Embodied energy and carbon

Embodied energy is the amount of energy consumed to extract, refine, process, transport and fabricate a material or product. It is often measured from cradle to factory, cradle to use, or cradle to grave (end of life). Likewise, embodied carbon footprint is the amount of carbon (CO₂) emission to produce a material.

Except for biodegradable plastics, plastics are made from so‐called feedstocks derived from crude oil refining and natural gas processing. About half the fossil fuel goes into the plastic itself while the remaining half is combusted to provide the energy during manufacture, meaning it takes about 2 kg of fossil fuel to produce 1kg of plastics. Petroleum holds in average 43 MJ/kg, plastic production requires about 86 MJ/kg. With about 3 hydrogen atoms for every carbon atom (15 g/mol) in the fuel consumed, the CO₂ (44 g/mol) emission is 44/15 = 2.9 kg of CO₂ for every kg of plastics produced.

Because different production paths consume different amounts of energy, the energy used in the production of a chemical depends on its feedstock. Chemical obtained from the cracking and distillation of petroleum or inorganic sources are called raw materials. The total energy consumed in the production is the sum of the energy inputs for itself and all its predecessors, starting from the raw material.

Energy is not only spent and CO₂ released in producing the material but also in shaping it into its desired form. Primary shaping processes are e.g. casting, rolling, extrusion, molding etc. Secondary processes are e.g. welding, heat-curing, painting, coating, etc. The listed values are supposed to contain the energy and CO₂ for material and processes for cable production.

The sources are:

The world's leading source of embodied energy and carbon data, the Inventory of Carbon & Energy .
'Useful Numbers for Environmental Studies and Meaningful Comparisons, Chapter 1 Materials' by B. Cushman-Roisin and B.T. Cremonini (2017)
'Materials and the Environment: Eco-informed Material Choice' by M. Ashby, 2nd edition (2012)
'Carbon Footprint and Sustainability of Different Natural Fibres for Biocomposites and Insulation Material' by M. Barth, M. Carus (2015) (used for Jute)
'Environmental Impact of Membrane and Foil Materials and Structures' by J. Cremers (2014), Technical Transactions (used for ETFE)
'Sustainable Engineering and Eco Design' by Chaouki Ghenai, intechopen.com (used for PTFE)
'Life Cycle Assessment of the Transmission Network in Great Britain' by G. P. Harrison at al (2010) (used for Mineral oil)
'Material Selection in Mechanical Design' by M. Ashby, 5th edition (2018), Rule of thumb

Note:

feedstock energy is typically included (if applicable)
Assumption for aluminium is a ratio of 25.6% extrusions, 55.7% rolled, 18.7% castings and worldwide average recycled content 33%
Value in MJ/kg for Aldrey (AL3) and EN-AW 6060 (AlMgSi0.5) are acc. to the publication 'Temperature Profiles of All-Aluminum-Alloy Conductors near Wedge Tension Clamps' by P. Bühlmann et al, 2018. Values for CO₂ are assumed to be identical to aluminium.
There is are no significant differences between the fibres hemp and jute with respect to embodied energy and CO₂.
Assumption for PPLP is a ratio of 50% paper, 50% PP plus volume 30% oil/rosin soaked
The book 'Material Selection in Mechanical Design' gives a rule of thumb for embodied energy that is 26 times the price in USD/kg for metals and ceramics and 7 times the price plus 65 for oil-based polymers. For embodied carbon, the rule of thumb is 0.06 times the embodied energy for metals, polymers and ceramics.
Not for all materials the end-of-life value is available or meaningful.
Not all values listed below can be selected in the cable editor.

Symbol

$EEC$

Unit

MJ/kg

Related

$M_{cable}$

List of materials in a cable

Choices

Id	MJ/kg	kgCO₂/kg	kgCO₂e/kg	Remark
PVC	77.2	2.61	3.1	(1) general type
PE	81.1	2.04	2.54	(1) general type
sPVC	77.2	2.61	3.1	≈PVC
sPE	81.1	2.04	2.54	≈PE
LDPE	78.1	1.69	2.08	(1)
MDPE	78.1	1.69		≈LDPE (no reference found)
HDPE	76.7	1.57	1.93	(1)
XLPE	76.7	1.57		≈HDPE (no reference found)
XLPEf	76.7	1.57		≈XLPE
PP	89.5	3.69		(2) production 83/3.2 plus extrusion 6.5/0.49
PPLP	71.3	4.11		50/50% paper/PP, paper 50% soaked oil/rosin
PUR	102.1	4.06	4.84	(1) flexible foam
PS	108.4	4.48	4.39	(2) production 102/4.0 plus extrusion 6.4/0.48
PA	135.5	8.79	7.92	(2) production 129/8.3 plus extrusion 6.5/0.49
STPe	81.1	2.04		≈PE (no reference found)
POC	81.1	2.04		≈PE (no reference found)
ETFE	168.0	10.08		80% of max value or range 26.5-210, CO₂ acc. rule of thumb
PET	85.0	2.35		(2) production 89/4.1 plus extrusion 6.4/0.48
PTFE	180.0	7.0		approx. value from figure
HFFR	81.1	2.04		no reference found, ≈PE
FRNC	81.1	2.04		no reference found, ≈PE
NR	88.0	3.6		(2) production 71/2.2 plus moulding 17/1.4
EPR	140.0	8.3		≈IIR (no reference found)
EPDM	140.0	8.3		≈EPR
EVA	89.0	2.68		(2) production 83/2.2 plus extrusion 6.0/0.48
XHF	76.0	1.7		≈PE
HFS	76.0	1.7		≈PE
CR	86.5	2.2		(2) production 68.0/1.7 plus moulding 18.5/1.5
CSM	81.1	2.04		≈PE (no reference found)
IIR	140.0	8.3		(2) production 124/6.9 plus moulding 16/1.4
PIB	88.0	3.6		≈NR (no reference found)
OilP	53.2	3.04		paper 50% soaked mineral oil (49.9/3.09)
Mass	53.2	3.04		paper 50% soaked oil/rosin (≈mineral oil)
CJ	41.8	3.91		60% jute + 40% PP
RSP	88.0	3.6		≈NR
BIT	51.0	0.43	0.55	(1) bitumen
tape	28.2	1.49		≈paper
SiR	235.5	14.1		(1) silicon, CO₂ acc. rule of thumb
fPOC	81.1	2.04		≈POC
fPP	115.1	3.93	4.49	≈PP
fPVC	77.2	2.61	3.1	≈PVC
fPE	81.1	2.04	2.54	≈PE
PRod	77.2	2.61		≈PVC (no reference found)
PTube	77.2	2.61		≈PVC (no reference found)
OilD	53.2	3.04		assuming similar to oil impregnated paper
Jute	10.0	4.05		(4) ≈hemp
TY	56.0	3.5		(2;3) ≈wool
Paper	28.2	1.49		(1) excluding calorific value of wood
Air	0.0	0.0
Cu	55.0	2.6	2.71	(1) EU tube & sheet type
Al	155.0	8.24	9.16	(1) general type
AL3	218.0	8.24	9.16
ENAW6060	218.0	8.24	9.16
Pb	25.21	1.57	1.67	(1) general type
Brz	69.0	3.73	4.0	(1)
CuSn	69.0	3.73	4.0	≈Brz
CuZn	44.0	2.46	2.64	(1)
Fe	25.0	1.91	2.03	(1)
S	20.1	1.37	1.46	(1) general type, 59% recycled content
SS	56.7	6.15		(1)
Zn	53.1	2.88	3.09	(1) general type
Ni	190.0	11.5

Image

Materials Engineering Science Processing and Design, Figure 2.10 - M. Ashby et al. (2007)