Increasing energy efficiency

Gränges works actively to reduce the energy consumption in its melting and casting processes to reduce both environmental impacts and costs. Energy costs are the most significant expense after metal and personnel costs. Gränges primarily consumes energy in its furnaces, where aluminium is re-melted either via direct combustion or via induction. Important energy sources are natural gas, electricity, and liquefied petroleum gas.

To improve energy efficiency, Gränges continually carries out energy audits, implements related improvement actions, and considers the best available technology for new investments. Energy efficiency measures are primarily linked to increased metal yield, improved thermal processes and recovery of waste heat. Gränges also re-melts recycled aluminium from its own production to avoid quality degradation and energy losses involved in transporting recycled aluminium to third parties.

Promoting renewable energy

Gränges’ operations in Europe primarily uses induction melters and sources electricity from low carbon sources (hydro and nuclear) through the deregulated energy market in Sweden. The operations in Americas and Asia use natural gas in their production, and in these regions electricity is sourced from regulated energy markets which currently are primarily based on nuclear and non-renewable energy.

Gränges works to evaluate alternative energy sources and to increase the sourcing and usage of renewable energy, in line with the company’s long-term target.

Energy use by type, 2019

Energy intensity

Sourced renewable energy, 2019

Reducing natural gas consumption in the Asia operations

Gränges’ operations in Asia has managed to reduce costs, increase productivity and achieve a more sustainable production thanks to an improved control of the natural gas flow in the casting process. By changing to a new type of valve on the burner, it has been possible to monitor the process and optimize the natural gas flow. A consistent flow with precise control means less waste and lower energy usage. Also, by adding an alarm which turns on whenever the flame is extinguished in the melting furnace, the uptime and burning performance on the machine has been improved. Since 2016, natural gas consumption has been reduced by 0.4 million m3 per year, slab production has increased by 4,500 tonnes, an annual cost saving of CNY 1.2 million has been achieved. This corresponds to a saving of 970 tonnes CO2e.

Targets and target fulfilment

See detailed information about Gränges’ long-term sustainability targets and target fulfilment.

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