Optimal use of the sun
François and Gideo live in South Africa, where there is an abundance of sunlight. “Here in South Africa we couldn’t understand why you would want to use artificial light instead of sunshine. It’s such a waste of energy – and there’s a free supply of sun!” CAN-Agri’s current production facility, which is based in the South African city of Pretoria, looks very different from a typical greenhouse. It comprises rows of vertical ‘plant walls’ that are strategically placed in the greenhouse with ample space in between them so that the whole of each wall receives plenty of sunlight. "We are aware that there are locations in the world where supplementary lightning is unavoidable. We apply this where necessary, but it is important to harness the sun energy when and where it is available," explains François.
Unique closed-loop water system
Besides saving energy by tapping into the power of sunlight, at CAN-Agri they also make smart use of their irrigation water. In conjunction with Priva, François and Gideo have developed a concept for the safe reuse of all the irrigation water and the high-value fertilizers it contains. The concept is based on an irrigation system that pre-treats the water, doses the fertilizers and then disinfects the irrigation water afterwards.
The design phase was not without its challenges. “The water system at CAN-Agri is more complex than most. Whereas most growers largely have a monoculture with just one or two water storage tanks for their daily supply, at CAN-Agri they work with lots of smaller tanks,” explains Kees van der Kruk, Product Manager at Priva. “This enables them to adjust the nutrient levels and pH values based on the specific needs of whichever variety is being grown in a particular area of the greenhouse. Another advantage of this kind of modular system is that it keeps the drainage water from the various crops separate, which minimizes the risk of cross-contamination between the systems in the case of a waterborne disease.” To completely eliminate the risk of contamination, the Priva Vialux M-Line disinfects all the water from the storage tanks to kill all bacteria, viruses and other pathogens.