The turbine came about following a RIA report in 2001 that said groundwater was becoming depleted and salty after years of poor rainfall.

The island used to rely utterly on liquid petroleum fuel, the authority's website says.

This gave rise to the Integrated Water and Power Development Plan to source most drinking water through desalination, which needed a new power system to be viable.

So the 600 kW turbine was installed in 2004, more than half-way funded with a $2.1 million grant from the former Howard government, with the remaining $1.75 million coming from the state government, Minister Hames' office said.

The turbine now provides 35 per cent of the island's power needs, complementing low-load and standard diesel generators.

It saves about $350,000 worth of fossil fuel per year – more than $3.5 million across its lifetime so far – and reduces greenhouse gases by about 1100 tons per year.

As intended, it also fully powers the desalination plant that provides 80 per cent of the 112kL of drinking water the island requires each year, with the rest being made up by rainwater.