Australia’s largest cooling-only geoexchange installation is used for cooling on the astonishing Australian Square Kilometre Array Pathfinder project in remote Western Australia.
Murchison region, Western Australia
Located 350km north-east of Geraldton in mid-west Western Australia, the Australian Square Kilometre Array Pathfinder (ASKAP) opened in 2012 at the Murchison Radio-astronomy Observatory.
The remote site was selected by the CSIRO because of the region’s low population density and lack of man-made radio signals.
ASKAP features 36 12m-diameter dish antennas that work together as a single instrument.
It is a pathfinder for the international Square Kilometre Array (SKA) project, which aims to answer some of the most fundamental questions asked by modern astronomy and physics.
Pioneered by the CSIRO, the technology employed by ASKAP is able to survey the whole sky with unprecedented sensitivity. However, it also produces data at terabytes-a-second speed, which is then handled by onsite custom super-computers before being sent via optical fibre to CSIRO sites in Geraldton and Perth.
Such is the amount of data created by ASKAP that it is impossible to store it all. Rather, algorithms have been created to process data “on the fly”, creating final complex – but much smaller – data “cubes”.
Yet such computer power creates its own problems, including radio frequency interference (RFI) and a heat load that makes heat rejection in the forbidding environment challenging.
So how to keep everything appropriately cool at the onsite control centre?
With a peak heat load of 390kW – the majority of which is due to computing equipment – the task of rejecting this heat while maintaining a radio-quiet environment presented challenges.
And the site’s weather conditions coupled with the requirement for a radio-quiet environment all but ruled out traditional water-cooled and air-cooled plant options.
A geoexchange system designed by Aurecon with assistance from GeoExchange Australia was ultimately the preferred option, based on the advantages it offered in terms of RFI emissions and energy efficiency.
The final system comprises 96 boreholes across a field covering 45,000 sq m, each borehole measuring 125mm in diameter and drilled to a nominal depth of 124m using equipment specially shipped out from Europe for the project.
It is thought to be Australia’s largest cooling-only geoexchange installation.