Aluminium is everywhere, from drink cans and smartphones to high-speed trains and solar frames, because it is light, strong, corrosion-resistant and endlessly recyclable.
The catch is its climate bill: the industry still emits about 1.1 billion tonnes of CO₂ each year—roughly two per cent of all human-made emissions. These arise from two very different, energy-hungry stages, plus the recycling loop:
- Refining bauxite to alumina – high-temperature calciners and other furnaces (≈700–1,000 °C) are still fired mainly by coal, oil or natural gas. However, green hydrogen can deliver the same heat without the carbon.
- Smelting alumina to primary aluminium – the Hall–Héroult electrolytic process is far more energy-intensive and draws almost all its power from electricity; when that electricity comes from fossil-fuelled grids, it becomes the largest single source of the sector’s CO₂.
- Melting scrap for recycling – remelting secondary metal also requires molten-metal temperatures, and hydrogen-fuelled burners can substitute for today’s gas-fired furnaces here as well.
If aluminium is to remain the metal of the clean-tech age, it has to ditch those fossil flames.
One promising alternative is green hydrogen—hydrogen gas produced by splitting water using renewable electricity. When green hydrogen burns, the only by-product is water vapour. The paragraphs below explain how it works, what engineers have proven on real factory floors, and why policy, economics, and customer demand all point to hydrogen shaping the next decade of aluminium-making.
1 Green Hydrogen—Why It Fits the Job
Hydrogen flames reach full heat in seconds, can be stored for use when the sun is not shining, and flow through pipes much like natural gas. That means aluminium producers can retain most of their existing furnaces and workflows while significantly reducing their on-site emissions. Green hydrogen also acts as a sponge for surplus wind or solar power, converting what would otherwise be wasted electricity into a high-value fuel.
2 Five Real-World Case Studies in Aluminium Recycling and Alumina Production
Norsk Hydro – Navarra, Spain
In June 2023, Hydro swapped natural gas for green hydrogen in a casting furnace at its Navarra recycling plant. Over nine melts, the furnace processed 225 tonnes of scrap into billets for an electric bus manufacturer. Throughout the product quality matched business as usual, yet direct CO₂ emissions fell by about 90 per cent. This was the world’s first industrial batch of “hydrogen aluminium”, proving the concept at plant scale (Bloomberg, 15 June 2023).
Novelis – Latchford, United Kingdom
Backed by a £4.6 million grant from the UK Industrial Fuel Switching programme, Novelis ran a full-size recycling furnace on 100 per cent hydrogen for a week in February 2025. Again, the switch cut furnace emissions by roughly 90 per cent, with no rise in dross or defects. The company now plans to convert further lines during routine shutdowns (Novelis press release, 21 Feb 2025).
Rio Tinto – Yarwun, Australia
Primary aluminium involves an upstream step called calcination, where alumina is heated to about 1,000 °C. Rio Tinto is installing a 2.5 MW electrolyser at its Yarwun refinery to feed green hydrogen to one of four calciners. Commissioning is due late 2025. If rolled out site-wide, the project could eliminate up to half a million tonnes of CO₂ each year, equivalent to taking more than 100,000 cars off the road (Rio Tinto project page).
Constellium – Voreppe, France
Under the EU-funded HyInHeat project, Constellium cast a 12-tonne aluminium slab with hydrogen burners in 2024. Inline sensors confirmed that the slab met demanding automotive sheet standards, and oxidation levels remained normal. The firm is now mapping hydrogen options for its large mills in France and Germany (Constellium news, 2024).
Speira – Bonn, Germany
Speira converted a 1.5-tonne pilot furnace to operate in two modes: air-fired and oxy-fuel (hydrogen burned with pure oxygen). The oxy-fuel setup trimmed overall fuel use by about 30 per cent and almost eliminated NOₓ pollution, while producing high-quality metal. Engineers are now designing hydrogen-ready lines for the Rheinwerk plant, Europe’s largest aluminium foundry (Speira newsroom, 2025).
Across thousands of furnace hours, these sites reported no serious safety incidents, demonstrating that hydrogen can be handled as safely as other industrial gases when the right sensors and procedures are in place.
3 How Engineers Make Hydrogen Work in a Furnace
Hotter, faster flame. Hydrogen burns hotter and quicker than methane, risking damage to refractory linings. Trials at Speira and Constellium addressed this issue with staged-mix and oxy-fuel burners, which maintain wall temperatures within design limits while enhancing efficiency.
Invisible flame. Hydrogen flames are almost colourless. Plants in Spain and the UK have added UV flame scanners, extra leak detectors, and automatic purge systems that shut off the gas if a fault is detected. No leaks or flare-ups were recorded.
Water-vapour worries. Hydrogen combustion releases more moisture, raising concerns about excessive oxidation (dross). Operators used conventional cover fluxes and, in oxy-fuel mode, removed nitrogen (and a significant amount of the moisture) from the furnace atmosphere. Constellium’s 12-tonne slab showed no rise in oxides or porosity.
Fuel logistics. Moving compressed hydrogen by lorry is costly, so most projects plan on-site electrolysers powered by renewable electricity. Rio Tinto’s electrolyser will sit beside its calciner; Norsk Hydro is planning a similar arrangement for its next Norwegian plant. In Europe, the proposed Hydrogen Backbone pipeline network aims to link such sites later this decade.
4 Europe’s Tail-Wind of Policy and Funding
Europe is charging ahead because regulation, finance and market signals all push the same way:
- HyInHeat, a €24 million Horizon Europe project, is rebuilding burners, sensors and safety systems across eight aluminium and steel demonstrators (hyinheat.eu).
- From 2026 the Carbon Border Adjustment Mechanism (CBAM) will make aluminium importers pay the EU carbon price on embedded emissions, protecting clean European metal from dirtier imports (EC CBAM page).
- The European Hydrogen Bank, launched in 2024 with €3 billion, will auction support for early purchases of renewable hydrogen used in industry (EU Energy – Hydrogen Bank).
- The EU Emissions Trading System (EU ETS) keeps carbon allowances in the €70–90 range—every upward tick makes hydrogen heat more competitive (live EUA data via TradingEconomics).
5 The Economics—Closing the Cost Gap
Running a furnace on green hydrogen still costs more than natural gas, adding roughly US$1,000–1,500 per tonne of aluminium today. Three forces, however, are squeezing that premium:
- Cheaper hydrogen. The International Energy Agency expects renewable-based hydrogen to fall below US$2–3 kg¹ by 2030 as electrolysers go mass-market and wind-solar costs keep sliding (IEA Global Hydrogen Review 2024).
- Higher carbon prices. At €80 per tonne CO₂, a smelter emitting 10 t CO₂ per tonne of aluminium carries an €800 penalty if it sticks with fossil gas. The price trajectory points higher still.
- Customer pull. A Boston Consulting Group survey found 57 per cent of consumers will pay a premium for net-zero products (BCG report, 2023 PDF). McKinsey research suggests over a third of aluminium buyers expect to pay 5–10 per cent extra for “green metal” by 2030 if supply is scarce (McKinsey aluminium study, 2023 PDF).
Public grants cushion early movers—Novelis tapped UK funds; Speira uses German support; Hydro’s Norwegian electrolyser will draw on national aid. Analysts now expect hydrogen heat to reach cost parity with gas before the mid-2030s, especially in regions rich in cheap renewables.
6 Benefits Beyond Carbon
- Cleaner air. Hydrogen contains no sulphur or carbon, eliminating SO₂, soot and carbon monoxide. Oxy-fuel designs can almost erase NOₓ.
- Grid balance. Electrolysers ramp up when wind or solar output peaks, storing energy as hydrogen instead of curtailing it.
- Water recycling. Steam from hydrogen combustion can be condensed and fed back into the electrolyser, keeping net water use low.
- Circular metal. Recycled aluminium already needs just five per cent of the energy used in primary metal. If that five per cent comes from green hydrogen, scrap becomes virtually carbon-free.
7 What Happens Next?
- Bigger hydrogen hubs in Spain, Scotland and Norway will pair multi-megawatt electrolysers with aluminium plants.
- Hydrogen-ready burner kits from suppliers such as Fives and Tenova will let operators swap fuels during annual maintenance campaigns.
- Long-term offtake deals between smelters and carmakers, drinks-can companies and tech brands will guarantee demand and unlock project finance.
- Global copy-and-paste. Once Europe proves the business case, China—home to 60 per cent of global output—and Gulf producers with ultra-cheap solar power are poised to follow swiftly.
8 Straightforward Conclusion
Aluminium helps to build a greener world; green hydrogen helps to clean up aluminium. Real factories in Spain, Britain, Australia, France, and Germany have demonstrated that the switch works: furnaces reach the desired temperature, metal meets quality specifications, and on-site emissions decrease.
Costs are falling, carbon prices are climbing, and customers are willing to pay a fair premium. The fuse is lit. Over the coming decade, hydrogen burners are set to transition from pilot bays to full production, allowing aluminium to finally live up to its reputation as the low-carbon metal of the future.
Ready to act?
Hydrogenera designs and builds complete green-hydrogen solutions for heavy industry. Explore how your plant can make the switch at https://hydrogenera.eu or contact our team today.