Greenhouse gas emissions (GHG) are the natural corollary to AWAC’S energy intensive operations. High energy use results in high emission levels, especially when much of that energy is sourced from fossil fuel products such as fuel oil, coal and electricity generated from coal fired power stations.
In an increasingly carbon concerned and constrained world with expanding regulations to counter climate change (link to carbon tax box), AWAC’s GHG emissions present sustainability and business challenges for the AWAC joint venture. Our focus and importantly, that of operating partner Alcoa is on decreasing GHG intensity by:
A major challenge is balancing the need to ensure energy security with energy diversification. Currently base-load electricity supply at AWAC’s Victorian aluminium smelters depends on long-term contracts, reducing opportunities to switch energy sources. Despite these hurdles, Alcoa continue to pursue opportunities to reduce the carbon intensity of the electricity AWAC purchases.
At the Pinjarra alumina refinery in Western Australia, two onsite gas-fired cogeneration power plants save approximately 450,000 metric tonnes of greenhouse gas emissions annually compared to a similar-sized coal-fired plant. In addition, the cogeneration plants reduce the refinery emissions by 270,000 tonnes per year through more efficient steam generation.
In 2010 total greenhouse gas emissions from AWAC’s operations equalled 20. 17 million tonnes of CO2, an increase from 2009 due to raised production levels. Performance on a CO2 intensity basis (metric tons of CO2e per tonne of production) demonstrates a substantial improvement over the past eight years with intensity dropping by 12 per cent for the smelting operations and 17.5 per cent for the Australian refineries. The year-over-year performance improved through the curtailment of higher-intensity production.
| Greenhouse gas emissions AWAC Full Facility of tonnes of CO2 equivalents. |
||
| 2009 | 2010 | |
| Direct (Scope 1) | 9,635,880 | 10,294,527 |
| Indirect ( Scope 2) | 10,296,662 | 9,875,112 |
| Total | 19,932,542 | 20,169,639 |
Scope 1 (direct GHG) emissions are those released directly by AWACs’ sites through energy sources such as natural gas, while Scope 2 or indirect emissions are those from power stations that supply energy to AWAC’s sites.
The Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard (Revised Edition), Australia - National Greenhouse and Energy Reporting Act, Brazil GHG Protocol Programme and The Climate Registry: General Reporting Protocol. Emission per source calculated by applying WRI Calculation Tool