Green hydrogen: Australian demonstration closely watched by New Zealand firm

Gas pipeline company Firstgas is closely monitoring an Australian project to deliver a blend of 10% green hydrogen and 90% fossil gas to 4,000 homes.

Firstgas says it could start delivering its green blend of hydrogen to New Zealanders’ homes later this year, subject to WorkSafe approval.

Green hydrogen is produced using renewable energy, which distinguishes it from “gray” hydrogen produced from fossil fuels.

Marcos Pelenur from the Energy Efficiency and Conservation Authority (EECA) says green hydrogen has great potential in New Zealand, but direct use of electricity is likely to be a more efficient way of powering household appliances.

The Adelaide facility also supplies a 100% hydrogen-powered bus and an industrial plant producing clean hydrogen.

Hydrogen produced by the leading Australian Gas Infrastructure Group (AGIG) facility in South Australia is considered ‘green’ because it is produced using renewable energy that is drawn from the grid during times of abundant hydro, wind or solar power.

The plant takes only a few seconds to start up, so it can be brought online quickly when there is a surplus of cheap electricity.

Electricity is used to split water into oxygen and hydrogen, which are placed in tanks or mixed with fossil fuel gas and delivered to homes.

According to Australian research, household appliances adapted to burn fossil gas can cope with a hydrogen mixture containing a maximum of 20 percent of this gas.

“Research from the Australian Hydrogen Center shows that the networks we have in the ground are compatible with 100% hydrogen… but the devices are designed to run on natural gas and hydrogen burns slightly differently,” says Krissy Raman, head of sustainability at the gas company.

Running on 100% hydrogen would require households to replace their appliances, although mixing green hydrogen with biomethane – rather than fossil fuel gas – is another option if enough biomethane is available.

Two more Australian power plants, under construction or due to start operating soon, will supply a green mix of hydrogen and fossil gases to more than 40,000 homes, AGIG says.

In New Zealand, Firstgas’ Ben Gerritsen said the gas network operator was watching the Adelaide project with interest.

“We are also in the advanced stages of planning our own hydrogen blending pilot project and have submitted an application to WorkSafe, the regulator. We are not sure when they will contact us, but we hope it will be within the next few months, in which case we will be able to conduct a pilot project later this year,” he said.

Gerritsen said Firstgas would not release the location until it received approval.

He said Firstgas, as the owner of the pipeline, was focused on how to use the existing pipes to ensure lower greenhouse gas emissions in the future.

“All expert reports suggest a growing role for hydrogen (however) exactly how far it extends… is a matter of debate and unknown,” he said.

“Currently, our network connects industrial users with high heat consumption as well as domestic users, so there are many options for our network.”

Creating a supply of green hydrogen depended on having plenty of renewable energy.

One option previously discussed was to use electricity from hydroelectric dams in the lower South Island to produce hydrogen, but this would involve closing the Tiwai aluminum smelter and freeing up supplies. Tiwai’s owner has now extended its electricity contract for another 20 years.

Gerritsen said there are other options. Offshore wind in Taranaki was one opportunity to grow the sector, he said.

“You have two options for exporting energy from a huge offshore wind farm, firstly via a power line and secondly via hydrogen, via molecules, and I understand developers are considering both of those options.”

While gas networks want to explore the use of hydrogen in households, expert reports prepared in New Zealand suggest it will be more profitable in sectors that do not have other good, low-emission alternatives.

Pelenur said the first and most obvious use for green hydrogen was to replace existing “gray” hydrogen produced using fossil fuels that was already being used in factories.

Heavy transport may be next. His agency has helped test hydrogen fuel cells for trucks, as well as an alternative to electric batteries. Medium- and long-haul aviation is another possibility, he said, as is heavy industry.

But when it comes to powering homes, Pelenur said electric devices are a simpler option.

“If you have to use electricity to make hydrogen and then use the hydrogen for heating and cooking in your home, you’re adding an extra step to that, whereas with electrical appliances you can generate electricity and just use it.

“By missing that extra step, you save a ton of energy waste, which in turn makes it cheaper.”

Pelenur said that using a heat pump for heating again saves more energy because heat pumps produce three times more heating or cooling per unit of energy used compared to standard electric or gas appliances.