The site

Banimboola Power Station is on the bank of the Mitta Mitta River downstream of the Dartmouth Regulating Dam (Lake Banimboola). Irrigation water is released from Dartmouth Dam via the Dartmouth Power Station, or via the high and low level outlet conduits and irrigation valves. This water is captured in Lake Banimboola, and is then released into the Mitta Mitta River as a regulated flow, the majority of which now passes through the power station. The power station is connected to the regulating dam wall via three penstocks, which each supply a separate generating unit. The power house is located to take advantage of an existing cutting, to ensure smooth flows into the river and to keep all new infrastructure within a 100 metre boundary from the dam wall. The design is such that the building is effectively within the excavation, with the transformer yard and penstock being the main above-ground facilities.

Technology

The turbines are horizontal S-type tubular turbines with adjustable guide vanes and adjustable pitch (Kaplan type) runners. Speed increaser gearboxes connect the turbines and generators. The power station takes its water by three penstocks and directs it into each turbine intakes. Penstock intake gates, designed to be able to close into flow, are provided for isolation of penstocks. New intake holes cut through the dam wall are located at a level that will enable water releases from the existing regulating gates during future maintenance activities. The three new penstocks are above ground as they leave the dam wall and descend to the turbine intakes below ground level. The intakes are provided with a fully automated, trash rack cleaning machine. Discharge of trash material is via the spillway dissipater area.

Article continues below…
Advertisement

Energy purchase and supply

The plant is expected to produce 37 gigawatt hours of electricity per annum, with the output contracted to Energy Australia under a long-term power purchase agreement. The generator is a non-market, non-scheduled generator and is also accredited under the Mandatory Renewable Energy Target scheme and the Green Power Scheme. The plant is connected to the 220 kilovolt (kV) transmission system at Dartmouth Power Station via a dedicated 22 kV line.

Environmental impact

The project will provide enough renewable energy to power 6,000 average Australian households. It is expected to save 35,244 tonnes per annum of greenhouse gas emissions, which is equivalent to removing 8,200 cars from the road.

Success of the project to date

Given the drought situation, Lake Dartmouth has been progressively emptied over the last 12 months in order to maintain water supplies for the River Murray communities downstream from Albury, with all volumes passed to Hume Dam going via Banimboola Power Station. The economic impact of the project has been enormous considering the large amount of energy that has been generated since commissioning, purely due to the water transfers.

Quote from local prominent person on benefits of the project:

AGL’s hydroelectric power plant at Banimboola provides additional electricity generation capacity for Victoria and increases the amount of zero emission electricity produced by AGL’s power generation assets. This represents an enormous boost to the local economy in my electorate of Indi and beyond. The development is the largest of its kind seen in Australia for more than a quarter of a decade. Sophie Mirabella MP, Federal Member for Indi.