Using water from Lake Geneva to cool buildings is the bet made by the United Nations to cool the buildings of the Palais des Nations, the European headquarters of the UN, without resorting to air conditioning.
This fight towards carbon neutrality has been facilitated by the GeniLac project, which is an infrastructure for producing cold and heat with local renewable energy. In 2021, Geneva Industrial Services (SIG) first built three kilometers of underground network and connected nine new buildings.
Work to lay pipes at the bottom of the lake began last June. With this green device, the entire installation works with 100% renewable electricity. Above all, it allows an 80% reduction in electricity consumption for air conditioning and an 80% reduction in CO2 emissions for heating.
UN Geneva, a pioneer in ecological air conditioning
But before the implementation of the GeniLac project, the UN showed the way, by being a pioneer in ecological air conditioning. When the Geneva authorities launched this first renewable thermal network on the edge of the lake, it was the international organizations that took the ecological step first. The UN agencies have therefore undertaken the necessary work to connect to GLN (Genève-Lac-Nations).
“UN Geneva is a pioneer in renewable thermal energy and was the first to be connected in 2009,” recall the SIG in a press release. The World Health Organization (WHO), the International Telecommunications Union (ITU), the World Trade Organization (WTO) and the World Meteorological Organization (WMO) follow in the wake.
This decision will allow these various UN organizations to reduce their energy consumption for the cooling of their buildings by 80%.
To better achieve this shift towards carbon neutrality, the United Nations Office at Geneva (UNOG) has decided to build installations to produce heating with GeniLac. Heat pumps (PAC) that will run on 100% renewable electricity will also be installed and commissioned in 2025.
80% reduction in greenhouse gas emissions
At that time, UN Geneva will reduce its greenhouse gas emissions for heating by 80%, emissions which currently amount to approximately 3,500 tonnes per year. A great contribution to the fight against global warming.
It should be noted that the Geneva hydrothermal network Genilac, which makes it possible to produce cold and heat using water from Lake Geneva, must be connected to 350 buildings by 2045. Genilac consists of two underground networks, one of which is in open loop to the city center and the other, which connects the airport, is closed loop. Placed end to end, the water pipes will ultimately represent a circuit of 30 kilometers.
Pumps and energy exchangers have already been installed. The commissioning of the machinery is scheduled for 2024, specify the SIG, which notes that the construction of the Vengeron pumping station, the heart of GeniLac, has progressed with the installation of pumps and energy exchangers.