Power cables’ aluminium and copper consumption are quantified in this data-file, in order to estimate the upside for both metals in the energy transition, especially amidst the expansion of renewables, power transmission and fast-chargers for electric vehicles.
Our best estimate is that a typical EV fast-charger would most likely require over 100kg of copper cabling, costing $800 in 2019-20 terms and emitting 5 tons of CO2; rising to $1,600 amidst the energy transition, after including attempts to lower the CO2 intensity of copper production.
Copper is used in EV cabling because it has low resistance losses. However, copper is heavy, with a density of 8.9 tons/m3. Aluminium cables of the same diameter will have c50% higher resistive losses, but they are also 70% lighter and stronger, which in turn explains why overhead transmission lines will use aluminium cabling instead of copper (full research note on power transmission and minimizing line losses here and here).
Thus a typical new wind or solar farm might require 100 tons of aluminium, costing $260k, emitting 1,000 tons of CO2 (chart below). Again, attempts to decarbonize aluminium could double the costs.
Material costs of conductors are usually around 40% of total conductor costs. Installation and accessories inflate these costs by 2.5x. A good ballpark for conductors on an overhead transmission line is around $0.15/kW-km (chart below).
Overall, in the energy transition, we think that the use of aluminium to inter-connect renewables will most likely rise from 0.3 million tons per year (MTpa) in 2021-22 to 3-5MTpa by the 2030s (versus a total global aluminium market of 65MTpa in 2021). The numbers depend on the quantity of renewables being connected, the size of the lines and the distance from production bases to consumption centers.
The full data-file is linked below, outlining all of our calculations. It allows you to test the numbers, and how they change based on the power cable distance (linear), copper and aluminium prices (linear), voltage (decay function), diameter (quadratic function) and tolerable resistance losses (decay function). Generally, high voltage lines, closer to consumers, will be most efficient.
To read more about aluminium used in transmission lines for wind and solar, please see our article here.