Heat pumps are becoming an increasingly popular and efficient solution to raise the share of residual heat sources in district energy systems.
This Celsius webinar brought together experts from the International Energy Agency’s (IEA) Heat Pumping Technologies programme Annex 47, to explore the main drivers and barriers for the deployment of heat pumps in district energy systems.
1. IEA Annex 47 – Heat Pumps in district heating and cooling systems
Svend Vinther Pedersen, Senior specialist at the Danish Technological Institute
Power point presentation by Svend Vinther Pedersen / Short cut to the video recording
The evolution of the four generations of district heating is described, and the classification of DHC is presented, based on temperature levels. The integration of heat pumps in the DHC is crucial, and it can be either de-central (close to the heat source) or central (close to the user), or a combination. In Europe, presently 12% of the households have district heating (DH) today, although it varies significantly between countries. However, in order to minimize CO2 emissions, it is recommended that the share should be around 50% in 2050, and in the Heat Roadmap Europe 2050, heat pumps cover 25% of the DH.
2. Barriers and opportunities for large-scale heat pumps in district heating and cooling networks
The motivation to use heat pumps in domestic heating and cooling can be divided into the following areas:
- Usage/capture of low temperature alternative heat
- Enabler for other alternative energy sources
- Link to electricity grid (balance of energy domains)
- Reduction of the network temperatures
- Increasing transport capacities, by using the return line as a source.
In Europe, Sweden stands out with a very high installed heat pump capacity, about 2/3 of the capacity of Europe in total.
Within the project connected to Annex 47, challenges were investigated related to customers, society/politics, market, and technology/innovation. The challenges were then sorted into social, technical and economic barriers, with some natural overlap between the three. Economic and political framework, new business models, local involvement, system thinking, circular economy, fair pricing, capacity expansion, and standardisation were suggested as possible solutions to overcome the barriers. Success factors for heat pumps in DHC include strong partners, projects, energy spatial planning, and price signals to fossil fuels. A network in Vienna, Austria, is presented which includes central Europe’s largest heat pump as an example of DH.
3. Heat pumps in district heating systems
On the Swedish heating market, district heating dominates in multi-family houses, and heat pumps in single-family houses. Facilities and multi-family houses with an installed heat pump are often connected to district heating. DH is often used as auxiliary heat, when needed. Future smart grids would benefit if it would be possible to alter the heat production based on the demand and supply. Hybrid heat pumps exist on the European market, with the possibility to alter between heat pump and gas/oil boiler.
Along that line, a project is described on how to optimize the combination of heat pumps and district heating in multi-family-houses. This is done by minimizing the variable cost by using an algorithm that was developed in the project. For each hour, the algorithm chooses the lowest cost, by selecting heat from heat pump or from district heating. This is demonstrated in a case study, performed in the city of Linköping, Sweden.
4. Questions from the audience
- What has been your operational experience on running heat pumps on part-load?
- Have you estimated GHG savings from the HP-DH hybrid project (RISE)?
- Which generation of district heating does cities normally start in nowadays?
- How quickly are heat pumps able to respond to peaks in demand?
- What are the favourite solutions for domestic hot water (tap water) for domestic multi-family houses?
- To what degree is noise a factor for neighbours for these large heat pumps?
Date of webinar