IIT-B researchers assess feasibility of DSWC systems for cooling data centres

Mumbai, Aug 22 (PTI) Amid rapid expansion of data centres driven by growing demand for digital services, researchers at the Indian Institute of Technology (IIT) Bombay on Friday said they have come up with a new methodology to assess the feasibility of Deep Seawater Cooling (DSWC) systems.

Researchers from IIT Bombay, under the guidance of Prof Gurubalan Annadurai, have unveiled a comprehensive methodology to assess the feasibility of DSWC systems, presenting an alternative to conventional, energy-intensive cooling methods.

"As the planet warms and our digital footprint expands, finding energy-efficient and sustainable cooling solutions is a critical necessity. In DSWC systems, cold water from deep ocean layers is transported through long pipelines to land-based facilities," said Dr Kashish Kumar, a postdoctoral fellow at IIT Bombay and the lead author of the study.

The new study presents a framework that enables the precise calculation of the resources required and the payback period on investments, while implementing a DSWC system based on the prescribed methodology.

According to the International Energy Agency, data centres accounted for approximately 1-1.13 per cent of global electricity consumption in 2022, a figure projected to rise significantly in the coming years, the report stated.

Cooling these server-packed facilities is a significant part of this energy burden, often consuming up to 40 per cent of a data centre's total energy use.

This demand is expected to more than double by 2030, primarily driven by the expansion of Artificial Intelligence.

While the depths of the ocean offer easy solution to our cooling needs, transporting large amounts of water over long distances, while maintaining its temperature and rate of flow, can be cost-intensive to both install and operate.

"As the cold water travels through warmer upper ocean layers, it can absorb heat and become less effective for cooling. Each segment (of pipeline) is also exposed to harsh marine conditions, including salinity, high pressure, and biological activity (biofouling)," said Dr Kumar while explaining the challenges of using DSWC.

In tropical oceanic regions, particularly around the equator and extending into low latitudes such as the Andaman and Nicobar Islands, seasonal variations in seawater temperature, especially at depths beyond 100 metres, are minimal, she explained.

"This consistent deep-sea temperature ensures that the DSWC system delivers reliable cooling performance throughout the year, without requiring seasonal modifications or recalibrations," Dr Kumar added.

Researchers found that when applied to a data centre with a 100 MW cooling load in a tropical region like the Andaman and Nicobar Islands, a DSWC system could achieve an impressive annual energy saving of 79 per cent.

The approach promises substantial environmental benefits, including over 79 per cent annual reduction in carbon dioxide emissions, the study revealed.

However, the researchers acknowledge certain limitations, as their study relies on some simplifying assumptions, such as fixed supply air temperature and heat exchanger performance based on standard guidelines, which might vary in real-world scenarios.

The system also performs economically and operationally better in coastal regions with easy access to deep ocean cold water.

Nevertheless, the framework developed allows for investors to carefully assess the economic and technical feasibility of switching from conventional to DSWC systems.

By harnessing the naturally cold temperatures of the deep ocean, DSWC systems can alleviate strain on electrical grids, lower operational costs for businesses, and contribute substantially to reducing greenhouse gas emissions, Dr Kumar said.

"Developing nations may benefit immensely, particularly island nations and coastal regions. However, international cooperation, technology transfer, and targeted policy support (green finance or infrastructure subsidies) are essential for scalability," Dr Kumar added. PTI SM ARU