Aluminium smelting is a continuous electrolytic process that requires significant quantities of electrical energy.
Before looking at the primary production process, it is worth taking a moment to understand that unlocking the power of aluminium through smelting demands significant levels of electricity.
Why such a need for energy? Because aluminium’s strong chemical bond with oxygen requires a power surge to separate it from alumina. This means that aluminium smelters thrive near sources of abundant, reliable power, particularly hydropower, which accounts for 40% of the global share of the industry’s energy consumption.
The demand for electricity requires a multi-faceted approach to acquiring it. Around 70% comes from local, regional, or national suppliers, while approximately 30% is self-generated by aluminium-producing companies.
Power Plants
In thermal power plants, chemical energy is converted into heat energy. This is transferred to a turbine and transformed into mechanical energy, then electricity.
All thermal power plants share the same theoretical efficiency for steam conditions. Constant operation (base load) proves more efficient than intermittent use (peak load). Aluminium smelters, which require a continuous power source, are crucial in maintaining base load. Smelters can also modulate their power requirements, giving power generators and distributors a base load and allowing them to meet peak demands when required by other consumers.
Hydroelectric stations utilise stored water energy through turbines, generating cost-effective, renewable electricity. Despite the low costs of hydroelectricity generation, dam construction demands significant capital. Therefore, a reliable aluminium smelting facility benefits generators and communities by offering stable, reliable, low-emission power.
Rectification & Use
While generated power is in the form of alternating current (AC), the Hall-Héroult process for smelting requires direct current (DC). Because of this, smelters transform AC into DC power using rectifier transformers for the aluminium reduction process.
Manager for Power Maintenance & Projects
Aluminium Bahrain (Alba)
“I take immense pride in the fact that I am part of a team that is turning energy into a high value metal and bringing benefits to the Bahrain economy, while supplying ‘Aluminium for the World’.”
