Why isn't copper wire used for high voltage transmission lines?

Why isn't copper wire used for high voltage transmission lines?

Copper wire is not typically used for high-voltage transmission lines for several key reasons:

1. Cost: Copper is significantly more expensive than aluminum, which is the most common material used for high-voltage transmission lines. Since transmission lines require a lot of wire, the cost of copper would be prohibitively high for widespread use in power grids.

2. Weight: Copper is denser and heavier than aluminum. For high-voltage transmission lines, weight is a critical factor, as the cables must be supported by towers over long distances. The greater weight of copper would require stronger and more expensive support structures.

3. Electrical Conductivity: While copper has better electrical conductivity than aluminum, the difference is not large enough to outweigh the other disadvantages. Aluminum, although slightly less conductive, is still highly efficient for power transmission and is often used in larger quantities to compensate for the lower conductivity.

4. Strength-to-Weight Ratio: Aluminum has a better strength-to-weight ratio than copper, making it a more practical choice for long-distance transmission. The lower weight of aluminum allows for more efficient design and lower material costs for the towers and cables.

Because of these factors, aluminum is the preferred material for high-voltage transmission lines, offering a balance of cost, weight, strength, and conductivity.