Harnessing green hydrogen for New Zealand’s energy future

Photo caption: Te Whare Wānanga o Waitaha | University of Canterbury Civil and Natural Resources Engineering PhD candidate Rafaella Canessa.

That’s a question Te Whare Wānanga o Waitaha | University of Canterbury Civil and Natural Resources Engineering PhD candidate Rafaella Canessa hopes to answer through her research on New Zealand energy transitions.

“Establishing green hydrogen infrastructure in New Zealand requires a significant shift to achieve 100% renewable electricity, as green hydrogen production relies on green energy sources,” Canessa says. 

“Producing green hydrogen requires renewable electricity. Although New Zealand has substantial hydropower, achieving 100% renewable energy will require phasing out coal and diesel, and increasing reliance on solar and wind.

“An energy shift will impact not only electricity but also heat and transportation, necessitating sustainable solutions across these sectors and requiring a national-scale energy transformation.” 

To understand the need for green energy use in New Zealand, Canessa is using Renewable Energy Mix (REMix)—a framework for modelling energy systems developed by the German Aerospace Centre’s Institute of Networked Energy Systems and adapting it to meet New Zealand’s needs.

“REMix has already been tested and proven in Europe, but Europe has a highly interconnected grid, higher demand and different renewable energy potentials. This makes it very different from an island nation like New Zealand that uses predominantly hydroelectricity,” she says.

“What makes REMix-NZ unique is that it analyses multiple energy sectors—like transportation and electricity—together, rather than separately, to better understand how they interact in hourly, detailed time periods, especially with energy carriers like hydrogen that work across various sectors.

“The role of green hydrogen in New Zealand involves exploring its practical applications and the potential for the country to become a player in the global hydrogen market, possibly even as an exporter. While hydrogen is often discussed, its full impact—particularly on infrastructure requirements for electricity generation and energy transport—remains largely unquantified.”

Hydrogen demand is already high as it is widely used in the fertiliser, oil refining and chemical industries, however Canessa says that just because  green hydrogen can do many things, does not necessarily mean it should.

“An example of this is electric vehicles (EVs). We need cars without emissions, and electric vehicles can do that already, if charged with green electricity. Using hydrogen as fuel would be much more inefficient and expensive, as electricity would have to be converted to hydrogen first,” she says.

Getting to green hydrogen is also a key factor. “The current hydrogen process uses steam methane which creates CO2 and is not a green solution.  If the process changes to splitting water into hydrogen and oxygen with electricity (electrolysis) it is only a green solution if the electricity comes from clean energy like wind or solar—not from fossil fuels like diesel.” 

There are also other factors that can determine the need for green hydrogen.

“Green hydrogen will play a crucial role, but whether a country produces it locally or imports it, as well as the most suitable uses for it, will vary based on geographical, economic, social, and technological factors,” Canessa says.

REMix-NZ will be the most detailed and advanced energy systems model created for New Zealand and will consider all factors. 

“Unlike earlier models, it has higher resolution in technology, time, and location, and includes updated assumptions and trends. 

“REMix-NZ integrates hydrogen into the modelling, accounting for costs such as system expenses, operational costs, installation costs, as well as carbon emissions, where to build the plants and lifetime efficiency,” Canessa says.

“We are grateful for the support of the MBIE Catalyst: Strategic Fund and the German Federal Ministry of Education and Research grant in making the HINT (New Zealand-German Platform for Green Hydrogen Integration) project possible.”