The right choice of cable material and the right cable cross-section are essential to ensure the best electrical conductivity.
By using highly conductive copper instead of lower grade copper or aluminium, energy losses in the cable will be lower and the conductor will produce less heat. Using such a highly efficient electrical conductor also results in a smaller cable section for the same current carrying capacity, which saves on space and insulation material.
The cable cross-section is measured in most countries in square millimeters. In North America, the sections of smaller cables are measured by American wire gauge, and larger cables are measured in circular mils.
What constitutes the ideal cable section depends on the criteria that are used. The technical standards on cable sizing are based on safety criteria and certain power quality aspects such as minimizing the voltage drop. From the point of view of life cycle costing and taking the energy losses inside the cable into account, however, the optimal cable section will be significantly larger than what minimum technical standards prescribe. The environmental optimum, calculated by Life Cycle Analysis, lies at an even larger cable cross-section. To learn more about calculating the optimal cable section, read the Leonardo Energy publication Cable Conductor Sizing for Minimal Life Cycle Cost.