This project has received funding from the European Union’s Seventh Framework Programme for research,

technological development and demonstration under grant agreement no ENER/FP7/609127/READY

District heating topics

List of topics

• Individual heating vs district heating – competitiveness

• Heating and cooling – Tåstrup case

• District heating and cooling – Vaxjö case

• Use of surplus heating – Vaxjö case

• Smart meters in district heating – an investigation from Aarhus

• Heat pump in a district heating system

• Summer shut down of production

This project has received funding from the European Union’s Seventh Framework Programme for research,

technological development and demonstration under grant agreement no ENER/FP7/609127/READY

Introduction to district heating in Denmark

Nina Detlefsen

Kolding

Copenhagen

Buildings with district heating

1.7 mill.

Price reduction in 3 years

13%

400Heating companies

Danish District Heating Association

Renewable energy

53%

99%District heating supply

From black to green energy

100% RE by 2050

Biomass and biogas

Power to heat and recycling heat

Efficiency and coherent

cooperation

Intelligent utility with ICT

Fuel free energy

Urbanization = megatrend

We want to live in large cities

To live in large cities is a goal for many people.

High density of humans and activities requires intelligent and sustainable solutions.

Energy must be supplied in a secure and connected system based om environmental friendly harvest of energy.

Past

Present and future

Intelligent energy supply

Example. Denmark has 900 water treatment plants

Water supply

SewageWater

treatment

Point source

Heat PumpDistrict heating

Sludge BiogasBio

Methane

Gas engine

Power

District heating

Climate adoption

Grey water

District Heating – From oil to multiple fuels

Change in fuel used for district heating generation 1972 – 2012

Coal

Electricity for heat pumps

Natural gas

PJ

Renewable energy

Oil

Waste – non biodegradable

From fuels to no fuels

Fossil fuels

• Fossil share of waste

• Natural gas• Oil• Coal

RE fuels

• Agricultural waste• Biogas • Biomasso Straw (annual)o Wood chip (years)

o Wood pellets (years)o Biodegradable share

of waste

Fuel free heat

• Recycling heat• Solar thermal• Geothermal• Power (from RE)o Heat pumps and

electric boilers

Multiple source energy system

Coal

Oil

Natural gas

Wood chips

Wood pellets

Straw

Biogas

Solar thermal

Recycling heat

Heat pumps

Waste (fossil)

Wind power

Heat and power

CHP

Boilers

Direct

Conversion

Storage

District heating

Power

District cooling

Geothermal

LEGO® model of Brædstrup CHP with 8,000 m² / 5.6 MW Solar thermal

Large storage of hot water

Dam store – highly efficient with solar thermal

Coverage for solar thermal increases from 20% to 50% with a storage.

Vojens Fjernvarme generates 50% of the district heating from 70,000 m2 solar thermal and a 203,000 m3 dam store. Opened in 2015.

VEKS are designing a 60,000 m3 storage for day balancing.

Aalborg Forsyning are designing a 1,000,000 m3 seasonal storage.

CHP in Denmark460 units generates district heating

§ Heat units and industrial units. Central and decentralized plants.

Manny different fuels

§ Coal, biomass, natural gas, waste

and biogas.

§ Solar thermal, power to heat and a little geothermal.

Large penetration

§ 40.000 km district heating pipelines

§ 65% of buildings uses district heating.

Kilde: Energistyrelsen

District Heating from CHP – Large and small

District heating from power plant cooling water is still a large share

PJ

Industrial, CHP Industrial, heat only

Electricity production in Denmark

Decentralized CHP-units

Large variations between units

Efficiency

Calculated as:

Total output/productionTotal input of fuels

RE share

Questions?

This project has received funding from the European Union’s Seventh Framework Programme for research,

technological development and demonstration under grant agreement no ENER/FP7/609127/READY

District heating or individual heating in new areas

Introduction

Heatdensity matters

Prices in different networks

• Yearly heating prices for district heating in different networks

• The distance between houses is increasing

District heating Individual heating

Competitiveness

Yearly heating prices of district heating compared to individual solutions

Conclusions

• District heating in new areas – good idea?

• Cheap heating

• Integrated energy system

• Low total investments

• Large investment costs

• Requires common consensus

Advantages Disadvantages

For each area: Make individual business cases

This project has received funding from the European Union’s Seventh Framework Programme for research,

technological development and demonstration under grant agreement no ENER/FP7/609127/READY

Innovative smart city solutions

For sustainable planning using smart for greenbusiness solutions within transport, district heating and cooling, building

retrofitting, renewable energy, energy storage and balancing.

This project has received funding from the European Union’s Seventh Framework Programme for research,

technological development and demonstration under grant agreement no ENER/FP7/609127/READY

District Heating and CoolingStrategic solutions for low-carbon energy systems

TechniquesDistrict heating and cooling

CO2 is absorbed by

the growing forest

Ash• Provides minerals• Fertilises• Counteracts acidification

Biofuel • Branches and tops from logging• Wood chips• Bark and sawdust

Hospitals, offices, shopping malls

Flue-gas treatment

Steam boiler

Turbine Generator

Condenser

Cooling unit

DISTRICT HEATING

DISTRICT COOLING

10-16 °C

6-8 °C

Produce green electricity and heat from biomass

CO2 is absorbed by the growing forest

Efficient production gives sustainable district cooling• DC network in Växjö is flexible, energy efficient and available

• Innovative DC cycle network

• Total capacity 11.5 MW + 2.37 MW (excluding free cooling)

• 28 Customers connected to the grid

• Consumed energy: 10 417.21 MWh (2017)

Integration of two production plants gives new opportunities

• After the DC network was fully integrated, the system is more efficient, environmentally friendly and economically beneficial.

Reduced electricity by using district heating

• Lower the electricity consumption by 25 % compared to before the integration.

0

500

1000

1500

2000

2500

Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

MWh

Production of energy before the integration with two

separated district cooling networks

Total production

SVV

V-Mark

0

500

1000

1500

2000

2500

Jan Feb Mar Apr Maj Jun Jul Aug Sep Okt Nov Dec

MWh Production of energy demand after the integration

Total produktion

SVV

V-Mark

More flexible production of cooling

• Cooling tower to increase the capacity of existing machines

Reduce heat losses

Heat losses are expected to be reduced by 58 % in a

low temperature district heating network compared to

a traditional district heating system with traditional

pipes, insolation and temperatures.

From 105°C to 65°C

Traditional District Heating SystemDimensioning lifetime of pipes 35 years

Design outdoor temperature (DOT) -19 °C

Flow temperature of district heating at customer-central

at DOT (winter season)

105 °C

Flow temperature of district heating at customer-central

at DOT (summer season)

65 °C

Return temperature from the customers centrals at max

load (winter season)

50 °C

Return temperature from customer centrals at DOT

(summer season)

50 °C

Low Temperature District Heating SystemDimensioning lifetime of pipes 35 years

Design outdoor temperature (DOT) -19°C

Flow temperature of district heating at customer-central

at DOT (winter season)

65 °C

Flow temperature of district heating at customer-central

at DOT (summer season)

65 °C

Return temperature from customer centrals at max load

(winter season)

38 °C

Return temperature from the customers centrals at DOT

(summer season)

22 °C

Self-organising Thermal Operational ResourceMagnagement

An innovative DHC networks’ controller for enhanced district energy efficiency

For typical networks with a smaller sustainable energy source (biomass boiler, heat pump) and a larger fossil backup è Elimination of fossil fuel.

For networks coupled to the electric grid by heat pumps/CHPs è Switching the devices at interesting power price.

For more sophisticated networks: balance supply and demand of heat/cold in a cluster è increased efficiency.

Demonstration sites in STORM

A very typical 3rd generation network

• 180 customers

• 10 large buildings connected to the STORM controller (36 % of the total energy consumption in Rottne)

• 2 wood chips boiler (1.5 MW + 1.0 MW) + bio fuel boiler (3MW) (backup)

• Design temperature 90-60°C

• Objective: eliminate the operation of the expensive peak fuel boiler

Rottne, Växjö, Sweden

A highly innovative 4th generation network

• Very low temperatures (‘hot’ pipe 28°C – ‘cold’ pipe 16°C)

• Heating & cooling

• Coupled to underground mine water storage

• 11 buildings connected (4 clusters) to the STORM controller

• Objective: balancing of heat/cold producers and consumers

Heerlen, the Netherlands

Smart Heat Grid in Rottne

Surplus heatingDistrict heating and cooling

How to use surplus heating in Växjö

Potential solutions of increasing the amount of waste heat

• Wasted heat from computer center

• Potential wasted heat recovery from process production industry

• Potential wasted heat from grocery store

• Potential of utilize wasted heat from industry processes

• A technique of utilising wasted heat from a customer building.

• The purpose of this deliverable is to describe the design of how one can utilise wasted heat from a cooling system and at the same time supply

the district heating network.

Design note for implementing wasted heat recovery technology

1. Heat is transferred from the customers cooling machine to the refrigerant liquid in the evaporator, causing the refrigerant liquid to evaporate.

2. The pressure of the refrigerant vapor is increased due to work added in the compressor. Since the compression isn’t isentropic, the temperature of the vapor will rise a bit further.

3. In the condenser the vapor releases heat to the district heating water and goes through a second phase change once again turning in to liquid.

4. The choke valve decreases the pressure, ensuring that there will be no mix of vapor and liquid on the low pressure side.

Design note for implementing wasted heat recovery technology

This project has received funding from the European Union’s Seventh Framework Programme for research,

technological development and demonstration under grant agreement no ENER/FP7/609127/READY

Sea water driven heat pump –A multifaceted DH supply in Aarhus

Introduction

What is a smart city?

Aarhus DH system

Climate strategy

Aarhus DH system

• Supply to:• AVAs own distribution network• 7 consumer owned DH companies• 3 neighbouring municipalities

• Approximately 3.100 GWh in 2016 from:• Studstrup CHP plant approx. 50%• 2 waste incineration plants approx. 25%• Lisbjerg biomass fired CHP plant approx. 20%• Surplus heat approx. 3% [from where?]• Electric boiler approx. 1%• Oil boilers <1%• Biogas fired plants <1%

3 straw fired areas (green arrows)Geding 0.25 MW oil boiler (grey arrow)

Aarhus DH system

Technical system

System sketch of the heat pump

Location

Project budget

Expected heat demand development

Comparison of two options

System sketch of the heat pump

Location of the heat pump

Visibility