Hydroelectricity supplies a small proportion of power to the national market, but the lion’s share of renewable energy. In recent times, South Australia is sometimes touted as the leader in renewables (it is quite sunny and windy here) but in fact Tasmania’s responsive, reliable hydro generation has kept it far out ahead. If it was operated as baseload supply, along with Snowy Hydro as well as Victorian and Queensland capacity (all 60 Twh per year – deemed feasible by BREE), on paper hydro could meet around a fifth of normal peak demand and 31% of average demand based on 2013-14. But it is not and cannot be utilised this way.

With due consideration given to rainfall forecasts, environmental flows, irrigation and drinking water, Australian hydro capacity factor was limited to 19% in 2011-12. Somewhat higher levels of generation were rewarded under the carbon price. Further perspective can be gained from reservoir data supplied by Snowy Hydro and Hydro Tasmania.


Hydro remains the bulk of the world’s non-combustion electricity generation. Its effective expansion is welcomed by populations in developing countries. However, concerns regarding biological emissions may mean climate action and alleviation of poverty will require an alternative to shoulder the burden of providing reliable and plentiful electricity.

Competition for water resources will also affect the availability of water for hydroelectricity generation. Demand for water for urban and agricultural uses is projected to increase. It is likely that these uses for scarce water resources will take precedence over hydroelectricity generation. Generators face increasing demands to balance their needs against the need for greater water security for cities and major inland towns. The maintenance of environmental flows to ensure the environmental sustainability of river systems below dams is also an important future consideration which may further constrain growth of hydroelectricity generation.
pp 234

Environmental flows as well as supply to Australia’s food bowl regions may not be sexy headlines these days but Australia should be focusing on ensuring their security. Coupling reliable nuclear-powered desalination on the lower east coast with either large-scale offset of coastal and metropolitan water demand, or physical transport up to the hydro reservoirs themselves could achieve this on a scale not seen since hydroelectricty was initially expanded last century.

When the Snowy Mountains Hydroelectric Scheme was built in the later part of the last century… it was seen as a wonder of engineering. A young country, calling on skilled people from around the world, to complete a massive project that would deliver water for agriculture, and be paid for by supplying electricity to a growing nation.
~ Steve Liebmann

I wonder if similar words will be said, decades after Australia adopts reliable, ultra-low emission nuclear energy?


A week from last year that I noted for high, somewhat sustained winds. Consider the contributions of wind and hydro to overall NEM demand, the way hydro more (at low wind) or less (at high wind) follows that demand.


A close-up of the dance.

Nevertheless, hydro appears to be a considerable factor in demonstrated low-emissions regional grids:





4 thoughts on “Hydro

  1. I think hydro dams are pretty much maxed out in Australia with some potential new expensive or NIMBY infested sites given in
    That includes cliff top seawater. Run of river hydro sites are also getting scarce and are usually limited to 49% flow diversion. I believe desalinated water is pumped high for energy recovery on El Hierro in the Canary Islands but that is competing with diesel power not coal.

    The Gordon R in Tas has no irrigation demands. Back in the Hawke era they wanted to build a 180 MW station where it meets the Franklin R but ‘greens’ opposed it. Now we need 100 X 180 MW = 18 GW to replace dispatchable but dirty coal and gas but greens don’t have a coherent solution. I agree that already built hydro is low regret as will nukes be when we’ve gotten used to the idea.

    • The more research I did for this post, the more I realised there is more and more to know about Australian hydro!

      The guy I completed confined space training under had apparently worked on one of the dams, and told me of a fatal accident which had happened on his watch.

      Hydro is definitely part of Australia’s identity. The way Snowy is utilised these days seems pretty smart. But if artificially “topping up” the major reservoirs is at all feasible, I don’t see how it can be powered with insufficiently reliable renewables, or gas let alone coal (sort of cutting of your nose to spite your face)… leaving the best heavy lifter for last.

  2. I predict there will be no more hydro dams >5MW built in Australia ever. Small hydros were grid connected in Tas in July and August 2014, the former 10 km from me. For pumped hydro energy storage Tumut 3, Shoalhaven and Wivenhoe on the mainland are pretty much it so any more is a fantasy. I wonder though if unregulated wind power could be used to recycle outfall water in chronically low dams (eg US Hoover Dam) without the need for expensive earthworks. That leaves us with battery energy storage at $300/Mwh. The longer we indulge high renewables fantasies based on energy storage the longer we are stuck with coal and gas. At some point greens must realise they are not part of the solution they are part of the problem.

    • We will see increasing hyperbole around domestic battery storage tech, which, if Weißbach is at all an indication of carbon intensity by way of the EROI proxy, will only degrade any realistic claim to emissions reductions through rooftop PV. I won’t be surprised if the majority of greens maintain that Grid Storage Is Coming, especially in the face of Barry and Corey’s efforts – never mind that somehow tying a hypothetical national battery exclusively to intermittent generators is the least economical way to operate it and will ensure a minimised ROI in the 10 or so years before it must be replaced.

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