Cool water key to clean green tomatoes in the Outback

Cold Logic has won a A$1m (US$760,000) contract with Sundrop Farms to refrigerate desalinated water for a state-of-the-art irrigation system in rural South Australia. 

Sundrop Farms will open its first fully operational 20-hectare sustainable greenhouse facility in Port Augusta, about 300km north of the South Australian capital Adelaide, in the second-half of 2016. 

The sustainable farm is powered by a solar-thermal desalination process using two abundant fuels: sunlight and seawater. 

Computer-controlled mirrors focus sunlight onto a tower to super-heat the seawater and convert it to steam. The steam drives a turbine to generate electricity, desalinate the water and power the farm. 

The desalinated water is then used to irrigate the tomatoes, which is where Cold Logic comes in. 

Cold Logic partner Eddie Lane said his company had developed a system using ammonia technology to chill more than 2.8m litres of water daily. 

He said the processed water was about 35C after it had been desalinated. 

“Our component really is to make sure there is an effective water supply at the right temperature that can be sent via the pumps to the greenhouses​,” Lane said. 

“We’ve got a fairly large ammonia refrigeration plant we designed and built to cool that water from 35C down to 18C, and that will allow that water to then be utilised on the vines​.” 

Installation of the Cold Logic refrigeration system at Sundrop’s Port Augusta plant was completed in March, ready to water the first tomato seedlings. 

Sundrop Farms aims to produce up to 15,000 tonnes a year as part of a 10-year contract to supply 750 Coles supermarket outlets with truss tomatoes across Australia. 

Cold Logic is based in Adelaide and has specialised in the manufacture and supply of industrial refrigeration solutions to the beverage, food processing and cold storage industries since 1984. 

It has had a particular focus in the key South Australian wine industry and has helped chill more than 650m cases. 

Lane said the Sundrop project was an opportunity for the company to bring some innovative technology into the on-farm space. 

“Utilising ammonia has been around for a long time, it’s one of the most efficient forms of industrial refrigeration when you’re talking large scale and it’s also the most environmentally friendly—it has a zero global warming potential factor​,” he said. 

“It’s a natural refrigerant and that was the basis of ensuring that Sundrop remained clean and green and bringing forward the most up-to-date technology they could get their hands on​. 

“This certainly opens our eyes to the opportunities within the Australian produce markets in the on-farm side of things​. 

“We’re starting to see that food bowl for Asia and it shows us that there are some great opportunities for South Australian businesses​.”