Power-to-heat will increase power system weather risk: The Nordic case

Abstract

The transition from fossil fuels to renewable power for heating is a cornerstone of the sustainable energy transition. However, the simultaneous increase in power-to-heat and renewable power generation exacerbates the weather risk experienced by the power system. The aim of this study is therefore to quantify the increase in weather risk caused by replacing fossil fuels with power-to-heat in the Nordic region, as variable renewable generation expands concomitantly. Probabilistic load forecasting techniques are used to estimate a power consumption model, which is modified to represent increased power-to-heat in the Nordic countries in 2040 and jointly simulate power consumption and variable renewable generation for a large number of weather scenarios. The results indicate that replacing fossil fuels with power-to-heat causes annual power consumption in a normal weather year to increase by 30%, from 512.1 to 667.2 TWh, compared to a business-as-usual scenario. However, peak hour consumption in a one-in-twenty weather year increases by over 70%, from 102.8 to 176.6 Gwh. Furthermore, wind and solar generation contribute little during consumption peaks. The increased weather-driven variation and risk implies that the transition from fossil fuels to power-to-heat must be accompanied by increased power system flexibility to ensure a stable and secure power supply.