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areal photo of Karmøy plant. text overlay; production start 2018, annual production 75000 tonnes aluminium, 15% nmore engery efficient compared to world average, worlds lowest co2 footprint

Stories by Hydro

The world's most energy-efficient aluminium production technology

Hydro's pilot plant in Karmøy, Norway, began operations in January 2018 with the most climate- and energy-efficient aluminium production technology in the world. Here's how we do it.

The biggest challenge in aluminium production has always been to achieve stability and control in the electrolytic bath where production takes place. Large amounts of electricity are passed through an electrode in the bath to create the chemical reaction that creates aluminium.

When the electricity is then led out of the cell, powerful magnetic forces are created that draw the metal and the electrolytic bath horizontally and create sideways movements.

What makes the technology in the pilot cells innovative and unique is that we lead the current through new circuits and at the same time gain better control of the magnetism.

We harness the forces and stabilize the bath. Greater stability means that we can reduce the electric voltage, thereby saving energy and avoiding anode effects that create unnecessary emissions of greenhouse gases such as CO2.

computer illustration of the new production floor

Using this technology, energy consumption has decreased to 12.3 kWh. This is well below the world average of 14.1 kWh and Hydro's own average of 13.8 kWh.

We are also testing another variant of the new technology, which we hope will reduce energy consumption even further to 11.5 kWh per kilo of aluminium.

Compared with the technology used in our modern plants in Sunndal, Norway, and in Qatar, the new electrolytic cells are 50 percent larger and will produce 50 percent more metal per cell, using less energy per kilo aluminium produced.

computer illustration of the new production floor

What will this mean for the environment?

By using hydropower instead of coal, the pilot plant in Karmøy also saves the global environment from 1 million tonnes of CO2 emissions.

Direct CO2 emissions with the new technology in the pilot will be 0.8 kg lower per kilo of aluminium than the world average. Compared to world average CO2 emissions, the pilot plant in Karmøy will produce 60,000 fewer tonnes a year.

If the rest of the world produced aluminium with the technology Hydro is now rolling out, the energy savings would equate to almost the entire Norwegian annual hydropower production.

Norwegian Prime Minister Erna Solberg was at Hydro Karmøy when the technology pilot was announced. This is how she summarized the importance of this new technology:

Svein Richard Brandtzæg serving cake to prime minister erna solberg

"This is the biggest investment in Norwegian mainland industry in over 10 years, but the most important in many decades. Hydro built up Norway a hundred years ago. Now you are leading the way in the green shift."