Securing Sydney’s water pumping needs

ABB’s high-efficiency motors and variable speed drives have provided an energy-efficient solution for transporting large volumes of desalinated water from Sydney’s newest water supply to over 1.5 million Australian residents living in New South Wales.

Clean water is being supplied from the newly commissioned desalination plant, based in Kurnell, south of Sydney, and is capable of producing up to 250 million litres of water a day, which is up to 15% of Sydney’s water needs. The new pump station and pipeline were built by Water Delivery Alliance (WDA), comprising Kellogg Brown and Root, Bovis Lend Lease, McConnell Dowell, Worley Parsons, Environmental Resources Management and Sydney Water, to ensure the city’s water supply against population growth and the damaging effects of climate change and drought caused by reduced rainfall.

“The high efficiency pump-motor-VSD set allowed the alliance to minimise life-cycle costs. ABB’s ability to guarantee an equipment efficiency rating of more than 96% played a major role in this decision as it directly translates into affordable potable water,” said the Project Manager for the pump station.

Adrian Heaton, ABB’s NSW regional sales manager for drives and motors, explains why evaluating operating costs is critical for water applications: “Electrical power consumption is one of the largest running costs of a desalination plant that uses reverse osmosis technology. Therefore, it was important for WDA to ensure that all the necessary factory and efficiency string tests were carried out in conformance with the contract requirements.

“The string testing involved running the pump, motor, variable speed drives with integral transformers in sequence at actual load conditions to prove minimum life-cycle costs. We are pleased to report that the water pump discharge system, which is capable of discharging water at 3183 litres per second, satisfied the test requirements in every respect. String testing was performed at Nijhuis, the pump manufacturer’s plant in Holland,” said Heaton.

According to Heaton, the water consortium’s investment in ABB’s technology will have a huge impact on reducing their daily operating costs because water consumption can vary greatly during any given day. Consequently, the flow and pressure of the Nijhuis pumps need to be controlled and adjusted either electrically with variable speed drives or mechanically with fixed-speed solutions, such as inlet guide vanes, throttling valves or hydraulic couplings. Since pumps typically run at partial load, huge energy savings are achieved by controlling their speed with variable speed drives.

The motors that drive the pumps are two 1.35 MW, 3.3 kV 66 Hz high-efficiency motors from ABB’s AMA family of modular induction machines, and are used in combination with the ACS 1000i model drive, a fully integrated standard drive which includes input transformer and input contactor.

Sydney Water reinforced its commitment to sustainability by opting for a renewable energy power supply to run the desalination plant and the pump station. The plant, which uses reverse osmosis technology to extract fresh water from the seawater, is completely powered by renewable energy sourced from the Capital Wind Farm in Canberra.