Geneva, Switzerland

One of the first principles of sustainable living is to make the best use of the resources that are closest at hand. Genève is putting this principle into practice using a resource that is right at its doorstep: the water of Lake Genève. The lake´s water – nearly 90 km³ in volume – has a conveniently constant temperature of eight degrees Celsius on the ground. This makes the water an ideal source of energy for heating and cooling buildings of Switzerland´s second largest city.

The project TetraEner is refurbishing seven buildings and constructing five more to take advantage of this renewable energy source. The existing buildings are located in the Genève-Lac-Nations district and include offices of the United Nations, the International Labour Organisation and International Committee for the Red Cross. New buildings will include residential units, offices and a school.


The CONCERTO approach

The backbone of the Geneva CONCERTO project is a low-temperature thermal exchange network that will use water from Lake Geneva as a heat source/sink which remains at a nearly constant temperature of 8ºC near the ground. The use of this specific network, combined with an intelligent design or adaptation of the connected new and/or existing buildings, enables the district to develop a highly efficient production and conversion system for heating and cooling (esp. due to direct cooling). Consequently, existing buildings from Geneva's community will reduce their electrical consumption for cooling purpose by about 50% and new ecobuildings will achieve at least 30% energy reduction compared to National Buildings Standards.

The main components of the network are:

• a water pumping station, (including a system on the return line which recaptures hydraulic energy to drive the pumps, resulting in reducing energy needs for pumping).
• the water distribution network that extends five kilometers inland from the lake through a previously developed region of Geneva.
• sub-stations for each supplied buildings including heat pumps (for heating) and/or heat exchangers (for direct cooling).
• thermal heating capacity is about 3 MW and the thermal cooling capacity of the network is 16.2 MW

Use of Renewable Energy Sources

• Photovoltaics
• Solar thermal
• Geothermal Energy

Low Carbon Technologies

• Reinforced insulation
• Monitoring & Targeting (M & T) / real time monitoring of heat and power consumption for supplier and consumerVentilation with heat recovery
• High temperature cooling and low temperature heating in connection with surface heating and cooling systems
• High efficient heat pumps for new buildings
• Minergie standard for 10 new buildings  (Swiss low consumption label for buildings consuming 30-50% less fossil fuels than standard regulation)

Highlights
 


The Serono-Building – part of the CONCERTO-Project TetraEner


Site facts & figures

• Estimated population involved: 14,000
• Approx. geographical area coverage: 368,000 m²
• Approx. energy saving: 25% reduction in conventional energy consumption
• Approx. energy from RES: 20%

The consortium

• Ente vasco de la Energía (EVE), Bilbao, ES
• Service Cantonal de l´Énergie, Genève, CH
• Services Industriels de Genève, Genève, CH
• Université de Genève, Genève, CH
• Ecole Polytechnique Fédérale de Lausanne, Lausanne, CH
• Ecole d´Ingenieurs de Genève, Genève, CH
• Bonnard & Gardel, Lausanne, CH