Simultaneous development of green and blue hydrogen is vital if the world is to reach net-zero emissions by 2050, according to a study by an international team of researchers led by Imperial College London.

Both blue and green hydrogen production have drawbacks. The potential of blue hydrogen as a low-carbon fuel is threatened by upstream methane leaks, while green hydrogen production is expensive and requires the use of rare metals that are not in abundant supply.

Thinktank the Energy Transitions Commission estimates that 850GW of hydrogen production will be needed under a scenario where the world meets net-zero emissions by 2050. But current platinum production—even if entirely dedicated to electrolysers—will only allow for 600GW, according to the study.

And powering this number of electrolysers would would require 3,600TWh of zero-carbon power—more than the EU’s total demand today, the study finds.

The drawbacks to both blue and green hydrogen production have potential solutions: regulations can be introduced to minimise emissions across the natural gas supply chain, and electrolysis can be adapted to reduce the use of rare materials.

Twin-track approach

But advancing both forms of the fuel offers the best chance of finding the quickest and cheapest way to reach net-zero emissions, according to study co-author Nixon Sunny, from Imperial’s Centre for Environmental Policy.

850GW – Electrolyser capacity needed under net-zero scenario

“To move to net zero requires a pragmatic approach. We should move all things forward at once,” he says.

An early focus on blue hydrogen will also deliver material reductions in emissions while providing a market into which electrolytic hydrogen can grow, the study finds.

Regions with a history of oil and gas production are better placed to pursue a twin-track approach, whereas others such as India might prioritise energy independence and growth in renewables capacity—leading them to put a greater emphasis on green hydrogen.

Furthermore, near- and medium-term deployment of green hydrogen with dedicated renewable power means choosing not to use that renewable power on the grid.

“Until the electricity grid is deeply decarbonised, this is a wasteful choice,” says the report.

Developing both forms of the fuel will help meet the required high levels of demand from the mobility, industrial and power sectors, according to co-author Professor Nilay Shah, from Imperial’s Department of Chemical Engineering.

“Hydrogen should not be thought of as a point-source solution to a specific problem, but an important part of an overall net-zero energy and industrial system,” he says.

The study and the analysis behind it was published in the scientific journal Joule.

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Author: Tom Young