The role of large-scale heat pumps in the future Finnish energy system
The extensive integration of renewable resources into power grids and power-to-heat technologies facilitates sector coupling and accelerates the decarbonization of the energy sector. This study investigates the introduction of large-scale heat pumps (HPs) into Finland's national power and district heating (DH) networks. The research conducts an analytical and optimization study using actual hourly generation data from 2023 and models the energy system for 2030 with projected capacity development and a focus on the significance of HP and the heat generation side. The energy system is modeled and evaluated using the Calliope and EnergyPLAN frameworks across several future scenarios. The costs and capacity of power and heat generation technologies, storage technologies, cross-border electricity import and export, DH, electricity consumption, power curtailment, and fuel use are investigated. Findings show that increasing the capacity of the HPs will reduce the biomass fuel use of the system by 9.1% by 2030 as the total wind and solar capacities are raised simultaneously. Furthermore, the development of power generation capacity significantly influences the system's cost savings. While HP and thermal energy storage (TES) can help to reduce excess electricity generation, sufficient dispatchable generation capacity or electricity storage must be maintained in the power system, which cannot be reduced with TES alone. It can be concluded that Finland can take decisive steps to the electrification of its heating networks by applying renewables and HP technologies, reaching up to 78% and 37% share of HP generation in DH networks without and with cogeneration technologies. This study offers an estimation of future production and a dynamic overview of potential shortages, emphasizing the operational limitations that must be resolved to ensure energy reliability and autonomy in the future, along with limitations in the sector coupling of power and heating sectors.