Coal for power - Snapshot of Australia’s producers

Brisbane (Barlow Jonker) - As pressure from the global warming debate mounts against coal as an electricity generating source, Weekly Focus offers timely snapshots of the national black coal-fired power stations. Profiled this week are Queensland stations and in the next week edition, New South Wales and Western Australia generators.

While the climate change debate has focused on greenhouse gas emissions from coal-burning, the major operational issue for established Australian generators in recent years has been drought - and its attendant, increasing pressure on water supplies for power plants.

In many cases, power producers in Australia have stepped up to the challenge of cutting – in some cases slashing – water usage in their operations.

Four of Queensland’s coal-fired power stations, including the 840MW Callide-C, the 840MW Millmerran, the 450MW Tarong North and the new 750MW Kogan Creek power stations, have adopted the more efficient supercritical boiler technology to generate more electricity from the same amount of coal and thereby reduce greenhouse gas emissions. These power stations generate more than 27% of the state’s coal-fired electricity.

Using supercritical technology, power plants are able to operate at higher boiler temperatures and pressures, resulting in an improvement of thermal efficiency from about 36% to 38%. This equates to at least a 50 kilogram reduction in greenhouse gas emissions per megawatt hour of electricity generated.

The Millmerran and Kogan Creek power stations also both use air-cooled technology that in theory reduces water usage by up to 90% compared with conventional technologies.

A Queensland consortium of investors is also developing the world’s first demonstration project for oxy-fuel technology with carbon dioxide emissions capture and storage. It will be used on an existing 30MW coal-fired boiler at the Callide power station near Biloela in Central Queensland.

The dominance of coal-fired power stations in Queensland, which supplies more than 90% of the state’s electricity needs, is due to the abundant supplies of low cost, high quality black coal. Many of the power stations are located adjacent to their coal suppliers in the coast hinterlands to reduce coal transport costs.

Collinsville Power Station

The 188MW Collinsville coal-fired steam cycle power station, 4km west of Collinsville and 270km northwest of Mackay in Central Queensland, is owned by international infrastructure management company Transfield Services.

It consists of two 30MW, two 31MW and one 66MW generator units, all of which were completely refurbished in 1998. Coal to fuel the power station is supplied from local mines.

Stanwell Power Station

The 1,400MW Stanwell coal-fired power station, operated by Stanwell Corporation, a Queensland government owned corporation, is 22km west of Rockhampton in Central Queensland. Its four 350MW steam cycle generating units were progressively commissioned between 1993 and 1996.

Coal is delivered to the power station by rail from a number of Central Queensland mines. Each of the boiler bunkers holds about 350t of coal from where it is fed to the pulveriser. Stanwell power station over the past six years has consumed an average 3.4Mtpa of pulverized coal.

Gladstone Power Station

The 1,680MW Gladstone Power Station (GPS) is Queensland’s largest coal-fired power station. About half of the power generated is supplied to Rio Tinto Aluminum’s Boyne Smelters, Australia’s largest aluminum smelter, and the remainder provided to the Queensland Electricity Grid.

Rio Tinto Aluminum owns GPS, along with three Japanese partners in the Boyne Smelters project, and US-based power provider NRG Energy. GPS, which began operations in 1976, has six 280MW steam cycle generating units.

Callide A & B Power Stations

Queensland government corporation CS Energy’s Callide A and B power stations are located 18km east of the Central Queensland town of Biloela. The 120MW Callide A coal-fired steam cycle power station is currently in storage. One of its 30MW units will be used for CS Energy’s oxyfuel clean coal demonstration project.

The 720MW Callide B power station employs two 360MW coal-fired steam cycle generators, with coal supplied from Anglo Coal’s adjacent Callide Mine.

Callide C Power Station

The 914MW Callide C coal-fired supercritical steam cycle power station is a 50/50 joint venture between CS Energy and international power company InterGen. Commissioned in 2001, it was the first power station in Australia to use supercritical technology to reduce coal consumption and reduce greenhouse gas emissions. The two-unit advanced cycle steam turbine power plant is fuelled by coal from the Callide mine.

Tarong Power Station

The 1,400MW Tarong Power Station, 180km west of Brisbane, is operated by Tarong Energy, a Queensland government-owned corporation. Tarong’s four 350MW coal-fired, steam cycle generating units became operational between 1984 and 1986. Coal is supplied by conveyor from the Meandu mine, 1.5km away, at a rate of up to 1,800t/h. Two of the generating units are currently off line to conserve water, but can be quickly brought back into production when needed.

Tarong North Power Station

The single unit 443MW Tarong North power station uses supercritical steam cycle technology. Its advance cycle technology, when combined a with water-cooled condensing system, is able to reduce carbon dioxide emissions by about 10% for each unit of electricity generated, compared with conventional coal-fired boilers.

The Tarong North Power Station, adjacent to the existing Tarong Power Station, is a 50/50 joint venture between Tarong Energy and TM Energy (Australia), which is owned by Tokyo Electric Company and Mitsui & Co. It was commissioned in 2002 and is also supplied with coal from the Meandu mine.

A new coal handling plant has been designed for the future growth of Tarong North to a two-unit power station. It has a 1,000t/h capacity per route. The National Electricity Market Management Company (NEMMCO) estimates Queensland will need an additional 218MW of power to meet peak demand in 2009/10, but this demand will be met by the gas-fuelled 450MW Braemar and 150MW Condamine power stations due to be commissioned in 2009. The 630MW gas-fuelled Darling Downs power station is also expected to be fully operational in early 2010.

Kogan Creek Power Station

CS Energy’s $1.2B soon-to-be commissioned 750MW Kogan Creek supercritical steam cycle power station will be supplied with about 2.8Mtpa of coal from a new open cut coal mine, 4km away, via conveyor.

Located near Chinchilla in southeast Queensland, the power station will be Australia’s largest single generating unit. Kogan Creek also employs air-cooled technology to reduce water usage.

Millmerran Power Station

The 860MW Millmerran coal-fired power station near the Darling Downs town of Millmerran in Southern Queensland is operated by InterGen and was commissioned in 2002. It is the largest “greenfield” private investment in electricity generation in Australia.

Coal for the power station comes from the adjacent open cut Commodore mine. Millmerran uses supercritical steam cycle technology to drive its two 430MW generating units, which require about 10% less fuel than equivalent conventional units. It also uses air-cooling technology to reduce water consumption.

Swanbank B Power Station

The 480MW Swanbank B power station near Ipswich is supplied with about 1Mtpa of coal. It is trucked and railed from New Hope’s Oakleigh and Acland mines in south east Queensland. Swanbank B’s four 120MW steam cycle units were commissioned between 1970 and 1973.