A techno-economic study of energy efficiency technologies for supermarkets in South Africa

The food retail sector is energy intensive, consuming large amounts of electricity for refrigeration, air-conditioning and cooking. Retailers are aiming to reduce their electricity consumption in supermarkets and thus their carbon footprint using energy efficiency technologies. This paper reports on a techno-economic analysis of energy efficient technologies to recommend to the food retail sector for use in supermarkets. The targets and needs of food retail companies were surveyed and thereafter, the retailers were divided into three categories. Category 1 retailer had the highest targets for electricity and carbon reduction and was willing to take on more risk. Category 2 retailer had intermediate targets and would only use developed technologies, while category 3 retailer would only invest in developed technologies if they were proven to show significant long term saving with short pay back periods. The analysis showed that closed refrigerators had the highest electricity/carbon savings and the highest profit (NPV), followed by heat reclamation from refrigeration. Both these technologies were recommended for category 1 retailers. A combination of heat reclamation, energy efficient lights, fridge curtains, electronic controls for refrigerators and POS power management systems were recommended for category 3 retailers. A combination of the two recommendations was identified for category 2 retailers. Behavioural changes of all staff were identified as important for energy efficiency technologies to work at optimum levels.