www. refrigerationandaircon. co. za RACA Journal I September 2025 1
RACA Journal: ISSN 1812-772X
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RACA Journal Publication www. refrigerationandaircon. co. za eamonn @ interactmedia. co. za
WHY CIRCULAR WATER SOLUTIONS ARE KEY TO SUSTAINABLE DATA CENTRES
The feature in this issue is data centres. RACA Journal is having more and more of a focus on data centres and artificial intelligence- given its importance as a cooling market and to life in general. There is also a growing anxiety around how much power and water they consume.
These vast facilities are the hidden powerhouses that store and process the immense volumes of information fuelling our modern world, from social media browsing and streaming services to complex artificial intelligence( AI) models and bitcoin mining. However, the indispensable nature of data centre operations comes with a significant environmental footprint, particularly concerning materials, energy, and most notably, water usage.
According to a report by the World Economic Forum 1, even a relatively small 1MW data centre can consume up to 25.5 million litres of water annually just for cooling. This staggering figure is equivalent to the daily water consumption of approximately 300 000 people, exacerbating water stress in vulnerable regions already grappling with shortages. The rapid proliferation of AI further intensifies this challenge; for instance, the AI model GPT-4 is estimated to consume 500 ml of water for every 10-50 responses. When multiplied by billions of users, the total water footprint of AI becomes enormous.
Despite its critical environmental impact, water consumption in data centres remains an often-overlooked aspect compared to carbon emissions. This oversight highlights a crucial opportunity for scaling strategic circular water management solutions, such as water replenishment and optimisation.
Data centres primarily consume water for cooling through chillers, cooling towers and increasingly, liquid cooling systems. Indirectly, they also consume substantial amounts of water through the electricity generation processes that power them, which often involve water-intensive methods like steam production in thermoelectric power plants. Annually, a medium-sized 15MW data centre can consume as much water as three average-sized hospitals or more than two 18-hole golf courses.
A significant reason for this high water consumption is the limited reuse of water in cooling processes. As freshwater evaporates during cooling, the remaining water becomes wastewater, often contaminated with dust, chemicals and minerals. These contaminants reduce cooling efficiency if recirculated, leading operators to frequently discharge wastewater rather than treating and reusing it to its maximum capacity.
The escalating demand for digitalisation and AI-enabled services continues to drive computational power and energy consumption. By 2027, global AI demand alone is projected to account for 4.2 to 6.6 billion cubic metres of water withdrawal, a volume four to six times greater than Denmark ' s total annual water withdrawal- or approximately onefifth to one-third of South Africa ' s total annual water withdrawal.
Despite cooling dictating water consumption in data centres, water conservation often remains a low priority. Less than a third of data centre operators actively track water usage metrics. This lack of transparency and measurement severely undermines efforts to understand the full
environmental impact of data centre operations, especially in water-stressed regions, says the report.
While Water Usage Effectiveness( WUE) was introduced as a metric for water consumption efficiency, similar to Power Usage Effectiveness( PUE) for energy, it only accounts for on-site water use. This metric fails to capture the substantial indirect water consumption associated with electricity generation. By focusing solely on direct usage, operators miss a significant portion of their true water footprint, highlighting the urgent need for more comprehensive metrics that include both direct and indirect water use.
The issue of water usage in data centres extends beyond a technical challenge; it is an urgent environmental and societal concern. The socio-economic well-being of regions is imperilled when data centres increase their reliance on scarce water resources. For example, farmers may face lower crop yields due to water scarcity and rising water prices, sometimes leading to social unrest.
While the growth of data centres is not expected to slow, advancements in technology offer a hopeful outlook. Data centre operators are increasingly recognising water consumption as a critical challenge and are setting ambitious water-positive targets, integrating water management as a core consideration in their operations. This proactive approach helps mitigate environmental impacts and supports long-term operational efficiency.
To further address these broader environmental and societal impacts, operators can adopt innovative circular water solutions. These strategies involve reusing and recycling water to create sustainable and efficient water management systems. Practices such as closed-loop cooling systems, wastewater recycling and rainwater harvesting have already demonstrated significant reductions in freshwater use, with potential savings of 50-70 % where implemented.
The integration of circular water management principles is a critical step towards ensuring data centres can continue to support the next wave of technological advancements in a world where water resources are increasingly strained. RACA
REFERENCE:
1. https:// www. weforum. org / stories / 2024 / 11 / circular-water-solutionssustainable-data-centres /
Eamonn
www. refrigerationandaircon. co. za RACA Journal I September 2025 1