Instead, solar cells use a range of minor metals including silicon, indium, gallium, selenium, cadmium, and tellurium. Minor metals, which are sometimes referred to as rare metals, are by-products from the refining of base metals such as copper, nickel, and zinc. As such, they are produced in smaller quantities.
Unlike the wind power and EV sectors, the solar PV industry isn’t reliant on rare earth materials. Instead, solar cells use a range of minor metals including silicon, indium, gallium, selenium, cadmium, and tellurium.
PV cells contain semiconductor materials that absorb light and transfer it to electrons that form an electric current. Silicon is still the dominant semiconductor metal used in solar cells, accounting for more than 90% of the market.
However, due to the green energy transition the metals current most important use is not only in the manufacture of batteries for laptops and mobile phones, but also in lithium-ion batteries for EVs as well as for the storage of power from solar and wind energy devices (Evans, 2014).
The huge expansion of electricity grids requires a large amount of minerals and metals. Copper and aluminium are the two main materials in wires and cables, with some also being used in transformers. Copper has long been the preferred choice for electricity grids due to its high electrical and thermal conductivity.
Metal content in an energy technology – often called metal intensity – is a key parameter for evaluating metal demand induced by PV developments. Metals contribute to everything from bulk material in supporting frames and mountings to integral components of wires, devices, electronics, and even the PV cells themselves.