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2008 — Environment
Optimizing every kWh, the way into Hydro-Quebec’s Écolectrique network
Electricity is more than just a raw material needed to manufacture aluminum. It is also a precious resource. Since every kWh saved can be used to produce a bit more aluminum, it is in our best interest to be extremely vigilant.
This issue has long been a concern for Alcoa Canada Primary Metals, and especially for the teams from the Deschambault and Bécancour smelters, both of which were inducted into the Hydro-Québec Écolectrique network in 2008. This group gathers energy efficiency leaders among Québec corporations that have reduced their energy consumption by at least 5% thanks to Mieux consommer – Grandes enterprises d’Hydro-Québec programs. This distinction from Hydro-Québec acknowledges the work accomplished by all the employees at these smelters, particularly the members of their Energy committees.
A new offensive began in 2008 at the Deschambault Smelter with a full energy use analysis of the facility to identify the best potential sources of savings. Logically, significant focus was put on the Electrolysis sector, which is the smelter’s biggest energy user.
Through a number of actions taken to optimize the process control and the design of the electrolytic pots, the latter’s intensity was increased from 345,000 amps to 353,500 amps, without purchasing any additional energy. This intensity gain enabled a reduction of close to 2.5% in the amount of electricity consumed per tonne of aluminum produced.
The logics for the alumina intake control and the instability reduction control were also improved. In addition, the control recipe for the chemical bath was optimized and newly installed pots have a new design that reduces energy consumption. This has helped increase the daily tonnage of aluminum produced to more than 700 tonnes in the electrolytic line.
Another system contributes to the smelter’s capacity to maximize the energy it is allocated and the programs that control the power level available to the sub-station have also been improved several times. In addition, following the example of the Bécancour Smelter, Deschambault also optimized its use of compressed air. The savings resulting from these energy efficiency measures total 91 GWh/year.
The Bécancour Smelter soon joined its counterpart in Deschambault as a member of the Écolectrique network, and the facility’s Energy Committee and employees have reason to be proud of their accomplishment. “We have three ongoing energy efficiency projects thanks to which we have achieved reductions in electricity consumption of 112 GW/h in the last year alone. That is equivalent to the electricity consumed by 6,200 homes over the course of a year,” said André Beaulieu, Head off the Energy Committee. “We really succeeded in raising awareness because, to achieve such a significant improvement, it takes small actions every single employee,” added Pierre Girard, a member of the Committee.
Identified as a major energy user, the compressed air network was analyzed from one end to the other. Some pressure levels were decreased and work practices related to its use were modified. Efforts also continue to optimize pot operation, notably through better thermal balance. “Our pots are now EnergyStar!” enthused Grégoire St-Amant, another committee member. Heating requirements for every building on the site were also analyzed and are being more strictly controlled.
“Finally, we launched a widespread campaign encouraging people to turn off their computer, turn down the heat and shut off the light before they leave the office,” explained Martin Brière, a sponsor of the smelter’s committee. And, there’s more! All of the small actions taken and new habits formed are encouraging the smelter’s employees and the members of the Energy Committee to go even further in optimizing energy consumption and sustainability.
The commitment of Alcoa Canada Primary Metals smelters towards these key issues, which are more important than ever, has been recognized globally by Alcoa. The facilities were rewarded with several awards from the company for their achievements and innovative approach.