From BHP websiteHow will BHP Billiton off-set the extra...

From BHP website

How will BHP Billiton off-set the extra greenhouse gases resulting from the expansion project?

This very important issue is the subject of intensive work during the pre-feasibility phase. Results of this work will be explained in the Draft Environmental Impact Statement.

It is important to recognise that Olympic Dam needs a secure base load energy source which at present is only available from the state grid. However the project team is examining a range of options such as gas, wind and hot rocks.

At present the National Grid does not offer greenhouse credits for companies that use low emission energy sources. The future of a so called “Green Grid” will ultimately depend on the legislative and regulatory requirements set by government.