Power Supply

In early colonial NSW the only power available was that of muscles – those of men, horses and bullocks. There were some windmills built in Sydney, but these were isolated installations used to mill grain, not any sort of widely available power source. Streams in NSW are rarely voluminous or reliable enough to power water mills without the deliberate construction of storage dams.

Once steam engines were introduced they powered individual factories by driving lines in the roof of the building from where power was brought to individual machines by pulleys and belts. The system worked but required the maintenance of a steam engine in every factory and careful construction and adaption of the belt lines. After 1879 local transport in the city was provided by steam trams, which were really just small steam trains running on the streets. In 1899 electric trams were substituted and they derived their power from overhead lines which were energised by a coal-fired power station close to the heart of the city in Ultimo. The Railways Department, who operated the trams, also supplied power to general customers nearby. The Sydney City Council then built a small power station within the city, soon replaced by larger stations at Pyrmont and Bunnerong. A private company built a power station at Balmain and when the capacity of Ultimo was taxed by the electrification of the suburban railways a new and larger power station was built by the Railways at White Bay. Power for industry became electricity derived from a general supply rather than an in-house engine.

The technology of these times dictated that power should be generated close to the point of use as transmission losses and therefore costs were high. Having the power stations in the city meant that large quantities of coal had to be carried to them at great cost and that the results of the burning of the coal – smoke and other noxious gases – was dumped over the populated area.

Electrical technology developed to the extent that power could be transmitted economically over state-significant distances by using very high voltages. This made the positioning of the power stations in the coal fields to the north, south and west of the city attractive both in terms of the elimination of the transport costs of the coal, as well as the removal of the pollution to a remote site away from populated areas. Power stations were built around Wallerawang in the west, around the coastal lakes between Sydney and Newcastle, in the Hunter Valley and around coastal lakes in the Illawarra – all adjacent to coal mines.

By the second decade of the twenty first century these large thermal power stations have passed, or are approaching, the end of their economic lives and will almost certainly not be replaced. Wind power, solar power derived from photo-voltaic cells and domestic roof mounted electricity generating and water heating installations will carry the load, backed up by battery storage and pumped storage hydro-electric schemes.