The impact of electric boilers and heat storages in the Nordic power markets and district heating systems

Electrification of district heating systems has been considered as a potential solution for the decarbonisation of the heating sector. Electric boilers can utilise cheap electricity prices in the power system with a high share of intermittent renewable production. Therefore, they are an attractive technology for district heating operators. Electric boilers coupled with thermal energy storages can also increase the flexibility of the power system and decrease the curtailment of variable renewable electricity production. Diminishing carbon sinks combined with potentially increasing biomass utilisation create additional pressure to find alternative heat sources for the carbon-neutral district heating systems in Finland and Europe. Electric boilers were rare in the heating sector in the past, but they will undergo a major rollout in the Finnish district heating systems in a couple of years.
Backbone model was used to study the impact of electric boilers and thermal energy storages on the Northern European energy system. The model enables the analysis of individual district heating systems in greater detail while allowing studies on large scale system impacts. Multiple scenarios with varying capacities of electric boilers and thermal energy storages were modelled. The results show that electric boilers can reduce the use of fossil fuels and biomass in district heating production. The electric boilers mostly used electricity from renewable sources, thus the curtailment of wind power decreased. However, fuel consumption in electricity production also increased slightly. Thermal energy storages were able to reduce the curtailment further. District heating production costs decreased, but electricity price increased.