Terminal Storage Mini Hydro

The site

The Terminal Storage Mini-Hydro project utilises energy that was previously wasted in the SA water system. Prior to the Terminal Storage mini-hydro development, water was conveyed from the Anstey Water Treatment Plant to the Anstey Hill Tanks and then to the Terminal Storage tank via a dissipating valve. The dissipating valve is now bypassed by a new pipeline, which feeds the mini-hydro power station and discharges into the Terminal Storage.

Design and construction

The project is a joint venture development between SA Water and Hydro Tasmania. Design and construction of Terminal Storage Mini-Hydro was carried out by Hydro Tasmania in association with Tyco Tamar. Construction took 10 months.

Electricity is generated using a vertical shaft, six-jet Pelton turbine with a maximum flow of approximately 1.4 m3/s providing output down to a minimum flow of 0.2 m3/s. All aspects of the power station are automatically controlled using instrumentation and an integrated Programmable Logic Controller control system.

The control system monitors tank levels both upstream and downstream of the power station and adjusts turbine flows automatically. This enables optimisation of power output from the system and provides a safe shutdown of the plant in the event of a loss or failure. Monitoring and remote operation is by means of a communications link to the SA Water control centre.

Energy purchase and supply

The Terminal Storage Mini Hydro has an average annual energy output of 6,821 MWh or enough electricity to supply about 1000 homes. Annual energy production was estimated based on seven years of historical flow data with the worst-case being 5387 MWh and the best-case being 8730 MWh. The power station is connected to the existing 11kV distribution network via a 150m long underground power cable.