Large heat pumps in district heating systems. A state-of-the-art study

The report "Large heat pumps in district heating systems. A state-of-the-art study" explores the role of large-scale heat pumps in district heating networks, particularly in Finland and the Nordic countries. Readers will learn about Finland’s energy policy goals, which focus on reducing fossil fuel use and transitioning to an emission-free energy system. The report highlights the increasing importance of heat pumps, waste heat recovery, and thermal energy storage in achieving these goals. The study reviews key manufacturers of large heat pumps and presents case studies from Nordic district heating systems. These case studies provide insights into the practical implementation, benefits, and challenges of integrating heat pumps into existing networks. The evolution of district heating and cooling systems from the first to the fifth generation is also discussed, emphasizing the role of heat pumps in lowering distribution temperatures and increasing the share of renewable energy. The report highlights how the growth of district cooling, data centers, and Power-to-X (PtX) plants will increase the availability of waste heat, which can be effectively utilized by heat pumps. Additionally, the study examines how district heating systems with electric boilers, heat pumps, and large thermal energy storage can help balance fluctuations in wind and solar power generation, improving overall energy system stability. The report presents a fossil-free scenario from the Heat Circulation Innovation Platform North-Savo (HCIP-NS) project, estimating that Finland’s district heating could fully replace fossil fuels by 2030. In this scenario, heat pumps would supply 12% of district heating, with installed capacity increasing from 300 MW (2022) to 1,000 MW (2030). Overall, the report provides a comprehensive overview of large heat pumps in district heating, offering valuable insights for professionals, policymakers, and researchers interested in sustainable and efficient heating solutions.