Enter your username and password here in order to log in on the website
District Heating and Cooling

Annex XII Project 03

The Research / IEA DHC Annexes / 2017-2020 / Annex XII / Annex XII Project 03

Integrated Cost-effective Large-scale Thermal Energy Storage for Smart District Heating and Cooling

Overview of available underground thermal energy storage concepts


Register for free and Log in in the upper right corner of the website to download the final project results.


Modern DHC systems are a key technology for the energy transition to a green economy, because they enable at a large scale to couple the heat and electricity sector and hence to increase the flexibility of the overall energy system. Large thermal energy storages (TES) in
DHC systems further render possible the integration of high shares of renewable energy sources, to integrate excess electricity from renewable energy systems (RES) and to optimize CHP. The proposed research contributes towards the development of data, information and analysis tools to encourage the use of costeffective large scale underground thermal energy seasonal storage (UTES) in smart district heating and cooling systems.

Large scale thermal energy storage technologies of interest for this international collaboration are aquifer and pit thermal energy
storage (ATES and PTES, see figures). Aquifer and pit thermal energy storages offer cost-effective solutions for large-scale
thermal energy storage applications. Where applicable, these TES types have a significant cost advantage compared to conventional
heat store. Cost levels of less than 50 €/m³ have been reached and are in particular interesting for DHC applications with a low
number of storage cycles (e.g. long-term or seasonal storage of cold or heat).

Deliverables / Outcomes

The main deliverables of this project is the completion of two base case studies:

  • York University District Cooling with integrated ambient air-cold aquifer seasonal storage study
  • Case study for a district heating system with integrated solar pit seasonal storage for a municipality in a rural area in Germany
  • a state-of-the art report on proved concepts, cost data, technology suppliers and experiences from realized projects

Project lead

Natural Resources Canada (NRCan)- CanmetENERGY
1 Haanel Drive
Building 5A
Ontario K1A 1M1

Reda Djebbar, Ph.D., P.Eng
+1 (613) 996-8828


  • PlanEnergi - Denmark
  • Steinbeis Research Institute for Solar and Sustainable Thermal Energy Systems
    (Solites) - Germany
  • Thermal Energy System Specialists (TESS) - USA