The indiscriminate use of clean hydrogen could slow down the energy transition, so policymakers need to prioritise its use in so-called “hard-to-abate” sectors that cannot be electrified, according to a new 144-page report by the International Renewable Energy Agency (Irena).
“Despite hydrogen’s great potential, it must be kept in mind that its production, transport and conversion require energy, as well as significant investment,” says the study, entitled Accelerating Hydrogen Deployment in the G7. “Indiscriminate use of hydrogen could therefore slow down the energy transition. This calls for priority setting in policy making.”
The first priority, it explains, “should be to decarbonise existing hydrogen applications”.
“About three-quarters of pure hydrogen today is produced from fossil gas, with the remainder produced from coal (mainly in China). This results in annual CO2 emissions of almost 900 million tonnes, which is about 2.5% of global energy-related CO2 emissions.”
Hydrogen is mainly used today to produce chemicals such as ammonia fertiliser and in oil refining to remove sulphur from crude oil.
“The second priority is to use hydrogen in large demand centres that cannot be easily electrified,” the report continues. “These are called ‘hard-to-abate applications’ because the decarbonisation alternatives either have a higher mitigation cost or low technology maturity. Hard-to-abate applications include chemicals, steel, shipping and aviation.”
Hydrogen is the only currently viable clean solution for extracting iron from iron ore in steel making, while H2 derivatives such as ammonia and methanol are widely considered to be the best fuel for decarbonising shipping, due to their higher energy density by volume compared to liquid or compressed hydrogen. While H2 is being considered as a fuel for short- and medium-distance aviation, synthetic kerosene produced by combining hydrogen and captured carbon dioxide is thought to be the most viable solution for long-distance flights.
The Irena report adds in a footnote that long-term seasonal energy storage is also an application where hydrogen or its derivatives are “better placed to satisfy, but this is not a final energy use”.
“The rest of the [potential] applications [for clean hydrogen] should be last in priority. Hydrogen use for these applications will depend on technology evolution, and hydrogen could be attractive for a niche set of conditions,” it says.
The report — which was written in response to the Hydrogen Action Pact agreed by the G7 countries in May — cites residential heating as the lowest priority use case for clean hydrogen.