The milk must be cooled and this heat energy can be recovered and used to preheat drinking water and tap water. Requires some more equipment and thus additional investment. For new milk tanks, this is standard equipment
The temperature must be cooled from 38°C to 3.5°C and we can take care of this heat. If we start from 400,000 kg EKM milk, we will be able to set up a calculation like this, where the heat capacity is 3.88 W/K*kg
Theoretical heat to extract 400,000 * 34.5 * 3.88 /( 60 * 60) = 14873 kWh per year
We measure somewhat lower than this: 12,000 kWh / year at Mære