The Tasmanian “energy crisis”

In August 2012 Australia imposed a carbon tax on fossil fuel generation, and almost immediately Hydro Tasmania took advantage by shipping large quantities of cheap hydropower to the mainland via the 500MW “Basslink” interconnector (image). But the shipments  combined with a lack of rainfall in 2015 depleted the volume of water stored behind Tasmania’s dams – and then the Basslink interconnector failed. As a result Tasmania has now had to purchase diesel generators and reactivate its only gas-fired plant to avoid potential power shortages. Tasmania’s case is a classic example of how misguided government attempts to decarbonize electricity generation can seriously distort an electricity market.

First acknowledgements. What brought Tasmania to my attention was an article in the Marcus Review, and much of what I say here is repeated there. So why am I writing this post? Partly because the “Tasmanian crisis” merits a lot more publicity than it’s received, partly because I present some new data, and partly to give our Down Under readers a chance to sound off on a local issue which I’m sure some of them have strong feelings about.

Is there a drought in Tasmania?

We’ll get this out of the way first. As I’ve noted before just about everything bad that happens these days gets blamed on climate change, and the state of Tasmania’s dams is no exception.

ABC:  Drought conditions hit Tasmanian farmers. After the hottest and driest spring on record for Tasmania in 2015, dams are drying up while dairy, beef and sheep farms are destocking.


Reneweconomy:  Tasmania struggles with drought. The Apple Isle’s main source of electricity – hydro power – is being challenged by its driest ever spring, pushing reserves down to just 18.9 per cent.


the Tasmanian Government is refusing to call it a drought.

So officially there’s no drought. However, the one GHCNv2 rainfall record I can find for Tasmania that has data to 2016 (Hobart Airport, all the other records end in 2005), shows a drier-than-average 2015 and a declining trend in rainfall since 1958. This trend is most probably a result of shifts in ENSO patterns in the Pacific Ocean, but if it continues then watch out, Tasmania.

Figure 1: GHCN v2 monthly and annual monthly average rainfall, Hobart Airport. Data from KNMI Climate Explorer.

Tasmania’s electricity sector

Hydro Tasmania does a conspicuously poor job of supplying hard data on its operations so information is limited. Various sources of data have been used to compile the data shown below:

Figure 2: Tasmania electricity demand 2015. Data from Marsden Jacob Associates

According to Figure 2 Tasmania consumed about 10TWh of electricity in 2015. Average daily consumption was around 27GWh and peak load of around 1,650MW occurred in early June.

Tasmania’s installed generating capacity, including recently-purchased diesel units, is around 3,000MW according to Wikipedia . Note that the mothballed 208MW Tamar CCGT plant is now back up and running:

  • Hydro:      2,341.3 MW
  • CCGT:         208.0 MW
  • Wind:           310.5 MW
  • Diesel:       ~100.0 MW
    TOTAL:  ~2,959.8 MW

And 3,000MW is enough to supply demand at a capacity factor of about 40%, all other things being equal.

Reservoir Depletion

But of course all things are not equal. Tasmania can only generate electricity from a dam if there’s water behind it, and there’s precious little left:

Figure 3:  Storage in Tasmania’s reservoirs 2010-16, data from Hydro Tasmania

Between July 2012 and July 2014, while the Australian carbon tax was in place, power sales to the mainland through the Basslink interconnector lowered Hydro Tasmania’s dam storage capacity from about 7,700 GWh to about 4,100 GWh – a loss of 3,600 GWh. But this isn’t what did the damage. In July 2014, when the carbon tax was repealed, hydro storage was not that much lower than it was in 2010 and there was no immediate cause for alarm. But then came 2015, a low-rainfall year that didn’t replenish the reservoirs, and then in December Basslink failed. This mandated an immediate increase in hydro generation which led to the rapid drawdown of what water was left, as shown by the precipitous decrease at the right edge of the Figure.

Figure 4 gives a detailed picture of Tasmania’s generation over the period of the Basslink failure. Before the failure Tasmania was importing up to 40% of its power through Basslink, presumably to give its depleted reservoirs a chance to recover. But Basslink began to give problems early in December (note the thinning of the red layer) before failing completely, and to pick up the slack hydro generation had to be upped from 600 to 1,000MW, although by February it had fallen back to 600MW again because of the recommissioning of the Tamar Valley CCGT plant.

Figure 4: Tasmania generation by source during period of Basslink interconnector failure. Image from CEDEX‎.

How much money did Hydro Tasmania make on hydropower sales?

A cool $300 million.

Figure 5 shows Basslink interconnector flows over the period of interest. Note how the flows changed immediately to dominantly positive (Tasmania exporting) as soon as the carbon tax came into force and immediately back to mostly negative as soon as it was repealed.

Figure 5:  Basslink flows before, during and after Australian carbon tax. The vertical dotted red lines show the period over which the carbon tax was applied. Data from Marsden Jacob.

The impact on Tasmanian electricity export revenues is shown in Figure 6.

Figure 6:  Hydro Tasmania export revenues before, during and after Australian carbon tax. The vertical dotted red lines show the period over which the carbon tax was applied. Data from Marsden Jacob.

A question that arises here is whether Hydro Tasmania’s exports were planned or whether the Australian carbon tax automatically generated flows of cheap energy going north across the Bass Strait. According to O’Gorman & Jotzo ‎(2014) it was all  planned in advance:

With the knowledge that the (carbon tax) policy may be short-lived, hydroelectricity generators rushed to take advantage of higher prices in 2012/13. Once the carbon price was legislated in late 2011, some hydro producers conserved water until July 2012 when they were able to sell electricity at an inflated price (Hydro Tasmania 2013, p.22). The increase in hydroelectricity production in 2012/13-2013/14 was expected and was an example of the carbon price doing exactly as intended, making it more appealing for renewable generators to produce more power.

So whose fault was it?

If the last sentence of the quote above is correct and Australia’s carbon tax did exactly as intended then the lion’s share of the blame falls on the carbon tax. It can also be argued that Hydro Tasmania acted reasonably in taking advantage of the situation, particularly when it made $300 million without seriously depleting its hydro resources (Figure 3) – certainly if they hadn’t someone would be asking why they didn’t.

Where Hydro Tasmania fell down was in failing to maintain an adequate reserve margin. Their reserve margin consisted effectively of the Basslink interconnector, and interconnectors break, and Basslink broke. They also failed to allow for a low-rainfall year, which can happen any time and which happened in 2015. As a result they have had to purchase 100MW of diesel generators at a reported cost of $44 million and restart the Tamar Valley CCGT plant to avoid potential blackouts, which they claim are highly unlikely even while their staff are reported to be preparing for them.

Tasmania is in fact in a situation similar to Venezuela, where continuity (or in Venezuela’s case reestablishment) of electricity supply is contingent on rainfall eventually refilling the reservoirs. At the moment Tasmania’s reservoirs are reported to be at less than 15% of capacity, so the future is very much hostage to the weather. A few more dry years and Tasmania could be in trouble.

Finally, a link to Hydro Tasmania’s plans to extricate itself from its current predicament is provided here. It doesn’t read very convincingly.

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101 Responses to The Tasmanian “energy crisis”

  1. Alex says:

    Wow – Tasmania has a huge amount of storage. According to to the spreadsheet, much is made up by their Lakes.

    It seems they are depleting their storage by 12GWh per day, which seems logical. A full supply gives them about 3 years at half their power. Even when the Basslink failed, they had 300 days. They’ll need a long time to fill up.

    It would make sense to balance Australian wind power – import for a week, export for a week, and make money as Norway does. However, it’s not really enough for them to be a steady major exporter.

    • Euan Mearns says:

      It seems that Tasmania runs its hydro along the lines of Norway where reservoirs are significantly depleted in winter and allowed to fill in summer.

      The UK I believe is much stricter on maintaining water levels and generation is more limited to matching daily inflows which do match the demand pattern – more rain in winter.

      But UK hydro generation does vary with the weather. It goes down in drier years.

  2. Syndroma says:

    Tasmania looks a lot like Crimea. The same electricity consumption, the same demand profile. And both had problems started in Dec 15. But Crimea has no hydro capacity and a limited amount of gas generation. It has significant amounts of wind and solar, but they turned out to be useless for the grid in the “island” mode.

    Tasmanian interconnector is 1 cable DC, 500MW, Crimean interconnector is 16 cables AC, 800-1000MW. I understand that Bass Strait is wider than Kerch Strait, but still think that the decision to lay just one cable is overly optimistic.

    • Euan Mearns says:

      I guess the interconnector was built primarily to export electricity to the mainland and that it was never considered that hydro rich Tasmania may one day become dependent upon imports.

  3. climanrecon says:

    South Australia is also sailing very close to the wind, it seems like the smaller the area (Scotland and Ireland are other examples), i.e. the places totally unable to make any impact on atmospheric CO2, the more zealous they are about attempting to do so. The world is certainly going to take note of their efforts, but not in the way they hope.

    Tasmania is part of the National Electricity Market (NEM), its past electricity supply and demand data are available online, see the NEM ELECTRICITY DATA page of this blog for links:

    I had a quick look at their total demand data at the time the Basslink went down, and could see no sign of it going down, they were very lucky that it happened in summer, and not in the higher demand winter period.

  4. Peter says:

    “According to Figure 2 Tasmania consumed about 10TWh of electricity in 2015. Average daily consumption was around 27MWh….”

    Multiplying 27MWh * 365 is around 10 GWh, not 10TWh.
    Also it’s been reported they now have 200 diesels in operation.

  5. Thinkstoomuch says:


    I found some unverified rainfall files from Hydro Tasmania from 2005 to 2015.


    Data provided: “Flow (megalitre per day), meters below full dam level (metres), meteorological rain (mm) and water temperature (C) data for the Mersey-Forth Hydro Scheme in Tasmania, for the period January 2005 to June 2015. ”

    If it can help. Serious sorting to figure anything from it. Downloading the zip gets a bunch of .csv files. Hourly data on the rainfall. Lots of lines.


  6. Euan Mearns says:

    I’m struggling to reconcile some of the numbers. Population of Tasmania is about 515,000, about one tenth of Scotland. Scotland has peak electricity demand of the order 5.5 GW while Tasmania is about 1.6 GW. On a per capita basis they seem to be using about 3* the electricity?

    The Marsden Jacob report has a number of nice graphs including one that shows annual demand running at about 10 TWh.

    • Thinkstoomuch says:

      According to a 2009 report. Page 10 of 40. They were figuring on less than 1% growth per year at that time.

      Current Tasmanian annual electricity
      consumption is estimated at 10,441 GWh,
      comprising residential (19%) and
      commercial and industrial (81%).
      End Quote


    • Willem Post says:


      Demand is MW, consumption is MWh

      It looks like the $300 million revenues, due to the ill-considered carbon tax, will be eaten up by the diesel purchase, diesel fuel and CCGT fuel, while reservoirs may SLOWLY fill over the next 2-3 years.

      • Laogmyon. says:

        Exactly. Now Turnbull has hinted at another cord across Bass Strait at 1 billion. This suggests disclosure to me that the Bass Link will not be repaired. 100 years of clean generation thwarted.

      • Geoff says:

        It all about two reservoirs, Lake Gordon and Lake Pedder, 12,000+ GL.

    • duffer70 says:

      Tasmania’s higher per-capita consumption is a direct, deliberate result of the ‘hydro-industrialisation’ strategy to attract energy-intensive industry to Tasmania. This was largely successful, starting with a zinc smelter in ~1916. It’s still going today, and together with aluminium and manganese smelters and a paper mill makes up ‘the big four’ Tasmanian power users, consuming several times more than households.

      • Greg Kaan says:

        Yes, and these smelters are largely why Tasmania’s grid has not yet collapsed as they have been able to reduce production to lower demand. But they may soon get to the point where they need to shut down completely. If they do and the smelting pots solidify, the restart costs may be enough that the smelters are never reopened.

        • Or the smelter will simply drain the pots and then shut down meaning they can come back on, though with the loss of production. No need to sensationalize a simple task.

  7. Greg Kaan says:

    A few of extra points:

    Hydro Tasmania was planning to sell the Tamar Valley CCGT as BassLink imports of Victoria electricity during periods of low demand and/or high intermittent renewables generation were cheaper than running the station

    The cost of BassLink was largely justified by giving Hydro Tasmania the capability to arbitrage electricity in Victoria.,_Expectations_and_Outcomes.pdf

    There is a strong case that the water levels in Tasmania’s lakes did not recover significantly after the repeal of the Carbon Tax because they continued to arbitrage. From the last graph on page 4 of the of the Marsden Jacob report, you can see that Hydro Tasmania was exporting substantial amounts of electricity to Victoria between May and September 2015. Although the Carbon Tax had been repealed, substantial amounts of wind generation have been deployed in Victoria and South Australia leading to high volatility in the wholesale spot price in the South East Australian grid, making arbitrage highly profitable for rapidly dispatchable generators.

    So Tasmania’s situation has almost wholly been brought about by carbon abatement policies, both directly via the Carbon Tax and indirectly through the pricing consequences of intermittent generators favored by legislation ostensibly for carbon abatement.

  8. gweberbv says:

    According to Fig. 3 Tasmania entered the year 2015 with roughly the same amount of water behind the dams as at the beginning of 2010. If this situation turned out to be dangerous today, then it was also dangerous 6 years ago. In other words: The carbon tax has nothing to do with it. Instead a strict regulation of reservoir levels is missing to shield Tasmanie from droughts and interconnector failures.
    Just think about it: Not only a carbon tax can give rise to an increase of electricity prices from FF plants. A rally of the coal price as happened in 2008 would do the same. And probably the reaction of Hydro Tasmania would have been also the same.

    By the way: In 2008 the reservoirs were as empty as they are now. Just have a look:
    See Fig. 2.3 for reservoir levels (at least I think so) and Fig. 2.2 shows that at that time Tasmania was heavily importing through Basslink.
    Were was the bad guy called carbon tax at that time?

    • gweberbv says:

      P.S. What you can learn from Fig. 2.2 of the study linked above is that when reservoir levels are pretty low (2008 and 2009), Tasmania imported roughly 2.5 GWh p. a. through Basslink. This is equal to a continously running 300 MW plant. And this import was in addition to roughly 1.25 GWh of domestic oil and gas generation.

      1) Even without any exports, the reservoirs in Tasmania can run dry as a result of a few dry years. See the period from 1996 to 2008. -> and
      Note that there was some recovery after 2008, but the peak level in 2012 is only something like 60% of full supply (as defined by Hydro Tasmania).
      2) When reservoirs are nearly empty and hydro production has to be cut, Tasmania needs about 500 MW of additional capacity (based on the years 2008/09). This means that the authorities in Tasmania fully relied on the availibility of the interconnector when deciding to get rid of their gas plant. Very stupid. But people are stupid from times to times. That’s why you need regulations to prevent them from doing stupid things. Luckily, it was just mothballed, not already scraped.

      • Thinkstoomuch says:

        The data sets from eight different points I mentioned above is unverified. So take it as you will. But using the average from the years 2005-2014 (goes from Jan 2005 to June 2015).

        Comparing the (2) three year periods to the ten year average.



        19% more rain for the later period might seem to mean something.

        Then again this mismash probably won’t say what I am trying to say. Or else I horribly messed up the data and/or the presentation.


      • Kieran D says:

        So “the authorities” need “regulations to prevent them from doing stupid things”. The problem with that argument is that is the authorities are the ones who make the regulations.
        The other problem is that during the 99% of the time when there is water in dams, and a working interconnector, not being “stupid” amounts to telling Tasmanians “you are going to have to pay $xm a year through taxes/electricity bills for some infrastructure that you’re not using, but you might have to one day, maybe, if a series of unfortunate events coincide”.

        • Greg Kaan says:

          you are going to have to pay $xm a year through taxes/electricity bills for some infrastructure that you’re not using, but you might have to one day, maybe, if a series of unfortunate events coincide

          Such is life when your primary electricity supply is dependent on weather. Hydro is buffered vs wind and solar PV where you use it or lose it but the underlying power source is still weather dependent.

          Hydro Tasmania had the option of building a large amount of thermal generation or BassLink to cover low rainfall periods. Both would not have been used to an efficient capacity factor purely to back up the water storage but the arbitrage option was open with BassLink. We can argue that Hydro Tasmania was stupid/greedy to arbitrage when water levels were less than the amount needed to cover a dry spell without BassLink but the distortion of economics caused by firstly The Carbon Tax and then catering for wind (and solar) generation in SE Australia made the gamble compelling (along with the pseudo commercial operation of Hydro Tasmania where it is expected to generate dividends for it owner – the state government).

          Guenter chooses to ignore the economic factors due to carbon abatement legislation that altered the behavior of Hydro Tasmania from its more conservative operations, prior to The Carbon Tax.

          • gweberbv says:


            I do not dispute that the Carbon Tax was an incentive to export more electricity from stored water than was healthy for Tasmania. But I guess that the same effect would have come from a ‘normal’ increase in FF prices that are happening from times to times. Rember that coal and oil prices reached record values around 2008 without any additional taxation in place. When the economy is driving up FF prices, Hydro Tasmanie would have encountered the same incentive to empty their reservoirs.

            I think the main problem here is the absence of a clear regulation that satifies the n-1 rule. Meaning that even with the outage of a main power station and/or transmission line the remaining system must be sufficient at all times.
            Obviously, Tasmania was heading in a direction, where in times of low water levels, a significant share of electricity demand would be covered by the Basslink interconnector WITHOUT any backup. Such a strategy should not be allowed by regulators. In particular as just a few years ago Tasmania already experienced quite low reservoir levels as a result of roughly 10 years in a row with rainfall ‘lower than normal’. Thus, even without any export it seems to be impossible to operate the reservoirs with a safety margin that shields Tasmanian electricity supply fom droughts.

            I will not make many friends here with my proposal, but I suggest that Tasmania should install much more wind turbines to lower its dependence on rainfall. The varaition of wind production that is a problem in a ‘normal’ grid could conviently balanced by hydro production.

          • duffer70 says:

            I agree with your prescription. The best form of energy storage is the water you don’t have to release from hydro impoundments because an intermittent source like wind is producing. This makes Tasmania one of very few places that can sustain substantially more wind generation.

          • Euan Mearns says:

            Yes, but why would you want to do it? “Lets build wind turbines to destabilise the grid and make the electricity more expensive”? If there is a power shortage why not build another hydro dam?

          • gweberbv says:


            if it was (easily) possible to extend the hydro production by another dam or whatever, it would have been done already. Since 2003 the hydro production is lower than demand.
            If you can ignore the ‘non-dispatchable’ issue (which should be the case if stored hydro is your main power source), wind power at a good location is cheaper than new FF plants.

          • Graeme No.3 says:

            There is more hydro capacity available but following the Greens campaign in the 1980’s leading to Federal Labor intervention banning the dam on a claim that it would contravene a UN Treaty. The whole idea was shelved, partly because of the hysterical opposition. That was followed by 16 years of Labor government with Green support.
            Regarding your idea of using more turbines for pumped storage, most of the water comes from the SW heavily forested mountains making turbine installation costly.
            Turbines elsewhere would have transmission losses.
            In any case what is the point of using wind at $120 a MWh ($160 after storage loss) when you could import coal fired at $30?

          • gweberbv says:


            if it was possible to build more dams, this would be the cheapest option to deal with the fact that Tasmania consumes significantly more electricity than its hydro plants can produce in a year with average rainfall.

            But importing cheap electricity instead is no save option, unless you have two or three interconnectors so that the failure of one of them can be compensated. And if you were going to build a new coal-fired power station in Tasmania, you will not end up with 30 $/MWh (at least not with the dollar currencies that I know).

            Wind energy does not need additional pumped storage schemes. It is enough just to lower the flow through the hydro plants in times when wind power has a good production. By this you keep more water behind the dams for times, when wind is not blowing.

            I found that recently, Tasmania decided not to build a 600 MW wind farm with an expected capacity factor of 46%. The price tag was 2 billion $ (Astralian ones, I assume). Over 20 years this amounts to production costs of about 50 $ (US ones) per MWh. I think this is – over 20 years – singificantly cheaper than any type FF plant on Tasmania. Still it is probably more expensive than just to build more interconnectors and to profit from very low electrictiy prices on the mainland.

          • Greg Kaan says:

            If you are referring to the $2 billion, 600 MW wind farm proposed for King Island, that was to be connected to the Victorian grid, not Tasmania’s. And judging by the performance of the existing Huxley Hill 2.5MW windfarm, the projected 46% capacity factor is yet another grossly optimistic figure.

            There has been interesting figures of late from the 2 wind farms on the North East and West corners of Tasmania – the North Eastern farm’s capacity factor has been far lower than the other. If you were to visit Tasmania, you would find that suitable site for wind farms would mainly be in the East.

            Graeme has already pointed out that most of the dams are in the South Western region so either large transmission networks need to be set up in the Eastern portion of the state or massive deforestation would be required in the rugged Western (wilderness) portion for the farms and access roads and also transmission lines to the hydro generation stations.

            I have also recently seen a paper describing the Australian wind farm operational costs as being $20 / MWh – higher than that of a coal plant.

          • singletonengineer says:

            @ Greg Kaan May 8, 2016:
            The two large Bass Straight islands are interesting studies due to the renewable energy upgrades which took place from the early 2000’s. The full proposals covered a suite of subsidised systems including a mixture of additional wind, PV, batteries, more batteries following the failure of the first high tech bank, proposed new abattoirs which didn’t eventuate, hence the supply of biodiesel is not as planned, DC interconnections and partial smart grid solutions which were truncated due to cost. Much money has been spent, but not much good appears to have come from it.

            An official overview is here:

            Flinders Island here:

            King Island:
            The vanadium redox battery installed in the early 2000’s failed and has been replaced.

            I don’t have a clear picture of the whole story. The Hydro’s PR seems to die off circa 2014, which suggests that the projects did not progress after Tony Abbott became Prime Minister in 2013.

            I’d very much like to see a detailed review of these two linked projects from their inception to the present day, but they are not directly related to either the failed Bass Straight 500V DC Interconnector or to the current status of Tasmania’s hydro assets.

          • Greg Kaan says:

            singletonengineer, if you look at this page within the KIREIP site, you will find most of the information you are after – as much as is available anyway.
            You will need to trawl through some meaningless event press releases but there is real information about milestones in there.


            From what I have been able to gather, Flinders Island will soon have their version of KIREIP based largely on the lesssons learnt with KIREIP.


            One thing about KIRIEP is that the original 250 kW Nortel turbines were installed in 1998 and the additional 850 kW Vestas turbines in 2003 so they must be planning for replacement of at least the Nortel trio in the near future yet there is no news at all about this.

    • Guenther: The fact that Tasmania’s water storage was as low in 2007/2008 as it is now is valuable information that I previously didn’t have, and here are the graphs you mention that give the details:

      • Thinkstoomuch says:

        The cause of that was the Millennium Drought, I believe.

        Look at figure 2 in particular. Compare it to figure 6.

        Attempting to put some data in from Hydro Tasmania’s unverified rainfall. I think it is the closest to Lake Gordon.

        site = MISERY PLATEAU
        location = Meteorological
        latitude = -42:31:28.4
        longitude = 146:30:26.6

        Year ||| Rain ||| % of ave ||| Rank
        2005 ||| 1382 ||| 110.87% ||| 3
        2006 ||| 1125 ||| 090.27% ||| 8
        2007 ||| 1197 ||| 096.03% ||| 6
        2008 ||| 1082 ||| 086.77% ||| 10
        2009 ||| 1364 ||| 109.41% ||| 4
        2010 ||| 1088 ||| 087.25% ||| 9
        2011 ||| 1433 ||| 114.96% ||| 2
        2012 ||| 1232 ||| 098.80% ||| 5
        2013 ||| 1437 ||| 115.31% ||| 1
        2014 ||| 1126 ||| 090.33% ||| 7
        average ||| 1247 ||| 100.00% |||

        Rain is in mm. For 5 of the 8 sites data sets provided 2013 was the wettest year.

        Funny thing I didn’t notice until I was checking the post. 2008 ranked 9th in all but this one.

        If it is unwanted info please let me know and I will shut up.


        • Euan Mearns says:

          On the contrary, this is exactly the kind of commentary we like to get. And “Misery Plateau” brings a smile too 😉 Its good to know there’s maybe worse places to live than Aberdeen.

          • Andy Dawson says:

            I’m sure given your background, you’ve visited Al Khobar….

            That takes some beating.

        • I checked into the BOM rainfall records and finally found one close to Tasmania’s “hydro zone” that runs from 1924 to the present with only a few months missing – Conorville: Here it is:

          The low reservoir levels in 2006-2008 and 2015 correspond with unusually dry years, but there’s been no significant change in rainfall since 1924 (the red trend line is almost dead flat) and there’s certainly no sign of a “Millennium Drought”.

          • Thinkstoomuch says:

            Look at your graph.

            The points above the trend line for the period 1995 to 2008, 4.

            Points below the trendline, 10.

            At least a dryish period.

            Just looking at the rest of the graph not seeing another period the same.

            In this case a running 5,10, and maybe 15 year running averages would seem to illustrate better than a simple trend line. Eyeballs are easy to convince they see what I want. At least mine are. 🙂

            If you want I can post the annual totals for the other datasets or email them to you. Due to my kludges to make them the files became somewhat huge. Also have graphs for monthly. They are mostly completeI only noticed about a month and a half of missing data but I might have missed more. Something like 90k of lines for each location.

            Thank you again for the graph,

          • gweberbv says:


            the problem is that rainfall needs to be significantly above your trendline to yield enough stored water for covering electricity demand only by hydro power. Look at the yield curve (red line) in Fig 2.2 from above.

          • T2M:

            The points above the trend line for the period 1995 to 2008, 4. Points below the trendline, 10. Just looking at the rest of the graph not seeing another period the same.

            Try 1933-45. Points above trendline 3, below 10.

            A 5 year running average will give you data only to 2013. You need data through 2017 to construct a 5 year average centered on 2015.

          • Thinkstoomuch says:

            Not getting a reply click box on Roger’s comment @10:14


            First thank you for the response!

            Understood about the trend line limitations. But as we are dealing with the period up to 2009 for the drought figured it would work.

            Also the reason for the 10 year sets I didn’t even bother. Trend line for months is pointless for other reasons.

            Like I said my eyes only see what I want them to see. 🙁 Proven true again. Totally missed the other one you pointed out.

            Have fun,

          • duffer70 says:

            Though Connorville is only a dozen or so kilometres as the crow flies from one of Tasmania’s largest hydro storages, Great Lake, it would be unwise to use it as a proxy for our catchment rainfall. It sits at the base of a kilometre-high escarpment, many hundreds of metres lower than Great Lake. Not only does this obviously mean it’s not in the catchment, but the escarpment creates a rain shadow, such that the rainfall at Connorville would be less than half that on the plateau, and probably not that well correlated.

          • Duffer. Maybe you could present some rainfall records to back your assumption up.

          • duffer70 says:

            First try at posting an image link in comments, here goes:
            Correlation coefficient between Strathgordon and Connorville 1969-2014 (duration of former) -0.008

          • Duffer: Thanks for responding with data – it’s appreciated.

            Here’s your plot of rainfall at Conorville on the dry east side of Tasmania’s hydro lakes vs. Strathgordon Village on the wet west side. The annual variations indeed don’t match up too well. Your low R2 value, however, is explained largely by the fact that both records show substantially flat trends.

            Now here’s a plot of the stations I have in this area. One is Poatina, not far from Conorville. When we allow for the absolute difference in annual rainfall the the two records match very closely.

            The other is Strathgordon Power Plant, less than five miles from Strathgordon Village. Except for the fact that both records again show substantially flat trends any resemblance between them is largely coincidental (note the 2,000mm difference in 1989 annual rainfall). If these results are typical of the area then a large number of close-spaced records will have to be averaged before a reliable rainfall record for Tasmania’s “Hydro Zone” can be constructed.

          • gweberbv says:

            Roger and T2M,

            inflows from 1924 to 2006:

            Maybe one of your rainfall probing locations resembles this data nicely and can be used to estimate inflows for the years after 2006.

  9. Graeme No.3 says:

    the Bureau of Meteorology site leads to rainfall figures.>climate>climate data online>(monthly rainfall)
    You can search for the rainfall by the name of the hydro station as a guide or by station number (if known). It looks like the rainfall Jan. to April this year has been below average e.g. Poatina (Great Lake) Jan 47.2/96.4 Feb. 80.4/79.8 Mar. 49.4/100.6 Apr. 81.8/141.3 First current, mean for month.
    Butlers Gorge (096003) on the Derwent River has the same figures as above.

    Hydro Tasmania has a reputation of being very defensive. As the largest Gov. entity and under fire for years from the Greens who were against dams, and waged a successful campaign in the 1980’s to stop future dams, so it might seem not unjustified. the decision to shut the gas station may have something to do with the Greens having a lot of influence for many years. They were strongly against the BassLink too.
    Many of the hydro stations are small, and there are often multiple stations on a river (the Derwent has 11 [ 7 of them below 40MW]).
    The largest stations are Gordon River and Poatina.
    Wayatinah (095047). Lake Echo (096014).

    • Am I correct in thinking that the Tasmanian government won’t declare a drought because it would then have to start handing out relief payments to farmers?

      • Graeme No.3 says:

        I have no idea but think it unlikely.
        Launceston (second city, North) had 247 mm v 169.2 mean for the first 4 months of 2016, although a record for Jan, high for Mar and low for other 2 months.
        Wynyard (airport, NW coast) had above ave. Feb. just below Mar., down ~9% Jan. and well down Apr.
        Hobart was fairly dry, but still got rain every month.
        The rain comes mainly from the SW.

          • From the Federal, not the State Government.

          • singletonengineer says:

            @Roger, May 5th:

            At all political levels in Australia, the definitions of drought are overshadowed by continually changing definitions.

            States and Commonwealth pretend to cooperate regarding declarations, but the bottom line is that there is no such thing as either a state or a federal drought. It isn’t that simple. Drought policy in Australia has been a political football since Adam was a lad and, in the final analysis, it is more about votes and dollars than it is about rainfall.

            Here’s a quote from a ABC news item from 2014:

            While states can still apply to the Commonwealth to have Exceptional Circumstances declared in a drought-affected region, the policy is now effectively irrelevant, as the assistance programs it once triggered are defunct.

            The state governments also have their own drought relief measures, including transport and fodder subsidies, and sometimes reductions in local government fees and charges.

            Mick Keogh [of the Australian Farm Institute] says state governments administer drought assistance on an “ad-hoc basis”.

            “They usually move pretty quickly to get an Exceptional Circumstances declaration because the financial responsibility then lies with the Commonwealth,” he said.
            End quote.

            If you want politics, consult a politician.

            If your interest is in rainfall and runoff, trust the rainfall statistics and the flow guages in the rivers.

  10. singletonengineer says:

    A side issue for the Tasmanian population was the loss of about half of their data connection to the mainland. The fibres are part of the cable which is currently being repaired. The other main cable is owned by Telstra. News items suggest that Telstra have made commercial arrangements with their competitors to share the remaining capacity, but I have no reliable references to all of this.

    Too many eggs in one basket?

  11. Thinkstoomuch says:

    Ok I am going to post what I have that will post somewhat neatly. Not going to be all that fastidious and won’t break my heart of it gets deleted. Just doing a copy and paste from excel. Those of you who are GIS whizzes I am trying to give you what you need.

    Best I can go no longer have the software I used to. Plus I really have no clue as to the geography. Beware you are trusting my fat fingers on this.

    site = GAIRDNER LAKE [ FSL 472.44 m ]
    location = AT DAM
    latitude = -41:28:20.3
    longitude = 146:04:23.2
    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 1715 ||| 115.43% ||| 3
    2006 ||| 0889 ||| 059.87% ||| 10
    2007 ||| 1478 ||| 099.47% ||| 6
    2008 ||| 1118 ||| 075.25% ||| 9
    2009 ||| 1608 ||| 108.23% ||| 4
    2010 ||| 1874 ||| 126.16% ||| 1
    2011 ||| 1790 ||| 120.50% ||| 2
    2012 ||| 1454 ||| 097.89% ||| 7
    2013 ||| 1521 ||| 102.37% ||| 5
    2014 ||| 1409 ||| 094.82% ||| 8
    average ||| 1486 ||| 100.00% |||
    2006-2008 ||| 1162 ||| 078.19% |||
    2012-2014 ||| 1461 ||| 098.36% |||

    site = IRIS RIVER
    location = Meteorological
    latitude = -41:31:19.4
    longitude = 146:00:32.3
    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 1952 ||| 107.38% ||| 5
    2006 ||| 1158 ||| 063.71% ||| 10
    2007 ||| 1750 ||| 096.29% ||| 7
    2008 ||| 1589 ||| 087.39% ||| 9
    2009 ||| 1939 ||| 106.65% ||| 6
    2010 ||| 1967 ||| 108.18% ||| 4
    2011 ||| 2070 ||| 113.85% ||| 2
    2012 ||| 1980 ||| 108.90% ||| 3
    2013 ||| 2182 ||| 120.04% ||| 1
    2014 ||| 1593 ||| 087.62% ||| 8
    average ||| 1818 ||| 100.00% |||
    2006-2008 ||| 1499 ||| 082.46% |||
    2012-2014 ||| 1918 ||| 105.52% |||

    location = AT DAM
    latitude = -41:40:49.0
    longitude = 146:22:59.5
    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 2373 ||| 122.57% ||| 2
    2006 ||| 1291 ||| 066.70% ||| 10
    2007 ||| 2005 ||| 103.57% ||| 6
    2008 ||| 1497 ||| 077.30% ||| 9
    2009 ||| 2181 ||| 112.62% ||| 3
    2010 ||| 2384 ||| 123.11% ||| 1
    2011 ||| 2146 ||| 110.86% ||| 5
    2012 ||| 1603 ||| 082.79% ||| 8
    2013 ||| 2156 ||| 111.36% ||| 4
    2014 ||| 1725 ||| 089.11% ||| 7
    average ||| 1936 ||| 100.00% |||
    2006-2008 ||| 1598 ||| 082.52% |||
    2012-2014 1828 094.42% |||

    location = Meteorological
    latitude = -41:39:41.6
    longitude = 146:10:37.6
    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 1506 ||| 111.63% ||| 4
    2006 ||| 918 ||| 68.01% ||| 10
    2007 ||| 1343 ||| 099.55% ||| 6
    2008 ||| 1061 ||| 078.65% ||| 9
    2009 ||| 1530 ||| 113.43% ||| 2
    2010 ||| 1530 ||| 113.41% ||| 3
    2011 ||| 1293 ||| 95.83% ||| 7
    2012 ||| 1354 ||| 100.34% ||| 5
    2013 ||| 1668 ||| 123.64% ||| 1
    2014 ||| 1289 ||| 095.51% ||| 8
    Average ||| 1349 ||| 100.00% |||
    2006-2008 ||| 1107 ||| 082.07% |||
    2012-2014 ||| 1437 ||| 106.49% |||

    location = METEOROLOGICAL
    latitude = -41:44:42.5
    longitude = 146:10:15.5

    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 1366 ||| 105.49% ||| 5
    2006 ||| 0918 ||| 070.87% ||| 10
    2007 ||| 1387 ||| 107.07% ||| 4
    2008 ||| 0966 ||| 074.61% ||| 9
    2009 ||| 1113 ||| 085.90% ||| 8
    2010 ||| 1388 ||| 107.16% ||| 3
    2011 ||| 1234 ||| 095.24% ||| 7
    2012 ||| 1307 ||| 100.87% ||| 6
    2013 ||| 1868 ||| 144.20% ||| 1
    2014 ||| 1407 ||| 108.59% ||| 2
    average ||| 1295 ||| 100.00% |||
    2006-2008 ||| 1090 ||| 084.18% |||
    2012-2014 ||| 1527 ||| 117.89% |||

    site = CRADLE VALLEY
    location = AT WALDHEIM CABIN
    latitude = -41:38:16.9
    longitude = 145:56:42.2

    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 3000 ||| 111.81% ||| 2
    2006 ||| 2501 ||| 093.21% ||| 8
    2007 ||| 2751 ||| 102.52% ||| 4
    2008 ||| 2444 ||| 91.10% ||| 9
    2009 ||| 2885 ||| 107.53% ||| 3
    2010 ||| 2661 ||| 099.20% ||| 5
    2011 ||| 2635 ||| 098.20% ||| 6
    2012 ||| 2504 ||| 093.31% ||| 7
    2013 ||| 3043 ||| 113.41% ||| 1
    2014 ||| 2407 ||| 089.70% ||| 10
    average ||| 2683 ||| 100.00% |||
    2006-2008 ||| 2565 ||| 095.61% |||
    2012-2014 ||| 2651 ||| 098.81% |||

    location = U/S L.MACKENZIE
    latitude = -41:41:51.2
    longitude = 146:23:48.6

    Year ||| Rain ||| % ave ||| Rank
    2005 ||| 2410 ||| 117.53% ||| 2
    2006 ||| 1311 ||| 063.94% ||| 10
    2007 ||| 2091 ||| 101.99% ||| 6
    2008 ||| 1534 ||| 074.82% ||| 9
    2009 ||| 2296 ||| 111.98% ||| 4
    2010 ||| 2449 ||| 119.43% ||| 1
    2011 ||| 2091 ||| 102.01% ||| 5
    2012 ||| 2024 ||| 098.72% ||| 7
    2013 ||| 2388 ||| 116.48% ||| 3
    2014 ||| 1909 ||| 093.10% ||| 8
    average ||| 2050 ||| 100.00% |||
    2006-2008 ||| 1645 ||| 080.25% |||
    2012-2014 ||| 2107 ||| 102.77% |||

    location = Meteorological
    latitude = -42:31:28.4
    longitude = 146:30:26.6
    2005 ||| 1382 ||| 110.87% ||| 3
    2006 ||| 1125 ||| 090.27% ||| 8
    2007 ||| 1197 ||| 096.03% ||| 6
    2008 ||| 1082 ||| 086.77% ||| 10
    2009 ||| 1364 ||| 109.41% ||| 4
    2010 ||| 1088 ||| 087.25% ||| 9
    2011 ||| 1433 ||| 114.96% ||| 2
    2012 ||| 1232 ||| 098.80% ||| 5
    2013 ||| 1437 ||| 115.31% ||| 1
    2014 ||| 1126 ||| 90.33% ||| 7
    average ||| 1247 ||| 100.00% |||
    2006-2008 ||| 1135 ||| 091.02% |||
    2012-2014 ||| 1265 ||| 101.48% |||

    Now for the real fun the average of the averages.

    Year ||| Average ||| Ramk
    2005 ||| 111.45% ||| 2
    2006 ||| 72.84% ||| 10
    2007 ||| 100.42% ||| 6
    2008 ||| 81.23% ||| 9
    2009 ||| 106.16% ||| 4
    2010 ||| 108.69% ||| 3
    2011 ||| 105.80% ||| 5
    2012 ||| 99.83% ||| 7
    2013 ||| 119.35% ||| 1
    2014 ||| 94.24% ||| 8

    Remember it is worth every penny you paid for it,

    • Thinkstoomuch says:

      So why is it in a ten year period, the year with rainfall, 2013, the reservoir dropped ~15% or so according to figure 3 in the original post? One would have thought based on the historical data Roger found and looking in their own data Hydro Tasmania would have tried to end that year at 90%. In this case for a not rainy day fund.

      Yet the year before was ranked 7th (just about an average year for those ten years) and it went up ~7%.


      PS Roger my hat’s off to you for finding any data set that near complete. I quit after an hour of looking. Far better person than I. I think. 😉

    • Euan Mearns says:

      So this shows that 2014 was on the dry side but not exceptionally so. But it is now 2016.

      • Thinkstoomuch says:

        Which gets us to Roger’s frustrations. I was hugely impressed he found anything that had as complete data set as he did. All of the recent data I have found is spotty at best. I looked for another 1.5 hours this morning and gave it up as a bad job.

        If you want a big overview that means relatively little. At least to me.

        Shows yearly rainfall but the scaling leaves much to be desired. Pretty pictures. I even downloaded from 2004-2015 shows some of what is happening but details are not there, It is even possible to set start and end dates, somewhat.

        It does give fair overview. Especially, of where the rain falls.

        Also I may have gotten a little focused on the bad management practices and why 2013 was so important. Wettest year and the levels go down.
        Data I am using goes to June of last year and I may have made a mistake in not sorting for June to May to encompass the latest data. Which would be a 5 minute job now but would most likely add to the noise for no meaningful return.

        Thinking I may give it a rest for a bit as my frustration levels are getting a bit high.

        Good luck all,

      • Thinkstoomuch says:


        I went ahead and did the numbers for going from July to June. For the data sets above may help or may not. This would make the data end less than 11 months ago.

        Compared each location to it’s ten year average rainfall in mm. Then averaged across years. I think, I said what I did correctly.

        July to June
        05-06 || 114.47%
        06-07 || 77.77%
        07-08 || 89.43%
        08-09 || 91.97%
        09-10 || 103.83%
        10-11 || 117.84%
        11-12 || 104.84%
        12-13 || 83.11%
        13-14 || 124.57%
        14-15 || 92.16%
        average || 100.00%

        For a comparison of Jan to June to total yearly rainfall.

        Jan to June
        05 || 31.29%
        06 || 34.23%
        07 || 40.77%
        08 || 30.58%
        09 || 42.75%
        10 || 40.83%
        11 || 49.47%
        12 || 49.10%
        13 || 35.66%
        14 || 43.31%
        15 || 42.99%
        Ave || 40.09%

        I have no clue if it will help or just add to the noise.

        This gets us 6ish months closer to current minus a few days as the numbers end around the 21st of June 2015.

        Make of it what you will or nothing of it at all.

        An email address is

        Thank you for thought fodder,

        Enjoy all,

        • Greg Kaan says:

          T2M, how did you treat the missing data periods? I also looked into the rainfall data for a few sites a while back and the whole month would be invalidate by just a single day without a reading.

          Did you extrapolate the average rainfall for the recorded days to cover the missing ones or did you worst case things and assumed zero rainfall for the missing days?

          Also, I have to say I applaud your efforts. There is “noise” on this site at times but I don’t rate your posts as being among them.

          • Thinkstoomuch says:

            I mainly didn’t. I managed to thoroughly corrupt one of the files spent a bunch of time trying to fix it. Then just decided to recreate it.

            I went through to see how bad I screwed up. Though the monthly graphs don’t show much of an issue (hard to tell really they vary so widely). Just counting the data quality labels from the data files

            Data quality label || instances || Percentage
            unverified data || 715,344 || 97.43%
            missing data || 11,340 || 1.54%
            poor data || 6,245 || 0.85%
            estimated data || 270 || 0.04%
            not within expected range || 150 || 0.02%
            unreliable data || 858 || 0.12%
            total || 734,207 || 100.00%

            Kind of hard when the past category is unverified.

            Gaidner Lake has 10,401 of those 18863 other than unverified data. All the poor data instances and 4,156 missing data instances.

            My apologies,

  12. jfon says:

    Reading this from New Zealand, where we have had zero news coverage of the Tasmanian situation, but have some striking parallels. Half of total electricity generated is from hydro, mostly in the southern half of the South Island, but the heaviest demand is in Auckland. The Cook Strait HVDC cable mainly shunts power north, but in winter, with low hydro flows and high demand from domestic heat pumps, it sometimes goes the other way. Auckland has had a couple of embarrassing blackouts from transmission failures over the last few years. The Bluff aluminium smelter, in the far south of the South Island, has a similar history to Tasmania’s smelters, and uses about eight percent of the country’s power. And finally, the Greens have been agitating for the closure of our last coal plant, near Auckland, though the gencos claim it is needed as backup.

  13. gweberbv says:

    I found to other blog entries that might be interesting to the readers: (more general) (very detailed!)

    Also for the rainfall data, it might be woth looking at this graphic:×0.png/1456985257082.png
    But it is unclear if rainfall can be translated 1 to 1 into inflows of the storage dams.

    • Thinkstoomuch says:

      Part of the problem is 20/20 hindsight.

      Most of my problem is lack of education and understanding simple things really are not all that simple. Anybody who has rebuilt an engine can tell you that everything is simple until you don’t have a part or a tool. Then things get incredibly complex.

      Anybody who trusts an undersea cable as a single point failure is playing with fire. IMO. Difficult to install and while robust are notoriously hard to repair.

      All that said if anybody thinks the flow data in the zip file I downloaded worth anything I can do the same I did with the rainfall data. But just going by the Fisher River flow data there are going to be issues. Like 2,252 instances labeled “poor data”. 8,671 instances of “missing data”. 808 instances of missing data. All grouped in 90K worth of lines each comprising an hour. I think.

      Can they in fact just be added? I am not sure if it is the same as rainfall. The data pretty much mirrors the ranking arrived at in the Fisher River rain data I posted above, if you can. Rankings change up or down one in 3 of the ten years and 2012 is 7 instead of a 5.

      What does that mean for the geography? I have no clue.

      Available locations in that data zip just truncated file names no lats and longs:


      I would be happy to while away an hour or 2 to crunch them but based on what I have posted not sure it really is of value. Spent more time than that composing this post.

      Have a good week end all,

      • Thinkstoomuch says:

        Oops the 8,671 instances of “missing data” was suppose to be “estimated data”. Thought I had fixed it until i read it this morning.

        My Apologies,

  14. John Reid says:

    As a local I should point out that, although it looks small on the map of Australia, Tasmania is about the same size as Scotland and has similar variations in climate. Most of the rainfall data quoted comes from sites to the east of the Central Highlands and would be in their rain shadow – particularly Connorville. Possibly the most appropriate site and the one with the longest continuous record would be Liawenee. Liawenee data shows that there were a similar multi-year Highland droughts from 1920 to 1926 (1072mm/yr average)and 1957 to 1963 (914 mm/yr average) compared with 2003 to 2015 (929 mm/yr average). In my view Basslink would be justified even without the carbon tax. However we certainly don’t need a second (expensive) cable, we need greater capacity. This could well come from biomass from our extensive forest resource.

    • Alex says:

      If Australia wants to go down a path of being powered by intermittents, then Tasmania has to be a key part of that.

      The Basslink will need to be upgraded to a few GW, and the hydro electric turbine capacity increased to a few GW.

      It seems that Tasmanian hydro can deliver an average of 500MW. That will need to be turned off when it’s sunny or windy in Australia, and run at GW levels when it’s not sunny and not windy.

      It seems the reservoir capacity can support Tasmania – from full – for 1,000 days. That probably means a few weeks for Australia. Given that much of the rest of Australia was made for solar power, that could be enough.

      Australia, with Tasmania, is one of the few advanced countries that could run its electricity generation on intermittents. It won’t be cheap, but unlike in Europe, it is possible.

      • Greg Kaan says:

        I would add “in theory”

      • Graeme No.3 says:


        We have our own enthusiasts who say the same thing, although they are always a bit vague on the actual details. Your mental image of Australia as a huge area constantly drenched with sunlight may need a little modification.
        Here in South Australia it has been wet and windy for 3 days, some sun Friday but little over the week end because of the clouds. The rain ‘band’ covers the State from the northern border (flooding for a few hundred km southwards) to the far south. This band also cover Victoria, Tasmania and a good deal of NSW. That is a rather large area and includes approx. 70% of the population. Adelaide is expecting rain until next Friday.

        Trying to run on solar means enormous storage capacity needed. How? We have limited capacity for pumped storage, at least outside the far north of Australia but then transmission loss over thousands of kilometres. Please don’t make vague references to lithium batteries, that has been thoroughly debunked.
        And the figures for isolation in the Outback have been measured and turned out to be much less than assumed – it is the dust in the air. Curiously after the rain has moved away the air will be clear and the figures better, but normally the Outback is dry and very dusty, so washing mirrors/panels is out.

        • Greg Kaan says:

          Graeme, Alex is referring to using the whole of Tasmania’s water storage purely as pumped storage backup to a mass renewables deployment across Australia.

          In theory it is possible, peak mainland demand would be in the order of 80 GW so let’s assume could demand shed the peak by 20% on cloudy, windless days and that only 80% of the renewables generation would be affected since the sun is always shining and the wind is always blowing “somewhere”. This leads to an interconnector capacity from Tasmania to the mainlaind in the order of 50 GW as well as that much hydro generation capacity.

          I don’t think it’s worth discussing the idea any further.

          • Euan Mearns says:


            We had similar discussion about building a massive pumped storage scheme in Scotland in the name of Green. You quickly reach conclusion that you need vast transmission system, power lines everywhere. Its bonkers. In the name of distributed generation you end up with a vast concentration of backup / balancing in one place.

            Nuclear power stations are probably the best form of distributed power. 1 GW here and another GW there.

        • Greg Kaan says:

          Sorry, I am out by a factor of 2. The requirements for Tasmanian generation and interconnector capacity is “only” about 25 GW.

          50 BassLinks and additional hydro generation equal to 11 x existing installations. Still not worth any further thought.

  15. Greg Kaan says:

    It looks like the heavy rain that has fallen on most of SE Australia over the past week will take Tasmania out of the emergency situation, just in time and BassLink will be repaired next month. So they have literally scraped by.

    Water storage has risen by 3.1% to 16.1% even though they have been generating heavily from the smaller reservoirs to avoid having to spill.

    Now we just have to watch South Australia this summer after the closure of their last (560 MW) coal plant on Monday.

  16. Tasmania used to get much more rainfall – when it was covered with indigenous forests. By logging their ancient forests, lots of unexpected consequences came about.

    Last year, we went on holiday there. We drove across the centre of the island and where there used to be forests was now empty. No one lives there either and no sheep either. A wasteland.

    Even during our brief trip we noted that the areas that were forested also had far more rain than those that were denuded of forests. I realize this is not a very scientific observation, but I am sure it is valid if properly tested.

    • singletonengineer says:

      Be careful not to confuse cause and effect,observation and causation.

      Denuded landscapes are far less water-retentive than forested ones. What you witnessed is quite possibly not drought. Slow runoff rates lead to better water infiltration into soils, hence better water reetention, hence higher growth rates. They also lead to lower, longer river flows, with lower peak flow rates, reduced velocities, retention of nutrient, reduced soil erosion and so forth.

      One sometimes overlooked benefit of a full forest is the tendency of watercourses to not dry out as quickly during times of real drought – the retained soil moisture feeds back into the creeks over time.

      Try this thought experiment. What dries faster, a bare stainless steel sink drainer or one covered in carpet?

  17. Grant says:

    According the The Guardian Tasmania are sending back the temporary generators and turning off the just re-commissioned gas plant. Great planning and investments all round, I’m sure.

    Tax payer and bill payers to the rescue no doubt.

    It’s so easy when using someone else’s captive cash.

    • Greg Kaan says:

      I don’t understand what you are implying here – they are minimising fuel and maintenance costs while there is water spilling in the upper dams by maximising the generation from those reservoirs. It’s exactly the correct course of action.

      Meanwhile, BassLink repairs have been on hold during the recent rains, due to the ocean swells that accompanied them. But they still hope for the repairs to be completed by mid June

      • Grant says:


        Simply that one might consider the short term but presumably high cost of the generators plus re-activating the gas plant for a few weeks to be costly when perhaps, without the earlier exports of hydro reserves, they would have been unnecessary.

        Hindsight, certainly, but that is what utility risk analysis is all about isn’t it? Unless the decision makers know they can rely on a cash cow to cover the poorer decisions and can point a finger of blame elsewhere – climate change is always a good direction to point – to explain why things went wrong.

        Has anyone yet been reported as claiming that “lessons will be learned….”?

        Ideally one would run a system with minimal excess overhead and maximum deployment of “paid for” plant. Margins for error should be tight – or at least as tight as social and economic consideration deem to be acceptable.

        Planning at that level does not suggest that intermittency and reliance on the continued consistency of natural weather activity will be easy to account for in all situations. If the backup options have a single point of failure even a strong model result suggesting total reliance on “natural” resources is suspect if continuity of supply is important.

        If it’s not important – no problem.

        • Greg Kaan says:

          Grant, if you read through the whole article and comments, you will see that we are not at all in disagreement. The whole saga is one of opportunism without proper contingency planning.

          The recent shut down of gas plants is purely due to the “use it or lose it” nature of renewables, even a buffered one like hydro.

      • Greg:

        they are minimising fuel and maintenance costs while there is water spilling in the upper dams by maximising the generation from those reservoirs.

        You’re saying that excess water in the upper reservoirs flows down and replenishes the lower reservoirs, so you don’t waste any stored energy by using it to generate electricity at the upper dams. Is that correct?

        • Greg Kaan says:

          Exactly, Roger. Plus they are also anticipating further rainfall in the near future so those reservoirs that are near capacity are also generating now to prevent or minimize spilling when that rain arrives.

        • singletonengineer says:

          Roger, there are instances where there are no “lower reservoirs”. Those reservoirs still should be usedtogenerate, when full, rather than allow water to spill.

          The very largest reservoirs are also the ones which take the longest to fill and which provide the best protection against drought.

          In other words, whatever the shape of the catchment and whether or not there is another dam lower down the river, the full dams should be scheduled in front of the part-filled, in order to minimise losses by operation of the spillways.

          Finer detail:
          1. Some rivers and streams need releases to ensure environmental health. These will be scheduled in front of even dams which are filled to overflowing.

          2. Some authorities, for misguided simplicity’s sake, will try to maintain the water levels in all of their dams at the same percentage full. This is a bit silly from a probablistic point of view, but perhaps make it easier to explain to the population when floods or droughts occur, because these will affect all dams simultaneously. This isn’t mathematically correct, but it provides a simple message to “explain” when things go wrong. An example is the river valley I live in. There are two large dams plus one significant off-stream pumped storage attached to two large power stations. Both on-stream dams have notional top operating levels which are below spillway level. The difference in capacity is referred to as “Flood storage capacity” and is intended to retain surges,or at least, part of them.

          Perhaps TOL should be better called Target Water Level.

          The operational storage capacities of both of these two dams are generally kept within a few percentage points of each other, despite having different catchment and downstream consumption characteristics.

          I’m sure that mathematicians have provided advice as to how to optimise operation of these dams. I am also sure that the simplest option is followed most of the time.

          The off-stream dam is topped up only by (a) harvesting released from the upper dam which come from high security licence allocations – the power stations are by far the largest water user along the river; or (b) during freshes, when the river is flowing at significant rates.

          I was project manager during the tripling in size of the river pump station a decade or so ago – the result is that minimum environmental flows down the river were doubled while at the same time, water security for the power stations was increased despite slight reduction of total annual water allocation.

          My apologies for writing this in a hurry. I hope that it helps to explain the nature of common factors involved in managing rivers and dams. It’s much more than simply looking at the “percentage full” and concluding that the situation is either good or not good.

  18. Greg Kaan says:

    A bit of an update on the Tasmanian situation by climanrecon, with a bit of additional information by yours truly in the comments.

    The storage level PDF that I have linked shows the generators sourced from the outflows of each of the reservoirs and clearly shows why some of the rainfall needed to be used.

    More information of the generators here

  19. Basslink back in service and lots of rain in Tasmania. I guess we can assume that the crisis is over, at least for the moment.

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