Electricity Trust of South Australia makes strong impact on the network from takeover of private firm in 1946

Power stations at Port Augustra were part of the strong growth of the network under the Electricity Trust of South Australia with the inset map showing, in red, the new transmission lines added during its first 10 years.
The nationalising of Adelaide Electricity Supply Company in September 1946 by the Tom Playford state government created the Electricity Trust of South Australia (ETSA), to co-ordinate, control and operate the electricity in South Australia, with all the staff and assets of the previous operator.
It paved the way for ETSA's strong growth in generation, transmission and a sophisticated of power system control, planning and radio/phone communication. The Electricity Trust of South Australia (ETSA) inherited a transmission network across countryside from Booleroo Centre in the north, to Rapid Bay in the south, and from Port Wakefield in the west, to Morgan in the east. ETSA soon added to its output with the Osborne B power station completed soon after 1947, with boilers at both Osborne power stations modified to burn Leigh Creek coal. In 1948, control of the Leigh Creek coalfield was transferred to ETSA as its largest user.
ETSA also built major power stations near Port Augusta; Playford A (1954). Playford B (1963), Northern (1985). Its other new power station was on Torrens Island, in Adelaide's northwest, in 1967. Port Augusta’s Playford A and B plant had a total capacity of 330 megawatts (440,000 hp). Northern power station was fuelled by Leigh Creek coal brought on a line rebuilt by the Commonwealth Railways.
The spread of the electricity transmission network throughout the late 1940s and 1950s included the first 132kV high voltage transmission line between Adelaide and Port Pirie, enhanced by another 132kV transmission line from Northfield to Waterloo and then on to Berri. The new Port Augusta power station would relink into this new backbone of 132kV transmission system – a major development for South Australia,
In 1955, a major line was extended from the North West Bend substation near Morgan, to the uranium mining centre at Radium Hill in the state’s north, through inhospitable country in a pioneering spirit of teamwork. By 1966, ETSA’s 20th year, power consumption and infrastructure had grown at the cumulative rate of 11% per annum. The total 24,150 kilometres of high voltage lines were added and Playford encouraged ETSA to buy regional and town electcity suppliers.
The early 1960s saw major development of the 275kV transmission system, including the Para substation, needed to transmit power from the new large gas-fired Torrens Island power station that commissioned its first unit in 1967 and the eighth in 1980. Although the community generally was convinced of the need for transmission lines from Whyalla to Port Lincoln, undersea to Kangaroo Island and to the site of the ill-fated Chowilla Dam on the River Murray above Renmark, disagreements arose about their routes.
During the 1960s, a line through the well populated Para Valley was influenced by public protest. From that point, the planning, survey and construction of transmission lines proceeded with a far greater amount of public consultation – a precursor to subsequent environmental impact studies.
Mains control of the whole South Australian electricity system was moved in 1969, via a small buidling at the rear of East Terrace substation, to new purpose-built offices at Pirie Street, Adelaide city. Laurie Ellison, the original system control engineer through the 1950s and 1960s, was responsible for setting up world-class processes, involving extensive remote control of substations from the centralised control centre.
An innovative electronic remote supervisory system was installed to monitor and control the Para substation and commissioned in 1968. This system was the foundation for the technology used to interface substation equipment to the control centre and enabled the complex system control capabilities needed for a modern power system.