Clean hydrogen isn’t really carbon free

Hydrogen is one of the most abundant molecules in the universe. On Earth, this element is mainly derived from water (H₂O) when separated to produce hydrocarbon compounds (fossil fuels), which can be used as an energy source. Current trend in energy and renewable energy production pushes hydrogen as a clean and safe alternative to oil and gas for heating and earthly modes of transport.

Despite efforts, the hydrogen industry remains to be vulnerable to numerous technical, economic, and policy challenges, particularly the issue surrounding hydrogen’s carbon intensity and color nomenclature. Generally, renewable hydrogen has lower carbon footprints compared to its fossil fuel counterparts. But, in certain cases, the carbon emissions of hydrogen production over a lifetime tend to be significant.

The National Renewable Energy Laboratory (NREL) in Colorado evaluated the life cycle of greenhouse gas emissions of renewable energy sources and concluded that it can still reach levels higher than 200g of CO₂e per kWh. The data provides that produced biomass-based hydrogen could still be comparable to that of fossil fuels in terms of carbon intensity.

Experts emphasized the need to be mindful that is not enough to assume that hydrogen produced from renewable energy using water electrolysis will always have to be classified as green or low-carbon. There must be an understanding of hydrogen’s carbon footprint at each step of the value chain.

Research by climate scientists (without fossil fuel links) has debunked industry claims that hydrogen should be a major player in creating a decarbonized future. Through, hydrogen extracted from water (using renewable energy sources) could – and should – play an important role in replacing the dirtiest hydrogen currently extracted from fossil fuels. It may also have a role in fuelling some transportation like long-haul flights and vintage cars, but the evidence is far from clear.  

Experts expressed that current efforts should be centered around how to make the production, storing, and transportation of hydrogen less to non-dependent on burning fossil fuels. Michael Liebrieich from Cleaning Up podcasts, shares, “The sooner we swap to green hydrogen (created from new renewables), the better. This could also be useful for some transportation, such as long-haul flights and heavy machinery, and maybe to store surplus wind and solar energy.”