Freezer energy savings

Posted by admin / 25.05.2016 / Case Studies

City was briefed by a UK supermarket retailer to evaluate the excess energy consumption caused by the automatic defrost cycles of shop floor freezer cases and implement a solution to save energy.

Shop Floor Freezer cases go through a defrost cycle between 2 and 4 times per day, occurring at fixed time intervals regardless of whether they are required or not. During the defrosts electrical heaters are used to defrost the case.

City extensively analysed the defrost cycles from each brand of freezer used by the retailer.

PLC programme was created for each store that analyses the case performance and data from previous defrosts. At each timed defrost the PLC program makes a decision based on performance data available whether to activate the defrost or skip it. The PLC programs were written and uploaded to each site remotely by the Energy Bureau.

A 21% reduction in freezer defrosts saving £334,000 per annum in electricity across 557 retail stores.