Minerals and Energy
The birthplace of Australian metalliferous mining was in the foothills of the Mount Lofty Ranges at Glen Osmond, now an Adelaide suburb. Outcrops of silver-lead ores were first worked there in 1841 and further minor discoveries of metal ores were made in the Ranges in the next twenty years. However, most South Australian discoveries of mineral and energy resources were to be made on the frontiers of agricultural settlement and beyond, in the remote interior. From 1842 to 1861, discoveries of copper lodes, unusually rich in their upper portions, greatly stimulated the economy, but thereafter the mineral wealth of the State was slow to be revealed or to have its potential recognised. Discovery and development often called for a high degree of technical and scientific ingenuity and commercial risk taking. In the 1981 census, 4151 persons were directly employed in the South Australian mining industry. That is 0.8% of the State's workforce, compared with 1.4% in the whole of Australia.
Copper dominated the State's mineral production until 1915 when it was quickly eclipsed by the rapid rise of iron ore production. Natural gas and opals assumed a significant share after 1970, with crude oil and condensate joining the list in 1983. Iron ore production has declined since the early 1970s with the expansion of output from the much larger deposits in Western Australia.
Most future production is likely to come from the Olympic Dam mine on Roxby Downs pastoral station, by far the most significant metalliferous ore discovery in South Australia this century.
The large reserves of high grade iron ore in the Middleback Range west of Whyalla were recognised by the 1890s. In 1897 the Broken Hill Pty Co Ltd (BHP) pegged its first claims there and in 1900 commenced mining on a small scale. The ore was taken by cart to Port Augusta and then by rail to Port Pirie for use as a flux in the lead smelters. Dwindling ore reserves at its Broken Hill mine encouraged BHP to diversify into iron and steel production at Newcastle, and later Port Kembla, using South Australian ores shipped from Whyalla. Local production of pig iron began at Whyalla in 1941, with the Middleback Range supplying most of the ore requirements of the Australian iron and steel industry until the mid-1960s. Over 160 million tonnes of iron ore have been mined here by open-cut methods since 1900; recent production has been about 1.5 to 1.7 million tonnes annually.
Opals were first discovered at Coober Pedy in 1915 by fourteen-year-old Willie Hutchison who was accompanying his father on a gold prospecting expedition. Mining developed quickly at Coober Pedy after the First World War when returned servicemen migrated there and established a distinctive dug-out style of housing to cope with the scorching summer temperatures. Opals occur in weathered rocks to a depth of about 40 metres and today are worked by individuals or small syndicates of miners using bulldozers, electrically powered tunnelling machines, and blowers. South Australia supplies an estimated 80% of the world's opal output, production coming from three main fields at Mintabie, Coober Pedy and Andamooka. The opal industry, in contrast to the company structure of other mineral production, is highly individualistic. As opal miners are not required to report their production statistics, the value of out-put is only an estimate - in recent years between $20 and $40 million annually. High quality nephrite jade was discovered near Cowell on Eyre Peninsula in 1965.
The State is also well endowed with many industrial and non-metallic minerals whose exploitation lacks the glamour of mining for metals and precious stones. South Australia produces about 80% of the Australian output of gypsum. Deposits of rock gypsum - hydrated calcium sulphate - have formed in coastal basins cut off from the ocean. The most important deposits are at Lake MacDonnell west of Ceduna. New Lake on Kangaroo Island, and Stenhouse Bay on southern Yorke Peninsula. Over the past fifty years they have supplied most of the Australian and New Zealand requirements for plaster manufacture and the Portland cement industry.
The high evaporation rates and high salinity of the gulf waters provide favourable conditions for the production of salt by solar evaporation. The numerous small salt lakes on southern Yorke Peninsula were the main scene of activity until the turn of the century, providing accessible and easily harvested salt of a purity unequalled elsewhere in Australia. The first salt-field formed from artificial evaporating ponds was developed in 1915 at Yorkey Crossing, north of Port Augusta. Other salt works have been established at Whyalla. Lake MacDonnell and Price, and at Dry Creek, north of Adelaide. Salt is the principal raw material for the Australian chemical industry and provides the basis for the production of alumina from bauxite and the manufacture of glass, soap, paper and PVC.
Limestone, varying from dense crystalline marble to soft porous limestone, is widely distributed in South Australia. High grade marble from Penrice Quarry near Angaston in the Barossa Valley is combined with salt from the Dry Creek to produce a variety of chemicals at the Osborne works of ICI Australia Ltd. Portland cement is manufactured at Angaston using marble from Penrice, and at Birkenhead, Port Adelaide, using marble from Rapid Bay, Fleurieu Peninsula, and soft porous limestone from Klein Point on Yorke Peninsula.
Natural stone was abundant and widely distributed in the first settled areas of the State; it was a special boon in a land where suitable building timber was so scarce. High quality bluestone, sandstone, limestone, marble and granite were used in public and commercial buildings and many private homes in the nineteenth century. During the twentieth century, softer stone materials have proved popular in some localities, especially in the lower South-East where the white, very porous Gambier limestone is easily recovered and worked for residential construction. Norite, a black granite from near Mannum, is exported to many countries for building and ornamental use.
A mineral development of great potential importance to the State began with exploratory drilling at Olympic Dam on Roxby Downs pastoral station. The area, to the west of Lake Torrens, is referred by geologists as the Stuart Shelf. One of the world's largest deposits of copper-uranium-gold mineralisation has been identified beneath barren sediments of 350 to 400 metres depth. The Olympic Dam deposit, which includes minor silver mineralisation, extends over an area of 20 square kilometres. BP Australia Ltd and Western Mining Corporation Ltd formed a partnership to develop the Olympic Dam Project in a long-term programme of underground exploration and mineral sampling. A total ore resource of at least 2000 million tones has been indicated which contains copper at 1.5 to 2.5%, uranium oxide averaging 0.6 kilograms per tonne, and gold at 0.6 grams per tonne. Commissioning of the project is timed for June 1986. When fully developed, the project will support a new town of 3500 people, and lead to increased activity at Port Augusta and Whyalla.
During the nineteenth century South Australian energy consumption depended on imported black coal from New South Wales, supplemented by local wood fuel. South Australian energy resources are remote from population centres, and coal deposits, although substantial, have impurities which restrict their use.
Electricity supply began erratically as individual businesses and towns acquired small generators. In 1897, the Corporation of Port Adelaide entered into South Australia's first electric supply agreement with the SA Electric Light and Motive Power Company. The first central power-station went into service at Nile Street, Port Adelaide in 1899, and operated until 1907. In 1898, the Adelaide City Council entered into a five-year agreement with the company for thirty arc lamps to be provided in the city and North Adelaide; power was to be supplied by a power-station at the corner of Grenfell Street and East Terrace. The station was opened in November 1901 with a capacity of 0.28 megawatts, and soon expanded to 0.76 megawatts. While the Grenfell Street power-station was under construction, the assets of the original company changed hands twice and were eventually taken over by the Adelaide Electric Supply Company (AESCo) in 1904.
When electric tram services began, the Municipal Tramways Trust took a temporary supply from AESCo until its own power-station was opened at Port Adelaide in 1911 with an initial capacity of 4.5 megawatts; it was closed in July 1958.
As the AESCo supply networks continued to grow, the Grenfell Street power-station was extended; however, its location near the heart of the city was far from ideal. A new station was planned at Osborne, on the Port River, where New South Wales coal could be unloaded directly from ships and seawater was available for cooling. The new power-station which took over from Grenfell Street in 1923 with an initial capacity of 20 megawatts, become known as the Osborne A Station; it was ultimately expanded to a capacity of 79 megawatts by 1942, and continued to operate until 1968.
By the early 1920s many country towns had their own generating plants which supplied homes and businesses and sometimes the nearby district. In 1922, an Act of Parliament authorised AESCo to extend its mains to country districts. Work began on a northern extension in 1924, and by 1927 AESCo was supplying Angaston, Kapunda, Balaklava, Gladstone and Jamestown. The company also extended supply through the Adelaide Hills and south to Willunga.
South Australia has no hardwood suitable fro power poles. However, the economic expansion of the electric supply network was made possible by the development of a steel and concrete Stobie pole, that characteristic if much criticised feature of the South Australia landscape. The design was patented in 1924 and improved two years later with a taper below ground-level, making the pole easier to erect.
In 1938, the company began planning a second power-station at Osborne. The B Station, and construction commenced in 1942. The boilers of the Osborne A Station were designed to burn New South Wales coal, and the company's reluctance to consider the State's own Leigh Creek coal was one of the major factors behind the South Australian Government's decision to take over the company in 1946 and establish a statutory authority - the Electricity Trust of South Australia (ETSA).
South Australia's almost total dependence on coal shipped from New South Wales was highlighted during the Second World War. The long-known coal deposits at Leigh Creek, 250 kilometres north of Port Augusta, were reappraised and ETSA undertook to develop them as an open-cut mine for supplying electric power-stations, initially at Osborne and later at Port Augusta. Development involved the creation of a township at Leigh Creek, the construction by the Commonwealth of a standard-gauge railway to Port Augusta, and the building at Port Augusta, where cooling water was available, of the State's first major power-station outside metropolitan Adelaide. The station was designed with a capacity of 90 megawatts and began generating in 1954.
Further exploration of Leigh Creek confirmed the availability of sufficient coal for a second power-station. When the second (B) Station was opened in 1960 by the Premier, Sir Thomas Playford, the entire installation was renamed the Thomas Playfrod Power Station. The B Station was completed in 1964 with a 240 megawatt capacity.
Since most of the demand for electricity is in the metropolitan area, ETSA in 1962 decided to build a large power-station on Torrens Island. Construction of Section A began in 1963 and power was first supplied in May 1967. Although the boilers were designed to burn residual fuel oil from Port Stanvac, in 1970 Torrens Island became the first major Australian power-station to use natural gas.
The development of the natural gas resources of the Cooper Basin led to a major change in the primary source of energy for electric power generation in South Australia. Although the gasfields are even more remote from the main centres of population than the coal resources, the low cost of pipeline transmission allows power generation to be undertaken close to the centre of demand for electricity. The decision to use natural gas at Torrens Island made the economic development of the Cooper Basin gasfields possible and ETSA now consumes about three-quarters of the natural gas supplied to Adelaide. The total capacity of Torrens Island is 1280 megawatts, making it the State's largest power-station. Torrens Island meets most of the base load demand, and in 1984-85 produced almost 77% of the electricity generated in the State. Two smaller peak-load gas turbine stations at Dry Creek, north of Adelaide, and Mintaro, near Clare, are also fuelled by natural gas.
The rising costs of gas and the uncertainty of future supplies have encouraged ETSA to examine alternative sources of fuel. The first outcome was the construction of the Northern Power Station adjacent to the existing station at Port Augusta. Commissioned in 1985, this has a designed capacity of 500 megawatts and burns Leigh Creek coal much more efficiently than the older Thomas Playford Power Station.
Future options for electricity supply include: conversion of the Torrens Island power-station to burn black coal from New South Wales or Queensland; purchase of electric power from the Victorian and New South Wales grids by a proposed high voltage connection via Portland and Mount Gambier; underground gasification of the deeper Leigh Creek coal deposits; and development of other South Australian coal deposits for use in either conventional boiler plants or perhaps in new technology such as fluidised bed boilers or coal gasification plants.
Although demonstrated coal resources exceed 7000 million tonnes, South Australian coals generally have a low calorific value and their high content of ash, sulphur, sodium, and chlorine poses problems for their use in conventional coal burners. Coal of comparable quality to that of Leigh Creek has been located near Lock on central Eyre Peninsula, but its proximity to the important Polda groundwater basin may inhabit its exploitation. Four extensive lignite deposits of Tertiary age are located closer to Adelaide at Bowmans and Lochiel in the Mid North, Sedan near the River Murray, and Kingston in the South-East. Each of these deposits could provide fuel for a generating plant of a least 500 megawatt capacity. Another potential source, despite its remote position, is the sub-bituminous deposits of the Arckaringa Basin, especially in the Wintinna area north of Coober Pedy.
Natural gas - largely methane - has played a major role in the State's energy supply since 1970. In 1982-83 it supplied 41% of South Australia's primary fuel usage, as estimated by the Department of Mines and Energy; crude oil supplied 37%, coal 19%, and wood 3%. The use of natural gas for generating electricity provided the economic justification for the 790 kilometre pipeline from Moomba, in the Cooper Basin, to Adelaide. More than 70% of the gas transported is used in three ETSA power-stations.
Development of the oil and gas resources of the Cooper and Eromanga sedimentary basins began with the formation of SANTOS Ltd in Adelaide in 1954 and its acquisition of extensive exploration leases in north-east South Australia and south-west Queensland. The first traces of hydrocarbons were found at Innamincka in 1959 and the first encouraging gas find at Gidgealpa in 1963. Further discoveries in 1966 at Moomba and Gidgealpa indicated a gas reserve sufficient to supply a substantial market in South Australia. A pipeline to Adelaide was completed late in 1969 and in 1971 an agreement was made with the Australian Gas Light Company Ltd of Sydney to transport gas to New South Wales. Delivery by pipelines to Sydney began in December 1976 and was later extended to other New South Wales towns and to Canberra.
More than thirty gasfields and sixteen oilfields have been discovered in the South Australian sectors of the Cooper and Eromanga basins. Most of the proven and probable gas resources have been committed to New South Wales until the year 2006 by long-term agreement with the Australian Gas Light Company. Resources to supply South Australian gas consumers are not guaranteed beyond 1992, and continuity will depend on the outcome of exploration as well as complex negotiations on pricing. In the near future South Australia may need to develop less reliance on gas for generating its base load electric power.
The discovery during the 1970s of crude oil and 'wet' gas, saturated with liquid hydrocarbons, demonstrated the potential for marketing petroleum liquids. In 1983, a 659 kilometre liquids pipeline was completed from Moomba, in the heart of the gasfields, to Port Bonython near the head of Spencer Gulf. A crude stabilisation plant to stabilise oil and condensate before pipeline transport, and a liquids recovery plant to separate the propane, butane and ethane from the gas streams before transport, has been added to the existing gas treatment plant to Moomba. The Cooper Basin Liquids Project is the largest single development project undertaken in South Australia and supplies crude oil for Australian refineries, condensate for Australian and New Zealand markets, and liquefied petroleum gas (LPG) exports to Japan.