Photo caption:ҕl Associate Professor David Dempsey (left) and Professor Andy Nicol are conducting research to discover how to store large quantities of green hydrogen underground.
The ҕl | Te Whare Wānanga o Waitaha (ҕl) Earth and Environment scientist and Natural Resources engineer have contributed to a pivotal International Energy Agency (IEA) report, published on 12 March 2025 into the advancements and future potential of underground hydrogen storage (UHS) in the global energy landscape.
Led out of the Netherlands, with global expertise across industry and academia, the IEA report on UHS technology addresses the growing need for sustainable and efficient energy storage solutions. As the world transitions to renewable energy sources, the ability to store hydrogen underground offers a promising method to balance supply and demand, reduce carbon emissions, and enhance energy security.
With the right infrastructure, hydrogen can be used to power transport, buildings, and industry. It can be used to store electricity for peak winter electricity demands, to generate off-grid electricity, and decarbonise industrial chemical manufacture.
“This is about decarbonising economies and energy systems and to do that we’ve got to work together. Teamwork is incredibly important but that’s the overarching goal – we need to decarbonise. If we don't, sea levels are going to keep rising and it’s going to get hotter, with more natural hazards,” Professor Nicol says.
The report provides an in-depth analysis of the latest technological advancements in UHS, comparing them to previous methods in terms of efficiency and safety. It also explores the environmental and economic impacts of adopting UHS on a large scale. The focus on UHS stems from its potential to support renewable energy integration and contribute to a low-carbon future.
“Underground hydrogen storage is not widely deployed but in the future, we may need a lot more of it, so part of the job is to assess where the technology sits currently,” says Professor Nicol, an expert in Structural Geology. “Is it ready to be widely rolled out? If not, what are the challenges and what science needs to be done? What are the economics looking like? That detailed background on where it is and where it’s going.”
Assessing underground storage options
Professor Nicol visited Austria to see the early stages of a pilot project for storing hydrogen underground as part of the research looking into storage options in porous reservoirs, salt caverns, and other manmade spaces. “They are injecting hydrogen into the ground into what we call porous media. So, the hydrogen goes into the gaps between rocks and you can take it out at a later date when it’s convenient for you – proving the concept can actually be done.”
The international experts’ insights on the current state of UHS technology emphasise the importance of understanding where the technology stands and what challenges need to be addressed for widespread deployment.
“Our goal is to provide a detailed background on UHS, highlighting its readiness for large-scale implementation and identifying the necessary scientific and economic advancements,” Professor Nicol says. “The IEA report is more of a desktop study whereas a lot of the research that David and I are currently doing in New Zealand is actually the next step on, doing the research which helps us understand some of the factors which could be important for underground hydrogen storage.”
An 18-month lead-in to the development of the IEA report involved convening a series of workshops, webinars, and panel discussions with global experts on the main challenges involved, including technical, economic, and social aspects.
“One of the biggest hurdles is ensuring the safety and reliability of UHS, which requires extensive testing and validation,” Associate Professor Dempsey says. “It’s good that we've been able to contribute the New Zealand perspective to it because we’re doing a lot of research on it. We don’t want to overstate our contribution, but it’s important that New Zealand is part of this globally significant conversation.”
The IEA report highlights several cutting-edge advancements in UHS, showcasing improvements in efficiency and safety over previous technologies. These advancements are crucial for making UHS a viable option for large-scale energy storage, the researchers say, as is collaboration.
“It’s clearly going to be a very difficult technology to implement which means high-level coordination amongst countries, industries and academia is important. Otherwise, you can duplicate work and it’s just an inefficient way to study these technologies, particularly when you're up against the clock in terms of trying to deploy them,” Associate Professor Dempsey says.
Environmental and economic impact
UHS technology plays a significant role in reducing carbon emissions and supporting the integration of renewable energy sources. The IEA report outlines the potential economic benefits of UHS, including job creation and energy cost savings.
“The reality is that this sort of technology is not going to be brought onboard by governments – it’s going to be companies, so they need to see the profitability and economic benefits of it,” Professor Nicol says.
Looking ahead, the report identifies the next steps for research and development in UHS. Professor Nicol and Associate Professor Dempsey both see UHS evolving as a key component in the global energy landscape over the next decade, with increasing adoption and technological improvements as the hydrogen economy grows.
The report also provides policy recommendations to support the adoption of UHS, highlighting regions and countries leading the way in implementing these technologies. It addresses public and industry concerns regarding the safety and reliability of UHS, emphasising the measures being taken to ensure widespread acceptance and trust.
Read the report here:
Professor Nicol and Associate Professor Dempsey received $11.8 million from the Ministry of Business, Innovation and Employment (MBIE) to answer critical questions for the future of green hydrogen in ҕl New Zealand. Read more: How can hydrogen be safely stored to be useful as an energy source?
