Is a hydrogen-powered future hiding in our wastewater?
Its first steps may have been hesitant – thanks to a funding slump following the 2008 financial crisis – but hydrogen is now back and looking like a winner for renewable, clean energy. And its success may lie in a dirty source.
It could provide 24% of global energy requirements by 2050 – but creating hydrogen is a thirsty process, triggering anxiety about the cost to the world’s water. Hydrogen is produced by splitting the molecules in water, and when this is done using electricity from clean, renewable sources, it qualifies as ‘green’ hydrogen, providing a viable alternative to fossil fuels.
Only… it requires a lot of water. How do we square this with the urgent need to preserve and protect the planet’s ever more precious supply? A World Economic Forum report points out that the nations most in need of a hydrogen power revolution are also the driest. In some countries it would take a freshwater withdrawal of 10% to fully transition to a hydrogen-based economy – although the average water drain across 135 countries levels out at 3.3%. But science is the bringer of hope and frustration – and hydrogen power offers up both.
An H2O opportunity?
Hydrogen fuel consumption creates only air and water. What trickles from a hydrogen power cell as exhaust meets nearly all the WHO’s drinking water requirements. This means smaller countries which import hydrogen power could one day be simultaneously importing a boost to their water supply.
Even at the lowest level – less than 0.05% for Tajikistan – can we ever sanction the exploitation of yet more of our dwindling water supply for renewable energy? Can we even call hydrogen power green if it comes at this cost?
One solution to this conundrum could be water of a different colour.
A wastewater wonder
If electrolysed, this level of supply alone could generate 100% of Australia’s estimated hydrogen power by 2030. The by-product oxygen also offers significant benefits – improving the wastewater industry’s environmental footprint when used in further treatment processes, and equilaterally bringing down costs – a genuinely circular economy. Most significantly, it does not compete with existing potable water demand, avoiding knock-on impacts on freshwater supply.
Few offer up as many compensations as hydrogen power.
It may yet entirely mitigate what water it uses.
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