Low-cost technology converting seawater into potable water launched

Water temperature differences on sea surface and depth utilised

 Upgraded prototype to have a capacity of 10 million litres a day

 Technology appropriate for use in remote areas with no fresh water

 At 3 to 6 paise a litre, can be economically viable for coastal Tamil Nadu and Andhra Pradesh

CAMP KAVARATTI (LAKSHADWEEP): Union Science and Technology Minister Kapil Sibal dedicated to the nation on Monday a new technology that promises to convert sea water into potable water at a cost of just three to six paise per litre.

Mr. Sibal inaugurated an experimental prototype for the technology here. It has a capacity of one lakh litres a day. He announced that it was proposed to upgrade the technology soon to have a plant with a capacity of 10 million litres a day. The plant produced fresh water from the sea at a cost of 22 paise per litre. By upgrading the technology to one million litres a day capacity, the cost can be scaled down drastically to just 3 to 6 paise a litre.

The technology is appropriate for immediate use in remote islands like Kavaratti, where there are no other sources of fresh water. Once it is upgraded and the cost reduced, it would become economically viable even for areas like the coastal regions of Tamil Nadu and Andhra Pradesh, where there is possibility of bringing water from elsewhere, Mr. Sibal said.

The technology works by utilising the differences in the temperature of water on the surface of the sea and that deep inside the ocean. At Kavaratti, the plant exploits the difference in the temperature of the surface water and that at a depth of 350 metres in the sea around the island. While the temperature of the surface water hovers around 30 degrees Celsius, that at the depth of 350 metres hovers around 10 degrees Celsius.