Burrinjuck Hydro Project

Grid-connected, distributed generation, renewables
Location: Burrinjuck, NSW

Energy offering

The Burrinjuck Dam, near Yass in southern NSW, was completed in 1923 with extensive modifi cations completed in 1958 and 1994. The dam has a storage capacity of 1,026,000 megalitres and water is released for irrigation and environmental flows. This project involved the construction of an additional 16 MW generator, the refurbishment of the two existing units and an upgrade of the substation. The total power station capacity is now 28 MW. The additional generator provides the opportunity to fully capture the energy benefit of water releases. Prior to this only 50 per cent of the water releases were utilised.

The units can be operated manually or automatically.

Technology

The hydro project comprises one turbo generator rated at 16 MW, an Alstom generator rated at 20 MVA and an 11 kV to 132 kV Alstom transformer. The turbine is rated for 49 m head with a maximum flow of approximately 3350 megalitres per day. The shaft speed is 300 rpm.

The uprated 5.6 MW turbo generators are double runner horizontal design and were manufactured in 1938. The generators are rated at 7 MVA and have been rewound from the original 6.6 kV to 11 kV. The turbines are rated for 49 m head with a maximum flow of approximately 1600 megalitres per day each. The shaft speed is 500 rpm.

The new and existing units have a common 11 kV electrical and auxiliary systems. The control system for the turbines, generators and switchyard is a completely screen-based system, enabling both local and remote control. As the only electrical connection with the grid is via a 132 kV transmission line, the smaller units can black start and operate as an isolated system supplying the dam and Burrinjuck village.

Energy supply

The plant's long-term average energy output has been estimated to be enough to supply approximately 15,600 average households. The power is exported to the national grid via a connection to the Tumut to Yass 132 kV transmission line. The generation plant is a non-scheduled market generator, with power from the project sold to Country Energy, who will distribute the energy as part of its Green Power scheme.

Environmental impact

The project will save 88,200 tonnes of CO 2 -equivalent per year. One important outcome of the design process was the installation of a bi-level intake on the dam wall. The device will enable warmer, more oxygenated water from the upper levels of the storage to be directed through each of the three hydro units. This will allow the operator of the dam to divert water through the power station while still satisfying downstream water quality requirements.