On the one hand, I can see why they make this claim -- their energy efficiency is a competitive advantage, and could tip off the competitors as to how large their infrastructure in Australia is.

On the other hand, they're a public company that has to release their financial information publicly, and that too is a competitive advantage. If everyone has to share the same info, is it really an advantage anymore?

I think they're just trying to avoid getting to a point where energy use is required to be shared in the same way as financial information.