Researchers including William Collins, Professor of Climate Processes, examined the use of hydrogen in many sectors of the economy and calculated its climate impact.
They found the release of one tonne of hydrogen into the atmosphere corresponds to the emission of nearly 13 tonnes of carbon dioxide (CO2) equivalent, so it will be important to prevent leakage from pipe networks.
Based on their calculations, a clear climate benefit arises from a transition to a green hydrogen economy. For a leakage rate in the range of 1-3%, the use of hydrogen makes it possible to avoid 90% to 99% of CO2 emissions. However if blue hydrogen is used, a leakage rate of over 3% would offset the climate benefits.
Collins said, “All the scenarios considered in this study clearly suggest that green hydrogen is beneficial compared to fossil fuels in terms of CO2 emissions mitigation. Reducing the leakage rate of hydrogen and increasing the fraction of green hydrogen production appear to be the key levers towards maximum mitigation of CO2.”
The use of green hydrogen enables energy conversion and storage, and can provide a way to help hard-to-decarbonise sectors such as long-distance transport by truck, train or plane, heavy industries, or for domestic use in mixture with natural gas.
Fulfilling hydrogen’s potential as a decarbonisation tool will require a significant scale-up of clean hydrogen, which can be produced with renewables or with fossil fuels combined with measures to significantly lower emissions, such as carbon capture, utilisation, and storage (blue hydrogen), according to a recent McKinsey paper.
“Hydrogen demand will reach mass-market adoption only when low-cost clean-hydrogen supply is available. This will require a scale-up in electrolysis capacity and accompanying renewable-energy capacity, as well as the build-out of carbon capture, utilisation, and storage infrastructure. The sooner these investments in gigascale production are made, the earlier hydrogen will reach cost competitiveness,” it concludes.