A crop production system that doesn’t depend upon the scarce fresh water for irrigation has been developed by a group of international scientists working in the outback of South Australia. A team of engineering and water experts has been brought together outside Port Augusta by Philipp Saumweber of Sundrop Farms. Though, it is an unusual sight to see a state of the art greenhouse that is powered by sun and relies only on salt water for irrigation in the dry outback, but according to Philipp, it is a unique set up and as far as his team knows nobody has done anything like it before or even similar to it.
To be exact, sun’s heat is being used by the team for removing salt from seawater in order to generate cooling, heating and power for growers to deliver vegetables and fruits. Black tubing filled with thermal oil that runs through the centre of the stretch of 70 meter long solar panels is heated up to 160 degrees Celsius using the energy collected by these panels. Then through the tube, oil is pumped to a storage shed where a water storage system uses the heat. How the heat is to be utilized is determined by a control mechanism, which uses most of it for desalinating sea water, some for controlling the temperature of greenhouse and some to provide power to the set up. Once the heat reaches desal unit and meets up comparatively cold sea water condensation takes place due to temperature difference producing fresh water for use on crops whereas the seawater is transferred to ponds where salt can be extracted as a byproduct.
Apart from Philipp the other members of team are Reiner Wolterbeek with civil engineering background and Masters in water management from Netherlands and David Pratt, an expert in greenhouse management from Canada. It is believed that savings between five to fifteen percent can be achieved over glasshouses powered by fossil fuels. In summers it can rely fully on solar power, but in winters for 20 percent of the time the resolve is diesel power. It was also pointed out by the team that control is achieved due to glasshouse as fertilizers can be targeted specifically, it is easy to manage pests, diseases etc and the water used for irrigation doesn’t evaporate. The greenhouse created for experimentation is 2000 square meters, but plans for US$30 million, eight hectare commercial glasshouse on the present site are placed before the local council.