The low and variable rainfall in Australia and limited areas of high elevation, combined with high temperatures and high evaporation rates means that the nation’s technical and economic hydroelectric potential is small, relative to that of many other countries.

Current total installed hydroelectric generation capacity in Australia is 8,186 megawatts (MW), representing approximately 1 per cent of the total installed hydroelectric generation capacity in the world. The total amount of electricity generated from hydroelectricity in Australia in each year is about 13,816 gigawatt hours (GWh), which represents less than 0.5 per cent of the world total. This total annual output of hydroelectricity in Australia is reduced during periods of prolonged drought. Furthermore, most sites with potential for large-scale hydroelectric potential have already been developed or are now protected in wilderness areas.

Tasmania accounts for 29 per cent of the installed capacity in Australia, and New South Wales accounts for over half (55 per cent).The Snowy Mountains Hydroelectric Scheme, which has a capacity of 3,800 MW, accounts for around half of Australia’s total hydroelectricity generation capacity, but considerably less of actual production. There are also hydroelectricity schemes in north-east Victoria, Queensland, Western Australia, and a mini-hydroelectricity project in South Australia. Pumped storage accounts for about 1,490 MW.

Tasmania

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Hydroelectric development occurred soon after the development of the incandescent light globe and the Pelton wheel in the 1870s. Hydroelectric technologies were adopted in Australia, and Tasmania in particular, very soon after the technology was developed. The first driver of this was the electricity needs of remote mining operations that lacked access to coal. The commercial electric direct current motor was developed in 1871 and that technology was first coupled with existing hydraulic technology in 1878 when the first hydroelectric plant was built in Cragside, England. Three years later a hydro scheme was supplying electricity at a remote tin mining operation at Mt Bishoff in Tasmania. Other remote mining operations such as the Mt Lyell Mining and Railway Company copper mine in Queenstown, and the Pioneer Tin Mining Co. in eastern Tasmania, followed soon after.

A number of entrepreneurs became interested in investing in hydroelectric schemes. According to a report written in 1892, a syndicate of directors on the board of BHP saw the economic potential and formed a company with a view to building a large hydroelectric scheme on the Pieman River on the West Coast of Tasmania to supply gold mining operations in the area, while Waverley Woollen Mill in Launceston formed a company to harness the waters of the South Esk River and sell the electricity to the Launceston municipality for street lighting. The Australasian Rights Purchase Association, a group of investors mainly from Melbourne, sought suitable locations for commercial scale hydroelectric schemes. They first sought rights to generate electricity at Zeehan on the West Coast of Tasmania, but the proposal never proceeded due to the closure of mines. The Association then proposed a hydroelectric scheme on the Colo and Grose rivers in NSW to supply Sydney.

In the case of the South Esk River proposal, community resentment to the idea of private ownership of a hydroelectric scheme used to supply public street lighting led the Launceston municipality to seek and obtain rights to harness the waters of the South Esk River to generate electricity and in 1885, Launceston became the first town in the world with public street lighting supplied from hydroelectricity. When the scheme was expanded soon after, households in Launceston became the first in Australia to be supplied with electricity from a hydroelectric plant.

In 1901 a proposal to construct a large hydroelectric scheme on the Shannon River, draining Great Lake on Tasmania’s central plateau, was taken to the Tasmanian Government. Being risk averse and not wanting to commit to such a large investment ahead of a market for the electricity materialising, the government demurred. A market for hydroelectricity did, however, materialise eight years later. It came in the form of a BHP metallurgist, John Gillies, who had developed a new electrolytic zinc refining process and who was looking for a low cost source of large amounts of electricity. Gillies formed the Complex Ores Company and in 1909 the company was granted concessionary rights to use the waters of the central plateau to generate electricity. The project involved building a 49.1 MW scheme at Waddamana. At the same time as work began on that project, the Mt Lyell Mining Company began work on a 9 MW scheme at Lake Margaret using migrant labour from Malta.

In northern Queensland, construction of a scheme on the Barron Gorge began, but the difficult terrain and lack of roads made construction difficult and the scheme was not completed until 30 years later. The Waddamana project in Tasmania also struggled due to the harsh conditions, the difficulties of construction in a remote area, and the outbreak of World War I.

Not wanting to lose the project, the Tasmanian Government acquired the company’s assets and established the Hydro Electric Department (now Hydro Tasmania). The Department proceeded with the project and the first stage of the Waddamana Power station was commissioned on 6 May 1916.

The Snowy Mountains Scheme

The next phase of hydroelectric development in Australia occurred in the post-World War II era. In Tasmania, planning and construction of hydroelectric schemes accelerated while on the mainland the largest engineering project ever undertaken in Australia, the Snowy Mountain irrigation and hydroelectric scheme, was planned and started.

The Snowy Mountains scheme was initially instigated by the NSW Government in 1918 as an irrigation scheme. In 1946, the Victorian and federal governments joined the NSW Government in planning a larger scheme that was designed to collect waters flowing eastward from the Great Dividing Range and divert it through the Snowy Mountain Ranges westward into the Murray-Murrumbidgee river system. It was a nation building project and one of the most complex irrigation-hydroelectric systems in the world. It required a workforce of over 100,000 and the development of new tunnelling and transmission techniques. It took 25 years to complete the 16 dams, 225 kilometres (km) of tunnels, pipes and aqueducts, and 7 power stations. Only two per cent of this total infrastructure is visible above ground. The system included the only three mid-sized hydroelectric plants (under 500 MW) in Australia, including the largest hydro power station (1,500 MW), and the first underground power station in the world.

The turning point: small-scale hydro gains focus

As the Snowy Mountain Scheme was being completed, the rolling program of hydroelectric scheme construction in Tasmania continued to be driven by the political, organisational and industrial benefits that it provided. The proposed schemes became larger and more costly and encountered increasing public opposition. The flooding of Lake Pedder in Tasmania’s rugged south west wilderness also triggered a major public controversy. The flooding of Lake Pedder was followed by a proposal to construct a dam on the Lower Gordon River scheme that would have flooded the Franklin River. A political controversy ensued that saw a Tasmanian government toppled, and a High Court decision ruling in favour of the Federal Government’s constitutional power to halt the construction of the dam.

An alternative scheme, the King River scheme, was built – officially opening in May 1992 – but it was the last major hydro scheme to be built in Tasmania. This marked the transition in Australia to the next phase of hydroelectric development: small-scale hydro-telemetric schemes.

The commencement of the Mandated Renewable Energy Target in April 2001 provided new funding for investing in refurbishment of Australia’s aging hydroelectric infrastructure and in new, small hydro schemes.

Small-scale hydro in Australia

The history of small and micro-hydroelectric schemes in Australia are not well documented but the potential in some states, such as Victoria and NSW, has been assessed. Opportunities are known to exist on many streams and in the retrofitting of dams used for irrigation and town water supplies. There is already investment in innovative small hydroelectric systems retrofitted onto water supply and sewage treatment plants: for an example turn to page 84 for a case study on the Melbourne Water Mini-Hydro project.

Phasing out large-scale hydro

As no new large hydroelectric projects are being planned and the potential is very limited, other renewable electricity generation technologies are projected to overtake hydroelectricity as the largest source of electricity generated from renewable energy in the near term.

David Harries is an environmentalist and a physicist who has a background in energy planning, policy and regulation and in energy research. Having spent much of his life in Tasmania, his work in energy planning has required an understanding of hydroelectric schemes. Mr Harries undertook research on energy policy and planning using Tasmania’s hydroelectric development as a case study. He subsequently joined the Tasmanian Government's Office of Energy Planning and Conservation and worked closely with Hydro Tasmania on a number of projects. Mr Harries is now a Director of EMC Solar, a company that invests in renewable energy projects and technologies. He is also a renewable energy consultant and this work has included the restoration of historic small scale hydroelectric systems in Australia and the development of a number of micro-hydro projects in developing countries.

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