Home Economics New Zealand is touting a inexperienced hydrogen financial system, however it should face large environmental and cultural hurdles

New Zealand is touting a inexperienced hydrogen financial system, however it should face large environmental and cultural hurdles

New Zealand is touting a inexperienced hydrogen financial system, however it should face large environmental and cultural hurdles

In its plan to retool the financial system, the New Zealand authorities highlighted inexperienced hydrogen as a game-changing gas. It may well certainly be used to make climate-friendly fertilisers and metal or to energy some modes of transport that aren’t suited to batteries.

However to offer a buffer in opposition to the volatility of abroad markets, Aotearoa would have to be as vitality unbiased as attainable. Ideally, this could imply consuming solely inexperienced hydrogen produced right here, utilizing considerable renewable hydro, wind and photo voltaic assets.

A hydrogen financial system is sweet in principle, however to make the swap on the scale of Aotearoa’s local weather ambitions would require about 150 petajoules of hydrogen annually, based on one estimate. That’s a few quarter of our present vitality use.

Hydrogen is produced in a course of often known as hydrolysis – the splitting of water into hydrogen and oxygen gasoline, utilizing electrical energy. To provide 1 / 4 of Aotearoa’s vitality consumption, hydrolysis would eat an unlimited quantity of water, about 13 million tonnes annually, the equal of a month’s price of Auckland’s water demand.

This raises each cultural and technical points, which we should tackle earlier than embarking on a transition to hydrogen as a inexperienced gas.

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Consuming water has cultural implications

Freshwater has monumental significance to iwi and hapū. Nonetheless, their views on hydrolysis as a consumptive use of water are usually not broadly understood. If cultural complexity is ignored, hydrogen infrastructure or processes might fail to attain an applicable match inside Aotearoa New Zealand society and the expertise may very well be orphaned.

As an alternative, we might begin addressing this early via wānanga with representatives from a variety of doubtless affected iwi. Recognising and addressing cultural considerations on the outset will permit Māori to form how the expertise is developed and to share within the financial advantages of a hydrogen financial system. The intention is to raised perceive how inexperienced hydrogen applied sciences and infrastructure might belong in Aotearoa New Zealand.

Inexperienced hydrogen manufacturing would require monumental quantities of water.

Supposing we’re prepared and in a position to make this huge amount of hydrogen, our expertise with different fuels suggests we would want a few month’s price in storage at any given time. Storage helps to easy fluctuating market demand, takes benefit of seasonal extra of renewables (in very windy, very sunny weeks) and supplies emergency reserves for “dry yr” crises.

Storing hydrogen underground

Sadly, hydrogen can’t be saved as a liquid besides in specialised containers that maintain it at extraordinarily low temperatures. Like a freezer, that is all the time consuming vitality.

A hydrogen storage tank at NASA's Kennedy Space Center.

Hydrogen is saved in liquid type at NASA’s Kennedy House Middle.
Wikimedia/Doe, CC BY-ND

Hydrogen may very well be saved in particular high-pressure tanks, however we would want extra of those tanks than we’ve got individuals in New Zealand. These tanks can be expensive, cowl giant tracts of productive land and can be inclined to wreck by pure hazards. The place would all of them go?

Scientists have been the potential of storing hydrogen underground, in nice caverns carved in salt or in outdated oil and gasoline fields.

We already do that with pure gasoline in Taranaki. When it’s not wanted, gasoline is injected into an outdated discipline referred to as Ahuroa after which extracted as required. Underground storage of gasoline (methane) is frequent follow, offering vitality resilience. For instance, given the disruptions attributable to the struggle in Ukraine, Germany is accelerating gasoline storage in geologic reservoirs in time for winter.

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We’ve just lately proven there could also be sufficient house in different Taranaki rock reservoirs to retailer hydrogen underground. Nevertheless it received’t be straightforward.

We all know the gasoline can react with sure sorts of rock. It may well even be a meal for hungry microbes. Each these processes would eat a helpful gas. However predicting whether or not they’ll occur requires particular laboratory experiments that may replicate the acute stress and temperature three kilometres beneath floor.

We’re additionally nonetheless studying find out how to predict how hydrogen will transfer underground. We all know that a number of the injected gasoline won’t ever come again out. That is the “cushion” that acts a bit like a spring that pushes the opposite hydrogen again to the floor.

Some hydrogen might also escape into the ambiance via small cracks within the rock. We’ll have to understand how a lot, arrange surveillance to look at for it and think about its impact on the local weather.

These are only a few of the challenges posed by underground storage of hydrogen. However our expertise with pure gasoline storage provides us confidence we are able to handle them with the fitting analysis and planning.

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Making it work

New Zealand’s hydrogen future stays unsure, however work is underway to arrange. Early indicators for underground storage of inexperienced hydrogen are promising and there’s numerous enthusiasm for it abroad.

However technical feasibility isn’t sufficient: any resolution should make financial sense and be acceptable to the broader public, significantly tangata whenua.

Proving the feasibility of any new concept takes time. We have to develop, generally fail, refine after which discover success. However with every new excessive climate occasion, its clear we don’t have numerous time. On this new period of adaptation, governments, business, communities and scientists might want to work extra carefully than ever.