As part of attempts to reduce its embarrassing post-Kyoto greenhouse gas emissions profile, Australia has discovered over 60MW of hydro potential in New South Wales (NSW) that needs only turbines to harvest.

Some of 36 or more sites that could each produce at least 1000MWh annually are at existing water supply dams, but others are much closer to home. The 10m head cooling water outfall from the 2640MW Eraring thermal power station could, for example, generate 50,000MWh per year with the installation of a 7.4MW turbine.

The sites were located by New Zealand specialists Leyland Consultants in a mid-1998 survey of over 600 dams, weirs, water and sewage treatment plants and pipelines in NSW.

Few of the sites could produce economic power in the existing market. However, the top 20 sites combined could produce 350,000MWh of electricity per year at an average cost of A$40/MWh, potentially displacing coal fired power that would emit some 350Mt of greenhouse gases each year.

The most attractive sites include the 82m head at the Nepean dam outlet where one 710kW turbine could produce over 6000MWh per year at around A$27/MWh.

Warragamba dam outlets on the Prospect river could produce 35,200MWh annually for much the same price.

The Eraring outfall offers some of the cheapest available hydro power at A$25/MWh but the station has no plans to capture its potential A$1.25M annual earnings.