Victoria is set to spend about $650 million on a bushfire prevention technology that could pose a fire risk, an expert says.

Key points: Victoria is rolling out technology that is supposed to stop powerlines starting bushfires

Victoria is rolling out technology that is supposed to stop powerlines starting bushfires One device being used in the program is called the Rapid Earth Fault Current Limiter (REFCL)

One device being used in the program is called the Rapid Earth Fault Current Limiter (REFCL) But one test found the REFCL technology stressed the network and subsequently started a fire

Electrical safety expert Bill Carman has warned that Victoria's Rapid Earth Fault Current Limiter (REFCL) rollout, which has quadrupled in cost, will not control all the risks associated with powerlines starting bushfires and could potentially create other serious electrical faults.

One test of the technology, obtained exclusively by 7.30, shows the device actually creating a "cross-country fault" on an electricity network that subsequently starts a fire.

Other tests show the technology functioning normally and preventing fires from starting.

A report outlining the results of at least 259 tests carried out at the Frankston South electrical substation for the Powerline Bushfire Safety Program shows at least 80 of those tests were excluded from the test results because they were for setup or were ruled invalid for some other reason.

This includes test 217, where there were "multiple faults".

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 14 seconds 1 m 14 s Rapid Earth Fault Current Limiter (REFCL) test 217, where there were "multiple faults".

Dr Carman, who worked for Ausgrid for 37 years and is known internationally for his work on powerline safety, said he was not surprised by the result of the test which started a fire.

"I was expecting to see it because I was looking for cross-country faults," he told 7.30.

Of the 173 people killed in the Black Saturday fires, 159 died in fires started by powerlines.

The Black Saturday Royal Commission recommended insulating powerlines or putting them underground. A Powerline Bushfire Safety Taskforce then investigated these options, as well as the REFCL technology.

REFCLs have never been widely used in Australia, and Victorian electricity networks are the first in the world to apply the technology to bushfire prevention. It was investigated by at least one other network in New South Wales, which rejected the technology.

Victoria's Department of Environment, Land, Water and Planning (DELWP) secretary, John Bradley, said he now expected the REFCL program to cost between "$550 million, up to $650 million".

The forecast cost of the state's REFCL program was initially $150 million.

But Mr Bradley insists it is still a good use of money.

"We're thinking about those costs in the context of the scale of devastation this state saw in Black Saturday when we saw $4.4 billion worth of damage done to the Victorian community," he said.

"So we think although the program has had its teething problems, it's money well spent."

"What we know is that the package that was delivered ends up being around 30 to 60 times less expensive than the alternative ways of achieving that critical protection of the community."

Concerns about REFCL

Dr Bill Carmen says one option during extreme bushfire conditions is to turn the power off. ( ABC News: Cate Grant )

REFCLs function like a safety switch — rapidly detecting a powerline fault and reducing the power flowing through the faulty line.

When the REFCL device shuts off the power on a faulty wire, the voltage can almost double on the other wires, putting stress on the entire network.

This means they can potentially create secondary faults — known as cross-country faults — elsewhere on the network.

"Once there is a cross-country fault, you actually have a fault at two different locations. And so the current is released of both of those locations. So there's a safety risk," Dr Carman said.

"It will start a fire. It will more likely start a fire."

REFCL devices can only function on certain types of powerlines and are only designed to prevent fires starting when powerlines hit a tree branch or the ground — just two of the ways that powerlines can start a fire.

There is no suggestion that the REFCL devices are in any way defective. The potential for fires to start from REFCL installations are related to other weaknesses in network infrastructure, which can be subject to stress over time and can potentially fail when a REFCL device is activated.

Dr Carman did his own research on REFCL some years ago and said even from the start, he was concerned.

"I could see that it would look like a panacea, but I knew that it could not actually control all the risk associated with electrical assets," he said.

"Since it has been put into wider use, more and more problems have been found and they've had to keep adding new fixes and spend a lot of money working out how to make it work. And that's where we are at the moment."

He said the costs clearly outweigh the benefits of REFCL technology, in part because it can only manage certain types of electrical faults.

Dr Bill Carman says he was not surprised to see an REFCL test start a fire. ( ABC News )

"It cannot handle the cases where a number of the wires clash together or a tree lands on them and sparks and catches alight," he said.

"And even under the best conditions, it can actually fail to operate in certain cases. So we were quite worried.

"I've seen statistics in one utility in Germany where some years [REFCL technology caused] as high as 37 per cent of faults. And that's quite high.

"Under extreme bushfire conditions, really there's only one way — you either have to remove the lines by undergrounding them, or covering them, which is extremely expensive. But the other option really is to turn the power off."

Mr Carman said once the power is off, the lines cannot start a bushfire: "The progressive utilities are doing this, they plan well ahead.

"They will work with the emergency services, they work with the public. And they plan for that. And they provide places where people can go."

Mr Bradley said the DELWP was continuing to monitor how the REFCL devices were working in practice.

"We don't see evidence at this stage that REFCLs have done anything other than protect the community. We've seen 16 occasions on a code red day with total fire bans across the state last week where those REFCLs came into operation and protected the community," he said.

'I don't think REFCL will keep us safe'

Brad and Jill Porter lost much of their dairy farm in the St Patrick's Day fires in 2018. ( ABC News: Kirsten Robb )

More than ten years on from the worst bushfires in Australia's history, residents in Victoria's rural communities have said the technology does not make them feel any safer heading into another potentially deadly fire season.

One Victorian resident who is against the use of REFCLs is dairy farmer Jill Porter.

Mrs Porter and her husband Brad lost their cattle and much of their farm at The Sisters in Western Victoria, during the St Patrick's Day fires in March 2018.

Energy Safe Victoria found it was caused by a broken power pole.

"The fire devastated our farm. It took more than half of our much loved and prized jersey herd," Mrs Porter said. "It takes a long time to breed a herd of cattle … It also takes a long time to remove the images of those cattle that you see being burnt.

"So as the next season approaches, you're on edge all the time. I think it doesn't take much to set off memories or thoughts when the wind whips up."

Dead cows after fire tore through Jill and Mark Porter's farm in Western Victoria. ( Supplied: Jill Porter )

As the Porters began the painful process of recovery, Mrs Porter began asking questions. She said she met with Victoria's Department of Environment, Land, Water and Planning; Lily D'Ambrosio, the Minister for Energy, Environment and Climate Change; and Energy Safe Victoria.

"I've spent an enormous amount of time reading and researching," Mrs Porter said. "There's a reluctance to even want to listen to me as a member of a rural community.

"I think their mind's made up, bushfire safety program is done, dusted, finished. And I don't think they want to hear my concerns.

"I don't think that REFCL is going to do enough to keep communities like mine safe."

'No doubt that REFCLs work'

Dr Tony Marxsen says REFCLs reduce the risk of fires started by powerlines. ( ABC News: Angelique Donnellan )

An original member of the Powerline Bushfire Safety Taskforce, and the former chairman of the Australian Energy Market Operator, Dr Tony Marxsen, was hired as a consultant to investigate REFCL technology.

He carried out a series of tests on REFCLs at substations in Victoria.

"I've watched hundreds of ignition tests where live conductors have fallen into beds of ultra-dry grass under very hot conditions. And in not one of those tests, if a REFCL was in service, did a fire start — so it works," he said.

Of the test that did start a fire, Dr Marxsen said these types of faults are rare and should be uncovered during the commissioning of REFCL equipment.

"The first REFCL went in two years ago and no cross-country faults. So look, they're a fact of life, they're rare, they do happen. If they do happen they pose a risk, but it's not necessarily a catastrophic risk."

But Dr Marxsen says the REFCL device is not to blame for cross-country faults on the network.

"It's not a stress caused by the REFCL.

"A cross-country fault occurs when the voltage on the two wires that are not involved in the fault causes some other asset to fail at a remote location.

"Typically on a big network, like we're talking a thousand kilometres of powerlines and all the assets that go with that, you'll have a handful of things that can't take the voltage and they have to be replaced."

He is confident the REFCL technology reduces the risk of bushfires started by powerlines.

"REFCLs alone, we estimate, will cut the fire risk in the extreme fire risk areas by about 75 per cent across all fault types. For the most common type of faults, that's a tree into the line or a wire down, it will cut it by about 90 per cent."

When the Victorian Government decided to introduce regulations to mandate the introduction of REFCLs, Dr Marxsen was again hired to analyse objections to the proposed regulations.

But he rejects allegations he had a conflict of interest and says the Government was free to ignore his advice.

Mr Marxsen said REFCLs are only one of three technologies that are being rolled out.

"And you've got to consider the whole package," he said.

Bushfires hit Victoria again last Thursday and REFCL devices dealt with 12 faults.

Energy Safe Victoria says it is likely those faults would have started fires without REFCLs in place.

REFCLs already in action

REFCLs are being installed around Victoria. ( ABC News )

A Powercor spokeswoman said it was installing the REFCL technology in 22 locations in high bushfire risk areas.

"We want to ensure that even through the hottest and most challenging days we continue to supply electricity to people in the communities we serve, unlike what is happening elsewhere," the spokeswoman said.

"Powercor has completed over 2,000 tests validating the performance of these devices," she said. "Installation of these devices is complex and we have upgraded and tested our assets to ensure our network can support these safety devices."

The company said REFCLs activated 12 times on total fire ban days last summer. It also said REFCLs operated in eight locations on Thursday last week.

"They will continue to operate throughout summer," the spokeswoman said.

An AusNet Services spokesperson said the company currently had nine REFCL systems in operation.

"We have conducted extensive testing of this world-leading technology as we have rolled out the program and this has confirmed that REFCLs are effective in reducing the risk of bushfire starts from electrical powerlines," the spokesperson said.

It also said its REFCL systems responded to faults last Thursday at Kilmore South, Rubicon and Woori Yallock.

'REFCL will not cause other faults on the network'

Swedish Neutral AB, the company making Victoria's REFCL devices, says comprehensive tests have been carried out. ( ABC News )

The company that makes Victoria's REFCL devices, Swedish Neutral AB, says the Victorian Government has comprehensively tested its use for bushfire prevention.

Andreas Winter, co-CEO of Swedish Neutral AB, said the Victorian Government has performed the most comprehensive powerline protection test in the world, aimed to specifically test bushfire prevention capability.

"Many, many hundreds of real high-voltage tests were performed and documented," Mr Winter said.

"Statistics say 75-100 per cent of all faults are earth faults. The testing in Victoria showed that the REFCL can prevent fire ignition from these kinds of faults, which no other protection system can."

He said the product does not cause other faults on the network it is operating on — but it could be used to pressure-test the network.

"REFCL can be used to flush out weak points in the high-voltage network. These weak points will eventually turn into a fault that could cause a fire."