Let’s present today a retrofit solution developed for a supermarket, where traditional AC motors have been replaced with electric EC motors that can be regulated with 0-10 V signal. The substitution has been done on the totality of refrigerated counters, evaporators and chillers employed in the supermarket.

The installation of electric fans with EC motor and external rotor granted significant advantages, first of all allowing a reduction in power consumption, with an annual saving of 138.970 kWh, approx 1/3 of the amount of energy previously consumed by AC motors.

Despite a higher initial investment, the installation of EC motors had thus a second relevant benefit, due to the fact that this kind of technology doesn’t require maintenance costs, while maintenance costs for 10 years of operations on AC motors can be calculated in 72.000 €.

The retrofit substitution of AC motors with EC motors on the totality of refrigerated counters, evaporators and chillers in the supermarket granted then an annual saving of 21.527 €.

In this specific application, considering an energy cost of 0,11 €/kWh, the comparison for the totality of equipments is as follows:

 

Overall costs AC motors in 10 years:
– 12.800 € initial investment
– 72.000 € maintenance
– 381.568 € operating costs

Total amount on 10 years: 466,368 € – annual cost of 46.637 €

Overall costs EC motors in 10 years:
– 22.400 € initial investment
– 228.701 € operating costs

Total amount on 10 years: 251.101 € – annual cost of 25.110 €