IEA-DHCǀCHP 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)
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Initiation of the project
• 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
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Aim of the project
The aim of the project is to bring experience,
knowledge and solutions for the 4th Generation
District Heating systems to a level where they are
ready to be implemented widely
Phase II: analyze and extend
the scope of lessons arising
Phase I: document
from early examples of lowexperiences in mature DH
temperature systems, in order
countries with very low
to improve the costeffectiveness and
temperature systems serving
environmental benefits,
highly energy-efficient newbuild developments
effectively formulating a
blueprint for a new generation
of district heating.
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District Heating and Cooling, including the integration of CHP
Project participants
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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
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Close link with other projects
IEA
DHC
Annex
TS1
4th Generation District
Heating Research Center
slide 6
Low temperature district
heating for future energy
system
IEA
DHC
Annex
XI
IEA DHC
Annex X
INTERNATIONAL ENERGY AGENCY
Transformation roadmap from
high to low temperature
district heating system.
EUDP
project
Danish Lowtemperature
district heating
projects
District Heating and Cooling, including the integration of CHP
The evolution of 4 Generation DH
Cited from the 4DH paper
slide 7
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
4th Generation DH Concept
SH and DHW
supply
Low network heat
loss
slide 8
• Low-temperature SH and DHW supply
• Building energy conservation parallel with DH
expansion
• Intelligent building heating load control
• Low/ultra-Low temperature supply
• Improved network design and insulation
• Intelligent control and metering
Use renewable and
waste heat
• Renewable energy in different forms, together with
thermal storage
• Industrial process heat and commercial waste heat
• Waste incineration
Institutional
framework, Energy
planning
• Integrated energy planning
• Tariff and cost reformation to support long term
stategic development
• Coordinated effort between different parties
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Impetus for LTDH Development
• Further DH market penetration requires extension
of DH to low heat density area
Mature DH
countries
• Maintain economic competitive advantages in the
future low energy society
• Improve current system energy efficiency and bring
additional economic benefits
Less
developed DH
countries
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• Transition from 1st or 2nd generation DH directly to
4th generation DH
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Advantages of LTDH
Heat distribution
Heat supply
Reduced network heat loss
Improved power to heat ratio in CHP
plant
Lower supply temperature due to
lower heating load and radiator temp.
Reduced pipe thermal stress
Reduced boiling and scalding risk
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
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INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Major research questions
 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?
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INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Structure of the IEA Report
Specific DH
distribution
cost
Safety DHW
supply
LTDH supply
low-energy
buildings
Strategic
energy planning
DHW
Installation
LTDH supply
existing
buildings
Energy saving
and renewable
energy planning
Low heat loss
distribution
network
Low
temperature
heat sources
slide 12
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Case
studies
LTDH experiences
2
1
3
6
4
5
7
1. Lystrup, Denmark 2. Ackermannbogen, Germany
3. Okotoks, Canada 4. Chalvey, UK 5. Kırşehir, Turkey
6. Falkenberg, Sweden 7. Halmstad, Sweden
slide 13
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Major conclusions
 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
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INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
Major conclusions
 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
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INTERNATIONAL ENERGY AGENCY
 ctivities, as well as main contents of the project participants, interlink with
District Heating
and Cooling,
the integration
of main
CHP
other relevant
4th generation
district including
heating activities,
as well as
Thank you for your attention!
Contact: Svend Svendsen and Hongwei Li
Email: ss@byg.dtu.dk, hong@byg.dtu.dk
INTERNATIONAL ENERGY AGENCY
District Heating and Cooling, including the integration of CHP
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