Increased Electrification of Heating and Weather Risk in the Nordic Power System

Weather is one of the main drivers of both the power demand and supply, especially in the Nordic region which is characterized by high heating needs and a high share of renewable energy. Furthermore, ambitious decarbonization plans may cause power to replace fossil fuels for heating in the Nordic region, at the same time as large wind power expansions are expected, resulting in even greater exposure to weather risk. In this study, we quantify the increase in weather risk resulting from replacing fossil fuels with power for heating in the Nordic region, at the same time as variable renewable generation expands. First, we calibrate statistical weather-driven power consumption models for each of the countries Norway, Sweden, Denmark, and Finland. Then, we modify the weather sensitivity of the models to simulate different levels of heating electrification, and use 300 simulated weather years to investigate how differing weather conditions impact power consumption at each electrification level. The results show that full replacement of fossil fuels by power for heating in 2040 leads to an increase in annual consumption of 155 TWh (30%) compared to a business-as-usual scenario during an average weather year, but a 178 TWh (34%) increase during a one-in-twenty weather year. However, the increase in the peak consumption is greater: around 50% for a normal weather year, and 70% for a one-in-twenty weather year. Furthermore, wind and solar generation contribute little during the consumption peaks. The increased weather sensitivity caused by heating electrification causes greater total load, but also causes a significant increase in inter-annual, seasonal, and intra-seasonal variations. We conclude that heating electrification must be accompanied by an increase in power system flexibility to ensure a stable and secure power supply.