Sewage-powered hydro plant up and running

The harbour-side plant, which generates energy by dropping treated wastewater down a 60-metre shaft, was switched on by NSW Water Minister Phil Costa and Climate Change Minister Frank Sartor.

The plant at North Head will reduce carbon dioxide emission equivalent to taking 3000 cars off the road, Mr. Costa told reporters.

The energy it produces will be enough to power 1000 homes, but will primarily be used to power about 40 per cent of the sewage treatment plant.

"Sydney Water is on track to deliver its carbon-neutral program and this is part of that process," Mr. Costa said.

The plant will reduce Sydney's greenhouse gas emissions by over 12,000 tonnes a year and is part of a $50 million upgrade to the North Head sewage treatment plant.

Mr. Sartor said the plant was only one part of Sydney Water's effort to go green.

"Sydney Water use to be the biggest user of water, now 95 per cent of its water is recycled," he said.

But opposition climate change spokeswoman Catherine Cusack said the plant doesn't go far enough and that emissions continue to "skyrocket".

"This government's renewable energy policies stink to high heaven," she told reporters in Sydney.