Rail travel is one of the most energy-efficient forms of transport – with only 2.6 per cent of Australia’s transport greenhouse gas emissions attributable to passenger and freight rail.
Greenhouse gas emissions per passenger kilometre for rail transport is up to five times less than that of car transport, according to the Australasian Railway Association (ARA), and moving freight on rail produces 16 times less carbon pollution compared to trucks.
With Australia striving towards the lofty goal of net zero emissions by 2050, the rail industry is thinking outside the box for ways to do better. This often starts before a railway is even built, as is the case with Western Australia’s METRONET Byford Rail Extension project.
Paving the way
Western Australia’s METRONET Byford Rail Extension project is stretching the Armadale Line approximately eight kilometres south to a new ground-level station in Byford and supporting one of the fastest-growing areas in the country.
In line with the State Government’s net zero goals, METRONET has set a 20 per cent emissions reduction target for the project – and it’s exploring innovative ways to do so.
In 2024, in a first for Western Australia, MetCONNX (the alliance name for the Bedford Rail Extension Project) began trialling the use of Hydrotreated Vegetable Oil (HVO) as fuel.
Made from fats, vegetable oils and waste products from the food industry and restaurants, HVO was used to replace regular diesel in a range of equipment including utes, watercarts, telehandlers, generators and excavators.
About 30,000 litres of traditional diesel were replaced with HVO, abating 7.98 tonnes of CO₂ emissions.
The trial, which has now come to an end, was run in collaboration with Perth’s Curtin University, which undertook studies to understand implications for fuel efficiency, emission reduction and impacts to engines.
The data captured will be provided to the Department of Transport to show the viability of HVO fuel for current and future infrastructure projects, and to help build the case for wider industry use once HVO is available in Western Australia in 2025-26.
Emma Kindness, MetCONNX’s Senior Sustainability Advisor, said that there were no issues reported with the operation, torque or efficiency of the machines the HVO was used in. “Feedback from the operators has been overwhelmingly positive, noting there has been no detectable difference between the plant running on HVO and fossil diesel,” she said.
“MetCONNX will be writing a case study to share with industry as part of our annual report to METRONET.”
According to METRONET, reducing reliance on fossil fuels can have other benefits too, as lowering exposure to diesel fumes can reduce the risk of asthma, headaches, and lung irritation for workers and nearby communities.
Kindness said the health and safety of crews working on the Byford Rail Extension is a top priority, and that no symptoms such as headaches were reported during the trial.
“However, please note that our outdoor worksites naturally disperse emissions, minimising exposure risks,” she added.
“The trial was conducted alongside standard diesel-powered equipment, making it challenging to attribute any noticeable changes to the use of renewable diesel alone.
“The trial focused on renewable diesel’s environmental benefits, such as reduced CO₂e- emissions.”
The next test
The project is now undertaking a new trial, testing a HYDI unit that can be retrofitted to existing diesel equipment to produce hydrogen on demand for engines, with a lifecycle of about 20 years.
Developed by South Australian hydrogen technology company HYDI, the compact, self-contained unit uses proton exchange membrane cells to produce hydrogen from distilled water without needing any additional chemicals.
So far, the HYDI has been tested on a CAT 150 grader and both the CAT 962 and CAT 950 loaders (20T), which have been used for bulk earthworks along the expanded rail alignment.
As hydrogen produces three times more energy than diesel and creates less pollution when burned, it’s a win for sustainability – and the trial is going well, with a 19 per cent increase in fuel efficiency recorded.
“We are very pleased with the trial of the HYDI unit,” said Kindness.
“The unit has operated without issues and provided a clear reduction in diesel burn, contributing to our carbon reduction targets.
“There have been no discernible operational changes with the introduction of HYDI on various pieces of plant that it has been installed on, and early data from the CAT loader showed that after the install there was an improved efficiency to approximately 6.56 litres per hour from 8.18 litres per hour.”
Although hydrogen is highly flammable, the MetCONNX team has had no problems.
“The only input required for the HYDI unit to operate is distilled water,” Kindness said. “There is then a catalytic conversion within the unit which produces hydrogen to supplement the diesel.
“The conversion and combustion processes are well-contained, with no issues experienced to date.”
Over 130 hours, the HYDI unit saved about 210.6 litres of diesel and used only 3.5 litres of distilled water.
Kindness said that in an industry such as construction, which is difficult to electrify, there is a need to explore other options.
“While electrification is the ultimate goal, its adoption faces challenges due to limited availability and high costs of electric equipment, as well as charging limitations, particularly for long, linear infrastructure projects and for the type of machinery required on large construction projects,” she said.
“The HYDI units are a novel solution, which work to immediately reduce carbon emissions by attaching the kit to a pre-existing combustion engine. Alternative fuels like HVO provide a practical interim solution as well by serving as a direct (like for like) drop-in fuel substitute for diesel – however we still face the challenge of cost (double the price, currently, of fossil fuel diesel).”
The use of HYDI and HVO allows businesses to achieve emissions reductions without incurring the substantial costs of replacing internal combustion engines that may already have locked in investment decisions, ensuring a smoother transition to decarbonised operations.
“A combination of technologies will be required to meet our net zero goals,” Kindness said.
In addition to these two trials, the Byford Rail Extension project has also implemented a number of initiatives including solar panels on construction offices, solar lighting towers, and a portable power station for hand tools.
The project has also endeavoured to reuse pre-existing materials within the project, avoiding transportation of new materials to site. Examples include re-use of rail sleepers and ballast from the original rail alignment, as well as furniture items from the original Armadale train station.
In a major sustainability milestone, Byford Station recently became Western Australia’s first train station to achieve a 6 Star Green Star Design Review. This is the highest rating under the Green Building Council of Australia’s Railways V1.1 Rating tool and represents world leadership in sustainability.
Key sustainability features of the station include the installation of solar photovoltaic (PV) systems capable of generating 100 kilowatts of electricity with future provisions for battery storage.
The station also boasts “quality indoor environments”, windbreaks, shading and rain protection and maximum natural light used to create “bright, inviting spaces”.
In a statement, METRONET said: “The 6 Star Green Design Review is a result of comprehensive, independent verification across multiple sustainability criteria including management practices, indoor environmental quality, energy efficiency, transport, water use, materials, land use and ecology, emissions reduction and innovation.
“The project is also exceeding recycled content targets for concrete used, further demonstrating a commitment to sustainable practices.”
METRONET’s official Sustainability Strategy states that it strives to create a sustainable legacy for Perth through the planning, design, procurement, and construction of transport infrastructure, stations and precincts.
It reads: “For METRONET, sustainability is the alignment of environmental, social and economic principles, to ensure ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’.”
