CHENNAI: Chennai-based National Institute of Ocean Technology (NIOT) is setting up the world’s first self-powered desalination plant using the technology of ocean thermal energy conversion (OTEC) in Kavaratti Island in Lakshadweep. Union Science and Technology Minister Harsh Vardhan laid the foundation stone for the project on Monday.
The OTEC is a method to generate power from the difference in temperatures between the surface and the deep sea. As we go deeper and deeper into the sea, the temperature becomes colder. In tropical countries such as India, the temperature gradient is more or less constant through the year, thus ensuring constant power generation potential.
The process involves vaporizing a low boiling point fluid like ammonia or water under vacuum using the surface warm sea water and condensing the vapour thus generated using deep-sea cold water. The vapour generated drives a turbine which is connected to a generator, thus generating power. This cycle can be continuously operated leading to a constant power generation. This process is a green technology and fully renewable.
Purnima Jalihal, Head (Energy and Fresh Water Group), NIOT, told Express that Kavaratti plant, which has a capacity to produce one lakh litre of fresh portable water, would be the world’s first prototype of the OTEC-powered desalination plant and would pave the way for future larger scaled-up plants.
“The main advantage of OTEC is that it is completely environment-friendly. NIOT installed low-temperature thermal desalination (LTTD) plants in Kavaratti in 2005 and subsequently in the Agatti and Minicoy Islands. The pumps used in these plants are run using the diesel generator grid on the islands. Transportation of diesel is difficult especially during monsoon. It is also better if we adopt clean and green energy sources for the delicate ecosystem of the islands,” she said.
NIOT officials say there are many challenges to this project since it is being carried out for the first time ever. The success of Kavaratti project will determine the proposed off-shore 10-MLD plant in Chennai.
“A deep-sea site that is 40 km from the Ennore coast has been finalised. NIOT has already submitted a detailed project report (DPR), which is likely to be considered by the Union government under Rs 7,000-crore deep sea mission scheduled to be launched shortly,” NIOT sources said.