What do you think of "replacing copper with aluminum"
For the wire and cable industry, the most obvious material replacement is to use aluminum conductor instead of copper conductor. In the relative cost of copper and aluminum conductors, we need to consider the price, specific gravity, conductivity and other factors, in order to get the real answer whether using aluminum conductors can save costs. Copper is heavier than aluminum. The specific gravity of copper is 8.9g.cm3, and the specific gravity of aluminum is 2.7g/cm3. That is to say, under the same conductor specification, the weight of copper conductor is 3.3 times that of aluminum conductor. However, the conductivity of aluminum is only 61% of that of copper, that is to say, the cross section of aluminum conductor is 61% larger than that of copper conductor under the same transmission current. Therefore, in terms of conductor weight, to make the two conductors have the same carrying capacity, the weight of copper conductor is about twice that of aluminum conductor. In addition, the price ratio of copper to aluminum is about 3.5, so the cost of equivalent copper conductor is seven times that of aluminum conductor.
Of course, the simple cost comparison mentioned above does not explain the whole problem. Because the cable product is limited by the standard conductor specification, it is impossible to buy the aluminum core cable with the same conductivity as the copper core cable. Therefore, if the cable is made of aluminum conductor, the aluminum conductor with larger cross section must be used. Experience shows that under the condition of equal carrying capacity, the conductor section of aluminum core cable should be twice that of copper core cable. Since the cross-section of the aluminum conductor is twice that of the copper conductor, the subsequent increase in the insulation, sheath and armor materials of the aluminum conductor weakens the price advantage of using the aluminum conductor. That is to say, the price advantage of aluminum and copper is not great, because the conductor is only a small part of the cost of the whole cable after all.
Taking 70mm2 copper core cable as an example, the cost of copper conductor accounts for about 65% of the cost of the whole cable, while the cost of 120mm2 aluminum core cable with equal current carrying capacity can be saved by 23.5%. If the cost of copper conductor accounts for 80% of the cost of the whole cable, the cost savings of aluminum core cable with equal current carrying capacity can reach 46%. Only when the cost of copper conductor in the cable drops below 50% of the cost of the whole cable, the aluminum core cable will lose its cost advantage. At present, the cost of most copper core low-voltage cables and many medium voltage cable conductors has exceeded 50%. Therefore, compared with copper core power cables, aluminum core power cables have obvious advantages in cost saving.
