Scientists are edging closer to making green hydrogen a star of New Zealand's clean energy future, as the Government injects millions more dollars into a major research effort.
Green hydrogen has become a growing focus of New Zealand's "just transition" away from oil and gas because it can be created sustainably, using renewable energy or biomass.
It's being eyed as a climate-friendly way to generate electricity, power engines and heat homes and make fertilisers.
While hydrogen is produced around the world, nearly all of it is "brown" hydrogen - or that made from coal and natural gas, and the source of hundreds of millions of tonnes of CO2 emissions each year.
But green hydrogen can be made by using electrolysis from renewable energy sources to split water into hydrogen and water - and all without any carbon footprint.
The biggest drawback?
It remains expensive to produce.
That's a barrier a GNS Science-led research programme is aiming to overcome, through pioneering new approaches to make the energy source affordable, efficient and plentiful.
With a $9 million boost through the Government's Advanced Energy Technology Platform (AETP), scientists will push ahead in developing three ways to make green hydrogen.
That includes creating it from water using an electrolyser - currently the most common approach - but also using energy directly from sunlight to split the water, as well as high-energy plasma.
Already, GNS scientists have been working to improve a system of water electrolysis called polymer exchange membrane, or PEM.
In contrast to the more commonly used "alkaline" electrolyser, PEM is better suited to working with the intermittent nature of renewable energy sources like wind and solar that could provide electricity for hydrogen production.
While it has the advantage of being readily adaptable to large-scale hydrogen production, PEM systems still rely on catalysts based on metals that are rare, expensive or inefficient – and which ultimately make green hydrogen more expensive than fossil fuels.
GNS Science scientists (from left) Dr John Kennedy, Dr Michelle Cook and Dr Jerome Leveneur are working to make green hydrogen a viable future energy source for New Zealand. Image / GNS Science
The project's leader, Dr John Kennedy, said New Zealand had a chance to be a "world leader" in the production and export of green hydrogen – shifting us from an importer to an exporter of energy.
Currently, New Zealand brought in about 60 per cent of its energy in the form of oil and coal - and green hydrogen offered a chance to make the country more self-sufficient. Specifically, hydrogen could replace fossil fuels for stationary power and transport industries that contributed 40 per cent of our greenhouse gas emissions.
"We'll be working with partners from across New Zealand and around the world, developing our industry capability and creating innovative solutions which will lead to a globally-connected green hydrogen economy," Kennedy said.
The project also aims to scale up the hydrogen industry by training engineers, scientists and technicians.
"The AETP funding will include grants, scholarships and placements to develop skills in the green hydrogen industry – to ensure that qualified people are available to fill the jobs that will be created as the industry grows," GNS Science energy materials scientist Dr Michelle Cook said.
"We're particularly focused on partnerships with iwi and wananga, to support the learning and development of rangatahi Māori in the energy sector."
The horizon-scanning H2 Taranaki Roadmap, produced by local agencies, has already forecast that hydrogen will be increasingly produced using electricity to split water, with the only emission being oxygen.
The report found hydrogen could be utilised as a fuel, particularly for heavy vehicles, as a feedstock for products such as urea or methanol, or to store electrical energy for long periods of time from weeks to years.
A new network could include storage of hydrogen or synthetic natural gas in depleted gas fields, it said, and electricity generation using green hydrogen in Taranaki's gas-fired peaker plants.
Earlier this year, New Zealand and German scientists joined forces in a new research alliance focused on advancing green hydrogen technology.
And last month, Christchurch-headquartered cryocooler developer AFCryo unveiled a new production system to provide a cheaper and more reliable way of generating green hydrogen.