Adding hydrogen to the renewable energy mix

Hydrogen produced from renewable sources, is an alternative source of clean fuel for industrial and domestic use, but currently faces challenges in terms of cost, and production capacity needed for widespread adoption.

A significant investment in infrastructure is needed for hydrogen production and storage. Blending hydrogen with natural gas in existing networks is a way of reducing emissions and providing a market which will assist in lowering costs.

University of Adelaide researchers, Dr Neil Smith and Professor Peter Ashman, from the School of Chemical Engineering, have led a series of research projects through the Future Fuels CRC, testing domestic and industrial appliances with various percentages of hydrogen to natural gas blends.

Tests were conducted on 26 domestic and light commercial appliances (also known as Type A appliances) commonly used in Australia including cooking appliances, heaters and water heaters, using natural gas and a blend of either 10 or 21.7% hydrogen by volume. A further study also tested Type B appliances, used in commercial and industrial settings. The appliances tested employed a wide range of burner technologies.

The Type A research was used by Australian Gas Infrastructure Group (AGIG), as part of the approvals required for hydrogen blending into existing gas networks from various renewable hydrogen production facilities around Australia.

Essentially AGIG wanted to build a safety case to present to the regulator to demonstrate confidence in the blending of hydrogen with natural gas and to determine optimal ratios.��Dr Neil Smith, School of Chemical Engineering, The University of Adelaide

One example of this is the AGIG’s Australia-first Hydrogen Park South Australia (HyP SA) facility. Renewable hydrogen is produced at HyP SA in Tonsley by an electrolyser that uses renewable electricity to separate hydrogen from water. AGIG blends this hydrogen with natural gas in the existing gas network, which supplies local homes and businesses.

“Using hydrogen is not a new idea, the Towns Gas we relied on historically comprised 50-60% hydrogen and globally projects have been blending up to 20% hydrogen volumes with natural gas. However, before beginning HyP SA, we wanted to confirm how much hydrogen end-user appliances could handle in an Australian context,” said Krissy Raman, Head of Strategy and Sustainability at AGIG.

The study aimed to establish the safety of the appliances when using 10% (volume) hydrogen, and to determine the maximum amount of hydrogen that could be blended using these appliances, as well as identifying any technical issues encountered with higher levels of hydrogen. Tests assessed ignition performance, flame abnormality, and emissions.

In May 2021, AGIG’s HyP SA plant commenced production, supplying around 720 local customers with an up to 5% by volume hydrogen to natural gas blend. In March 2023, this expanded to more than 3800 homes, businesses and schools in Adelaide’s southern suburbs of Mitchell Park, Clovelly Park and parts of Marion. In March 2024, because of the safety tests conducted by Dr Smith and the team, the renewable gas volume blend was increased from 5 to 10%.

“We found that blending up to 20% of hydrogen with natural gas poses no safety issues in household appliances, a finding consistent with international research,” Dr Smith said.

While data from overseas studies was available, conducting research in an Australian context was crucial due to differences in local appliances and operating conditions. The safety regulations could only be updated after testing appliances under these specific conditions.

Dr Smith and his team also tested industrial appliances (Type B) and industrial burners, to identify potential technical issues with higher levels of hydrogen than current equipment tolerates. The results indicated fewer issues with Type B appliances, allowing up to 40% hydrogen blending in existing industrial appliances, compared to 20% for domestic appliances (Type A).

AGIG currently blends up to 10% (volume) hydrogen into parts of its existing gas distribution networks at HyP SA and at Hydrogen Park Gladstone in Queensland, which came online in 2024 and reaches around 700 homes and businesses. AGIG has several hydrogen blending initiatives planned or underway, including the most advanced:

• Hydrogen Park Murray Valley (HyP Murray Valley): Construction at this 10MW facility commenced in 2024. When online, the project plans to blend up to 10% (volume) hydrogen into the local gas distribution network, and to produce Renewable Gas Guarantee of Origin certificates (pending certification), which will be used to support industrial decarbonisation.
• Hydrogen Park Adelaide (HyP Adelaide): A proposed 60MW renewable hydrogen facility to be located at SA Water’s Bolivar wastewater treatment plant, aiming to deliver up to a 20% (volume) hydrogen blend to AGIG’s existing gas network, which supplies over 350,000 customers as well as potentially supplying an adjacent power station.

Additional hydrogen blending projects online in Australia include:

• Jemena’s, Western Sydney Hydrogen Hub, which commenced production in 2021 blending hydrogen into the Western Sydney gas distribution network; and
• ATCO Australia’s Clean Energy Innovation Hub, which began blending hydrogen into the existing natural gas network at volumes of up to 10% in 2023, reaching more than 3,000 customers.

Further research sought to ascertain a higher upper limit for hydrogen percentage blend with natural gas if minor changes are made to various industrial appliances. Burner design changes or changing flame detectors would allow some industries to use blends with much higher percentages of hydrogen than the rest of the gas network, raising the potential for individual supply arrangements.

Research was also conducted on the use of 100% hydrogen in industry, and burner modifications that would be necessary

“Some industrial processes can be converted to either renewable electricity or hydrogen. We discovered that most of the current gas infrastructure could manage using 100% hydrogen, but burner components would need to be modified due to differences in fuel properties between hydrogen and natural gas. There would also need to be enough hydrogen available and at lower production cost than is currently possible,” Dr Smith said.

The research conducted by Dr Smith, Prof Peter Ashman and their team has helped define hydrogen blending limits within natural gas networks for present-day domestic and industrial applications and assisted regulators in updating Australian safety standards and in formulating new standards for future hydrogen utilisation.

All of the standards we have are based on a presumption of using natural gas as fuel. These standards are being adjusted for hydrogen and natural gas blends, and new standards are being created to reflect the possibility of using hydrogen instead of natural gas. Prof Peter Ashman, School of Chemical Engineering, The University of Adelaide

Krissy Raman from AGIG said the research conducted by 91���� and the Future Fuels CRC was critical for updating the safety standards and making AGIG’s hydrogen blending activities possible.

“Ultimately, the transition to net-zero is complex, but forecasts show renewable gases such as hydrogen and biomethane need to play a role. By using the existing gas networks to supply renewable gas to customers, we can deliver emissions benefits today, whilst growing renewable gas production capacity to the future. The work done by the team at 91����, funded by the Future Fuels CRC, was integral in the getting these Australia-first projects started,” Krissy said.

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In the media:

– Australia’s first renewable energy gas blend supplied to existing customers��

– Delivering blended gas across Australia

Reference:

Medwell, P., Smith, N., Proud, D., Gee, A., Yin, Y., Ashman, P., “”, Proceedings of the Australian Hydrogen Research Conference 2023 (AHRC 2023), 8-10 Feb 2023