How much energy does it take (on average) to produce 1 kilogram of the following materials?

• Wood (from standing timber): 3-7MJ (830 to 1,950 watt-hours).

• Steel (from recycled steel): 6-15MJ (1,665 to 4,170 watt-hours).

• Aluminum (from 100 % recycled aluminum): 11.35-17MJ (3,150 to 4,750 watt-hours)

• Iron (from iron ore): 20-25MJ (5,550 to 6,950 watt-hours)

• Glass (from sand, etcetera): 18-35MJ (5,000 to 9,700 watt-hours)

• Steel (from iron): 20-50MJ (5,550 to 13,900 watt-hours)

• Paper (from standing timber): 25-50MJ (6,950 to 13,900 watt-hours)

• Plastics (from crude oil): 62-108MJ (17,200 to 31,950 watt-hours)

• Copper (from sulfide ore): 60-125MJ (16,600 to 34,700 watt-hours)

• Aluminum (from a typical mix of 80% virgin and 20% recycled aluminum): 219 MJ (60,800 watt-hours)

• Silicon (from silica): 230-235MJ (63,900 to 65,300 watt-hours)

• Nickel (from ore concentrate): 230-270MJ (63,900 to 75,000 watt-hours)

• Aluminum (from bauxite): 227-342MJ (63,000 to 95,000 watt-hours)

• Titanium (from ore concentrate): 900-940MJ (250,000 to 261,000 watt-hours)

• Electronic grade silicon (CVD process): 7,590-7,755MJ (2,108,700 to 2,154,900 watt-hours).

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Note: 1 megajoule (MJ) = 277.77 watt-hour (Wh)

Source: Environmentally benign manufacturing.

Back to article "The monster footprint of digital technology"

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Comments

[john]

Men you need to be a good mathematician to get that answer right

[Random Person]

Hey, an air table or embedded google sheet would provide a better view.

[gianluca]

Hello everyone! Thanks for your article. I would ask if it is possible to have the energy consumption to produce 1 sqm of plywood. Would be perfect the follow details: birch fsc plywood 24 mm thick. Thanks

[Forty-two]

It has not been a trivial task for me to try to find these seemingly straightforward numbers! However I'd like to see the specific sources for the figures. At the moment the listed source is a website which links to over 70 papers. Would you have any time to be more specific with which papers were used for each figure?

I do love low tech magazine regardless, keep it up!

Cheers, Forty-two

[Owen Thurgate]

Amazing resource, really highlights the value of recycling aluminium and the high energy cost of plastic! Thank you!

[kris de decker]

@ forty-two

I made these calculations based on the data in those 70 papers...

[Johan]

The estimate for energy needed to produce 1kg of Aluminium is way off. According to Science Direct (which shows extract from per reviewed papers) the energy need to produce 1kg is more like 13-15kWh (and not 60kWh as you quote) This is from information from Alcoa which is the largest producer of Aluminum

See: https://www.sciencedirect.com/topics/engineering/aluminum-production#:~:text=8.1.&text=The%20process%20is%20large%20consumer,smelting%20technology%2C%20S%C3%B8derberg%20and%20prebake.