1. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP IEA-DHC ǀ CHP Annex X: towards 4 th generation district heating. Experiences with and potential of low-temperature district heating. IEA DHC Annex X – End of Annex Seminar Final results: Towards Fourth Generation District Heating: Experiences with and Potential of Low Temperature District Heating Stockholm 10 September 2014 Svend Svendsen, Technical University of Denmark (DTU)

2. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP IEA DHC call in 2010 for proposals for Annex X including: Low Temperature District Heating Application of project: Towards Fouth Generation District Heating: Experiences with and Potential of Low Temperature District Heating Initiation of the project

3. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Aim of the project slide 3 The aim of the project is to bring experience, knowledge and solutions for the 4 th Generation District Heating systems to a level where they are ready to be implemented widely Phase I: document experiences in mature DH countries with very low temperature systems serving highly energy-efficient new- build developments Phase II: analyze and extend the scope of lessons arising from early examples of low- temperature systems, in order to improve the cost- effectiveness and environmental benefits, effectively formulating a blueprint for a new generation of district heating.

4. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Project participants slide 4

5. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Collaboration between different participants The Danish group contributed with concept of Low Temperature District Heating – and demonstration projects in low density low energy buildings The UK group contributed with demonstration project and represented the new user of district heating The Swedish group contributed with the concept of LTDH and experience from swedish program on energy efficient district heating and analysis of heat load density and heat sources The German group contributed with expertise on Legionella bacteria and results from very large database on investigations of Legionella in large number of buildings

6. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Close link with other projects slide 6 IEA DHC Annex X IEA DHC Annex XI IEA DHC Annex TS1 Low temperature district heating for future energy system Transformation roadmap from high to low temperature district heating system. 4th Generation District Heating Research Center EUDP project Danish Low- temperature district heating projects

7. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP The evolution of 4 Generation DH slide 7 Cited from the 4DH paper

8. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP 4th Generation DH Concept slide 8 Low-temperature SH and DHW supply Building energy conservation parallel with DH expansion Intelligent building heating load control SH and DHW supply Low/ultra-Low temperature supply Improved network design and insulation Intelligent control and metering Low network heat loss Renewable energy in different forms, together with thermal storage Industrial process heat and commercial waste heat Waste incineration Use renewable and waste heat Integrated energy planning Tariff and cost reformation to support long term stategic development Coordinated effort between different parties Institutional framework, Energy planning

9. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Impetus for LTDH Development slide 9 Mature DH countries Further DH market penetration requires extension of DH to low heat density area Maintain economic competitive advantages in the future low energy society Less developed DH countries Improve current system energy efficiency and bring additional economic benefits Transition from 1st or 2nd generation DH directly to 4th generation DH

10. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Advantages of LTDH slide 10 Heat distribution Reduced network heat loss Lower supply temperature due to lower heating load and radiator temp. Reduced pipe thermal stressReduced boiling and scalding risk Heat supply Improved power to heat ratio in CHP plant Higher heat utilization from flue gas condensation High COP of heat pump Higher utilizaiton of low temperature heat source Higher utilization of geothermal and solar energy Greater utilization of thermal storage

11. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Major research questions slide 11  What are the main advantages of LTDH?  What technology options are available for LTDH, and what are the associated challenges to consider?  How can the risk of Legionella be mitigated in LTDH?  What lessons can be learned from early LTDH projects?  What heat distribution costs are associated with LTDH?

12. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Structure of the IEA Report slide 12 Specific DH distribution cost Strategic energy planning Energy saving and renewable energy planning Low heat loss distribution network DHW Installation Safety DHW supply LTDH supply low-energy buildings LTDH supply existing buildings Low temperature heat sources Case studies

13. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP LTDH experiences slide 13 1 2 3 4 5 6 7 1. Lystrup, Denmark 2. Ackermannbogen, Germany 3. Okotoks, Canada 4. Chalvey, UK 5. Kırşehir, Turkey 6. Falkenberg, Sweden 7. Halmstad, Sweden

14. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Major conclusions slide 14  Distribution cost: acceptable capital costs and acceptable heat losses of distribution can be achieved for low-energy buildings with low specific heat demands, if these buildings are concentrated in urban areas.  Strategic energy planning: DH network expansion can run parallel with building energy conservation. Investment of renewable generation capacity can be reduced if it can be based on energy conservation in buildings.  DHW supply: - It is possible to supply DHW based on low-tempeature district heating. - For single family houses with less than 3 liters DHW in pipes no special treatment for Legionella is needed. - For multi-family buildings flat stations can be a good solution - Further investigation is required with general solutions for low-temperature DHW supply without the risk of Legionella  ctivities, as well as main contents of the project participants, interlink with other relevant 4th generation district heating activities, as well as main contents of the project

15. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Major conclusions slide 15  LTDH Supply to residential buildings: - It is possible to supply LTDH to low-energy building and low heat density area - For existing buildings, it is possible to supply LTDH without major building renovation  LTDH Network - energy efficient network can be accomplished by use of low temperatures in existing network and further improved in new network by use of improved pipe insulation, small diameter pipe, improved network hydraulics - reduction of thermal bypass loss and better cooling af the district heating water can improve network operation  Heat sources - It is questionable if biomass can be the dominating fuel for DH in the future - Future DH systems tend to change from current highly hierarchical, large scale toward small scale, more flexible and controllable decentralized heat generation. - Future network can use ultra-low temperature heat sources  ctivities, as well as main contents of the project participants, interlink with other relevant 4th generation district heating activities, as well as main contents of the project

16. INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP INTERNATIONAL ENERGY AGENCY District Heating and Cooling, including the integration of CHP Thank you for your attention! Contact: Svend Svendsen and Hongwei Li Email: ss@byg.dtu.dk, hong@byg.dtu.dkss@byg.dtu.dkhong@byg.dtu.dk 16