In an Expert focus article for WaterBriefing, Lee Brock water and utilities sector director at Pell Frischmann, takes a look at how five impactful ways data centres can reduce their water consumption.
The recent report by Global Action Plan lays bare the impact of how the expansion of data centres in the UK could threaten resources and increase water scarcity. Global AI water demand is predicted to exceed the water use of all UK households by next year, and with a typical small one-megawatt data centre that uses traditional cooling methods expected to consume more than 26 million litres of water each year – enough to supply over 200 UK homes – solutions clearly need to be found to address such issues.
This is especially important as, according to the Global Action Plan report, the Environment Agency is not currently factoring the rapidly expanding data centre sector into its risk planning, which already models a water supply shortfall of around five billion litres per day by 2055 without new investment.
Furthermore, the increasing regularity of heatwaves will put extra pressure on water supplies. This has already been flagged as an issue in the US, where heatwaves are straining water systems at a time when the US is building thousands of new data centres to support demand for AI.
It means that to reduce cut consumption and protect water supplies for local communities, innovative water management initiatives – from optimisation to replenishment initiatives – will be required in the UK. Some of the most impactful steps that can be taken to reduce the water consumption of data centres are:
1. Using alternative water sources. Data centres can use rainwater for cooling instead of potable water. Rainwater harvesting can be achieved through installing collection systems, such as blue roofs, allowing data centres to capture natural precipitation for use in cooling towers. Another option is to locate a data centre close to a sewage treatment facility, where there may be the opportunity to directly utilise the final effluent, treated wastewater emanating from the sewage works. Such ‘closed-loop’ cooling systems, involving wastewater recycling or rainwater harvesting, have demonstrated water savings of 50 to 70 per cent.
2. Utlilise smart water management systems. These systems track and adjust consumption according to cooling demand through the use of real-time sensors, enabling predictive modelling and delivering up to 25 per cent less water consumption using algorithms that pre-empt and adjust water-based cooling.
3. Adopt liquid immersion technologies. With smart water systems in place, data centres are able to employ more advanced cooling systems, such as liquid immersion cooling. Liquid immersion cooling involves submerging electronic components, such as servers or central processing units (CPUs), in a non-conductive liquid that efficiently absorbs their heat and transfers it to a heat exchanger. This can reduce water consumption by up to 91 per cent.
4. Employ direct to chip cooling. Smart water systems also allow one of the newest innovations in the field – direct to chip cooling systems – to be introduced. By circulating dielectric coolant across the processor’s cold plate, heat is absorbed directly, maintaining optimal processor temperature and thereby minimizing overheating and excessive water consumption in the cooling process. Direct to chip cooling has been calculated to decrease water consumption by between 20 and 90 per cent.
5. Consider geothermal or water-side free cooling. This is a highly sustainable, energy-efficient method of lowering temperatures in data centres by using the natural, stable coolness of the earth or natural water bodies (such as lakes, oceans or rivers) instead of relying on energy-intensive mechanical refrigeration. Water is drawn from deep, cold sections of oceans, rivers or lakes and passed through a heat exchanger to absorb heat from the building. Studies show it can reduce water usage by 80 to 90 per cent.
There is a critical need for action, and in my view there needs to be an alignment between data centre expansion and water utility capital investment programs through integrated spatial planning, joint funding models and mandatory demand forecasting as currently this is not happening.
With the world increasingly using AI in a multitude of ways, the expansion of data centres is not going to slow down in the short and medium term at the very least. It means we all need to come together to focus on introducing innovative management systems, to ensure that the water keeps flowing for everyone.
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Lee Brockis water and utilities sector director at Pell Frischmann