India is advancing a bold coastal energy project on Kavaratti, in the Lakshadweep archipelago, where engineers are building a plant that taps the temperature gap between warm surface water and cold deep seawater to generate power around the clock.
According to the National Institute of Ocean Technology (NIOT), the system will pull water from nearly 1,000 meters below the surface and use that thermal contrast to produce 65 kilowatts of electricity while also creating about 100,000 liters of fresh water each day.
How the system works
The approach is known as ocean thermal energy conversion, or OTEC. Unlike solar and wind, it relies on a natural temperature gradient that remains available day and night. In Kavaratti, the project uses an open-cycle design: warm seawater is placed under vacuum so it boils at a lower temperature, the vapor spins a turbine, and cold deep water condenses it again. That process also yields desalinated water.
OTEC has attracted scientific interest for decades because it can combine electricity, water production, and cooling in one platform. A 2025 review estimated its theoretical global potential at 8 to 10 terawatts and highlighted three promising directions: improved thermodynamic cycles, hybrid systems, and valuable byproducts such as fresh water, cooling, and hydrogen.
For islands and remote communities, the value proposition is especially strong. The goal is not simply to compete with large mainland renewables, but to reduce dependence on imported fuel and support local infrastructure. NIOT says the Lakshadweep project could help power desalination without relying on the diesel-based island grid.
OTEC still faces major engineering demands, especially in moving huge volumes of seawater and building durable deep-ocean pipes. Even so, new offshore prototypes and island-scale deployments are helping the technology move from concept toward practical use.
If successful, this model could open a new chapter for coastal energy systems, where clean power and water security grow together in the decades ahead.
