Building on sustainable practices: hydrogen power in construction

By Kody Cook, Journalist, Utility Magazine

With the drive toward carbon neutrality becoming increasingly prevalent in Australia, it’s critical for utilities to be on the lookout for technologies that can keep their operations as sustainable as possible. As part of an ongoing effort to reduce its carbon footprint, Sydney Water is powering the construction of a major infrastructure project with hydrogen.

While searching for ways to reduce its carbon emissions during construction of the $1.2 billion Upper South Creek Advanced Water Recycling Centre (AWRC) at Kemp Creek, Sydney Water’s construction partner, John Holland, presented the idea of substituting its diesel field generator with a hydrogen one. Together, the companies conducted a 28-day trial of a revolutionary hydrogen generator to help power the construction of the AWRC.

The upper south creek AWRC

Located between Kemps and South Creek in the Western Parkland City, the AWRC facility will service up to 400,000 dwellings in the Western Sydney Aerotropolis Growth area and, once constructed, will be one of the most advanced wastewater recycling facilities in the southern hemisphere.

The facility’s primary function is wastewater treatment but that’s far from the only service to be performed by the facility. When complete, the plant is set to provide recycled water, energy generation and waste reuse to the community.

The AWRC is designed to collect wastewater from the Western Sydney Aerotropolis Growth areas and treat it to the highest quality of water possible, called advanced quality water. The technology used is called reverse osmosis – the technology used in desalination plants – where wastewater from homes and businesses is treated to produce recycled water for a range of residential, agricultural and industrial uses.

The plant will also be used to process other organic waste – such as food, fats, oils and greases – to create useful biogases and biosolids, making it one of the greenest infrastructure investments in New South Wales.

More than 80 per cent of Australia’s food waste is currently disposed of in landfill, where it decomposes to form methane, a potent greenhouse gas. Sydney Water’s modelling found that the AWRC could divert up to 30,000t of organic waste from landfill per year by 2030.

The move to a circular economy is an essential one and, once complete, the AWRC is positioned to have an incredibly positive impact on the environment. However, another important consideration that needs to be made is how the emissions produced during construction of this facility can be reduced.

Construction and building activity accounts for 18.1 per cent of Australia’s carbon footprint, and makes up 40 per cent of landfill waste, making the sector one of the country’s largest contributors to greenhouse gas. Building the Upper South Creek AWRC is no small task, and a job that will require a significant amount of power.

Diesel generators are often the power source of choice for construction sites, however in addition to being noisy they also rely on the burning of fossil fuels – a process well-known for producing harmful carbon emissions. To combat this, Sydney Water and its construction partner looked into hydrogen generators as a potential solution.

Hydrogen-powered equipment: a quiet achiever

There are significant benefits that come with using a hydrogen generator instead of diesel. Hydrogen is considered a clean energy source, as it doesn’t produce harmful greenhouse gases or pollutants when burned, making it an environmentally-friendly alternative to diesel – which currently powers generators and machinery at most construction sites around the country.

Sydney Water’s Environment and Sustainability Manager for Major Projects, Gill Fowler, said that hydrogen power could be a viable alternative for the future.

“The adoption of hydrogen technology positions Sydney Water at the forefront of innovation in the industry, potentially attracting future partnerships, and investment opportunities that align with our clean energy goals.” Ms Fowler, said that Sydney Water has a target to be carbon zero in its operations by 2030 and then in its supply chain or Scope 3 emissions by 2040.

“To do that, we’re looking at ways that we can reduce our carbon emissions, through energy usage or more energy efficient technology, alternative sources of energy, renewable energy, and also looking at the types of materials we use.” “The trial was carried out for 28 days on the site. It was put in place because the site is a greenfield site, meaning there was no power to it.

“This was an opportunity to power the site with a hydrogen generator rather than a diesel generator. Over the four-week trial, 28 days, we saw a reduction of just over 12t of carbon for that period.”

Noise reduction is another major advantage, with hydrogen-powered equipment being quieter than its diesel counterparts, which is especially advantageous for construction projects in noise-sensitive areas, such as urban environments or near residential neighbourhoods.

“It’s much quieter than our diesel generators. When you’re standing next to it, you don’t actually hear noise. That’s a big benefit of utilising a hydrogen generator within our construction projects. It’s got a much better amenity.” This factor is also incredibly valuable for projects that require work to extend outside of daylight hours.

“Some construction projects require night work. If they need a generator to power lights, or to power site sheds, if a hydrogen generator is used, then that removes that noise that would otherwise come from a diesel generator, and be a disturbance to nearby residents.”

Ms Fowler explained that as part of its delivery of the AWRC project, John Holland led the trial and worked with suppliers to have the hydrogen generator with the hydrogen fuel installed and operating.

Hydrogen generators, how do they work?

The GEH2 Hydrogen generator utilises the combination of a hydrogen fuel cell and a lithium-ion iron phosphate battery and has the equivalent power of a diesel generator. The 100kVA hydrogen generator can power more than 70 homes at any one time.

The utilisation of a hydrogen generator in place of a traditional diesel powered generator for a working year would eliminate 152t of greenhouse gas emissions being released into the atmosphere. Transitioning to clean emitting hydrogen generators similar to that used in this trial is equivalent to taking 50 cars off Australian roads every year.

They can be used in construction projects on any site that does not otherwise have access to the electricity necessary to power cranes, and other heavy equipment. Hydrogen generators produce energy by burning H2 gas.

Interestingly, hydrogen is considered the single most abundant element in the known universe, yet it very rarely occurs naturally on Earth in its pure gaseous form. It needs to be produced artificially, which is why a rapidly expanding hydrogen industry is being established right here in Australia, and why Australia’s hydrogen project pipeline is the biggest in the world.

The gas is carbon neutral, emitting no greenhouse gases when produced or burned. It is created using a process called electrolysis, which uses electricity to split water into hydrogen and oxygen gas. When burned in a fuel cell as part of a hydrogen generator, H2 gas expels only water vapour as a byproduct.

New tech, new challenges

Hydrogen generators are not without their own drawbacks and challenges. Ms Fowler explained that the hydrogen gas for the generator came in sets of singular bottles. “They have limited capacity, so they require changeover fairly regularly.

There would be opportunities for larger containers of hydrogen gas, which would then eliminate the need for the ongoing weekly deliveries if you’re doing it for a longer period of time. That could drive down costs by reducing the transport costs of getting hydrogen to the site.”

As Australia’s hydrogen industry grows, availability, storage and transport of hydrogen will improve, making devices like hydrogen generators more practical, efficient and, importantly, less expensive. Currently, one of the primary drawbacks of the hydrogen generator is its significantly higher running cost – compared to a diesel field generator, hydrogen costs as much as 15-times more to run.

Construction companies looking to improve the environmental impact of their operations will need to weigh the benefits of utilising hydrogen generators. A difficult decision, particularly in a time when construction costs are at a historic high. Ms Fowler said that Sydney Water will look to deploy hydrogen generators in its future construction projects, provided that there is a viable opportunity.

“We have to look at the cost of it, whether that stacks up, and also the space for it. Hydrogen needs an exclusion zone around it to operate, so if you’ve got a confined or a smaller space then it’s a bit trickier. “But on a large greenfield site like the Upper South Creek site, it’s a perfect opportunity to use it. At the moment, the costs are still much higher to rent the hydrogen generator compared to a diesel generator.

But when it becomes more widely available, then we’ll see a reduction in those costs.” John Holland General Manager Infrastructure, Steve Tolley, said that hydrogen generators are a step in the right direction when it comes to reducing carbon emissions.

“This revolutionary trial puts us at the cutting-edge of innovation and sustainability as we build one of the Southern Hemisphere’s most advanced water recycling facilities,” Mr Tolley said. “Hydrogen technology is a gamechanger – with its incredible potential to reduce emissions and noise pollution whilst reducing our industry’s carbon footprint.”

Although hydrogen generators are still expensive, they show great promise for enhancing the sustainability of field operations, not just in construction but across a variety of industries, and as the hydrogen industry continues to expand, this carbon neutral technology could play a major role in guiding Australia to a net zero future.