Have you considered a Solar Hot Water System ?

Solar hot water systems provide the greatest emission savings and account for 60 per cent of the hot water systems installed in NSW in 2007–2008 with the help of the rebate. Switching from an electric hot water system to a solar hot water system saves an average of 3.0 tonnes of greenhouse gas emissions a year. Switching from electric to a heat pump system saves 2.4 tonnes and switching to gas saves 2.9 tonnes a year.