Last day for Søderberg technology in Hydro

On Friday, March 13, at 09.01 am, the power in the Søderberg potroom at the aluminium plant at Karmøy in Norway was switched off. This marks the end of production in the very last electrolytic cell in Hydro to use the old Søderberg technology.

March 13, 2009

Environmental step

With the closure of its Søderberg production, Hydro has met important environmental requirements. But Friday’s closure of the Søderberg potroom at Karmøy was in essence marked by sadness.

The phasing out of Søderberg technology at Hydro’s Norwegian plants in recent years has brought the loss of many hundreds of jobs.

Once the biggest in Europe

When Hydro’s then CEO Rolf Østbye announced on June 11, 1963, that the company was going to build an aluminium metal plant at Karmøy, the flags were hoisted to the top of the pole locally.

A quarter of a century later, following the fourth extension in 1987, the Karmøy plant emerged as the biggest in Europe with an annual production of 220.000 tonnes.

But nothing lasts forever. The new millennium commenced with new and more stringent  environmental specifications issued by the Norwegian Pollution Control Authority (SFT), and Hydro decided to phase out the older production technology, which uses open Søderberg cells, at its Norwegian plants.

In Årdal and Høyanger the Søderberg cells were switched off a while back. In Karmøy’s case the Søderberg cells were to be discontinued by the end of 2009. But the global financial crisis that started last autumn speeded up the closure.

Friday, March 13, marked the definitive end of the Søderberg era at Karmøy as well. Pensioned control room operator Audun Fatland and Jens Inge Ve, responsible for the electrical installation at the plant, saw to it that the switch was pulled that cut the power supply to the last cells in potroom B in the Søderberg facility.

New forward-looking technology

With the closure at Karmøy all Søderberg technology is now history in Hydro. Primary aluminium is produced exclusively using prebake technology at the Hydro plants in Høyanger, Årdal, Karmøy and Sunndal.

Indeed, in Årdal test cells are in operation that use HAL4e, the advanced electrolytic technology developed by Hydro that represents a further step on the road towards greater energy efficiency, even fewer emissions and the concentration of CO2 for future capture and sequestration when this is technologically and financially feasible.

Hydro may have given up the old Søderberg-technology, but has by no means given up producing aluminium and constantly improving production technology.

Gladness and sadness

In terms of greenhouse gas emissions and environmental considerations, many will look upon Friday, March 13, 2009, as a happy day. For the Hydro employees who have worked shifts in the Søderberg potrooms, the day was also marked by reflection and sadness because of the jobs that have gone and the ties between colleagues that have been severed.


Why the Søderberg potrooms had to close

In May 2000 the Norwegian Pollution Control Authority (SFT) reviewed the emission permits for the country's aluminium industry and introduced new guidelines and emissions specifications, not only for individual production locations, but also for specific production lines or technologies. The basis for the new requirements was the Oslo-Paris Convention (OSPAR).

When the new SFT specifications were introduced, Hydro’s aluminium plant operated production lines using different technologies: prebake with built-in cells and Søderberg with open cells. Hydro’s prebake series met all the new requirements from the start. The situation was different, though, for the Søderberg series, which varied from plant to plant and was dependent on age and standard.

Hydro declared as early as 2000 that the company would comply with SFT’s emission specifications. How to do this needed to be considered by every single plant. It was made clear that there would be a total assessment, where the economic aspects would also weigh heavily.

For Sunndal it was decided, already prior to the launch of the new SFT requirements, to phase out the Søderberg technology in 2002 in connection with the construction of the Su4 potrooms. At Høyanger the Søderberg facility was closed down in February 2006, while in Årdal the last Søderberg cell was switched off in June 2007. And at Karmøy the Søderberg power was stopped on Friday March 13, 2009.

Updated: October 15, 2013