# Embodied energy trade: Efficiency and losses

Why shipping costs almost nothing next to the energy inside

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

What this tab covers How much energy is lost while it moves and while it waits in storage or transit, and how much energy the transport itself consumes, in per cent.

Shipping an energy-intensive product costs little energy compared with what it embodies: moving a tonne of aluminium 10,000 km by bulk carrier uses about 0.3 to 0.6% of its total embodied primary energy, or about 1.3 to 2% of its smelting electricity (calculated). The bigger losses are in conversion (ammonia synthesis, cracking) and, for food, in waste.

Chart: Efficiency ranges
 Used to drive transport Whole chain Lost while held Lost in transit

#### Losses by measure

| Measure | Range | Type | What is measured |
|---|---|---|---|
| **Bulk carrier energy to move aluminium 10,000 km** | 0.3 to 0.6%^[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/)^[3](https://giz.de/en/downloads/giz2025-en-factsheet-aluminium-smelting-with-use-of-low-carbon-electricity.pdf) | Used to drive transport | Ship fuel as a share of 186 GJ per tonne embodied primary energy (calculated; 1.3 to 2.0% of the 51 GJ of smelting electricity alone). Uses IMO 2022 median EEOI of 9.1 to 14.9 g CO2 per tonne-nautical mile for 10,000 to 99,999 dwt bulk carriers, 3.114 t CO2 and 40.2 GJ per tonne of fuel oil, giving about 0.06 to 0.10 MJ per tonne-km |
| **Ammonia synthesis energy** | 12 to 26%^[7](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Apr/IRENA_Global_Trade_Hydrogen_2022.pdf) | Whole chain | Energy used to make ammonia as a share of the hydrogen energy |
| **Cracking ammonia back to hydrogen** | 13 to 34%^[7](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Apr/IRENA_Global_Trade_Hydrogen_2022.pdf) | Whole chain | Energy used at destination as a share of hydrogen energy; avoided if ammonia is used directly |
| **Agrifood energy tied to food loss and waste** | 38%^[12](https://www.fao.org/energy/resources/facts-and-figures/en) | Lost while held | Share of energy consumed in agrifood systems that is embodied in food lost or wasted (FAO, 2014 estimate) |
| **Light pipe, 12 m run, 99.7% reflective tube (manufacturer data)** | 89%^[16](https://solatube.com/wp-content/uploads/2021/02/131203-Daylighting-Fact-Sheet.pdf) | Lost in transit | Share of entering daylight delivered after 40 ft (14% with 95% enhanced aluminium) |
| **Fuel saved by wind-assisted propulsion** | 5 to 20%^[15](https://engine.online/news/wind-assisted-propulsion-fleet-crosses-100-vessel-mark-iwsa-7c37) | Used to drive transport | Typical reported fuel saving from retrofitted systems; newbuilds may save more |

#### Holding periods and inventory

| Measure | Value |
|---|---|
| **Volume shipped, green iron versus inputs** | HBI for a 2.5 Mt a year plant needs 0.75 to 1 million cubic metres of cargo, under a third of the 3.5 million for ore plus hydrogen^[10](https://steelwatch.org/steelwatch-explainers/steelwatch-explainer-why-green-iron-trade-will-catalyse-steel-industry-decarbonisation/) |
| **Holding losses of metal and ammonia** | Metals do not lose embodied energy in storage; HBI must be kept dry to avoid re-oxidation^[10](https://steelwatch.org/steelwatch-explainers/steelwatch-explainer-why-green-iron-trade-will-catalyse-steel-industry-decarbonisation/) |
| **Data transmission energy** | Networks used 260 to 360 TWh in 2022, similar to data centres; fixed-line energy per unit of data has halved about every two years^[13](https://www.iea.org/energy-system/end-uses/data-centres-and-data-transmission-networks) |

Food is the exception to cheap embodied transport: about 70% of agrifood energy is used after the farm gate (transport, processing, packaging, storage, marketing), and much of it ends in food that is lost or wasted. For data, sending results is cheap per job, but networks as a whole used 260 to 360 TWh in 2022, comparable with data centres. The shipping figure is sensitive to ship size and route: small bulk carriers and containerships use more fuel per tonne-km than large bulkers.

#### Sources

1. [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
2. [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
3. [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
4. [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
5. [Energy: facts and figures](https://www.fao.org/energy/resources/facts-and-figures/en) FAO, 2025
6. [Data Centres and Data Transmission Networks](https://www.iea.org/energy-system/end-uses/data-centres-and-data-transmission-networks) IEA, 2023
7. [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
8. [Daylighting Fact Sheet (company data)](https://solatube.com/wp-content/uploads/2021/02/131203-Daylighting-Fact-Sheet.pdf) Solatube, 2013
9. [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)
- [Technology advances](https://www.materialinsights.org/energy/e_embodied/advances/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)