Why not hexagonal silver wires?

The Case for Silver in High-End Electric Motors

Electric motors are heavily reliant on copper, a remarkable material that has been used in wires and motors since their inception. However, could there be a better alternative for high-end motorsport applications?

Silver to the Rescue?

Silver boasts the highest electrical conductivity (and the lowest resistivity) among all known metals. This is a significant advantage because the lower the resistance to electrical current, the more efficiently energy is transmitted. In the context of electric motors, this means more electrical energy can be converted into motion, with less lost as heat.

However, silver comes with its own challenges. One of the main issues is cost—silver is significantly more expensive than copper, making it impractical for conventional motors. Yet, for low-volume, high-performance applications like race motors, the cost difference per kilogram is negligible. Another concern is weight: silver is denser than copper, which could result in heavier motors if more silver is used.

The Role of AC Motors and Wire Geometry

Formula E car motors operate on alternating current (AC), where the conductivity of electrical flow is concentrated near the surface of the conductor—a phenomenon known as the skin effect. For this reason, maximizing the surface area of the windings becomes crucial.

This is where hexagonal or even 3D-printed wires could offer a unique advantage. Compared to circular wires, hexagonal wires can fit together more tightly, reducing gaps between the windings. This denser packing not only optimizes the available space but also enhances the magnetic field produced, thereby improving motor performance.

A Silver Future for Motorsport?

Given the benefits of silver and the ability to optimize wire geometry, it begs the question: why not use silver for the next generation of electric motors? If cost is not a limiting factor and weight reductions can be achieved elsewhere in the vehicle, silver could represent a groundbreaking advancement in electric motor design for high-end motorsport.

Credits: Sergio Coutinho & Zasso Group