Using hydrogen-based fuels for cars and home heating risks locking in a dependency on fossil fuels and failing to tackle the climate crisis, according to a new analysis.
Fuels produced from hydrogen can be used as straight replacements for oil and gas and can be low-carbon, if renewable electricity is used to produce these “e-fuels”. However, the research found that using the electricity directly to power cars and warm houses was far more efficient.
The analysis estimated that hydrogen-based fuels would be very expensive and scarce in the coming decade. Therefore, equipment such as “hydrogen-ready” boilers could end up reliant on fossil gas and continue to produce the carbon emissions driving global heating.
However, a few sectors such as aviation, shipping, steel and some chemicals are extremely hard to electrify. The researchers said hydrogen-based fuels would be needed for these by 2050, when the world needs to have reached net zero emissions. But they said enormous investment in technology and fast-rising carbon taxes would be needed to achieve this.
Renewable electricity production is increasing rapidly as costs tumble. But it still makes up a small proportion of all energy used, which is mostly provided by coal, oil and gas. Using the electricity directly is efficient, but requires investment in new types of car and heating systems.
Using the electricity to create hydrogen from water and then using carbon dioxide to manufacture other fuels can produce “drop-in” replacements for fossil fuels. But the new study concludes this cannot work on a large enough scale to tackle the climate emergency in time.
“Hydrogen-based fuels can be a great clean energy carrier, yet their costs and associated risks are also great,” said Falko Ueckerdt, at the Potsdam Institute for Climate Impact Research (PIK) in Germany, who led the research.
“If we cling to combustion technologies and hope to feed them with hydrogen-based fuels, and these turn out to be too costly and scarce, then we will end up burning further oil and gas,” he said. “We should therefore prioritise those precious hydrogen-based fuels for applications for which they are indispensable: long-distance aviation, feedstocks in chemical production and steel production.”
Prof Gunnar Luderer, also at PIK and part of the study team, said: “As climate targets require immediate emission reductions, direct electrification should come first to assure a safe future. It is clear that the contribution of e-fuels and hydrogen will be marginal on the timescale of 2030.”
The research, published in the journal Nature Climate Change, calculated that producing and burning hydrogen-based fuels in home gas boilers required six to 14 times more electricity than heat pumps providing the same warmth. This is because energy is wasted in creating the hydrogen, then the e-fuel, then in burning it. For cars, using e-fuels requires five times more electricity than is needed than for battery-powered cars.
Romain Sacchi, from the Paul Scherrer Institute in Switzerland and part of the study team, said: “We are currently far from 100% renewable electricity. If produced with the current electricity mixes [in Europe], hydrogen-based fuels would increase – not decrease – greenhouse gas emissions, [compared with] using fossil fuels.”
Daryl Wilson, the executive director of the global, industry-backed Hydrogen Council, said hydrogen could become the most competitive low-carbon solution for some sectors by 2030, such as long-haul trucking and steel. “Other applications such as buildings and power will require a higher carbon cost to become cost-competitive,” he said. “However, these are currently also seeing strong momentum as large-scale and long-term solutions to decarbonise the gas grid.”
Members of the global Hydrogen Council include Saudi Aramco, BP and Total, and some critics say hydrogen provides a “cover story for fossil fuels”.
Luderer said the EU target for green hydrogen production in 2030 was a thousand times higher than current levels of production, suggesting the scale-up would have to go far faster than even the rapid solar energy rollout of the last decade.