The idea of using green hydrogen to power the world is nearly everywhere – it has the potential to alter the playing field for sustainable power, but it’s just that – an idea. So, what happens when two Te Whare Wānanga o Waitaha | University of Canterbury (UC) researchers get NZ$11.8 million dollars to start making that idea a reality?
UC Earth and Environment scientist, Professor Andy Nicol and Civil and Natural Resources Engineering Senior Lecturer, Dr David 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 Aotearoa New Zealand: how can hydrogen be safely stored to be useful as an energy source?
Professor Nicol and Dr Dempsey already know that storing hydrogen in its liquid form isn’t feasible for the massive amounts we’ll need, so their research will focus on storing it as a gas.
“Hydrogen doesn’t become a liquid until around minus 260 degrees Celsius” says Dr Dempsey, close to absolute zero, which is the lowest limit temperature can be recorded at. If you want to store it as a liquid it’s a lot of effort – it takes a lot of energy. It’s constantly boiling off hydrogen to keep that temperature low, and that all adds to the cost”.
“We’re probably going to have to store it as a room-temperature gas, but even at really high-pressure hydrogen’s density is quite low. We estimate Aotearoa might need about 10% of its annual hydrogen consumption on hand in storage and that’s an enormous volume. That’s like covering an area more than the size of 450 rugby fields with tanks if you put it all on the surface… the underground option is quite nice, if you can make it work of course.”
While underground storage solves the problem of scale there are still potential risks to mitigate, says Professor Nicol. “One thing we’ll look at is leakage scenarios because that’s both an environmental and a social licence risk.