The Victorian government will consider mixing carbon-free green hydrogen with fossil gas as it pushes to reduce the state’s heavy dependence on gas for heating and cooking.
Victoria’s Energy and Environment Minister Lily D’Ambrosio said this policy could go hand in hand with electrification – the more commonly touted method of decarbonising gas-dependent households and businesses.
Speaking via videolink at the Clean Energy Conference in Sydney, D’Ambrosio said the Andrews government was committed to replacing gas with carbon free alternatives, but was undecided on what those alternatives would be.
“There’s two ways here, and they’re not exclusive of each other,” she said, referring to hydrogen and electrification. “We know hydrogen has a potential to be mixed in or blended in with a gas distribution network, and there are a number of pilot projects that have been mooted and tested, [or] are being tested right now to see how viable that is.
“But what are the long term prospects … if you’d like a greater mix of hydrogen, say, from renewable sources in with our natural gas?” She floated the possibility of getting the hydrogen share up to 50 per cent.
The advantage of doing that would mean gas mains infrastructure would continue to be used, and households would not necessarily have to replace all their heating and cooking equipment – a huge task that would take both money and a shift in mentality.
Using hydrogen in gas mains is not new. In the days before naturally occurring fossil methane gas was abundantly available – up to the middle of the 20th century – city gas mains distributed “town gas”, a synthetic gas that often contained 50 per cent hydrogen extracted mostly from coal. Town gas also contained methane, carbon monoxide and some other gases.
The UK, which is heavily dependent on gas for space and water heating and is many steps ahead of Australia in decarbonisation policy, is currently struggling to wean households off the fossil fuel. It is trialling hydrogen blends in existing gas networks, but has put much more emphasis on electrification of heat systems combined with energy efficiency through insulation.
But electrification has proved extremely difficult in the UK, and there have been some embarrassing missteps. A recent scheme that subsidised households to replace gas boilers with electric heat pumps was abandoned earlier this year thanks to major problems in the roll out.
The reality is even if Victoria managed to find a viable way to pump green hydrogen into the gas supply, it would almost certainly have to be mixed with high levels of methane gas to be compatible with the existing pipes and appliances, meaning its combustion would still produce carbon dioxide, albeit a bit less than pure methane gas.
Rebecca Burdon, chief executive of Climate Resource, said if the goal was total decarbonisation, electrification would generally be the cheaper option for space and water heating. But putting total decarbonisation aside, she said the economic viability of hydrogen-methane gas blending depended on what happens overseas.
“If in the medium term … appliances and industrial process equipment that can run off blended gas networks is not viable globally, well we won’t expect to see the requisite equipment at the required costs in Australia,” she said.
“We’re looking at a zero emissions future, so we need a very high proportion of very low emissions hydrogen, and that’s 100 per cent, and that’s not the same as the sort of 10 or 20 per cent transition pathways which are currently being contemplated by most studies in Australia.
“So I think it’s about the pace at which you think things might unfold. I don’t think it’s good end game.”
D’Ambrosio said the government was also looking seriously at electrification of household heating systems, and was trialling the roll-out of 250,000 reverse cycle air conditioners – effectively heat pumps that also work as air-conditioners.
James Fernyhough is a reporter at RenewEconomy. He has worked at The Australian Financial Review and the Financial Times, and is interested in all things related to climate change and the transition to a low-carbon economy.