Data Centre PUE in general is lowered through immersion cooling since components are fully immersed into a dielectric fluid that conducts heat and does not conduct electricity, therefore, the heat of all IT components is fully removed by liquid, which increases the power usage efficiency (PUE) of the data centre. PUE as a number reduces but efficiency increases.
In air-cooled facilities, the heat rejected by servers is dissipated through cooling towers, consuming a substantial amount of water. To put this into perspective, a 20-megawatt facility can consume up to 480,000 gallons of water per day, equivalent to 24 swimming pools. In 2022, Google shared its commitment to climate-conscious data centre cooling with the release of its water consumption statistics from the prior year. In 2021, Google's data centres consumed approximately 4.3 billion gallons of water. On average, a Google data centre consumes 450,000 gallons of water a day. While calculating the average global WUE for data centres is challenging due to a lack of published data, estimates suggest that the median WUE is around 1.3 litres per kilowatt-hour (kWh). In contrast, immersion cooling significantly reduces water consumption. The heat absorbed by the dielectric fluid can be efficiently dissipated using a heat exchanger, which often employs a closed-loop system. This method consumes substantially less water and can utilise non-potable water sources, thereby minimising the strain on freshwater resources.
Data Centres leave a significant carbon footprint and, as the need for these mission critical facilities continues to surge, the current trajectory is toward increasing power use and greenhouse gas emissions. Greenhouse gas emissions can contribute to extreme weather and put the health of our planet at risk. There is growing demand from both the public and industry to reduce the environmental impact of all businesses. Sustainability has moved into the corporate domain due to ESG regulations and the cost implications of reducing a carbon footprint. With these economic and political pressures driving Data Centres to seek alternative approaches to conventional facility design, owners and operators are turning to liquid immersion cooling to reduce power use and drive sustainability efforts.
Immersion cooling provides a method of capturing up to 100% of the heat from submersed IT components and equipment which in turn provides a creative scenario when considering how best to repurpose that energy. There are many different ways that waste heat can be repurposed to provide cheaper energy, reduce costs and meet your sustainability goals (ESG). The most obvious use case would be to repurpose the waste energy to heat buildings; however, in warmer climates, it could be smarter to look at heat to cold use cases, growing crops or desalination of water.
