Refrigeration technologies are one of the most energy intensive used in the food supply chain and pose a number of sustainability challenges. Refrigeration accounts for 35 per cent of electricity consumption in the food industry and overall the cold chain is believed to be responsible for approximately 2.5 per cent of global greenhouse-gas emissions.
The International Institute of Refrigeration (IIR) has announced that a road map has been developed by a team from the faculty of engineering, science and the built environment at London South Bank University introducing the main saving opportunities for refrigeration in the retail sector. The map demonstrates how simple actions may save energy, cut costs and increase profit margins.
The work involved examining 72 technologies and their potential to save direct and indirect emissions in supermarkets and was divided into three sections: retrofit technologies, refit technologies and new store technologies. The various calculations were compared to a baseline typical supermarket operating on R404A.
The results showed that most technologies either save CO2 emissions from reduction in energy or from reduction in refrigerant leakage and only a few technologies demonstrated savings in both direct and indirect emissions. The study demonstrated that the potential to save indirect and direct emissions from supermarkets was considerable.
Among the 28 retrofit technologies, 16 were found to have the potential to save at least 50 tonnes of CO2 per annum for a typical baseline store.
Several of them were relatively simple to implement and required no actual modification to the installations; including proper cleaning and maintenance, resetting of store temperature and recommissioning set points. Large-scale savings were associated with training to tackle refrigerant leakage.
Two areas where supermarkets had already made major investments were the use of high-efficiency fan motors and LED lighting. The addition of doors to open-fronted cabinets was also shown to be beneficial but the paybacks were relatively long.
Of the 32 refit technologies identified with the potential to save carbon, 14 also had the potential to save more than 50 tonnes of CO2 per annum per store.
The largest saving was related to the selection of the most energy-efficient cabinets.
Other simple options included the use of evaporative condensers, better refrigerant piping, use of sensors to ensure lighting is off and doors are closed when customers are not present and better glazing for glass-door cabinets.
New-store technologies were more expensive and generally had longer payback times than the options investigated for retrofit or refit. Despite large carbon saving potential and available direct and indirect savings, the 11 technologies evaluated would be considered to have too long payback times for most commercial businesses. However, several of them were already being used or were very nearly being commercialised. These included polygeneration, centralised air distribution to cabinets, high efficiency compressors and absorption and adsorption technologies.
The technology with the most short-term potential that had a relatively short payback period was to install semi-open cold stores in supermarkets. Refrigerated cabinets use more energy per square metre than a poorly-performing, comparably sized cold store.