The South Australian Government has announced financial support for a multi-million dollar high-tech greenhouse expansion in the state's Mid North.

Sundrop Farms uses solar-thermal energy to desalinate water from Spencer Gulf to grow tomatoes in greenhouses - the only facility of its kind in Australia.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 4 minutes 42 seconds 4 m 42 s Sundrop Farms' Managing Director in Australia John Phinney. ( Caroline Winter ) Download 2.2 MB

The company is about to expand its pilot plant, 20 kilometres south of Port Augusta, from 2,000 square metres of growing area to 200,000 square metres.

"It was a productive facility and proved the concept and technology and our ability to grow in arid climates," said John Phinney, Sundrop Farm's managing director in Australia.

"Now we're taking what we've learned and expanding it to a proper commercial scale."

When completed, the facility will include four five-hectare greenhouse blocks, processing facilities and a solar-thermal plant.

The expansion is expected to create 100 jobs during construction and a further 200 during peak operation periods.

The State Government has committed $6 million towards the expansion.

Retailer Coles has also agreed to a ten-year contract to purchase truss tomatoes.

"At the start, we'll be producing somewhere in the neighbourhood of 15 million kilograms of tomatoes on a regular basis," Mr Phinney said.

Solar Panels at Sundrop Farms' greenhouse near Port Augusta ( Supplied: Sundrop Farms )

"There are a number of vegetables and fruits we can grow in our greenhouses with slight changes to the climate, nutrition and growing techniques.

"We're focusing on truss tomatoes because it's a product in real high demand, and a growing segment in the market."

Port Augusta Council approved the expansion project earlier this year, but has welcomed further investment from the State Government and the retail sector.

Mayor Sam Johnson says the project will provide a huge economic boost to the region.

"We're going to have people coming into Port Augusta and also local business will be providing and contracting over the construction phase,” he said.

"The ongoing phase is the impact of 200 jobs, and we would like to get as many jobs for locals."

Mr Johnson says the council is also working to ensure smaller construction contracts are awarded to local businesses.

"The State Government want to keep as much as they can in South Australia," he said.

"Sundrop has been really good and they've come out with a focus on continuing to support Port Augusta.

"They've also said if they can't source [businesses] in Port Augusta, they'll look nearby in the regions, Port Pirie and Whyalla for example."

Construction is expected to be completed within 18 months.