We enjoyed reading recently about an innovation developed by CSIRO to sustainably cool their supercomputers.
Groundwater cooling (GWC) describes a cooling technique whereby the excess heat generated from buildings, machinery or equipment is injected into underground stores of cool water. This innovative technology has now been adopted by CSIRO as a cooling solution at the Pawsey Centre in Perth – the largest supercomputer in the southern hemisphere.
Water of different temperatures can be extracted from underground layers of rock formations known as aquifers, and used for various thermal purposes. While the harnessing of geothermal energy from deeper high-temperature aquifers is a well-known procedure, cooler underground water found closer to the surface can also provide a useful thermal sink. CSIRO’s groundwater cooling system involves pumping cool water from a shallow aquifer beneath the Australian Resources Research Centre (ARRC) in Kensington, Perth, through an above-ground heat exchanger to cool the supercomputer, before reinjecting the water underground again.
Not only will the system save up to 14.5 million litres of water in its first two years, but the cost is significantly lower than conventional cooling systems that use a large amount of electricity. It is envisaged that soon this concept will also be implemented in large buildings such as hospitals and industrial operations. This geothermal cooling method is also much more environmentally sustainable and helps to ensure a low carbon footprint for the future.
This concept is still relatively new, and therefore the experienced research team at CSIRO are continuously monitoring the system to find ways to make it even more effective. Constant monitoring of pH levels, temperature changes and water flow are conducted to understand the system and how it can be improved.One of the key challenges for the system is ensuring that the warmed water injected does not significantly impact on the aquifer or neighbouring environments. Well separation distance, flow rate and temperature difference are key design parameters for groundwater cooling schemes, as is an understanding of the aquifer biogeochemistry and nearby users of the aquifer.
Photo Courtesy of CSIRO