Low Temperature Thermal Desalination (LTTD)

Union Minister for Earth Sciences Jitendra Singh recently visited the Low Temperature Thermal Desalination (LTTD) plant in Kavaratti to review the functioning of desalination facilities that supply drinking water to several islands of the Lakshadweep archipelago.

The LTTD programme has been implemented by the National Institute of Ocean Technology (NIOT), an autonomous institute functioning under the Ministry of Earth Sciences. At present, desalination plants based on this technology are operational across eight islands of Lakshadweep, helping address the region’s freshwater scarcity.

The LTTD technology converts seawater into potable water by using the temperature difference between warm surface seawater and cold deep-sea water drawn from depths of about 350–400 metres. In this system, warm seawater is flash-evaporated under low pressure, and the resulting vapour is condensed using cold seawater from deep ocean layers, producing drinking water.

A key advantage of the process is that it does not require chemical additives or high-pressure membranes, making it environmentally friendly. It also avoids the discharge of concentrated brine, which can damage fragile coral reef ecosystems around the islands.

The first LTTD desalination plant in Lakshadweep was commissioned in 2005 in Kavaratti. Following its successful deployment, similar plants were gradually installed on other islands to enhance sustainable freshwater availability for local communities.

Source: PIB