An industry expert has warned that  the insistent push towards hydrogen-powered buses, may see Australian governments repeating costly and energy-intensive trials that have not worked anywhere around the world.

An announcement by the  Victorian government last week revealed it would be adding two Australian-made hydrogen buses to service in Melbourne’s western suburbs as part of push for more sustainable transport.

The buses will apparently be part of a trial of 52 zero-emission buses, 50 of which will be battery electric buses, as many other states around the country  are trailing or are about to trial hydrogen- fuel cell powered buses,  as the pressure and focus to move to zero emission electric vehicles has intensified.

However the industry expert says that as the buses will run initially on  grey hydrogen, produced using natural gas, that they could be a costly and ultimately wasteful exercise.

Currently about 96 per cent  of the world’s hydrogen is produced using coal, which is known as brown hydrogen and by gas, which is called grey hydrogen. While there are no emissions from the bus exhaust pipe, releasing the hydrogen from water is energy intensive and both grey and brown hydrogen produce and release carbon monoxide into the atmosphere and unburnt fugitive methane into the atmosphere.

David Cebon, a professor of mechanical engineering at the University of Cambridge told The Guardian that hydrogen buses were “expensive, inefficient to run compared to electric vehicles and not a true zero-emissions solution”.

“It’s destructive from the point of view of emissions, it’s destructive from the point of view of the energy transition and it’s destructive in terms of finances and the economy because you have to subsidise them in order to make them financially viable,” Cebon said.

Cebon, is a member of the hydrogen science coalition, and said  that hydrogen is inefficient because of the energy-intensive process.

“It’s very, very inefficient, and that means that you use a lot more energy in that process than if you just took electricity and you put it in a battery and then just ran a battery electric bus,” he said.

Victoria’s hydrogen buses will go into service on routes across Footscray, Williamstown, Moonee Ponds and Sunshine in Melbourne’s west and the  state government said the trial would involve six operators,  and that they would provide information on how no-emission buses perform, including energy usage.

The government has said the hydrogen fuel cell buses will  save an estimated 90 tonnes of emissions annually with Prof Scott Hamilton, from Monash university’s department of chemical and biological engineering, saying the buses should use green hydrogen, which needs to be independently certified.

“If it’s not, the emissions profile can end up worse than if you were using petrol or other fuels because of the use of fossil fuels and electricity,” he said.

Trials  of hydrogen buses began recently in NSW on the Central Coast, while Queensland has invested  heavily in a joint partnership with bus operators,  purchasing two hydrogen-run buses for the eastern suburbs of Brisbane.

From 2025 onwards, all new buses bought for Victoria’s public transport system will be zero-emission vehicles. Queensland has committed to the same action for its south-east fleets while ACT has a territory-wide pledge. NSW has a plan for all buses in the greater Sydney region to be electric by 2035.

Cebon told the Guardian that  electric buses were becoming the standard globally and should be Australia’s preferred alternative to diesel vehicles.

The Cambridge professor said the capital cost of a hydrogen bus was typically at least double the cost of an electric bus, while the running costs were at least three times more.

Cebon claims that  trials of hydrogen-powered vehicles around the world had failed, including in the UK, Germany and France.

Alison Reeve, deputy program director for energy and climate at the Grattan Institute, said electric vehicles were the best option for city buses in terms of costs and emissions. But she said hydrogen buses for longer distances had the benefit of faster refuelling.

“The Australian context is often different to a lot of other countries because of distance and population density,” she said.

“You can get a bus from Darwin to Adelaide and that’s a really long trip and it has to refuel several times along the way and there’s limited electrical infrastructure along that route.”

A spokesperson for the Victorian government said six operators across Victoria would take part in the $20m zero-emissions bus trial in Melbourne, Traralgon and Seymour over three years.

“Each technology offers unique advantages,” the spokesperson said. “Electric buses have the potential to excel in shorter routes and urban settings, while hydrogen buses boast longer ranges and quicker refuelling which may make them more suitable for heavy-duty and longer-distance application.”