Natural gas has long been a key energy source for homes, businesses and industry in Queensland, but its future now lies in cleaner alternatives. Enter low to zero emissions gas – a critical piece of the puzzle in supporting Queensland’s clean energy future.

Natural gas is an essential part of Queensland’s energy mix, powering everything from household cooking appliances to large-scale industrial processes. It’s also used to power gas-fired generators, sometimes referred to as ‘peaking plants’ – flexible and dynamic power stations that have traditionally helped to ‘firm’ the electricity grid by filling the gap between supply from coal-fired generators and demand from energy users. 

But as the world moves towards net zero emissions, and Queensland targets 80 per cent renewable energy by 2035, the role of gas is evolving. 

To achieve a reliable energy supply when the majority of the generation in the grid comes from variable renewable sources, such as wind and solar, we’ll need the firming capacity that gas provides more than ever – but it’s expected that this firming will come from low to zero emissions gas. 

What is low to zero emissions gas? 

Under the Queensland Energy and Jobs Plan (QEJP), it’s expected that Queensland will need up to 3 gigawatts (GW) of new low to zero emissions gas-fuelled generation. 

Low to zero emissions gas refers to gases that produce significantly reduced or no greenhouse gas emissions when burned for energy. There are two primary forms of low to zero emissions gas – renewable hydrogen and biomethane. 

Renewable hydrogen 

Hydrogen is a versatile energy carrier that can be used to power almost anything, including heavy vehicles, refineries and other industrial facilities. 

Historically, hydrogen has been produced using fossil fuels, making the process highly emissions-intensive. But renewable hydrogen is produced using a process called electrolysis. Electrolysis involves passing an electric current through purified water, splitting the water into its basic components – hydrogen and oxygen. 

When the energy powering the electrolyser comes from renewable sources, such as solar or wind power, the entire process generates no carbon emissions. The oxygen produced is a harmless byproduct, typically released into the atmosphere, while the hydrogen is captured and stored for use in a variety of applications.

Domestic applications for renewable hydrogen include replacing or partially substituting natural gas for cooking and heating in homes, and powering energy-intensive industries like steel and cement production and chemical manufacturing that have traditionally been difficult to decarbonise. 

Renewable hydrogen can also be used to help power the transport, heavy haulage, shipping and aviation industries, which currently account for more than 20 per cent of Australia’s emissions. 

Under the QEJP, it’s expected that Queensland will convert existing gas turbines – and install new gas turbines – to be fuelled by renewable hydrogen. For instance, a hydrogen-ready, natural gas power station is currently being developed at Kogan Creek, approximately 260 kilometres west of Brisbane. 

In total, there are more than 50 renewable hydrogen projects across the state, including the Central Queensland Hydrogen Project (CQ-H2).

Stanwell is developing CQ-H2 in partnership with Japanese foundation companies Iwatani Corporation and Marubeni Corporation, and Singapore’s Keppel Limited. The project involves: 

• A hydrogen production facility: Located in Aldoga near Gladstone, this facility will use electrolysis to produce clean, green hydrogen. 

• A hydrogen gas pipeline: A dedicated pipeline will transport the hydrogen to Gladstone Port. 

• Hydrogen liquefaction and ship loading facilities: Hydrogen will be liquefied for export to international markets, particularly Japan and Singapore, from Gladstone Port. 

• Ammonia production: Hydrogen will also supply an ammonia production facility at Gladstone Port. 

CQ-H2 could become the largest renewable hydrogen project in Queensland, eventually scaling up to produce 800 tonnes per day of clean, green hydrogen by the early 2030s.

CQ-H2 is at an advanced stage, with the CQ-H2 consortium nearing completion of a Front-End Engineering Design (FEED) Study for the Project. The FEED study includes a commitment of AU$117 million from government and consortium partners.  The Australian Government, via its Clean Hydrogen Industrial Hubs program, has also announced $69.2 million in funding to Stanwell to support the development of the Central Queensland Hydrogen Hub.

Biomethane 

Biomethane is a renewable form of gas that’s produced by refining biogas. Biogas itself is created through anaerobic digestion, a biological process where microorganisms break down organic materials – such as agricultural waste, manure, food scraps, and sewage – in an oxygen-free environment. 

This process occurs in sealed tanks or digesters, and as the organic matter is digested, it produces biogas – a mixture of methane  and carbon dioxide – along with a nutrient-rich byproduct called digestate, which can be used as a natural fertiliser. 

Biogas, however, contains impurities that limit its applications. Through a purification process called ‘upgrading’, carbon dioxide and other trace gases are removed, leaving nearly pure methane – biomethane. 

This purified biomethane is almost identical to natural gas, and can be used for many of the same applications, including electricity generation; domestic and commercial heating and cooking; transportation; and as a chemical feedstock in industrial processes, replacing natural gas in producing materials like plastics. 

What are the environmental benefits of using low to zero emissions gas? 

As far as fossil fuels go, natural gas is relatively ‘clean’, producing around half the emissions of coal-fired power generation, but it is still a non-renewable resource that contributes to climate change. Low to zero emissions gases, on the other hand, either emit no carbon or recycle carbon already in the atmosphere, making them far more sustainable options.

Renewable hydrogen emits only water vapour when burned, producing no carbon emissions, while biomethane captures methane that would otherwise be released into the atmosphere from decomposing organic waste. 

Since methane is around 20 times more potent than carbon dioxide as a greenhouse gas, capturing and utilising it helps prevent its harmful effects on the environment. Biomethane also prevents this organic waste from ending up in landfills. 

Is low to zero emissions gas safe? 

Yes, with proper handling, low to zero emissions gas is safe. Hydrogen, for instance, is flammable, but modern storage and transportation technologies ensure that it can be managed just as safely as natural gas. 

If a hydrogen leak occurs, hydrogen gas is non-toxic, and disperses quickly into a non-flammable concentration. Even if a portion of hydrogen gas ignites, it burns out quickly and does not produce any hot ash. 

Biomethane is also flammable, but again, safety can be ensured with proper detection systems and regular maintenance of pipelines and storage facilities. Biomethane is nearly identical to natural gas after purification, meaning it meets similar safety standards for use in pipelines, appliances, and vehicles. During the upgrading process, impurities like hydrogen sulfide are removed, reducing risks associated with toxic gases.

In October 2023, the Queensland Government passed the Gas Supply and Other Legislation (Hydrogen Industry Development) Amendment Bill 2023, which applies the existing safety frameworks for gas pipelines in Queensland to hydrogen, hydrogen blends and biomethane. This includes the requirement to develop safety management systems and comply with safety requirements. 

This provides a clear regulatory pathway for the licensing and operation of transmission pipelines to transport hydrogen, as well as hydrogen carriers like ammonia and methanol. 

Ultimately, by harnessing low to zero emissions gases such as renewable hydrogen and biomethane, Queensland can reduce its reliance on traditional natural gas, lower emissions, and build a cleaner energy system to power generations to come.