Hydrogen has been praised for its versatility in helping industries decarbonize, earning it the nickname “Swiss army knife” of decarbonization. However, not all uses of hydrogen are environmentally friendly, as the majority of hydrogen produced today comes from fossil fuels. To truly decarbonize industries, a shift to green hydrogen produced from renewable sources is crucial.
Forecasts for green hydrogen production vary widely, with some estimates suggesting a significant increase in demand by 2050. In New Zealand, the demand for green hydrogen is estimated to be around 2.8 Mt/y if all technically feasible applications switch to hydrogen. Priority areas like fertilizers, methanol, shipping, steel, jet aviation, and long-term energy storage would require about 1 Mt/y of green hydrogen.
Fertilizers and methanol are considered “unavoidable” in the transition to green hydrogen due to the lack of alternative decarbonization options. Other key applications like shipping, jet fuel, steel production, and long-term grid storage also rely on green hydrogen. However, there are areas where hydrogen is deemed uncompetitive compared to alternatives like battery electric cars or heat pumps.
To meet the demand for 1 Mt/y of green hydrogen in New Zealand, a significant increase in renewable power plants’ capacity and the installation of 10 GW of electrolysers would be necessary. Long-duration storage of hydrogen is also crucial for balancing energy supply, especially in transitioning solar energy from summer to winter.
Decarbonizing steel production, which accounts for a significant portion of global greenhouse gas emissions, is another pressing application for green hydrogen. The hydrogen-based direct reduced iron process has shown promise in replacing coal with renewable electricity and hydrogen.
Exporting hydrogen presents another challenge due to the gas’s light nature, which requires specialized infrastructure for transportation. Options like cryogenic liquefaction, ammonia conversion, toluene hydrogenation, and e-methanol production are being explored to make hydrogen exports feasible.
Despite the potential of hydrogen in decarbonizing industries, cost remains a significant barrier. Scaling up electrolysers to reduce costs poses challenges due to the reliance on expensive materials like platinum and iridium. Research is focused on developing low-cost electrolysers using more abundant materials.
In conclusion, the success of green hydrogen in decarbonizing industries will depend on its competitiveness against alternative solutions like electrification and biofuels. While challenges remain, the potential of green hydrogen to significantly reduce greenhouse gas emissions in key industries is promising. New Zealand’s unique geology also offers opportunities to explore innovative methods of producing green hydrogen.