PROJECT DESCRIPTION
BACKGROUND
Heating and cooling systems are responsible for around half of all the energy consumed in the EU and represent the largest energy end use, ahead of transport and electricity. The supply of heating and cooling for urban areas varies markedly from one country to another and from city to city. Oil and natural gas boilers still account for a large share of all heating consumption, requiring a high consumption of natural resources and having a great impact on the environment. Reliance on boilers also increases Europe’s dependency on imported energy.
OBJECTIVES
LIFE4HeatRecovery aimed to demonstrate a new generation of highly efficient district heating networks. By means of reversible heat pumps used either for heat recovery or heat utilisation, the district heating networks involved in the project recovered urban waste heat sources available at low temperature, i.e., lower than 40°C. This included both district heating networks operated at conventional temperature (third generation, working at around 70°C to 90°C) and at low temperature (fifth generation, at 10 to 25°C).
Specifically, the LIFE4HeatRecovery networks aimed to:
- demonstrate the opportunity for and effectiveness of low-temperature waste heat recovery from multiple urban sources, through prefabricated substations based on skid-mounted heat pumps;
- demonstrate management strategies for district heating networks that can prioritise the harvesting of waste energy sources over fossil fuels use;
- demonstrate trading schemes (business models) that would allow utility companies to manage thermal energy fed by or purchased from different customers;
- develop financial schemes that enable large public and private investments to be mobilised.
LIFE4HeatRecovery also addressed climate change mitigation priorities by exploring the impact of different heating and cooling solutions on the urban heat island effect.
RESULTS
The LIFE4HeatRecovery project successfully demonstrated a series of effective interventions for waste heat recovery by implementing 3 pilot cases in Ospitaletto (Italy), Heerlen (The Netherlands) and Aalborg (Denmark). Each demo case utilised different waste heat sources for recovery: cooling processes of foundries in both Ospitaletto and Heerlen, and a data centre in Aalborg. The recovered heat is either consumed locally or redirected into district heating networks.
All demo cases recover energy through skids equipped with heat pumps and employ a complex operational logic to optimise energy use locally and its reintegration into the district heating network. The energy yields of the 3 demo cases are significant, achieving average coefficients of performance (COP) of 3–3.5, as measured during the monitoring campaign. The overall amount of recovered heat was around 90 MWh per month. Results were generally in line with expected targets. Only the prototype at the data centre in Aalborg could not deliver the amount of planned heat due to the lower number of connected servers. Nevertheless, it showed excellent performances in terms of temperature levels and system operation.
An in-depth study of management strategies for waste heat recovery enabled the design of tailored scenarios for each demo case. These scenarios consider optimal energy pricing, various incentives, and trading schemes, identifying pathways where such systems can lead to substantial energy and cost savings over the long term (different time snapshots were provided for the various demo cases, e.g., 2030, 2035, and beyond). This confirms that waste heat recovery stands as an excellent opportunity for utility companies and end users.
A replication study analysed potential partner cities and early adopters where similar solutions can be implemented, with particular focus on Castegnato (Italy), Plymouth (England), and Brunssum (The Netherlands).
