ICR2011 highlights: a refrigeration road map for supermarkets

A road map developed by a team from London South Bank University, Faculty of Engineering, Science and the Built Environment introduces the main saving opportunities for refrigeration in the retail sector
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% of electricity consumption in the food industry and overall the cold chain is believed to be responsible for approximately 2.5% of global greenhouse-gas emissions.

A road map developed by a team from London South Bank University, Faculty of Engineering, Science and the Built Environment (1) introduces the main saving opportunities for refrigeration in the retail sector and 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 in 3 sections: retrofit technologies, refit technologies and new store technologies. The various calculations were compared to a baseline typical supermarket operating on R404A. The work 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.

Retrofit technologies: among the 28 technologies that could be beneficially retrofitted, 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; these included cleaning and maintenance, re-setting of store temperature and re-commissioning set points. Large-scale savings associated with training to tackle refrigerant leakage were identified. The two areas where supermarkets had already made major investments were the use of high-efficiency fan motors and LED lightning. The addition of doors to open-fronted cabinets was also shown to be beneficial but the paybacks were relatively long.

Refit technologies: of the 32 technologies identified with the potential to save carbon when a store is refitted, 14 had the potential to save more than 50 tonnes of CO2 per annum. The largest saving (over 450 tonnes CO2 per annum) was related to the selection of the most energy-efficient cabinets. Other options with high carbon saving potential, short paybacks and reasonably short applications times 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: technologies available for a new store 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 commercialized. These included: polygeneration, centralized air distribution to cabinets, high efficiency compressors, novel building fabrics, natural store lighting, 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 (compared to them, cabinets use at least 2-3 times more energy per m3 than a poorly performing comparably sized cold store).

(1) A retail road map for supermarkets, J.A. Evans et al.