The aluminium industry is undergoing a period of transformation, with smelters seeking new ways to operate as flexible energy consumers. To support this shift, many are turning to technology for safe power modulation. 

The drivers for change are varied, shaped by each smelter’s power source and contracts, regulatory environment, and appetite for change.

The Chinese aluminium industry in particular is responding to a clear direction from their Government to reduce emissions from power sources by 30% before 2027.

These changes make sense for the industry’s producers for myriad reasons, not least because the smelters are sensitive to the rapid increase in power price volatility. This has served to accelerate their need for flexible production to better align with power availability and price.

Technology Development

To provide a solution for this challenge, the EnPot system for power modulation was developed at New Zealand’s Light Metals Research Centre over years of research and plant trials. Following developmental installations in Canda, Germany, New Zealand and Brazil the technology was rolled out on a full potline in 2019 at the TRIMET Essen smelter in Germany where it has been operating ever since.

More recently, the EnPot technology has been successfully demonstrated on six high amperage cells at Binzhou Beihai Huihong New Materials Co. Ltd. Smelter.

Altering Landscape of Chinese Aluminium Production

China, home to roughly 60% of global primary aluminium production, remains a cornerstone of the global industry.
As part of the nation's broader emissions reduction agenda, aluminium manufacturing faces significant challenges: each tonne of aluminium requires around 13,000 kWh of power, representing around 40% of the total cost of production.

Decarbonising the power supply, which is currently largely coal-fired, offers a clear route to emissions reduction, aligning with China’s targets to reach peak carbon emissions before 2030 and carbon neutrality by 2060.

And a shift is underway, largely driven by the nation’s 14th Five-Year Plan for a Modern Energy System. This plan emphasises clean energy integration and improved efficiency across industries.

In support of these objectives, the Special Action Plan for Energy Saving and Carbon Reduction in the Aluminium Electrolysis Industry (2024) sets clear targets for renewable energy use and efficiency improvements.

This direction is further reinforced by the Implementation Plan for the High-Quality Development of the Aluminium Industry (2025–2027) which aims for over 30% of aluminium production to be powered by clean energy by 2027.

The aluminium industry faces unprecedented pressure for energy conservation and carbon reduction.

Against that policy backdrop, the Government has tightened national capacity caps on production levels, curbing the proliferation of new production and capacity creep at existing smelters.

Caps are also set at a regional level considering each area’s power generation mix. For example, hydro-rich Yunnan province has seen smelting capacity physically moved in from regions more reliant on coal-fired power. The challenge in this region is true of many parts of the world reliant on rainfall - rain is not consistent.

Dry seasons, dry years happen - just ask the smelter operators in Yunnan Province, who feel the full force of production curtailments when lake and reservoir levels fall.

And the changes keep coming. In some regions, daily variable power pricing is increasingly being introduced based on the availability of renewable power.

Although many smelters still generate their own power, they are grid-connected and in some cases, there is an added incentive to take advantage of cut price, or sometimes negatively priced power.

Power pricing is also tiered in many instances, based on energy efficiency (DC kWhr/kg), penalising older or inefficient operations.

These changes have provided new stimulus in the industry for producers to look to flexible production to stay ahead of the curve and maximise profit per tonne of aluminium produced. Other important benefits include bolstering decarbonisation, via incorporating more renewable energy, or even enabling pots to run on less energy.

EnPot Installation at Binzhou Beihai Smelter

The EnPot system was installed in February 2025 at the Binzhou Beihai Huihong New Materials Co. Ltd. Smelter on six 440kA pots.

Until this time the technology has been installed on pots ranging from 160-340kA. As such, the new installation set out to demonstrate the effectiveness and safety of the technology on the largest pots to date.

The EnPot engineering team spent three months testing large changes in cell heat extraction or conservation. The process is ongoing; however, results show the EnPot technology enabled both very effective shell cooling and insulating on the 440kA pots.

The EnPot technology features stainless-steel Shell Heat Exchanger units attached to the upper sidewall of each pot, as seen below. Heat transfer control is maximised by the exchangers covering a large surface area of the pot, in the hottest shell location. Each exchanger is connected via suction manifolds to branch ducts and then to the main suction duct and fan located outside the potroom.

EnPot system schematic

The system design was customised for the Beihai pot shell by EnPot, with all pot-side hardware manufactured and shipped from New Zealand to China. The ducting, fans, and electrical and instrumentation equipment were supplied locally, including site installation labour.

The Beihai design features 96 heat exchangers and ten manifolds per pot, which can be controlled independently to improve the thermal condition and regularity of the pot, while maintaining operational stability and safety.

EnPot Technology mounted on the pot shell sidewall

Initial results

The EnPot team, together with the support of smelter operators and engineers, performed a wide range of tests to rapidly build a picture of the basic behaviour of the system and effectiveness on the large high-amperage pots.

Key highlights of the initial tests include successful stable operation with:

+10% high heat generation for 2 weeks
+15% for 2 weeks
 +20% for 8 hours, with many short duration tests of both positive and negative heat generation.

Another key benefit of shell thermal control included the ability to extend the life of the pots in a full shutdown scenario from four to six hours or longer, with further extended shutdown ability expected in future.

Another benefit was seen by operating the pots utilising EnPot’s insulation ability for 2% power conservation without current efficiency loss, with the expectation of further reductions.

EnPot’s external ducting and fans

Power in Numbers

Given the scale of the challenges facing the aluminium industry globally, and particularly in China, collaboration with established, like-minded technology partners will help to accelerate change.

In June 2025, EnPot signed a Collaboration Agreement with Siemens Energy China in an official ceremony in Shanghai with New Zealand’s Prime Minister Christopher Luxon.

The goal is to provide a clear pathway for China’s aluminium producers to integrate more renewable energy, enhance energy efficiency and reduce operating costs. Together, the companies’ technology is unlocking a more sustainable future for China’s aluminium industry.

EnPot and Siemens Energy signing ceremony with NZ Prime Minister, Christopher Luxon