Backup generators and the 1982 New South Wales power crisis

In Australia power generation has become another front in the culture wars, as backers of coal fired power stations fight the growth of renewable solar and wind power, blaming them for any minor power outage. But back in 1980s New South Wales far worse power restrictions were put into place – and failed coal fired power stations were to blame.

The story starts with the construction of Liddell Power Station in the Hunter Valley by the Electricity Commission of New South Wales (Elcom). The first of four 500 megawatt generators was completed in 1971, followed by two more in 1972, and the fourth in 1973. The complex was the first major power station in New South Wales to be built inland, and at the time of its completion was the most powerful generating station in Australia.

However a few years later all was not well at Elcom – maintenance on the generating system was being deferred, and the massive scale of new power stations left the system without reserve capacity should any of the units go off line.

This came to a head when in March 1981, when a stator winding fault at Liddell took one of the units out of service. Initially the Snowy Mountain Scheme was used to supply peak electricity load, but an ongoing drought had reduced the amount of water available, which led to the introduction of power restrictions in late June.

In November 1981 the situation worsened, when two more generators at Liddell suffered identical stator winding faults, with further power restrictions imposed for twenty days in December 1981, and twenty-six days in March-April 1982.


Canberra Times – 1 April 1982

Leaving both industry and households in the dark.

In one day of power rationing to industry it was estimated that 253,000 workers were stood down after 7,000 factories closed at a cost of $25 million to NSW industry.

Householders were restricted to half the normal lights on in a house, no air-conditioning, no radiators and, despite possible health risks, only two hours a day for filtering swimming pools.

To fill the gap, 300 MW of gas turbine generators was hurriedly acquired.

Twelve 25MW gas turbines were purchased by the Electricity Commission of New South Wales in 1982 to assist in meeting demand during the electrical energy crisis in that year resulting from the failure of alternator windings in three generating units at Liddell Power Station.

The units were connected to the State network in April, May and June, 1982. Total capital cost was $89 million. Two units are located at Bunnerong, two at Port Kembla, four at Eraring and four at Koolkhan near Grafton.

All gas turbines were used during the energy crisis in the period April to September, 1982. Operating times totalled approximately 5,000 unit hours, 85 per cent of the energy being generated using natural gas at Bunnerong and Port Kembla.

That were expensive to run.

For statistical and costing purposes a fuel consumption of 8.3 tonnes of distillate per hour is an average value recorded for each gas turbine when operating at full load.

The gas turbines at Bunnerong and Port Kembla use natural gas as fuel and for these units the gas consumption is 15.0 MJ/GWh.

In 1982 the cost of distillate was $267 to $3 10 per tonne. These values have been used to calculate a distillate fuel cost of $88 per MWh.

Under the current gas contract, fuel cost when burning natural gas is $84 per MWh for units at Bunnerong and Port Kembla.

The cost of running a gas turbine at full load (25 MW) for one hour is:
(a) natural gas fuel – $2,100 on current gas price.
(b) distillate fuel – $2,200 on 1982 fuel price. $3,875 on 1986 replacement fuel price.

With power restrictions finally averted by the commissioning of the first 660 MW unit at the coal fired Eraring Power Station in March 1982.

So what happened to the gas turbines?

After the power crisis had ended, some in parliament thought they should be sold off.

In 1982, in a panic move after the blackouts of 1981 the commission, at the Government’s insistence, purchased twelve gas turbines at a cost of $130 million. These turbines are not in use, have never been used and have no use, because they are too costly to operate.

The turbines should be sold to recoup the $130 million paid for them. The excuse that the turbines are to be used for a black start is not acceptable. It is absolute nonsense to give that excuse, and the Minister well knows it.

But Elcom did make use of the gas turbines in times of peak demand.

During autumn 1983 the natural gas turbines at Bunnerong and Port Kembla were operated due to reduced water storages in the Snowy Mountains Hydro-Electric Scheme as a result of a prolonged drought. Operating hours totalled approximately 1,700 unit hours.

In addition, gas turbines have been operated for brief periods, as follows:

  • Koolkhan to assist with a local supply problem in April 1984.
  • Bunnerong and Port Kembla to assist the State Electricity Commission of Victoria following plant failures in that State.
  • At all locations on one day in March 1983, as a result of loss of thermal generating plant due to switchboard flashovers.
  • At all locations for three days during February 1986, during the coalminers’ strike.
  • For one hour each month as a test on performance.

The units installed at Koolkhan have allowed deferment of some 330 kV transmission line projects in the area north of Armidale, with resultant cost savings of about $2 million.

Capable of generating at full load within 12 minutes of start-up, the turbines were seen as ideal emergency backup despite average annual maintenance costs of $3,200 per unit, which saw Elcom redeploy them to other parts of the network.

A review has been undertaken of the need to retain the gas turbine units.

Present forecasts of load growth indicate that there could be a need for the installation of additional combustion turbines towards the middle of the 1990’s and at this stage it has been decided not to sell any of the gas turbine units.

The benefit to the Commission of relocating gas turbines on the State grid would far outweigh the return obtained by selling this plant.

Action is in hand to relocate the Bunnerong units to the Upper Hunter district to provide “black start” capability for Liddell and Bayswater Power Stations, and it is proposed to relocate the Port Kembla units to Broken Hill as emergency standby supply in case of any failure in the transmission system.

The two units at Bunnerong Power Station were removed by 1984, and recommissioned between the Bayswater and Liddell Power Stations in 1988. They passed to Macquarie Generation as part of the breakup of Elcom, and remain in service today as the ‘Hunter Valley Gas Turbines’ owned by AGL Macquarie.


Google Earth 2020

The two units at Port Kembla were also relocated as planned to Broken Hill, being recommissioned in 1989.

Today it serves as a backup electricity supply to the isolated city of Broken Hill, should the single 220 kV transmission line be down for maintenance or an unplanned outage.


Google Earth 2020

Four gas turbines at Koolkhan fill a similar role, supplying to the far north coast of NSW should there be an outage on the 330 kV line from down south. Around 2000 Elcom successor Pacific Power decommissioned the gas turbines, which were sold off and exported to the USA. The site now lays empty.


Google Earth 2004

And finally, the four turbines at Eraring. They were passed to Elcom successor Eraring Energy, which operated two units as the ‘Northern Gas Turbines’ until they were decommissioned in 2001.

The site is now empty, but Eraring Energy did commissioned a 40 MW rated ‘Emergency Black Start Gas Turbine‘ in 2007 to meet the same role.


Google Earth 2020

Footnote: modern day equivalents

During the 2017-18 summer the Australian Energy Market Operator hired 105 diesel-powered generators that were setup at the Energy Brix Power Station site in Morwell, to supply up to 110 MW of electricity to Victoria in an emergency. They were never used, and did not return.


Aggreko Australia photo

In 2017 the South Australian government did something similar, purchasing nine new aero-derivative turbines to supply up to 276 MW of electricity to the state. After laying idle during the 2017-18 summer, they saw first use in January 2019, only be be sold to the private sector later that year.


South Australian government photo

Footnote: how did I get here?

The genesis of this post was a simple train photo, captioned “8119 and 8131 unloading at Eraring Power Station Coal Loop. 29 January 1994“.

To which someone replied:

Four 25mw diesel turbines just right of centre. I worked on some electrical modifications to these in about 1981.

And so I went this rabbit hole.

Sources

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5 Responses to “Backup generators and the 1982 New South Wales power crisis”

  1. Tony Taylor says:

    Snowy Hydro has a gas fired aero-derivative plant next to Loy Yang A. It uses Pratt & Whitney Thunderchief engines. Can’t remember how long they take to start supplying power, but it’s not long. Works like a charm, too. The only real problem they had was when they tried to synchronise the first turbine; it was a finicky procedure trying to synch the hot gas turbine to the network, but once they got the first one sorted it was all system go.

  2. Andrew says:

    I remember power shortages in Victoria because of industrial action in the 70s and 80s, I have no memory the NSW shortages and restrictions. Malcolm’s pet project the supplementary Snowy hydro scheme is very dependant on rainfall, which in our country can be very variable. What isn’t variable here is sun, wind and tides.

    BTW, do you know what the rig is in the bay that we could see from Altona Beach last week? Kind of south west.

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