Since opening the site in February 2004, Hydro has improved productivity of the plant’s original design by 15 percent, and increased energy efficiency by 25 percent. Contributing to the impressive improvements are the comprehensive power and automation solutions that ABB supplied for both of the plant’s potlines in connection with the site modernization and the transition from Søderberg electrolysis to Hydro’s own electrolyte reduction technology, HAL 250.
ABB has more than 80 years’ experience in power conversion for smelter applications.
Sunndal is the largest aluminum plant in Europe and the most modern of its kind in the world, producing 360,000 metric tons of primary aluminum a year from 516 electrolytic reduction cells in two potlines.
More than half of the energy used worldwide in the production of non-ferrous metals (metals other than iron and iron alloys) is for primary aluminum production, the International Energy Agency said in a 2007 report on energy efficiency and CO2 emissions in industry.
Aluminum is one of the most plentiful metals in the earth’s crust, but extracting it has always been an electricity-intensive process. Because electricity is a central component of the cost of aluminum (up to 30 percent of the metal’s value, according to Hydro), the industry is continually looking for ways to improve the efficiency of the smelting process.
A plant like Sunndal requires a very large amount of reliable electricity to run its production processes, because a smelter cannot be easily restarted once it stops. If power fails and the potline shuts down, molten aluminum can ‘freeze’ in a short time, and restarting can be an expensive process.
ABB’s scope of supply for both of Sunndal’s potlines was extensive, comprising power electronics and power supply systems to secure reliable power, as well as automation solutions.
It encompasses process-enabling technologies like rectifier groups and process control systems, harmonic filter banks, integrated switchgear modules, and low voltage and DC voltage distribution systems.
ABB was responsible for all aspects of the solutions – design, delivery, erection, testing, commissioning and completion.
As part of its optimization strategy and efforts to secure uptime at the potlines, Hydro awarded ABB a service and maintenance contract that covers ABB’s entire scope of supply in both power and automation at the site.
Hydro is one of the largest producers of primary aluminum in the world, and Sunndal is its largest facility.
ABB is the market and technology leader in power conversion for smelter applications with a global market share of 50 percent and successful projects around the world, including the world’s largest aluminum plant in Qatar.