The stations are located on the Tumut River in New South Wales, Australia, which are part of the Snowy Mountains.
The generating assets of the three Tumut power plants are owned by Snowy Hydro Limited, which is owned by the governments of Australia, New South Wales and Victoria. The company is also licensed to manage water rights used by power plants.
Tumut-1 is an underground power plant.
Located downstream of the Tumut Pond Dam at a depth of 366 meters below ground level and about 2.25 km southwest of Cabramurra, under the Happy Valley Road.
The HPP has four turbines with a total capacity of 330 MW. Generation of 847 GWh per year. The power plant was built in 1959 and has a nominal head of 292.6 meters.
The first 330 kV transmission lines came into operation in New South Wales at the Tumut 1 power station in the 1950s. These cables were made in England and connected to Tumut-1 underground transformers and power lines. The lines carried power to Sydney, where new substations were installed to upgrade the 132 kV transmission lines. This innovative idea, which at first caused considerable skepticism, was considered an advanced technological solution that challenged designers and foreign manufacturers. Ultra high voltage was in its infancy in the early 1950s. Before commissioning, the lines were tested on cables with a voltage of 1000 kV. These cables and transmission system have been in operation for over 50 years.
The original transformer at Tumut-1 weighed 81.2 tons; and each generator rotor assembly exceeds 203 tons, disassembled delivery and assembly on site is required.
The station is connected to the National Electricity Market through the Upper Tumut 330 kV distribution substation, located 2.75 km north of Cabramurra.
Upper Tumut Power Plant is sometimes used as a colloquial term for the Tumut 1 and Tumut 2 underground power plants.
Tumut-2 is an underground power plant.
The Tumut-2 power plant is located approximately 5.91 km north-northwest of Cabramurra.
The hydroelectric plant has four Francis turbines with a total capacity of 286.4 megawatts. Generation is 787 GWh per year. The power plant was built in 1962 and has a nominal head of 262.1 meters. Water passes through the turbines at a speed of 118.9 cubic meters per second.
A conventional gravity hydropower plant is powered by water contained in the Tumut-2 pond and from water discharged from the Tumut-1 HPP.
The station is connected to the National Electricity Market through the Upper Tumut 330 kV distribution station, located 2.75 km north of Cabramurra.
Tumut 3 is the first pumped storage plant in Australia.
Operates like a pumped-accumulator system, using off-peak power to pump water into a reservoir to a higher level. This water is then passed through turbines to generate electricity at peak loads in the grid when prices are higher. The only power plant is located above ground, below the Talbingo Dam.
Powered by six Toshiba turbines, each powered by Melco generators, the power plant has a total generating capacity of 1,800 MW. Three of the six units can work as pumps.
The power plant was built in 1973, modernized in 2012 and has a nominal head of 150.9 meters. Water is supplied by six pipelines 488 m long and 5.6 m in diameter each, delivering water both from and to the Talbingo reservoir. The pumps pump water from Junama Pond at a rate of 297 cubic meters per second, returning the water to the Talbingo Reservoir for later use during periods of peak demand.
In 2003, Snowy Hydro commissioned six 140 kW micro hydro generators in existing water cooling systems at each of the six power units of Tumut-3 CHP. These GreenPower-certified units allow Snowy Hydro to save around 3,137 tons of carbon dioxide per year. In addition, this unit not only captures previously wasted renewable energy, but also significantly reduces the noise that was associated with the old pressure reducing valves in the cooling systems of the six power units. Between 2009 and December 2011, a major modernization of Tumut-3 was carried out with the addition of additional capacity ranging from 25 to 50 megawatts per unit.
The station is connected to the National Electricity Market through the 330 kV Nizhny Tumut distribution station, located 500 m northwest of Tumut 3 or 3.0 km south-southwest of Talbingo.
