As the world’s digital appetite grows, so does its energy bill. Data centres — the backbone of streaming, e-commerce, artificial intelligence, and cloud services— already consume around 1–1.13% of global electricity and are projected to use far more in the coming years. Nearly 40% of this power goes into cooling the massive server farms, making energy-efficient alternatives critical.
A new study from the Indian Institute of Technology (IIT) Bombay, led by Professor Gurubalan Annadurai, Dr. Kashish Kumar and Moin Ali Syed, a former IIT Bombay student has unveiled a promising solution: Deep Seawater Cooling (DSWC). The research proposes a systematic framework for assessing the feasibility of using cold water from deep ocean layers to cool energy-intensive data centres — a method that could cut energy consumption by up to 79% and achieve payback in just eight months.
“In deep seawater cooling systems, cold water from deep ocean layers is transported through long pipelines to land-based facilities,” explains Dr. Kumar, the study’s lead author. “Our framework enables systematic calculations of resource needs and payback periods, helping businesses evaluate viability before investing,” he added.
How the system works
Using the Sister Islands in the Andaman and Nicobar Islands as a prototype location, the researchers analysed oceanographic data to locate deep, cold water ideal for cooling. They identified a depth of 2,770 meters, where seawater maintains a stable temperature of 18°C year-round, ideal for consistent performance.
A pipeline of approximately 2.78 km would transport the water to land. To optimise efficiency, the team recommended High-Density Polyethylene (HDPE) pipes for their strength, durability, and resistance to marine conditions like salinity, high pressure, and biofouling.
The study also developed a segmented insulation strategy, tailoring the thickness of insulation for different pipeline sections based on surrounding temperatures, preventing heat gain and reducing costs.
Efficiency, savings, and sustainability
Testing the system on a hypothetical 100 MW data centre, the study found that DSWC could reduce annual energy use by 79% compared to traditional air-based chillers. The method would also cut carbon emissions by the same margin, making it an environmentally friendly alternative.
Assuming an average electricity cost of $0.0851 per kWh and 24×7 operation, the estimated payback period is just eight months, even when accounting for maintenance and capital investments like pipelines, heat exchangers, and air ducting.
However, the researchers caution that DSWC works best in coastal regions, specifically islands with easy access to deep, cold seawater. For inland locations or sites far from suitable ocean depths, installation costs could rise significantly.
Beyond data centres
While the study focuses on data centres, its methodology can be applied across sectors. “Potential beneficiaries include hospital complexes, industrial processing units, desalination plants, and residential or commercial buildings in tropical coastal cities,” Dr. Kumar said.
The researchers also highlight the importance of international cooperation and policy support to scale technology globally. Island nations and developing countries, they argue, stand to benefit the most from reduced energy dependency and greener infrastructure.
By tapping into the naturally cold reservoirs of the deep ocean, IIT Bombay’s research framework provides a roadmap to sustainable cooling at a scale, cutting emissions while supporting the world’s rapidly expanding digital economy.
The researchers said that developing nations may benefit immensely, particularly island nations and countries with immense coastal regions like India. But success will depend on collaboration, technology transfer, and green financing.
Published – August 25, 2025 11:16 am IST
