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.
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Sip your summer drink while catching up on the RELaTED latest activities.
Olga Macias, researcher in the field of energy efficiency in buildings in Tecnalia, explains the intervention developed by the RELaTED project in the demonstration site of Iurreta (Spain), in order to test the possibilities of the ultra-low temperature district heating systems in a corporate building complex.
In general, metering of district heating consumption in ultra-low temperature district heating (ULT DH) systems is not different from traditional district heating. However, when electricity is used to boost DHW temperature, this share of the DHW production is no longer metered by the district heating company,or must be metered separately by an additional electricity meter.
The following article is resuming the main strategic and economic issues to be considered in developing new ultra-low temperature district heating (ULT DH) for new development areas.
RELaTED in the news
The new ultra-low temperature network in Iurreta will increase the efficiency of the existing heat plant reducing the energy bill and the CO2 emissions in the building complex.Learn more
District heating (DH) systems are one of the most energy efficient heating systems in urban environments, with proven reliability within many decades already. District heating systems are identified as key systems to achieve the de-carbonization of heating energy in European Cities.Learn more