Snowy Hydro 2.0 project involves expansion of the existing Snowy Mountains Scheme, which has been operational in New South Wales, Australia, for the last five decades.
The Snowy Mountains Scheme comprises integrated water and hydroelectric power generation units located in the Southern Alps, Australia.
The expansion project involves connection of two existing hydropower plants to increase the existing capacity by 2GW.
Estimated to cost between A$3.8bn ($2.9bn) and A$4.5bn ($3.4bn), the expansion project will further increase the operational life of the existing power units by 70 years.
Exploratory works for the development of Snowy Hydro 2.0 were approved by the New South Wales government in February 2019. Environmental impact study for the expansion project is scheduled for completion in late-2019.
Snowy Hydro 2.0 will generate electricity for approximately 500,000 Australian households. It will become the second biggest pumped hydro-electric power project in the world, when operational in 2024.
Snowy Mountains Scheme details
The Snowy Mountains scheme is divided into two major developments namely the northern Snowy-Tumut development and the southern Snowy-Murray development.
Four hydroelectric power plants installed with a total of 17 power generating units along with one pumping station form part of the Snowy-Murray development, while the Snowy-Tumut development contains five power stations including 16 generating units.
Other facilities of the Snowy Mountains scheme include inter-connected tunnels with a total length of 145km, reservoirs with a total water storage capacity of 7,000GL, and 80km of aqueducts.
Snowy Hydro 2.0 project history
The Snowy Mountains Hydro-electric Authority was established by the Commonwealth Parliament of Australia to develop and operate the Snowy Mountain Scheme, in 1949.
Snowy Hydro Trading Pty Ltd (SHTPL) was formed by the government of and the State Electricity Commission of Victoria in 1997, to sell the electricity generated by the scheme. The Authority and SHTPL were merged in 2002, to create Snowy Hydro Limited, a joint venture of Federal Government (13%), and New South Wales (58%) and Victorian (29%) governments.
The Snowy Hydro 2.0 expansion project was proposed by the Federal Government of Australia in March 2017. Snowy Hydro approved the feasibility study, which was completed by Snowy Mountains Engineering (SMEC), for the expansion project in December 2017.
The Federal Government entered an agreement with New South Wales and Victorian (29%) governments to acquire their respective stakes in Snowy Hydro in March 2018.
The final investment decision (FID) for the expansion project was concluded by Snowy Hydro in December 2018.
Snowy Hydro 2.0 details
The expansion will link the existing reservoirs of the Tantangara and Talbingo dams via 27km of new headrace and tailrace tunnels, which will be located at a depth of up to 1,000m below ground.
Built in 1960, the Tantangara dam is a concrete gravity-type dam with a height and crest length of 45.1m and 216.4m, respectively. The reservoir for the dam has a storage capacity of 254,100m³.
Completed in 1970, the 161.5m-high Talbingo dam is a rockfill-type with a length of 710m and a storage capacity of 920,600m³.
A new pumping facility integrated with an underground power station will be installed between the Tantangara and Talbingo dams. The reversible-turbines installed for Snowy Hydro 2.0 will have the capability to pump water between the two dams.
The water used for the power generation can be recycled between the Tantangara (upper) dam and Talbingo (lower) dam, via the pumping facility.
The expansion project will also act as a 350GWh-power saving facility as it will utilize the wind energy to store and pump the water in the Tantangara reservoir for generating electricity during periods of peak demand.
Electricity transmission for Snowy Hydro 2.0
TransGrid is responsible for connecting the Snowy Hydro 2.0’s new power station to Australian national grid.
A new substation will be constructed adjacent to the existing Transgrid-operated transmission line, located in the Bago State Forest, which links the Tantangara and Talbingo substations.
Two new double-circuit transmission lines with a total length of 9km will also be constructed to connect the Snowy Hydro 2.0 generator site to the new Maragle substation.
Contractors involved in Snowy Hydro 2.0 project
Snowy Hydro selected Future Generation, a joint venture between Salini Impregilo and Clough, as the preferred bidder for the civil works related to the project, in January 2019.
Voith Hydro was contracted for the electrical and mechanical works, while Leed Engineering was preferred for the pre-construction works of the project.