Tasmania appears to be on the brink of a crisis, with the island state only weeks away from a serious power crisis if there is no significant rainfall.
The seriousness of the issue at hand isn’t suggested by Techly as being down to mismanagement by Tasmanian officials, simply a sequence of unforeseen problems.
Multiple sources in Tasmania and the mainland describe the situation as dire.
Tasmania has just two months supply of water to feed its hydroelectric dams, unless there is significant rainfall. Energy storage, or the level of water available to generate hydro-power, is at historic lows. Rainfall into catchment areas in the past 12-months has been around one-third of projected rainfall, based on thirty-year modelling. Without hydropower, Tasmania’s energy demands at normal peaks far exceed current generation.
Dam levels were reduced during the carbon tax era, where hydroelectric or carbon neutral power generation was extremely valuable. Hydro Tasmania, the body who maintain and run a series of 55 major dams and 30 hydropower stations within, was very profitable during this time, as it drained water for great revenues.
Indeed, in the quirks of the carbon tax arrangements, the sale of renewable energy certificates or RECs accounted for more than 70 per cent of revenue inflows. (It is not suggested that reducing dam levels during this time was malfeasant.)
Basslink. Tasmania is supplied both power and data connections via the Basslink submarine cable. That cable is no small matter – it runs for 370 kilometres in total (290km undersea) it is rated to 500MW continuous (630MW peak) and cost around 800 million dollars to install over a decade until 2006, including testing and commissioning.
However, on 21 December 2015, it was announced the Basslink was disconnected due to a fault in the interconnector. Given the cable is underwater, and the fault was located as around approximately 100 kilometres off the Tasmanian coast, the Basslink controlling body called Basslink first announced that it would be repaired and returned to service by 19 March 2016.
That date has since fallen into the abyss as more than 100 experts, including 16 or more from Italy, plus a specialist ship, try to fix the cable. Basslink advised on March 13th that the cable would be fixed by late May. (Note – see update below – this date is now mid-June)
Consistent with previous advice, based on current best estimates and allowing contingency for weather and other unforeseeable conditions, it is expected that the interconnector will be operational again in late May.
Naturally, every effort will be made to ensure the return to service date is as soon as possible.
Techly contacted Basslink for comment on the 24th of March for a further update, with calls as yet not returned. (Update, Techly has been contacted with some clarifications late on Thursday)
Normally, a Basslink outage isn’t a big deal. The mainland has to adjust how it distributes power across the Eastern Seaboard, and given the cable supplies an absolute peak of 500MW, it doesn’t shoulder the entire load, but provides greater flexibility for operators, and reduces the average cost of power. It also helps to balance peak and off-peak loads across the grid.
Additional power from non-renewables in Tasmania includes three significant gas turbine and thermal power stations which provide 535 MWh of power at full capacity.
But Tasmania has far more hydroelectric power – more than 2300MW of hydropower at full capacity.
Techly understands that if Basslink can’t be fixed for an economic cost, it may not be fixed at all, depending on the assessments currently underway.
Update: Basslink assures Techly that “we are well over the half way mark of this repair”, and that “not fixing it is not an option”. Good to know.
Power problems start with water problems
As mentioned, the issue is that Tasmania is experiencing a serious drought. The Bureau of Meteorology shows that Tasmania has experienced continued low rainfall over the last 41 months, with data showing lower rainfall over the last 16 years, including the disastrous last 12 months.
Hydropower relies on dams and water in dams, which are at less than 15 per cent energy storage, according to Hydro Tasmania, who update each week with publicly available information.
Hydro Tasmania stated that on the 21st of March, that the company was down to 14.6% of full storage energy, a record low.
Those numbers are equatable with dam levels, but not the same. Not all water in a dam can be used to turn turbines, both for ecological and turbine safety reasons – if air gets into turbines, it can damage the spinning blades.
Tasmania does have significant wind power assets of up to 310MW of wind generation. The capacity has been around 35-40 per cent according to data from Green Energy Markets. Windy conditions must prevail, but not too windy which forces operators to shut down the turbines to avoid damage.
The isle has around 90MW in rooftop solar installed according to industry sources, but this only supplies during sunny conditions.
Tasmania has brought in more than 200 generators, including significant diesel generators of up to 200MW.
The issue is that Tasmania has a demand of around 1,000MW day to day. As of right now, NEM Watch shows a demand of around 1,060MW, at lunchtime. During winter, the average peak is more like 1,600MW as the cold weather pushes people to switch on heating.
Reducing power demands
The Tasmanian Government has asked the state’s biggest industrial facilities, an aluminium smelter and a manganese alloy smelter – to reduce output by up to 70MW to reduce peak demands. It has helped that aluminium prices are low, which meant an agreement was quickly reached.
Multiple sources questioned the delays in working to reduce power demands to save water. The cable was cut in late December, but the Government were refuting any notion of energy rationing as recently as February.
Where Tasmania is at now
With Hydro providing some 60 per cent of current power demands in Tasmania, it’s clear if there isn’t significant rainfall, the situation will move from being dire to outright disastrous.
The Basslink cable still only provides around 500MW of power when fully functional, leaving a shortfall.
The ABC published a frankly alarming article suggesting that Hydro Tasmania employees themselves are preparing for rolling blackouts, and buying up generators.
Professionals Australia, a Union for around 25,000 workers, said via spokesman Luke Crowley, that said his members “are frustrated that the Government appears to be downplaying the situation” and that “One of the member’s advice to me was: ‘Everyone should be ready for 24-hours [without power].”
If they’re the ones who are worried, shouldn’t everyone in Tasmania be alarmed?
Hydro Tasmania came out and blasted the reports, releasing the following statement:
Hydro Tasmania not preparing for blackouts
Hydro Tasmania has rejected claims by Unions Tasmania that energy blackouts are imminent.
Hydro Tasmania is working with the Tasmanian Government to implement the Energy Supply Plan, which is intended to ensure that Tasmanian demand is met through until winter rains.
Hydro Tasmania has no knowledge of our people preparing for blackouts, we are not advising our people to do anything of the sort and to suggest otherwise is irresponsible and an inaccurate representation of the business and our people.
The question is, will the winter rains arrive early enough? Indeed, it will take years of careful management and average or above-average rainfall to replenish the dams of Tasmania.
New infrastructure will take years, with massive investments possibly requiring privatisation of state assets. The Federal Government will be approached in April by the state government, but even a blank cheque can’t make it rain.
Update: Basslink have found the problem
In a release on March 29, Basslink noted a significant milestone in fixing the cable.
Having successfully pinpointed the fault location on the interconnector and removed it from the cable on Easter Sunday. The fault point was identified at 90.467km from the Tasmanian coastline. The cause of the fault is yet to be determined, subject to forensic testing.
“The analysis process, which saw us cut the cable 1150m from the fault, has been encouraging,” said Basslink CEO Malcolm Eccles. “This represents a difference of only 0.4% of Basslink’s entire cable length, which is a great result and vindicates the extent of testing and analysis undertaken. “
The team has worked hard over the last few days clearing around 63 tonnes of cable to ensure it does not interfere with the later phases of repair operations. We have also conducted extensive tests to confirm the removal of the fault and that the cable is ready for jointing, with both ends of the cable now capped and on the sea bed,” said Eccles.
The initial findings have revealed the degree of water ingress into the cable through the fault has resulted in more damaged cable that needs to be replaced, which will see a third joint required on the cable.
In simple terms, water got in and damaged the cable – this now needs to be removed.
It is understood the date for the cable to return to service has been extended out to mid-June as the extent of the fault has complicated matters.
Hydro Tasmania revealed water levels are at a record low, down to 13.9 per cent capacity statewide after falling 0.7 per cent in a week across Easter – better than the 1.6 per cent fall the previous week.
Hydro Tasmania had projected the dams would not go below 13.6 per cent by May, a number that looks frightfully shaky now barring significant rains.
Tasmania Energy Minister Matthew Groom called upon Hydro Tasmania to review its modelling, and again insisted the hydro system could operate until the figure reached 6.5 per cent.
Rainfall projections across the State aren’t significant, with showers and cooler weathers in rainfall areas.
Update 2: Hydro Tasmania have installed 100MW of diesel generation.
A release on March 31st noted Hydro Tasmania have installed 100MW of diesel generation.
Overview of diesel installation
Catagunya Power Station: 24 MW has been installed and is operating well.
Meadowbank Power Station: 24 MW is installed and is being commissioned, with operation starting this week.
George Town substation: 21 MW is installed and is being commissioned, with operation starting this week.
Port Latta substation: 20 MW is installed, with commissioning to commence this week.
Que River 1: 18MW is being installed with commissioning to commence this week.
Que River 2: 18MW to be installed; design completed, equipment procured and site works commenced and progressing to plan.
Savage River: 24MW to be installed; design completed, equipment procured and site works commenced and progressing to plan.
Bell Bay 1: 50MW of dual fuel capacity to be installed; design completed, equipment procured and site works commenced. First generation likely to be early May.
April 3rd: Water levels reach 13.6 per cent, down 0.3 per cent in a week
The fall of 0.3 per cent in one week is better than previous weeks, thanks to rainfall and inflows into catchments.
Hydro Tasmania had projected the dams would not fall below 13.6 per cent by the start of May.
Tasmanian Energy Minister Matthew Groom said the company was now advising storages would reach as low as 12 per cent by early May.
Crucially, Lake Gordon, a major dam, sits at just 5.9 per cent storage.
This week’s projected rainfall by the BOM indicates light falls across the west of Tassie.
Hydro Tasmania have brought forward a cloud seeding programme, designed to boost rainfalls. Traditionally, the company starts cloud seeding in May for winter rains but has arranged for additional flights in April. The right conditions need to prevail to seed pellets of silver iodide into clouds to form raindrops or ice to encourage rainfall.
April 11th: Water levels stabilised at 13.6 per cent
The rains came and helped fill up some of the dams, with the crucial Lake Gordon actually rising. Hydro Tasmania also credited its cloud seeding programme with keeping water levels stable.
It’s predicted levels will fall to 12 per cent by the end of May if half of average rainfall occurs, a crucial test ahead of normal winter rains.
April 19th: Water levels fall to 13.4 per cent
Water inflows, mostly on the West Coast, cooler weather, and slowly increasing diesel power generation continued to help Hydro Tasmania, with water falling 0.2 per cent for the week past.
Tristan Rayner is an Electrical Engineer who worked for TransGrid, the manager and operator of the high-voltage electricity transmission network in New South Wales.