Hydro Aluminium AS is building the most climate-friendly, energy-efficient aluminum smelting plant in the world on Norway's Karmøy peninsula. Siemens is supplying a VB1 high-current switchgear with vacuum switching technology and the high-current supply unit for production. Measuring 34 meters long with 26 switchgear panels, it will be the longest high-current and generator switchgear ever built by Siemens. This type of system protects equipment such as generators and transformers from overvoltage and short-circuits. To ensure the supply of electrical power for the production process, Siemens is also providing six large converter units, including the associated control and protection systems and the requisite cooling systems. The converters convert AC current to DC current for operating the power-intensive smelting furnaces. The scope of supply also includes automation technology with the PCS7 process control system and distributed I/O systems as well as operator control and monitoring systems. The high-current switchgear is to be delivered by the end of 2016, while the high-current supply unit will be handed over by the end of 2017. Siemens was already commissioned last year to supply the main transformers for this project.
High-current and generator switchgear with vacuum switching technology are important for protecting transformers and generators used in generator switchgear applications with high thermal and mechanical loads. Vacuum switching technology and maintenance-free components in generator switchgear guarantee minimum maintenance costs. Unlike gas-insulated circuit-breakers, vacuum circuit-breakers interrupt the arc in a high-vacuum interrupter tube. With its double busbar design, Siemens' VB1 fulfills the special requirements for high plant availability. Thanks to its arc fault consistency, it ensures a high degree of personal safety. It has a short-circuit breaking capacity of up to 50 kiloamperes (kA) at 24 kilovolts (kV) and can handle rated currents of up to 5000 amperes (A) without forced cooling.
In addition to delivering, Siemens is responsible for dimensioning, integrating, installing, and commissioning the plant components.
The new aluminum factory on Karmøy will produce 75,000 tons of aluminum per year and consume about 1 terrawatt hour (TWh) of electricity per year, thus placing high demands on all of the electrical equipment. 1 TWh roughly corresponds to the annual electricity consumption of 50,000 households.
With the Karmøy Technology Pilot, Hydro plans to reduce energy consumption in aluminum production by about 15 percent compared to world average. The project will also reduce CO2 emissions to the world's lowest level. Today the global average is over 14 kWh per kilogram. On Karmøy, Hydro is testing a new technology that should allow them to reduce consumption to 11.5-11.8 kWh per kilogram.