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District Heating and Cooling

Annex XIII Project 05

The Research / IEA DHC Annexes / 2020-2023 / Annex XIII / Annex XIII Project 05

Optimized transition towards low-temperature and low-carbon DH systems (OPTiTRANS)

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Project summary

District heating and cooling (DHC) can play a key role in 1) decarbonisation of urban heating and cooling systems as well as 2) supporting the overall development of the low-carbon energy system. The first is accomplished by replacing fossil-based heat supply by use of renewable, excess and natural heat sources, and by improving the system efficiency; the second by cross-sectoral linkages, providing flexibility through smart use of thermal storages, demand response and heat supply, e.g. combined heat and power (CHP) plants and heat pumps (HPs).

Previous research has confirmed that a transition to efficient, fossil-free and flexible district heating (DH) is an essential tool in meeting the ambitious emission reduction targets needed for avoiding global warming over the 1.5-2 °C limit. A concept of 4th generation district heating (4GDH) encloses the needed elements and can be considered as a useful toolbox for the transition.

A key aspect of the 4GDH concept is the lower distribution temperatures enabling the aforementioned new heat sources and improved efficiency. Instead of the already confirmed overall energy system level benefits, the focus of this project is on DH company and DH system level; how to facilitate the transition process in practice and to ensure adequate support for long-term decision-making.

Discussions with the DH companies and the industry in general have revealed a strong interested in 1) potential of the building level actions, 2) new business models and pricing, 3) potential of new heat sources, 4) managing a system with more complex heat supply and low-distribution temperatures and 5) assessing the uncertainties related to the transition. These topics form the basis of the current proposal with the relevance confirmed by numerous attached Letters of Support from each partner country. DH requires development on all heat supply, distribution and building-levels, supported by linkage to other energy sectors, storage and suitable demand response solutions. Proposed solutions will be applicable for both existing and new systems in developed and developing DH markets.

The project will utilise concrete case systems and build on previous and ongoing work.

Target Group

  • District Heating Companies

Deliverables / Outcomes

  • Report on how to overcome the practical barriers for developing DH into a low-temperature and a low-carbon system

Project lead

VTT Technical Research Centre of Finland
P.O. Box 1000 02044 VTT

Miika Rämä
Phone: +358 40 592 4000
E-Mail: miika.rama@vtt.fi

Project partners

  • IVL Swedish Environmental Research Institute, Sweden
  • DTU Technical University of Denmark, Denmark
  • VITO, the Flemish Institute for Technological Research, Belgium