Energy-efficient arena for Lausanne
ewz's energy concept for the three ice rinks and four swimming pools of the new Vaudoise aréna in Prilly near Lausanne takes advantage of the fact that both cooling and heating are needed there. The waste heat generated during cooling is used directly for the production of hot water.
In 2017, Services industriels de Lausanne (SiL), experienced in the implementation of energy projects, and Elektrizitätswerk der Stadt Zürich (ewz), which has extensive expertise in supplying energy to sports facilities such as the Hallenstadion Zurich, decided to jointly implement the energy-efficient supply of the new sports center on behalf of Centre Sportif de Malley (CSM SA). To this end, they founded LaZur Energie SA (La for Lausanne and Zur for Zurich), in which ewz holds a 51% stake and SiL a 49% stake.
The fact that both heat and cold have to be generated at the same location is a significant advantage for the energy concept developed by ewz. The five refrigeration machines provide temperatures of up to -13° C for the production of the ice surfaces, cold for the dehumidification of the ice hockey stadium and the building air conditioning. The waste heat thus generated is used directly for heating the building and processing the ice surfaces.
Optimal power balance
With the help of two heat pumps, the residual heat is further heated depending on the heat demand, for example for the swimming pools or to generate hot water for the sanitary facilities such as showers. Since the waste heat from the chillers already reaches 32° C, the heat pumps achieve above-average efficiency.
For cooling, 100% of renewable energy is used, including from 636 (out of a total of 2264) 305 watt peak solar panels installed on the roof of the Vaudoise aréna. SiL supplies the remaining electricity needs from 100% of renewable energy. The heat production is to 80% CO2-free. This is due in particular to the fact that renewably produced district heating is used to 50% cover short-term peaks in demand for heat, e.g. to refill the swimming pools.
The plants are financed according to the principle of energy contracting. LaZur Energie SA plans and builds the plants and maintains them over a period of 30 years. The output is sold on to Vaudoise aréna according to the heating and cooling energy actually used in kilowatt hours.
