A large, three-kilometre deep subterranean basin about twice the size of Perth’s CBD could be the answer to the state’s peak power needs this summer.
A large, three-kilometre deep subterranean basin about twice the size of Perth’s CBD could be the answer to the state’s peak power needs this summer.
The Mondarra basin, 80 kilometres south of Geraldton and 350 kilometres north of Perth, is the perfect place to store excess North-West Shelf gas, according to WA’s second largest pipeline operator, the Australian Pipeline Trust (APT).
“The gas can then be used by Western Power in times of peak demand,” APT’s Perth-based general manager, David King, told WA Business News this week.
“In November we signed a storage optimisation agreement (SOG) with Western Power to help address Perth’s power needs for the 2005-06 summer,” he said.
“This deal is good for the Perth region by addressing the energy supply problems which have plagued Perth over the years, and is good for our company. We are very pleased to be playing our part to improve the robustness and developable capacity of the West Australian gas market.”
APT already helps meet some of the state’s growing energy needs through its ownership and operation of its 420-kilometre Dongara-to-Perth Parmelia Pipeline (DPPP) and majority ownership of the 1380km Goldfields Gas Pipeline that runs from the North-West Shelf to Kalgoorlie.
APT is one of Australia’s biggest investors in natural gas pipeline systems. With interests in more than 7,500km of pipeline infrastructure, it transports about 25 per cent of Australia’s natural gas.
APT also owns the Mondarra basin, which was a producing gas field until its reserves were practically depleted in 1994.
The basin sits over a huge mass of shale bedrock overlayed by a dome-shaped caprock. APT says that its location and geological structure makes it the perfect place to “park” North-West Shelf gas not immediately needed down south.
“The stored gas could then be withdrawn when it is was needed most,” Mr King said.
“It could also be a good ‘rainy day’ source of energy should anything happen anywhere along the Dampier-to-Perth Natural Gas Pipeline (DBNGP) north of the basin.
“The DPPP runs parallel to the DBNGP between Dongara and Perth.
“But the bulk of WA industrial and domestic consumers rely only on the DBNGP between Dampier and Mondarra, meaning ruptures or other interruptions to gas flow over this longer segment would interrupt supply.
“If a storage basin like Mondarra was brought on stream it could be steadily injected with gas and become a permanently topped-up second gas source near Perth that could be tapped if the DBNGP ever ruptured or was temporarily out of commission.”
Ongoing estimates by APT’s engineering team have shown that the Mondarra basin is capable of holding up to 10 petajoules of infused gas from the DBNGP, which could comfortably meet Perth’s emergency needs for at least a month.
Ten petajoules is enough to ensure there would be time to repair the DBNGP, which, furthermore, passes directly over Mondarra basin, Mr King said.
APT acquired Mondarra early last year because its previous owners, American gas transmitter CMS Energy, was operating a smaller gas injection and extraction facility that it now knows can be markedly expanded.
APT’s plan is to initially inject and withdraw up to 50 terajoules daily into the basin, with longer term plans to triple that volume.
That would ensure Western Power could overcome problems like that encountered in February 2004 by the DBNGP’s former owner, Epic Energy, which resulted in a peak summer blackout. Other clients would also have access to the basin.
APT’s chief operating officer, Michael McCormack, said work on planning the project had commenced after the signing of the SOG with Western Power in November.
“This will help the company to address Perth’s power needs for the 2005-06 summer,” he said.
Mondarra’s intended expansion is estimated to cost up to $25 million.
If work gets the go-ahead it will be the second such back-up gas storage facility in Australia.
The other is at Port Campbell, 200km west of Geelong, which helps ensure Melbourne’s domestic and industrial gas requirements are secured in the event of a repetition of the September 1998 mishap at Longford in the Gippsland region.
Two maintenance workers were killed at Longford and gas supplies across Victoria were cut-off for a fortnight.
Work had commenced on the Port Campbell facility before the Longford explosion and was consequently speeded up for commissioning in 1999. A royal commission into that disaster found it cost industry $1.3 billion.
“During this period, Melbournians took to showering in the fountains of water outside Crown Casino,” one account later claimed.
“Essential service industries like hospitals had to have gas brought in to enable emergency operations to be performed, other industries closed their doors for the period of restrictions.”
If Port Campbell’s facility had been operational in 1998 Victoria’s gas consumers would not have endured such costly and difficult consequences.
“The project will enable gas to be stored and withdrawn at greater rates during times of peak need which could be used in times such as during the expected hot, high air-conditioning, electrical demand summer days,” Mr McCormack said.
Mr King said that, to ensure work could commence for the facility to be operating for the coming summer’s needs, a take-or-pay contract needed to be negotiated with Western Power.
“This decision is required in the coming weeks to ensure that the required commitment by APT for the capital investment is approved and that the fast-tracked project timetable can be achieved,” he said.
