Energy management
Comprising more than 2000 photovoltaic panels installed on the roof of the building, the solar power plant produces an annual average of almost 20% of the electrical energy required by the Vaudoise aréna. It is run by Si-REN SA, a company owned by the City of Lausanne and produces 700,000 kWh/year at a fixed price.
The energy solution applied to the whole complex combines profitability and sustainability: a permanent interaction between cold production and heating needs allows the use of the energy required to be optimised as accurately as possible.
The Vaudoise aréna has very high heat recovery efficiency of around 90%. Waste heat from the five refrigeration machines in the ice rinks is used directly to heat all the rooms, the water for showers and other purposes, and to maintain the water temperature in the pools at an appropriate 27 degrees. The Vaudoise aréna's installations cover 80% of its own heating needs. The remaining 20% is covered by the local district heating network, particularly during peak periods.
The energy solution in detail
To develop and implement this sophisticated system, Services industriels de Lausanne (SiL) and the energy solutions division of EWZ (Zurich Industrial Services) set up their own company in 2017 under the name LaZur Energie SA (LaZur stands for Lausanne Zurich). LaZur is responsible for financing, constructing and operating the facilities that supply the building with heating and cooling. The two companies have pooled their skills to create the new LaZur company: while SiL coordinates the legal and administrative aspects, EWZ contributes its technical know-how for sophisticated energy solutions.
A large amount of refrigeration is required for ice production and to maintain the skating surface at a maximum temperature of -6°C. Five refrigeration machines in the energy centre produce cold.
Some of the waste heat is used directly to heat the premises. Another part helps to run the two heat pumps that are also located in the energy centre. Given that the temperature of the waste heat is already high, the heat pumps can operate extremely efficiently. The installations are so efficient that only a small amount of electricity from renewable sources is needed to heat the air in the pool to the required level.
In the event of peak loads, the district heating distributed by the local network comes into play. Similarly, if the water in the pools needs to be replaced, the district heating system is called in. This happens once or twice a year. The fresh water must then reach its normal operating temperature within 72 hours. According to calculations, district heating requirements are around 2,100 MWh per year. The use of waste heat (directly or indirectly via heat pumps) amounts to around 4600 MWh.
Optimised ice production
The system also offers benefits for ice production. LaZur is also responsible for the glycol network piping, insulation and tubing, in order to ensure that the entire cold production process is optimally integrated into the energy concept. The ammonia-powered refrigeration machines supply cold to a dense network of glycol pipes totalling over 60 kilometres in length, keeping the 60 x 30 metre ice rinks at the required temperature. The ice controller supervises the maintenance of the ice. On peak days, when several competitions take place, it takes up to 30,000 litres of warm water to clean the three rinks.
To dehumidify the arena and prevent the creation of an annoying surface mist, cold air at 4°C is blown in, ensuring a good balance between cold and heat so that spectators enjoy maximum thermal comfort without feeling a draught.
A saving of 1230 tonnes of CO₂
If the facilities produce less electricity than is needed, energy from renewable sources is taken from the grid. Around 80% of the energy required for heat is produced from renewable sources or waste heat. Thanks to 100% CO₂-neutral cold production, around 1230 tonnes of CO₂ are saved per year.
The aim is to take as little district heating as possible and release only an absolute minimum of unused waste heat into the environment. LaZur is responsible for optimising, maintaining, operating and servicing the energy installations for a period of 30 years.
To find out more: Vaudoise aréna – energy solution
Water management
Water treatment and management meet the most stringent health and environmental standards for bathing water.
The technology used to treat the water consists of a membrane electrolyser that produces sodium hypochlorite solution, which is injected by metering pump into the filtrate water before it reaches each pool. The sodium hypochlorite solution has a concentration of around 3%. To maintain a stable pH (7 to 7.4), 18% hydrochloric acid is injected by metering pump into the filtrate of each circuit upstream of the disinfectant dosage. At the outlet of the particulate filters, the filtrate water is divided into two channels, each carrying 50% of the total flow. The second path, configured as a bypass, consists of a pre-oxidation treatment using ozone, followed by neutralising filtration of the water using activated carbons. After heating, neutralisation and disinfection, the flow from this bypass is combined with the other half to form the pool supply (100% of the recirculation flow).
Mobility
Located at a major public transport junction, the Vaudoise aréna is ideally served by train (Prilly-Malley station – a two-minute walk away), tram (from 2026, Galicien station), several bus routes and cycle and pedestrian paths. Around 500 parking spaces for bicycles and two-wheelers are available on the forecourt and nearby. The underground public car park has 200 paying spaces.
In addition, the Lausanne Hockey Club season ticket includes free public transport to and from the Vaudoise aréna on game days.
Waste management
Several EcoPoints for separate waste collection (PET, paper, glass, aluminium and incinerable waste) have been installed around and inside the Vaudoise aréna. This proactive approach aims to significantly reduce waste and optimise recycling.