Concorde

3G network

Picture credits: Drilling of the production well. Credit: SIG, François Martin
Facts at one glance
Status of the project: Commercially operating
Operation mode: Heating network
Geothermal source: Shallow / Ambient Geothermal
Max heat capacity: 1MW - 5MW
Network generation: 3G
Year of operation start: 2018
Contact: loic.quiquerez@sig-ge.ch
Description of the project
"Concorde" is a small district in Geneva with mainly residential buildings (old and new). 8 buildings are connected to a thermal newtork operating at 65-70°C that is supplied by a centralised geothermal heat pump. The source of the heat pump is water pumped in a shallow aquifer at 60m depth with a temperature of 13-14°C. This network is also interconnected trough an heat exchanger to the main district heating system today supplied by waste heat from the waste incineration plant and centralised gas boilers. This main district heating system is used to provide back up and peak loads for the "Concorde" thermal network.

Highlights of the project
This is the first district heating network suppling existing buildings with a centralised heat pumps based on an aquifer in Geneva. The use of this renewable resource helps reducing our dependency on fossil fuels. The coupling with the main district heating system provides a lot of flexibility.
The biggest challenges / obstacles
The local geological and hydrogeological context is quite complex and characterised by a lot of heterogeneity. As the aquifer was not very well known before, an important exploration phase has been required which consumed time and money. The project has been possible thanks to subsidies and the flexibility given by the interconnexion with the main district heating system.

Detailed characteristic of the project

Site description
Address
Rue Jean-Simonet 1a, 1219 Vernier, Switzerland
Status of the project
Commercially operating
Year of operation start
2018
Type of geothermal Heating / Cooling network
Heating network
Type of geothermal technologies involved
Shallow / Ambient Geothermal
Are heat pumps used within this project?
yes - heat pumps to supply the network
Heating network generation
3G
Number of clients supplied
< 10
Depth range
60
Temperature range
13-14°C
Involved companies
Owner / operator
Services industriels de Genève

Types of used geothermal sources
Source
Depth range
Temperature range
Purpose
Shallow groundwater - open loop
20 - 400 meters
< 20°C
Heat extraction

System design
Heat sources included in the network
Multivalent networks - geothermal is combined with more than one other heat source / sink
Max heating capacity supplied by geothermal energy
1MW - 5MW
Share of geothermal energy
< 50%
Annual operation hours for heating
4000 hours - 7000 hours
Annual heating production
1 GWh - 5 GWh
Annual heating production share
50% - 60%
Energy conversion factor linked to the use of geothermal energy
10 - 20
Has backup system?
Yes
Backup system
Same as peak load supply
Share of fossil fuels for annual gross heat production
10 % - 50 %