power utilities and the disruption of other critical infrastructure - either as a direct result of the natural event, or because of the loss of power supply.
The report makes a number of recommendations for building the resilience of the EU power grid, including:
Integrating risk assessment and risk management efforts across various policy areas that directly or indirectly affect the electricity infrastructure;
A transition of hazard mitigation strategy from ‘asset hardening’ (strengthening components of the grid such as buildings and equipment, to withstand hazard impacts) to ‘resilience building’ (designing the grid so that operation can continue when critical infrastructure is damaged);
Improving cross-jurisdictional and cross-border emergency management capabilities related to the provision of electricity. Policies should ensure interoperability between neighbouring transmitter and distributor system operators, and between these operators and emergency management organisations;
Space weather forecasting capabilities should be improved to provide transmission system operators with the information they need to prepare for a severe event.
Scientists analysed the performance of the power grid following the impact of real-world natural hazard events.
Earthquakes are a particular hazard in the Baltic and Mediterranean countries. They cause damage to heavy equipment and brittle items. Ground failure and soil liquefaction can be devastating to a grid’s infrastructure. In most of 16 earthquake case studies analysed, it took between one and four days to restore power supply after earthquake impact, although the timescale ranged from a few hours to months.
Fifteen space weather events were also looked at. Until recently, this hazard was little understood in the disaster risk management community. Space weather is created by solar activity. Through geomagnetically induced currents (GICs), it affects power transmission and generation equipment, with the potential to impact the entire transmission network. Although some early warning is possible, warning lead times are typically very short. When damage is limited to tripping of a limited number of protective devices, restoration time is less than 24 hours. However, repairs of damaged equipment may take up to several months.
Floods are a common hazard across Europe and are regularly associated with power outages. Erosion due to the floodwaters and landslides triggered by floods undermine the foundations of transmission towers. Serious, and often explosive, damage may occur when electrified equipment comes in contact with water, while moisture and dirt intrusion require time-consuming repairs of equipment. In contrast to earthquakes, early warning is possible. This enables electric utilities to shut off power to facilities in flood zones, therefore minimising damage. In this study of 20 floods, power was back online from 24 hours up to 3 weeks after the flood.