EnPot technology enables smelters to vary their energy usage to match electricity price fluctuations. Smelters are also in a position to secure cheaper power prices in return for modulating their energy usage on demand.
The significant impact on the cost of production for individual smelters is around $40M for a 600MW smelter, representing a return on investment of between one to four years.
EnPot allows smelters to respond immediately to market conditions, including the London Metal Exchange (LME) metal price and spot power prices. Historically, production constraints have prevented the worlds' smelters from taking advantage of prevailing spot electricity prices.
EnPot technology allows smelters to modulate electricity by curtailing, but not interrupting, production. This capability allows smelters to arbitrage between the electricity and aluminium markets, dependent on the price of metal versus electricity.
With EnPot smelters can vary their energy consumption up and down by up to 30%. The external control of cell heat balance allows this to be achieved without the internal temperature or stability of the pot changing. The heat balance control also allows the operating performance of the smelter to be optimised, increasing energy efficiency.
Enabling flexibility of operation means smelters can dictate exactly how much aluminium they produce and when, to take advantage of market signals. They can also wind down production and power consumption for longer periods without having to take pots out of service.
With EnPot, smelters can conduct full shutdown modulation in times of grid shortages and extreme power prices. Compared to what is possible without EnPot, shutdowns can be approximately doubled in duration or frequency with smoother potline recovery afterwards.
In times of unplanned outages, EnPot can double the time available for potline recovery.
With EnPot smelters can vary their energy use to match electricity generation fluctuations. This means smelters can release large amounts of electricity back to the grid in times of high demand or lower than normal generation, at a much lower cost than other storage options. This newfound flexibility means that many smelters can take advantage of low-cost renewable electricity because they are no longer locked into a 'constant production straight jacket'.
If EnPot was incorporated into the world’s smelters today, enabling 100% renewable energy usage, the cumulative savings over the next 30 years could be as much as 52 billion tonnes of CO2 - the equivalent to removing 90% of passenger vehicles on the road today.
1: Aluminium production pathway to zero carbon 2050, G.Matthews et al, Aluminium International Today, November/December 2020
Aluminium sector greenhouse gas pathways to 2050, International Aluminium Institute, September 2021
EnPot does not fundamentally change the smelting process. The only moving parts are the suction fans, which have built in redundancy. The installation process is also low risk because potlines remain fully operational during installation. Ultimately the system is non-invasive and likely to reduce business interruption premiums and insurance payments.
The EnPot team and technology partners provide an end-to-end solution, from initial specification to ongoing servicing and maintenance:
The process of upgrading a smelter with an EnPot conversion is broken into four phases:
Smelters remain fully operational during the conversion process, with no interruption to production. Our team have the experience to work alongside smelter management and staff to minimise disruption. They are also available to advise smelter management on how to maximise the benefits of their new dynamic control of the potline.