Despite being touted as a zero-emissions solution for steel production, green hydrogen derived from renewable energy will play a relatively minor role in reducing sector emissions between now and 2050, says the International Energy Agency (IEA).

By mid-century, less than 10% of steel produced globally will use renewable hydrogen as its energy source, according to the agency's new report, Iron and Steel Technology Roadmap: Towards More Sustainable Steelmaking and that is under a Sustainable Development Scenario (SDS) in line with the Paris Agreement goals. Even in this scenario, coal will still provide more than half of the steel sector's energy in 2050, and only about a third of that will utilise carbon capture and storage (CCS).

The roadmap states that the roughly 2.6 billion tonnes of CO2 emitted by the steel industry every year — 7% of global emissions — needs to be reduced by only 54% by 2050 to meet Paris Agreement goals.

Of this roughly 1.2 billion tonne reduction, only 8% is expected to come from switching from fossil fuels (mainly coal) to green hydrogen, despite companies such as Vattenfall and ThyssenKrupp already working on fossil-free steel from H2. This compares to 16% of the emissions cuts coming from carbon capture and storage (CCS), 6% from biofuels, 4% from electrification (ie, the use of electric-arc furnaces), and 5% from “other fuel shifts”.

A whopping 61% of emissions reduction would come from materials efficiency and technology improvements in the steel-making process itself.

Nevertheless, this 8% of the required emissions reductions still represents about 110 million tonnes of CO2 annually, and would require a large amount of green hydrogen — adding up to about 165GW of electrolysers and 700TWh of renewable energy each year.

Under the SDS, emissions from the steel industry will need to fall by 90% by 2070. As this scenario requires the global energy sector to reach net-zero emissions by 2070, the remaining 10% of steel-sector emissions would need to be offset by carbon removal technologies.

The IEA admits that it will be difficult for the steel industry to meet the emissions reductions required under the Sustainable Development Scenario — much of the required technology is still being developed, while governments would have to find ways to ensure that greener steel producers, which would inevitably face higher costs, would not be at a disadvantage in a global commoditised market.

“The high reliance on coal in current primary steel production [which provides about 75% of the industry’s energy demand], long-lived capital assets and the sector’s exposure to international trade and competitiveness make this transition towards near-zero emissions challenging,” the report states. “It is for these reasons that the sector is sometimes referred to as among those that are ‘hard to abate’.”