District heating systems (DHs) are identified as key systems to achieve a de-carbonized supply of heating energy in European Cities, as they allow the efficient integration and balancing of various sources of renewable and waste heat sources with high levels of efficiency and economies of scale. Yet, DHs only corresponds to a market share of roughly 12% of the EU heating market today. In order to increase that number, innovative solutions and technology demonstrations are needed to pave the way for expanding and modernizing existing DH networks as well as introducing and establishing DHs in emerging EU markets.

One way to achieve this evolution is by reducing the heat intensity in districts with the progressive transformation of the building stock to Nearly Zero Energy Building (NZEB) standards, with Positive Energy Buildings being increasingly common. Low (LT) and Ultra-low (ULT) temperature district heating (DH) systems present fewer technical constraints to incorporate low-grade heat sources. Also, they operate at substantially lower costs due to fewer heat losses, better energy performance of heat generation plants, which is further improved by the use of de-carbonized energy sources at low marginal costs. In the process to substitute present DH networks with LT (50-55ºC) and ULT (~45ºC) DHs, critical issues such as treatment against legionella, adequacy of heat delivery systems, methods to directly inject RES into the district energy network, etc. need to be solved.

RELaTED aims at solving these issues by providing a demonstrated concept of ultra-low temperature network solution for new district heating systems and by implementing the progressive conversion of systems already in operation.

What are the actions foreseen by the project?

  • RELaTED will be demonstrated in four different DH networks comprising different countries, climates and network scales (Denmark, Estonia, Serbia, Spain).
  • 2 regional studies will be performed to assess the feasibility of introduction of ULT DH in two Central and South EU regions.
  • In the transition to the RELaTED ULT concept, conversion route maps and hybrid schemes will ensure successful conversion of DHs already in operation, by progressive ULT conversion of subnetworks, and main heat distribution infrastructure, guided by progressive conversion of substations for each consumer, in order to ensure continuity of service.
  • Energy planning processes will allow the selection of suitable urban areas for the integration, extension and/or development of new ULT DH networks, with better cost/benefit scenarios.

The project will interact with an array of other EU funded projects focusing on developing sustainable heating and cooling solutions in Europe.


Get the latest reports

The wait is over, the 4th RELaTED project newsletter is here!

What have the RELaTED project partners been up to recently? Take a tour through the last organised webinars, the General Assembly visits in Denmark, IAQVEC and HVAC&R Conferences and much more!

Energy flexibility and District Heating Control

The activities carried out under the RELaTED project address the need for increased energy efficiency and ne management strategies in relation to ULT DH. Installing smart meters allows for increased insight into the conditions of networks and installations and by the use of machine learning to utilize these data in new algorithms and tools.

The 3rd newsletter of the RELaTED project is out!

The third newsletter of RELaTED offers a view on the last outputs and events where the RELaTED project was presented.

Development schemes for new district heating developments

How can low temperature concepts be applied in new urban developments? The RELaTED Task 2.5 describes a set of guidelines that are, in general terms, based on best practices as most new urban development areas are different in relation to visions, DH network topology, temperature levels, buildings installations, tariff structure, management and more.


RELaTED in the news

The RELaTED concept was presented at the 50th International HVAC&R Congress in Belgrade

The advances of the RELaTED ultra-low temperature district heating concept were presented in Belgrade as part of the 50th International Congress and Exhibition on heating, ventilation, air conditioning and refrigeration (HVAC&R).

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Webinar – An innovative approach to thermal energy storage and self-sufficiency in buildings

RELaTED project will be presented at the webinar “An innovative approach to thermal to thermal energy storage and self-sufficiency in buildings”, organized by its sister EU project CHESS SETUP.

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RELaTED project presented at International Buildings Conference In Bari, Italy

The RELaTED concept was presented at the 10th International Conference on Indoor Air Quality, Ventilation and Energy Conservation in Buildings (IAQVEC).

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RELaTED innovative technologies for district heating systems

The concept of RELaTED is that where lower distribution temperatures are paired by a set of innovative technologies enabling for the rearrangement of DH networks into a collection of energy hubs, not only with local heat consumption, but also heat production, based on the following technologies:

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RELaTED demonstrations sites: Denmark, Estonia, Serbia and Spain

Considering the complexities and particularities of each district heating (DH), RELaTED concept is being implemented in four different DH networks covering extremely different climatic conditions, construction traditions, urban density, pre-existing district scheme, ownership and energy services contract schemes.

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