‘Power to gas’ trial to inject hydrogen into gas grid

Excess renewable energy could be stored in the gas grid and used to decarbonise Australia’s gas supply if a new trial is successful.

The trial, supported by a $5 million grant from the Australian Renewable Energy Agency (ARENA), will allow Wollongong-based company AquaHydrex to commercially develop its new class of electrolyser.

In partnership with Australian Gas Networks (AGN), which owns the gas distribution network in South Australia, AquaHydrex will design and build an electrolyser pilot plant to trial injecting a small amount of hydrogen into the South Australian gas grid in a process known as “power-to-gas”.

Power-to-gas involves converting electricity into hydrogen by splitting water, then injecting this into the gas grid, providing long-term energy storage and stabilisation of variable output solar and wind power.

AquaHydrex managing director Paul Barrett said the funding would bring the Australian developed innovation closer to producing cheap hydrogen at commercial scale.

Storing renewable energy directly in the gas network was a logical first route to market for the invention.

“Hydrogen is an outstanding energy carrier, and has the potential to connect the electricity and natural gas grids, significantly increasing the storage capacity available for renewable electricity and helping decarbonize the natural gas grid,” Mr Barrett said.

“This renewable hydrogen also opens up the possibility to exporting renewable energy – which Australia, with its vast renewable resources, is well positioned to exploit.”

ARENA chief executive Ivor Frischknecht said the demonstration is the first Australian trial to test ‘power-to-gas’ that will see hydrogen being injected into the gas network.

“Hydrogen can be injected directly into the natural gas network without modification at levels of at least 10 per cent, with some experts recently suggesting levels closer to 30 per cent are viable to supplement our gas needs,” he said.

“Depending on the material the gas pipeline is made out of, the network can support up to 100 per cent hydrogen in due course, once appropriate regulatory transition and appliance modifications are implemented.

“When hydrogen burns, it produces only water vapour and no carbon dioxide.

“There is huge untapped potential in power-to-gas to convert surplus renewable energy to hydrogen and use our existing gas network infrastructure for long-term, safe, reliable energy storage.”

AGN CEO Ben Wilson has observed in line with Energy Network Australia’s recently released Gas 2050 vision, “the volumetric potential of renewable energy stored in the Australian gas infrastructure could be as much as 6 billion household Li-ion batteries. This provides what is for all intents and purposes a ‘bottomless battery’ that is already in place and capable of storing and transporting vast amounts of time-shifted renewable energy.”

The development of this process is the culmination of years of research at the University of Wollongong and Monash University.