The giant radiator keeping Kogan cool
Water is a vital input to the electricity generation process at thermal power stations. It is used to create the steam that drives turbines and for cooling purposes.
Most coal-fired power stations located near major water storages or the coastline use wet cooling technology.
Kogan Creek Power Station is located on the Western Downs where water is scarce, so dry-cooling technology was factored into the power station’s original design. This has resulted in 95 per cent less water use compared to an equivalent sized wet-cooled power station.
The air-cooled condenser
The centrepiece of dry cooling at Kogan Creek Power Station is the air-cooled condenser (ACC).
The role of the ACC is to cool and condense exhaust steam after it has left the turbine.
The air-cooled condenser is the largest single piece of plant on site and works like a giant car radiator. It consists of 48 fans, each with a nine-metre diameter, that force air over finned tubes containing the hot steam. The air cools and condenses the steam back into water so it can be used again in the power station’s boiler.
While dry-cooling requires slightly more electricity to drive the fans, it ensures prolonged periods of drought do not impact the power station’s output and minimises our impact on the local environment.
Above: The air-cooled condenser (at right) is the largest piece of plant at Kogan Creek Power Station.
improving our water management practices further
The limited water that Kogan Creek Power Station does use is for other plant operations and the boiler, where water is heated and converted to steam to spin the turbine. CS Energy sources this water from three local bores and surface water run-off collected in dams.
Because securing an uninterrupted supply of water is so vital for the ongoing operation of the power station the site chemistry team have made changes over the years to improve its water treatment processes.
In 2016 the Kogan Creek team installed a water clarification plant to recycle stormwater runoff collected on site so it could be used in plant operations such as the auxiliary cooling system. This resulted in a 20 per cent annual reduction in bore water use.
Further improvements were made in 2019 to allow additional sources of water to be treated specifically for use in the boiler where high quality demineralised water is required. These improvements have provided a back-up water source in the event of drought or a bore failure.
The power station also reclaims water from the ash disposal areas at the neighbouring Kogan Creek Mine for use its ash management processes.
Overall, Kogan Creek Power Station uses 0.08 megalitres of water for each gigawatt hour of electricity that it sends out to the grid, which equates to approximately five per cent of the water use of a typical thermal power station.