Hydrogen has been the technology companies and governments around the world look at as the most feasible replacement energy source for fossil-fuels in the future economy. Capacity has been increasing exponentially over the last couple of years.
Hydrogen demand rose from 20 million tons in 1980 to 90 million tons in 2020. The market is expected to grow from 90 million tons in end-use in 2020 to more than 200 million tons in 2030 and between 500 – 900 million tons in 2050. We think those estimates are understated.
As the industry is still in its infancy and is expected to reach large-scale deployment around the world, there is an opportunity to ensure the enormous investments in hydrogen projects worldwide deliver the emissions reduction benefits they are intended for.
Digging into the science of hydrogen, the gas has been known to produce energy when burned and release no harmful emissions as by-products, just water vapor. However, it is also known that hydrogen has a climate-warming potential when released directly into the atmosphere.
It contributes to climate change by increasing the amounts of other greenhouse gases such as methane, ozone and water vapor which results in indirect warming. One of the main problems of the industry is minimizing and preventing hydrogen leakages. As the molecule is small and difficult to contain, it can easily leak into the atmosphere.
As the UK government has released its UK Hydrogen Strategy in 2021 that pushes for 10GW of clean hydrogen production capacity by 2030, a UK Government study was published in April 2022 that determines the hydrogen’s Global Warming Potential (GWP).
The estimates show it is about twice as bad as previously understood. Over a 100-year time period, a tonne of hydrogen in the atmosphere will warm the Earth 11 times more than a tonne of CO2.
Other studies have also looked at the short-term effect of hydrogen leaks and show that over five years, the warming power from a pulse of hydrogen relative to CO2 is 20 times higher.
An estimate of the impact from continuous rather than pulse emissions – which are more representative of the real world, calls that hydrogen is 100X more potent than CO2 emissions over a 10-year period.
The good news is that none of that matters as research shows even with high leakage, the warming effect 100 years after the economy switches to hydrogen would be 80% lower.
Still, in hydrogen-intensive scenarios which means 50% or more of final energy demand is supplied by hydrogen, with high leak rates, it could contribute a tenth of a degree Celsius of warming in 2050.
As the short-term warming effect of hydrogen leaks is high, it makes sense for the industry to try and minimize them as much as possible to ensure the positive climate change mitigation impact.
Some of the measures that can be taken include conducting more research on hydrogen’s warming effects relative to other greenhouse gases and developing models that can increase confidence in the impacts hydrogen deployment would have on global temperatures at varying leakage rates.
As widespread deployment of hydrogen hasn’t been done so far, much research that accurately measures leakages hasn’t been needed.
Other measures that could be taken are including the likelihood of leakage and its impacts on decisions about where and how to deploy hydrogen. Production in close proximity to where it will be used would be preferable as the farther hydrogen travels between production and end-use the greater the potential for leaks.
Hydrogen is considered a holy grail of the future of energy due to its high energy density and green property of releasing no greenhouse gasses when burned. Therefore, extensive research needs to be done further into the technology, especially leakages to secure a smoother energy transition pathway.