Low rainfall a challenge for hydro
AFTER half a century as the workhorse of renewable energy supply in Australia, hydro- electric power’s niche is under challenge. While accounting for almost 70 per cent of renewable electricity supplied to Australians, hydro seems likely to be overtaken by 2020 as a result of the Rudd Government’s emissions trading scheme and its proposed enlarged target for clean energy.
In modelling undertaken for the petroleum industry, economists Brian Fisher and Anna Matysek of Concept Economics estimate that the combined effect of the two policies — as well as the limited availability of sites for the expansion of grid- based hydro power — will be to push wind well into the renewables lead, although clean energy will still be providing only 20 per cent of total national power consumption.
By 2020, they say, wind energy supply could be more than double hydro output, depending on how the new policies are framed — carbon constraining laws have still to be finalised. And the hydro- electric generators have the impact of the long drought on their hands.
Even though after the heavy rains of summer most Australians living on the eastern seaboard consider the drought over, both Hydro Tasmania and Snowy Hydro, government- owned corporations that provide most national hydro capacity, are still battling the effects of low rainfall.
Hydro Tasmania, with 27 power stations using water from 50 dams, says recent rain has had little effect. Overall storage stood at 18.3 per cent on April 1, the lowest for 40 years. David Marshall, the organisation’s energy resources manager, acknowledges that Tasmania would be ‘‘ facing a parlous situation’’ if the Basslink transmission line to Victoria had not been commissioned in 2006.
In the first nine months of this financial year the $ 780 million link has enabled Hydro Tasmania to import more than 1700 gigawatt hours from the mainland, while exporting 215 GWh.
On the mainland, Snowy Hydro, which generally provides power to meet peak demands, said this month its storages remain around their lowest levels since the scheme was constructed 50 years ago.
Meanwhile, in Victoria’s Alpine region 300 km from Melbourne, AGL is pushing ahead with the largest hydro- electric power station to be built outside Tasmania in two decades. The $ 230 million Bogong plant, of capacity 140 MW capacity, is scheduled to be commissioned late next year.