Embodied energy trade: Technology advances
Green iron, sail-assisted ships and data centres chasing clean power
What this tab covers The newest technologies in service or close to adoption, what each improves, and how the main options compare.The new wave is renewable-based embodied trade: green iron and green ammonia from sunny, windy exporters, low-carbon aluminium, data centres sited for clean power, and wind returning to ship propulsion.
Latest advances
Green iron (hydrogen-based HBI) trade demonstration · 2025Reduce ore with renewable hydrogen at the mine region and ship briquettes9
Improves: 5 to 40% cheaper clean steel for importers, by RMI modelling
H2-DRI steel plants in Europe being deployed · 2026Stegra (Sweden), thyssenkrupp and Salzgitter building hydrogen direct reduction10
Improves: First large-scale plants scheduled from 2026, able to use imported or local green iron
Green ammonia export being deployed · 2020sAmmonia from renewable hydrogen shipped as fertiliser, fuel or hydrogen carrier78
Improves: Uses existing ammonia trade, about 10% of production
Wind-assisted ships in service · 2026Rotor sails, rigid wing sails, suction sails and kites15
Improves: Over 100 large vessels fitted by June 2026; typical retrofit fuel savings of 5 to 20%
High-reflectivity light pipes in service · 2013Mirror films over 99% reflective (manufacturer data)16
Improves: 89% of daylight delivered after 12 m
Data centres in cheap-power regions in service · 2025atNorth, AWS and Microsoft in Sweden; Google, Microsoft and TikTok in Finland17
Improves: Low-cost low-carbon power and free cooling
Comparing the options
| Option | Efficiency | Cost | Capacity or distance | Maturity |
|---|---|---|---|---|
| Aluminium (product)23620 | about 0.3 to 0.6% of embodied energy to ship 10,000 km (calculated) | about 14.1 MWh of electricity per tonne | 73.8 Mt a year (2025) | mature |
| Green iron (HBI)910 | under a third of the shipping volume of ore plus hydrogen | about USD 390 per tonne iron at best sites | pilot to early commercial | demonstration |
| Ammonia as carrier78 | 12 to 26% synthesis plus 13 to 34% cracking if reconverted | USD 2.5 to 4.5 per kg H2 to move 10,000 km (2030) | about 10% of ammonia traded; over 120 ports equipped | mature trade, new as carrier |
| Remote data centre131417 | fixed-line network energy per unit of data has halved about every two years | low-cost hydro and free cooling | 415 TWh sector (2024) | mature |
| Light pipe16 | 89% delivered over 12 m (manufacturer data) | not stated | single rooms | mature |
Products beat wires when distance is oceanic and the product is energy-dense and stable. Aluminium and iron are irreversible energy sinks, so they suit industrial demand rather than power. Ammonia is the most flexible because it can be burned or cracked, but synthesis plus cracking costs about a quarter to over half of the hydrogen energy if fully reconverted (calculated by adding the IRENA ranges). Data centres move computing to the energy, the cheapest option of all when latency allows.
Sources
- Primary Aluminium Production statistics (2025 annual totals as reported by Mysteel, 27 January 2026) International Aluminium Institute, 2026
- Factsheet: Aluminium smelting with use of low-carbon electricity GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit), 2025
- Report on annual carbon intensity and efficiency of the existing fleet, reporting years 2019-2022 (MEPC 81/6/1) International Maritime Organization, 2023
- Global Hydrogen Trade to Meet the 1.5 C Climate Goal: Technology Review of Hydrogen Carriers IRENA, 2022
- Global hydrogen trade IRENA, 2022
- Green iron corridors: a new way to transform the steel business RMI, 2024
- SteelWatch explainer: why green iron trade will catalyse steel industry decarbonisation SteelWatch, 2025
- Data Centres and Data Transmission Networks IEA, 2023
- Energy and AI: Executive summary IEA, 2025
- Wind-assisted propulsion fleet crosses 100-vessel mark (International Windship Association data) Engine Online, 2026
- Daylighting Fact Sheet (company data) Solatube, 2013
- Nordic incentives keep data center costs competitive (Techerati article reposted by atNorth; company-hosted) atNorth / Techerati, 2025
- Aluminium recycling saves 95% of the energy needed for primary aluminium production International Aluminium Institute, 2021