A western Victorian mining company is turning poo into gold by converting the smelly waste into a valuable assets — smell-free fertilisers and energy.

The robotic dairy was the perfect testing ground for a biodigester because it collects all the manure. ( ABC Landline: Jess Davis )

Gekko Systems has designed and built a biodigester on a dairy farm at Bungaree, outside Ballarat, and is hoping the renewable technology could be used across farming and beyond.

Technical director of Gekko Systems Sandy Gray said the minerals processing specialists were becoming "true alchemists".

"The crap coming out of the shed — we used to look at it as something that was detrimental," he said.

"You had to deal with it, pump it, squirt it around the paddock. It really was crap, let's call it what it is.

"But now we believe we're going to turn it into gold and the more crap we can produce the more gold we can produce from it."

The biodigester, which is still in its start-up phase, will eventually contribute to at least half the power of farmer Mark Trigg's robotic dairy.

Mr Trigg's cows produce 24,000 litres of effluent a day, which is collected into an 80,000-litre pit, making it possible to transfer it to the digester.

Mark Trigg hopes the biodigester will contribute to half his energy. ( ABC Landline: Jess Davis )

"We've heard about digesters over the time in the industry and thought, 'Why can't we have it in the dairy industry?'," Mr Trigg said.

The technology also de-odourises the effluent, turning it into smell-free fertiliser.

"We have a problem with the aroma that it creates, the smell of the pastures and the warm weather," Mr Trigg said.

"Yeah, the neighbours don't appreciate it too much."

Building the biodigester

The project is the result of a collaboration between the mining company and a piggery just down the road where a biodigester has been operating for 27 years.

The poo these pigs produce saves Jock Charles $200,000 a year. ( ABC Landline: Jess Davis )

Pig farmer Melville Charles teamed up with an Italian engineer to design the biodigester, but it wasn't until his son Jock Charles found Gekko that they thought the time was right to take it further.

"I've always been asked a fair bit to assist people in building biogas plants, but if I was ever going to team up, it was to be with a good engineering company with a strong reputation," he said.

"And to be here in Ballarat with Gekko is an added bonus."

Gold mining might seem a far cry from the world of agriculture, but for Sandy Gray, diversifying into farming was a natural progression.

"I really love the whole farming thing, I ended up in mining by mistake," he said.

"We deliberately went into another area, another industry. Because mining goes up and down, it cycles quite heavily."

How it works

Jock Charles said the biodigester works in the same way as an animal's stomach.

"Basically the primary digester is an extension of the pig's stomach," he said.

Melville Charles built the first biodigester on his pig farm 27 years ago. ( ABC Landline: Jess Davis )

"It's heated up to 37 degrees and rather than feed being in a pig's stomach for a couple of hours, it gets 25 days to break down, so it's thoroughly decomposed by that stage."

The process creates methane gas, which is collected and transferred to engines to generate electricity. Mr Charles said it's also good for the environment.

"Methane gas is 25 times more harmful than carbon dioxide so it is a problem. By capturing it and combusting it you reduce your footprint by 25," he said.

And the Charles have turned the odour-free manure the biodigester produces into a side business, selling more than a million bags a year of fertiliser.

Future uses

Sandy Gray says getting into farming was a natural progression from mining for Gekko Systems. ( ABC Landline: Jess Davis )

Gekko is using a similar design to the Charles's digester but building it in shipping containers so it can be easily transported and eventually commercialised.

Mr Gray said it could even be used with human waste.

"We've got interest from a mining company in human waste, they've got communities they've got to deal with in remote areas," he said.

"And so we think we might be able to package these things up and transport them to other places."

See the story on Landline on Sunday at 12:30pm.