Shoprite Group will, by the end of this month, have added 39 solar-powered refrigerated rigid trucks to its existing solar-powered fleet of 749 trailers, says group sustainability manager Sanjeev Raghubir.
“It’s the first time we are adding solar-powered nitrogen refrigerated rigid trucks to our fleet. It is also a first for Africa.”
Shoprite has a fleet of 855 trucks and 1 247 trailers, of which 749 are solar-powered trailers. Of this solar-powered trailer fleet, 473 units are refrigerated. The remaining 276 units are not refrigerated, but the tail lift is powered by solar energy.
The non-solar-powered trailers in the fleet are traditional diesel-powered refrigerated trailers, with the diesel-powered cooling unit situated at the front of the unit.
Each solar-powered refrigerated trailer uses four solar panels to generate energy that is then stored in batteries. This energy is used to move nitrogen around to cool the trailer, explains Raghubir.
This means that the nitrogen has to be refilled at Shoprite’s depots, similar to the traditional cooling system, where the diesel has to be replenished.
Raghubir says the solar- powered units have been deployed in the Shoprite fleet since 2017, in an effort to reduce the company’s carbon footprint.
When approached by a local vendor with the solar solution, the company ran a pilot programme to test the technology, followed by large-scale deployment of the locally manufactured trailer.
“The solar-powered trailers mean that we have reduced our use of diesel and, therefore, our emissions,” says Raghubir. “With this system, it is not necessary to idle the truck when loading and offloading.
You can also uncouple the trailer from the truck, and it will run on its own power – also at night.
“The system also makes less noise, which is important when considering that many of our delivery areas are adjacent to office parks and residential areas.
“Nitrogen is also cheaper than diesel.”
Raghubir says the solar- powered units deliver a return on investment within two years.
The trailers have, to date, delivered a reduction of 471 t of carbon dioxide equivalent a year for Shoprite.
He adds that solar-powered units provide the same level of refrigeration as diesel-powered units.
“We are also able to monitor the temperature of the trailer remotely, to ensure the cold chain remains intact.”
Despite the success of the solar-powered units, Shoprite will not expand the technology to its entire South African refrigerated fleet, says Raghubir.
“It can become a risk to the cold chain if there is a shortage of nitrogen, as has been the case during Covid-19.”
The shortage of nitrogen arose as manufacturers switched to the production of oxygen for medical purposes.
Shoprite is, however, continuously refining the system, and recently increased the lithium- iron phosphate battery’s capacity by 40%, while also increasing the solar panel output per panel.