The Australian Renewable Energy Agency (ARENA) announced a trial for an innovative new type of electrolyser, which could see excess renewable energy stored in the gas grid and used to decarbonise the Australia's gas supply.

On behalf of the Australian government, ARENA has provided $5 million in funding to Wollongong-based company AquaHydrex to commercially develop its new class of electrolyser to produce cheap hydrogen from splitting water. 

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. 

ARENA chief executive Ivor Frischknecht said this 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%, with some experts recently suggesting levels closer to 30% are viable to supplement our gas needs," Frischknecht said. 

"Depending on the material the gas pipeline is made out of, the network can support up to 100% 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.

"In the future, there will be increasing amounts of surplus renewable energy when it is sunny or windy."

AquaHydrex was developed out of research undertaken by scientists and engineers at ACES (ARC Centre of Excellence for Electromaterials) - University of Wollongong and Monash University nodes.

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 decarbonise the natural gas grid," 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." 

AGN CEO Ben Wilson has observed that 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," Wilson concludes.