# Embodied energy trade: Technology advances

Green iron, sail-assisted ships and data centres chasing clean power

Source page: https://www.materialinsights.org/energy/e_embodied/advances/

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 · 2025

Reduce ore with renewable hydrogen at the mine region and ship briquettes^[9](https://rmi.org/green-iron-corridors-a-new-way-to-transform-the-steel-business/)

*Improves:* 5 to 40% cheaper clean steel for importers, by RMI modelling
**H2-DRI steel plants in Europe** being deployed · 2026

Stegra (Sweden), thyssenkrupp and Salzgitter building hydrogen direct reduction^[10](https://steelwatch.org/steelwatch-explainers/steelwatch-explainer-why-green-iron-trade-will-catalyse-steel-industry-decarbonisation/)

*Improves:* First large-scale plants scheduled from 2026, able to use imported or local green iron
**Green ammonia export** being deployed · 2020s

Ammonia from renewable hydrogen shipped as fertiliser, fuel or hydrogen carrier^[7](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Apr/IRENA_Global_Trade_Hydrogen_2022.pdf)^[8](https://www.irena.org/Energy-Transition/Technology/Hydrogen/Global-hydrogen-trade)

*Improves:* Uses existing ammonia trade, about 10% of production
**Wind-assisted ships** in service · 2026

Rotor sails, rigid wing sails, suction sails and kites^[15](https://engine.online/news/wind-assisted-propulsion-fleet-crosses-100-vessel-mark-iwsa-7c37)

*Improves:* Over 100 large vessels fitted by June 2026; typical retrofit fuel savings of 5 to 20%
**High-reflectivity light pipes** in service · 2013

Mirror films over 99% reflective (manufacturer data)^[16](https://solatube.com/wp-content/uploads/2021/02/131203-Daylighting-Fact-Sheet.pdf)

*Improves:* 89% of daylight delivered after 12 m
**Data centres in cheap-power regions** in service · 2025

atNorth, AWS and Microsoft in Sweden; Google, Microsoft and TikTok in Finland^[17](https://www.atnorth.com/in-the-news/nordic-incentives-keep-data-center-costs-competitive/)

*Improves:* Low-cost low-carbon power and free cooling

#### Comparing the options

| Option | Efficiency | Cost | Capacity or distance | Maturity |
|---|---|---|---|---|
| **Aluminium (product)**^[2](https://international-aluminium.org/statistics/primary-aluminium-production/)^[3](https://giz.de/en/downloads/giz2025-en-factsheet-aluminium-smelting-with-use-of-low-carbon-electricity.pdf)^[6](https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/DCS/MEPC 81-6-1 - Report on annual carbon intensity and efficiency of the existing fleet(Reporting years 201... (Secretariat).pdf)^[20](https://international-aluminium.org/landing/aluminium-recycling-saves-95-of-the-energy-needed-for-primary-aluminium-production/) | 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)**^[9](https://rmi.org/green-iron-corridors-a-new-way-to-transform-the-steel-business/)^[10](https://steelwatch.org/steelwatch-explainers/steelwatch-explainer-why-green-iron-trade-will-catalyse-steel-industry-decarbonisation/) | 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 carrier**^[7](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Apr/IRENA_Global_Trade_Hydrogen_2022.pdf)^[8](https://www.irena.org/Energy-Transition/Technology/Hydrogen/Global-hydrogen-trade) | 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 centre**^[13](https://www.iea.org/energy-system/end-uses/data-centres-and-data-transmission-networks)^[14](https://www.iea.org/reports/energy-and-ai/executive-summary)^[17](https://www.atnorth.com/in-the-news/nordic-incentives-keep-data-center-costs-competitive/) | 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 pipe**^[16](https://solatube.com/wp-content/uploads/2021/02/131203-Daylighting-Fact-Sheet.pdf) | 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

1. [Primary Aluminium Production statistics (2025 annual totals as reported by Mysteel, 27 January 2026)](https://international-aluminium.org/statistics/primary-aluminium-production/) International Aluminium Institute, 2026
2. [Factsheet: Aluminium smelting with use of low-carbon electricity](https://giz.de/en/downloads/giz2025-en-factsheet-aluminium-smelting-with-use-of-low-carbon-electricity.pdf) GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit), 2025
3. [Report on annual carbon intensity and efficiency of the existing fleet, reporting years 2019-2022 (MEPC 81/6/1)](https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/DCS/MEPC 81-6-1 - Report on annual carbon intensity and efficiency of the existing fleet(Reporting years 201... (Secretariat).pdf) International Maritime Organization, 2023
4. [Global Hydrogen Trade to Meet the 1.5 C Climate Goal: Technology Review of Hydrogen Carriers](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Apr/IRENA_Global_Trade_Hydrogen_2022.pdf) IRENA, 2022
5. [Global hydrogen trade](https://www.irena.org/Energy-Transition/Technology/Hydrogen/Global-hydrogen-trade) IRENA, 2022
6. [Green iron corridors: a new way to transform the steel business](https://rmi.org/green-iron-corridors-a-new-way-to-transform-the-steel-business/) RMI, 2024
7. [SteelWatch explainer: why green iron trade will catalyse steel industry decarbonisation](https://steelwatch.org/steelwatch-explainers/steelwatch-explainer-why-green-iron-trade-will-catalyse-steel-industry-decarbonisation/) SteelWatch, 2025
8. [Data Centres and Data Transmission Networks](https://www.iea.org/energy-system/end-uses/data-centres-and-data-transmission-networks) IEA, 2023
9. [Energy and AI: Executive summary](https://www.iea.org/reports/energy-and-ai/executive-summary) IEA, 2025
10. [Wind-assisted propulsion fleet crosses 100-vessel mark (International Windship Association data)](https://engine.online/news/wind-assisted-propulsion-fleet-crosses-100-vessel-mark-iwsa-7c37) Engine Online, 2026
11. [Daylighting Fact Sheet (company data)](https://solatube.com/wp-content/uploads/2021/02/131203-Daylighting-Fact-Sheet.pdf) Solatube, 2013
12. [Nordic incentives keep data center costs competitive (Techerati article reposted by atNorth; company-hosted)](https://www.atnorth.com/in-the-news/nordic-incentives-keep-data-center-costs-competitive/) atNorth / Techerati, 2025
13. [Aluminium recycling saves 95% of the energy needed for primary aluminium production](https://international-aluminium.org/landing/aluminium-recycling-saves-95-of-the-energy-needed-for-primary-aluminium-production/) International Aluminium Institute, 2021

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_embodied/index.md)
- [Overview](https://www.materialinsights.org/energy/e_embodied/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_embodied/correlation/index.md)
- [How it works](https://www.materialinsights.org/energy/e_embodied/explain/index.md)
- [Efficiency and losses](https://www.materialinsights.org/energy/e_embodied/efficiency/index.md)
- [Value chain](https://www.materialinsights.org/energy/e_embodied/valuechain/index.md)
- [Geopolitics and regulation](https://www.materialinsights.org/energy/e_embodied/geopolitics/index.md)
- [Unit economics](https://www.materialinsights.org/energy/e_embodied/economics/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_embodied/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_embodied/links/index.md)