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Testing green refigeration for SA retail

Woolworths was recently named responsible retailer of the year for the second time in three years, at the World Retail Awards held in Berlin, Germany, in October 2010 (Photo: Jeff Attaway)

An African response to the growing environmental awareness among consumers and retailers worldwide.

Woolworths has begun trials to test nitrogen refrigeration technology on its truck fleet, in an effort to further reduce its carbon footprint and improve the transport of temperature-sensitive products. It is the first retailer in South Africa, and one of only a few internationally, to experiment with the ecoFridge refrigeration system. Woolworths initially introduced the technology on one truck, but hopes to run four trucks on the system later in the trial. The retailer’s decision to test the technology forms part of its Good Business Journey, which focuses on four priorities: being proactive in fighting climate change, a stronger focus on the environment, social development, and transformation.

The company’s national general manager for transport, supply chain and IT, Johan Schafer, said that customer feedback about its delivery trucks, obtained by Woolworths’s customer services team, was also a factor in the decision to pilot the technology.


Kinder to the environment

The ecoFridge system is fuelled by naturally occurring nitrogen instead of diesel, providing significant reductions in carbon dioxide emissions. According to Schafer, the units can eliminate between 24 – 30 tonnes of carbon dioxide per year, per truck. Nitrogen, which constitutes 80 per cent of the earth’s atmosphere, is also non-toxic. If the refrigeration system is damaged in any way, the nitrogen simply evaporates immediately. Retailers who use the system will also find it easier to comply with emission standards prescribed by the Montreal Protocol and the Kyoto Protocol.

The Montreal Protocol is an international treaty to protect the vulnerable ozone layer by phasing out the production of substances that are believed to deplete the compound. The Kyoto Protocol is an international agreement containing targets for 37 industrialised countries and the European community to cut greenhouse gas emissions.

British supermarket chain Asda estimated in 2009 that if it introduced nitrogen-powered ecoFridges in 2,500 refrigerated trailer units, it could save about 23mn litres of diesel, 60,000 tonnes of carbon dioxide and US$33mn (R229mn) in fuel costs. In a statement, the president and CEO of ecoFridge, Tom Roller, said that the system is used in Israel, South Africa, France, the UK and North America.


Maintaining the cold chain

The ecoFridge system was designed by Ukraine-based Ukram Industries. The nitrogen technology used in the system makes it possible to more effectively control truck refrigeration temperatures. Schafer explained that this can ensure better product quality for the consumer. Temperature-sensitive products such as milk rely on a consistent cold chain. If the temperature of milk can be controlled more accurately from production until it reaches the store, the product will have a longer shelf life.

Trucks fitted with the nitrogen system can also maintain numerous temperature zones. This makes it easier for retailers to transport a variety of products, which may require different temperatures, at the same time.
When it comes to achieving optimum temperatures in the load space, nitrogen technology is 70 per cent - 80 per cent faster than mechanical systems, as nitrogen gas eliminates hot spots in trucks. Reaching the pull down temperature in the truck, which refers to the required temperature level, takes less than 40 minutes with the nitrogen system. With diesel, the same process can take up to 120 minutes. The truck operator also has access to a control panel in the vehicle, which allows him to monitor the system.

No moving parts

Schafer said that nitrogen-based refrigeration further differs from other mechanical systems because it has no moving parts, which reduces noise pollution. According to Ukram Industries the system operates at zero decibels, making it one of the quietest transport refrigeration systems of its kind. The commercial advantages also outweigh those of diesel systems. Companies need invest less capital and operational costs are lower.

Comparative figures indicate that the running costs of a mechanical system are much higher, particularly from the third to fourth year of operation. The running costs of ecoFridges remain largely stable because there are no factors such as labour, parts and downtime to consider. The nitrogen is contained within a storage vessel fitted to the truck. Once the doors are closed, nitrogen is released into the cargo hold to a pressure of approximately 1.8 bar. The system is designed to be completely safe. If someone is enclosed in the loading space, they can deactivate the system by pressing an illuminated button installed in the truck.

A new approach to fuel and transport

In addition to piloting nitrogen refrigeration technology, Woolworths recently introduced the use of biodiesel in its entire fleet. Biodiesel is a renewable fuel produced from vegetable oils, animal fats or recycled cooking oils. Woolworths pioneered the use of biodiesel in South Africa, being the first retailer to use biodiesel approved by the South Africa Bureau of Standards. According to Biodiesel South Africa, biodiesel produces 80 per cent less carbon dioxide, 100 per cent less sulphur dioxide - a major component of acid rain - and up to 75 per cent less exhaust emissions. Woolworths buys its biodiesel from the Cape Town-based Biodiesel Centre, which manufactures the fuel from recycled oil and plant materials.
Schafer said the growing environmental awareness among consumers and retailers worldwide is encouraging. As a result retailers have a better understanding about the impact of their operations on climate change and the environment.

Wilma den Hartigh