Climate change impacts on net load under technological uncertainty in European power systems

Abstract Renewable energy sources play a major role in future net-zero energy systems. However, achieving energy system resilience remains challenging, since renewables strongly depend on weather fluctuations, and future energy systems are subject to major design uncertainty. Existing literature mostly treats these types of uncertainty separately. Therefore, the assessment and comparison of uncertainties surrounding climate change and energy system design, and particularly their interactions, is insufficiently understood. To close this gap, we evaluate net load to assess energy system stress without relying on perfect foresight, while maintaining the temporal and spatial correlations of the climate system. Net load is calculated from hourly historical and future climate model data translated to on- and offshore wind, solar PV, run-of-river and reservoir hydropower, as well as heating and cooling demand. To scope the extent of plausible energy systems, we consider eight different design scenarios inspired by the European Ten-Year Network Development Plan and different levels of transmission expansion. We find that climate change impacts on net load are highly sensitive to the energy system design, implying that energy systems can be designed so that they are either hindered or helped by climate change. Furthermore, within an energy system scenario, climate change can change the frequency and seasonality of high net load events and their technological and meteorological composition. Wind-dominated systems with currently electrified heating levels, for instance, feature a 30% increase of high net load events under climate change, mostly in summer and fall, while fully electrified net zero systems are impacted by high net load events in winter and spring, which decrease by 50% with climate change. Our work thus calls for a wider perspective on energy-climate stress that captures the non-linear interactions of climate change and energy system design uncertainty, thereby overcoming the current focus on cold ‘Dunkelflauten’.