Case Study: The Caulfield McCarthy Super Valu group

The Solution

The first step was to install the Cross energy management system [CEMS] which would provide very detailed information on exactly how much energy was being used and where it was being used.

This installation involved fitting 9 No. CT meters to the following points for monitoring: High temperature Pack 1 & 2, Low temperature Pack 1, the refrigeration sub board, the air conditioning system, the shop lighting, the Bakery, the entire first floor area and the store mains supply.

All CT’s relay constant energy data back to our CEMS which tabulates the information into simple easy to read reports which can either be printed out in the store or accessed on line from any pc anywhere.

Initial findings

After analysing the first month’s data Cross energy was in a position to go back and meet the store owners with detailed recommendations on how to reduce the stores energy consumption. It was found that 50% of the energy being consumed in the store was from the refrigeration and of that 50%, 60% was from the plant and 40% from the cabinets.

The Solution

The first step as always involved making any common sense changes that were possible, like switching off lights at night, changing temperature settings on the air conditioning and making sure nothing was being left on when it should have been turned off. We discovered the ceiling lighting in the store was using far to much energy and was over specified so we simply turned off a certain amount of lights and we were able to reduce the energy consumption on the lighting circuit by >20%.

The following steps then took place:

Remove 366 No. T8 fluorescent strip lights from all chilled and frozen cabinets and replace them with T5 fluorescent strip lights reducing cabinet light energy consumption by 50%

Remove all [108 No.] mechanical fan motors from the evaporators within the chilled and frozen cabinets and replace them with new highly efficient EC fan motors which are >65% more energy efficient

We fitted 9 No. Tempro cold stop door curtains to all the coldrooms within the store. Cold stop curtains reduce energy consumption my approx. 30% within coldrooms by keeping cold air in when the doors are open.

We did a full deep cleaning of all chilled and deep freeze cabinets within the store. Deep cleaning frees up air flow within the cabinets and reduces energy consumption.

We did a full overhaul of the High and low temperature plant systems, re-commissioning both systems fully including to ensure the pack systems were running as efficiently as possible

We installed a time clock to the air conditioning system and we also set high and low limits which restricts any abuse on the system by staff.

We set up the Danfoss control system to turn off the minerals and beer cabinets at night time- this process, known as load shedding virtually halves the energy consumption by these cabinets.

Finally we re-commissioned the Danfoss control and monitoring system and installed the latest version of the Danfoss software.

The Result

Prior to making any changes the store was consuming 30314 units [KW’s] per week. Once all the changes we made the store was consuming 25471 units [KW’s] per week which represents a saving of 4843 KW’s. In monetary terms this represents a weekly saving of over €500.

The Summary

Cross Energy delivered exceptional savings with minimum capital investment from the store owners. With the level of savings achieved the return on investment was approx 2 years which is very attractive and proves that by a combination of careful analysis, common sense thinking and making simple and practical changes real savings can be delivered without costing a fortune.