Valldal Grønt is a large producer of strawberries in Norway. A few years ago, they were at a crossroads where further operations required large investments in a new freezing plant. As the operation of the freezing plant only revolves around 6-8 weeks a year, it was difficult to defend such a large investment as it would require. We launched the idea of establishing a district heating plant where the machinery is used for freezing during the strawberry season and as a heat pump for the rest of the year. Valldal Grønt thought this was a good idea and a year later the facility was ready for use.
The total heat output at the central plant is 2000kW, of which 800kW is covered by a high-temperature ammonia heat pump.
The freezing power is 310kW at -42°C, ensuring the freezing of 2000kg of strawberries per hour.
The plant is built as a cascade plant with ammonia on the top stage and CO2 on the bottom stage.
Statement from Knut Arve Tafjord – Operations Manager for Valldal District Heating:
As responsible manager for the development and operation of district heating in Ålesund for more than 30 years, I was engaged as operations manager for Valldal Fjernvarme AS. The energy center here consists of two GEA ammonia machines and two CO2 machines. The machines are seawater based, deliver 70 degrees C for district heating and -40 degrees C for freezing strawberries. The energy center is technically demanding with many variable parameters and fully automatic control, regulation and monitoring. Øen Kuldeteknikk AS has been a total supplier, which has been crucial for success. Knowledge, patience, availability and willingness to cooperate have provided a basis for trust. That in relation to manufacturers, technical solutions and improvements. We see strength in further collaboration for development and optimal operation, both technically and financially.