Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - RELaTED (REnewable Low TEmperature District)

Teaser

District heating (DH) systems are one of the most energy efficient heating systems in urban environments, with proven reliability within many decades already. DHs have traditionally been designed to be operated in a hierarchized way, with central energy production facilities...

Summary

District heating (DH) systems are one of the most energy efficient heating systems in urban environments, with proven reliability within many decades already. DHs have traditionally been designed to be operated in a hierarchized way, with central energy production facilities delivering heat to a variety of distributed consumption locations.
DHs are identified as key systems to achieve the de-carbonization of heating energy in European Cities. Renewable and waste heat sources are foreseen at the same time as de-carbonized heat sources and the way to guarantee competitive energy costs with limited influence of fossil fuel supply price volatility. To achieve this, conversion of DHs is needed regarding:
- The reduction of their operation temperature to avoid current technical constraints in the integration of low-grade industrial heat sources,
- The introduction of larger shares of renewable energy sources (RES) in the DH network.
- The introduction of distributed heat sources (reject heat from cooling equipment...).
- To guarantee economic viability with the trend of DH heat load reduction due to the evolution of the building stock toward NZEB (Near Zero Energy Buildings).
RELaTED develops an innovative concept of decentralized Ultra-Low Temperature (ULT) DH networks, which allow for the incorporation of low-grade heat sources with minimal constraints. Also, ULT DH reduce operational costs due to fewer heat losses, better energy performance of heat generation plants and extensive use of de-carbonized energy sources at low marginal costs.
The RELaTED ULT DH concept will be demonstrated in four complementary operation environments (new and existing DH, locations, climatic conditions, dimension…) in Denmark, Estonia, Serbia and Spain.
RELaTED approach will follow the strategy of the electrical smart grids, in which energy generation is decentralized and consumers evolve to prosumers (they consume and produce energy).

Work performed

RELaTED is ongoing since November 2017. In the initial 18 months of the project, RELaTED has set the ground of its ULT concept, specified & designed its core technologies, initiated its DH cost modelling activity, and set the ground for demonstration, exploitation and dissemination activity.
Detailed energy monitoring systems are in place in some demonstration sites and DH flow temperature reduction processes will be conducted in the 19/20 heating season.
Integration of RELaTED technologies in demonstration sites is expected to be done before the 20/21 heating season.

Final results

District heating systems date back more than 100 years. DHs have already faced progressive temperature reductions down to about 80°C during the 20th century, which at that time was considered low temperature systems. Today, systems are laid out for 60°C/30°C or even lower. The development towards “nearly zero energy buildings”, and the extension potential of DH networks into less populated areas has led the development of low temperature district heating systems.
RELaTED will integrate present technologies into a new ULT DH concept, at distribution temperatures below commercially operative DH networks today. RELaTED will innovate in the following directions:
- Lower network heat loss
- Increased performance of RES and waste heat sources
- Re-use of reject heat from building or industrial cooling applications
- Additional RES capacity provided by dual function heat pump applications

Expected Project Results
- An ultra-low temperature (ULT) heat distribution concept, with large shares of renewable and residual energy sources, allowing for heat delivery at 40-45ºC.
- Core Technologies in RELaTED concept:
o A triple function substation (3FS) concept for heat delivery, heat rejection and RES heat injection into the grid.
o A reversible heat pump concept for primary loop connection to DH (DHRHP), adapted to dual function for reject heat delivery to district network at low temperature.
o A building integrated low temperature solar thermal façade systems (BILTST) with direct connection to the district network.
- A proven concept in 4 clearly different environments, with Successful integration of local RES and waste heat production, and 3FS, DHRHP, and BILTST systems and replication studies performed in 2 European regions.
- An adaptable and fair energy price scheme for customers of various scales: Individual housing, large consumers, multi-owner housing, etc.

Expected Project Impacts
- RES heat production in the range of 700MW.

Website & more info

More info: http://www.relatedproject.eu/.