Improving thermal energy efficiency in a Norwegian dairy utilising integrated CO2 refrigeration systems: performance data and energy efficiency improvement possibilities

Dairies are considered very energy intensive due to the high demand for thermal energy at different temperature levels. This study investigates the thermal energy demand of the largest organic dairy in central Norway, which utilises a fully integrated CO₂ refrigeration system to cover their cooling and hot water demand and an electric steam boiler for pasteurisation, sterilisation and cleaning in place (CIP). The specific energy flows of 2024 were analysed monthly and thermal demand profiles created. The specific energy consumptions were found to be between 27.5 Wh/l to 43.0 Wh/l for cooling and 34.3 Wh/l and 48.4 Wh/l for hot water heating. The electric steam boiler accounted for 36.4% of the plant’s electricity consumption in 2024. Therewith, the study aims to present real world data of the (thermal) energy consumption of a dairy and thereby lay ground for further system developments, which are conceptualised in this paper.