To ensure high performance in service delivery, the electricity system must be resilient, i.e., it must be able to limit the severity, extent and duration of disruptions following the occurrence of extreme environmental or anthropic events. This requires a holistic view that extends the notion of risk and also includes identification and characterisation of threats, assessment of infrastructure vulnerability and the design possible countermeasures. These may consist not only in the strengthening of infrastructure (which generally expensive) but also in active measures aimed at preventing or mitigating possible impacts on the energy grid and infrastructure and accelerating the restoration of disconnected load.

Therefore, the project aims to develop methods and tools to improve system resilience.

The project consists of three distinct research strands:

• Threats: extreme events causing the greatest disruptions are analysed using the MERIDA meteorological reanalysis dataset, environmental scenarios inferred from the latest climate models (Euro-CORDEX) under different emission assumptions and advanced hydrodynamic models to identify the return periods of individual threats. Greenhouse gas emissions are also estimated using inverse modelling to understand the level of effectiveness of policy choices to counter climate change;
• Vulnerability and Security: focus is on vulnerability models related to meteorological, hydrogeological and seismic threats, to assess the return periods of grid component failures and to analyse the occurrence and propagation of contingencies in the grid; the calculation of system resilience indicators; probabilistic assessment and control of the security of electrical systems, considering the forecasting uncertainties of generation from non-programmable renewable sources and loads. Advanced methods are proposed for assessing the seismic safety of hydroelectric systems, to remove the simplifying assumptions underlying the generally used methods, which are often too conservative;

Increasing resilience: the goal is to create a software tool with GIS capabilities that incorporates data and information acquired from the first two strands of research and allows for the identification of the optimal mix of active and passive mitigation measures needed to improve and increase the resilience of the electrical grid. Arisk-basedmethodology will be integrated into the tool to assess resilience indicators that also take into account the effects of climate change and possible development of the electricity system. In addition,nowcastingmonitoring systems and diagnostics will be developed to improve the prediction of ice sleeves on the grid (WOLF) and strong winds (WIND), to map indirect risk to overhead lines due to the proximity of tall trees, and implement a prototype of strong thunderstorm warning system by integrating radar and satellite data.