The energy consumption of a milk cooling tank

On a farm with dairy cows, milk cooling tanks are necessary to, well, keep the milk cool. I highly doubt that anybody is interested in the energy consumption of a milk cooling tank, but since I measured it, I'm sharing this vital information with the world.

I measured the electrical energy consumption of two milk cooling tanks of the type IK-TAG/4 (coolant: R 404 A, maximum operating pressure: 2 MPa, operating voltage 3 x 400 V at a frequency of 50 Hz).

The first milk cooling tank has a content of 5000 liter, a mass of 1040 kg and was produced in 2001. The second cooling tank has a content of 1800 liter, a mass of 515 kg and was produced in 2000.

A three-phase energy meter (type 10/60 Landis & Gyr 212/161, form MG14, 3 x 220/380 V, 10 (60) A, Schltg 400, 50 Hz, 75 revolutions per kWh) was installed that measures the AC electrical energy consumption of both milk cooling tanks together.

The following figure shows the total AC energy consumption as a function of time from 19 December 2002 till 4 May 2003. As you can see, the consumption is quite linear. On average, both cooling tanks consume about 30 kWh per day, corresponding with an average power consumption of 30000 Wh / 24h = 1250 W.

The next figure shows the energy consumption in kWh per week of both cooling tanks.