What material contains the MOST embodied energy?

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    Michael Ermann

    Embodied Energy 

     

    Materials with high embodied energy

     

    Manufactured with high heat:

    Ceramics

    Glass

    Stainless or galvanized steel

    Concrete (but, because of its weight, can look on tables like it has low embodied energy when measured on a per-kilogram basis). Concrete is responsible for fully 8% of the total carbon humans emit into the atmosphere. If the cement industry were a nation, it would be the third largest carbon emitter behind only China and the US. It is unlikely we will fix climate change without addressing cement.

     

    Manufactured with intense chemical processes and petrochemical use:

    Epoxies/Resins/Formaldehyde/many adhesives

    Paints and stains

    Foam insulation (polystyrene, spray-foams, polyisocyanurate)

    Plastics/Vinyl/PVC/melamine/polycarbonate

    Engineered wood products (MDF, Glue-lam)

     

    Manufactured with intense mining processes:

    Copper

    Aluminum

    Stone

     

    Transported from far away:

    Anything heavy and brought far (like countertop granite from India when you live near a granite quarry)

     

    Materials with low embodied energy

    Cellulose and glass fiber insulation

    Wood (depends on what powers the kiln and whether you include the loss of the carbon-removal capabilities of the tree that was cut down)

    Gypsum board and plaster

    Rammed earth

    You can see how you've been exposed to conflicting content!

    *note that a given manufacturer can easily greenwash here by measuring embodied energy per weight (concrete looks better because it is heavy), per square foot (vinyl looks better because it is thin), or per volume (rigid foam insulations look better because they’re relatively big and light). The biggest greenwash comes from the concrete industry because their data usually fail to account for the insane amount of carbon released as cement cures and oodles of CO2 enters the atmosphere through that curing process. I don’t know that NCARB knows this yet (maybe word will get to them through this post? I think in their 2015 haste to include more environmental content, they fell prey to the "embodied energy trap". . . I'd rather focus on energy use through operations (airtight buildings, insulation in cold climates, efficient systems, etc.) which most (but, by no means, all) building scientists tell us is more important--maybe much more important--than focusing on material selection). If you see conflicting data, as you have, it’s often, per how I described above, that concrete (wood, or vinyl) comes out looking like the best low-carbon option (measured by embodied energy by weight but not accounting for the equivalent embodied energy from off-gassing during curing) or the worst (measured by equivalent embodied energy—including curing—by square-foot of surface area). Okay, wood is actually pretty good, even when you account for lost carbon removal from the fallen tree. . . especially with modern, industrialized-nation logging practices that replace felled trees. In fact, when I, while writing this post, google “embodied energy by material”, and then click on the images tab to see the most popular graphs. . .  your first graph has concrete as the worst offender and the second one has concrete as the panacea to solve our carbon problems. (The first one is right).   The most legit data I’ve found is from the University of Bath and can be accessed here but even that data over-relies on per-unit-weight.

    What should you do? focus on what you can know for sure. Materials made with more heat, more mining, more processing, and more petroleum have, almost always, higher embodied energy—Michael Ermann, Amber Book creator.

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    Kawai Yam

    Michael Ermann Thanks for replying. 
    If you have to "guess", Which one has the most embodied energy from your list above? 
    I am guessing Steel > Aluminum > Concrete? 

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    Michael Ermann

    Per weight, it’s aluminum that has the most embodied energy….partly bc aluminum is light.
    Plus, though it abundant in the soil, a lot of soil must be dug to process a relatively small amount of aluminum. . . But know that concrete has a larger carbon footprint for any decision (like cladding) where you might have to choose between concrete and aluminum.

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