GeniLac: Use of lake water to cool and heat buildings

Sissach, Switzerland, March 2020 – Lake Geneva is the biggest lake in Switzerland and has a high potential for creating energy. With the project “GeniLac”, SIG (Services Industriels Genevois) wants to exploit this potential. The company is currently building the biggest thermal exchange network in Switzerland. R&S Rauscher & Stoecklin contributes to the project with the delivery of 11 special low-loss transformers.

The idea behind the project is simple. Lake water is used to cool buildings, such as the UN building or the airport, in summer and heat them in winter. At a depth where the temperature is fairly constant, the water is pumped into an underground reservoir on land where it enters a system of pipes. For cooling, the water goes through a heat exchanger. For heating, the water goes into a heat pump. The cold or hot water is then piped through buildings and ends back in the lake.

To supply the network of underground pipelines, SIG is currently building a new pumping station in Le Vengeron. It is being built underground at a depth of 17 metres. Pipes of almost 2 metres in diameter will be laid. There are 11 new transformers that will be installed over a period of 10 years. The low-loss transformers supply the pumps with the required power.

Some specifications of the project:

  • 11 oil-type transformers
  • Power supply for the pumps
  • Transformers supplying a rectifier
  • Reduction of CO2 emissions by 80% (when used for heating)
  • Electricity savings of up to 80% (when used for cooling)
  • Completion in 2035

About SIG
Services Industriels Genevois (SIG) is a Swiss provider of local services regarding water, gas, electricity and thermal energy. The company, based in Geneva, supplies 225,000 customers throughout the canton. SIG actively promotes efficient and optimized consumption and contributes to sustainable development.

About R&S Rauscher & Stoecklin
R&S Rauscher & Stoecklin is part of the Swiss-based R&S Group, a leading provider for power products in selected niches. The company, founded in 1919, is a well-established and experienced manufacturer of transformers, switchgear, and other electrical equipment.