Energy Use in Western Australia
 
In Western Australia, our three alumina refineries are powered on gas primarily from North West Shelf Gas, and other suppliers such as Apache Energy.

Co-generation
In 2005 Alcoa partnered with Alinta in WA to build cogeneration power units to supply electricity to West Australians through the WA grid and to give Alcoa steam which is used in our refining process.
 
The cogeneration plants produce both electricity and heat from the same fuel source, delivering greenhouse benefits.  Gas-fired cogeneration is the most thermal efficient and greenhouse-friendly non-renewable energy source. 
 
There are currently two cogeneration units operating at the Pinjarra Refinery.  Cogeneration is around 75% energy efficient, compared with 30-50% for other power plants operating in WA.   A year’s electricity from each cogeneration unit saves around 450,000 tonnes of greenhouse gas emissions each year compared to a similar sized coal fired plant – that’s roughly equivalent to  preventing the emissions from around 112,000 average cars. 
 
In addition, the cogeneration plants reduce Alcoa’s refinery emissions by 270,000 tonnes per year through more efficient steam generation – equivalent to preventing the emissions from around  67,000 cars.
 
Two Open Cycle plants commenced operation at Wagerup in October 2007 to supply reserve capacity to the market and may be converted to cogeneration units to meet future Wagerup steam requirements.   Cogeneration plants at the Pinjarra and Wagerup refineries could save over 1.8 million tonnes of greenhouse gas emissions when compared to coal fired electricity generation.