IEA-DHC Annex X: 4th generation district heating

The high level objective of this project is to analyze and extend the scope of lessons arising from early exemplar low-temperature district heating (supply temperature 50-55°C) schemes, in order to improve the cost effectiveness and environmental benefits, effectively formulating a blueprint for a new generation of district heating systems. Secondary objectives to help this to be achieved are: - Collate information that is emerging from pilot studies (mainly in Denamrk) of low-temperature DH systems serving new-built developments. The objective then is to examine the successes achieved and the problems encountered so that lessons are learned and made available for future schemes; - Widen the applicability of these lessons to high efficiency new-built developments in new DH countries; - Apply the lessons learned from low-temperature systems supplying new-built developments to those serving existing built-up areas; - Comparing the specific distribution capital costs for 4th generation district heating technology with current technology.

• Phase 1: Collating existing experience. Deliverable: Summary of experience and lessons learned with low-temperature DH systems;
• Phase 2: Applicability to DH elsewhere. Deliverable: Assessing the wider potential for low-temperature systems;
• Phase 3: Deliverable report ''Towards fourth generation deistrict heating, experiences with and potential of low temperature district heating''