The main forms of ocean energy are wave, thermal energy and ocean currents. India being a tropical country a constant difference in temperature is available between surface water and the deep ocean. This gradient can be used to generate power and fresh water simultaneously. Using this method desalination has been very successfully implemented in the Kavaratti Island at Lakshadweep as also demonstrated on a barge moored in 1000m water depth and in a power plant using the condenser reject water. Now a floating offshore plant of larger capacity has to be attempted to serve coastal mainland water requirements. To this end industry participation has already been sought and the steps towards implementing the first phase, that of design, have been commenced. Parallel work is in progress towards harnessing power from ocean currents, increasing efficiency of power modules for harnessing wave energy and developing turbines for power from thermal gradients.

The acute shortage of power and water faced by the country, demands extensive studies in these areas.

Research on solar desalination has reached a stage where demonstration plants are established in selective localities.

a) Objectives:

1. Implementation of large scale floating desalination plant
2. Generating fresh water using the Low temperature thermal desalination technology by utilizing the waste heat at North Chennai Thermal power plant
3. Development of turbines toward OTEC / Wave energy to run LTTD plants or run small loads or increase efficiency of wave energy plants
4. Theoretical and experimental studies on components like heat exchangers for desalination and energy conversion
5. To install a floating wave powered device to power loads or to meet the lighting requirements of small islands
6. Generation of theoretical, experimental and field data for optimization of components and suitable adoption towards commercialization of extraction of renewable energies and fresh water including solar desalination.
7. Selection of working fluids, turbines, power plant components and experimental studies related with thermal gradients.
8. Develop hydro-kinetic ocean current turbines and wave turbines to suit for power generation along Indian coasts
9. Design and performance study of heat exchangers, turbines including Analytical modeling, numerical modeling, experimental comparison etc.
10. Design, Development and installation and commissioning of an improved power plant desalination technology in a coastal power plant for meeting the industrial and drinking water requirements
11. Develop techno-economical solar desalination units for commercial implementation in coastal and rural areas of the country.

b) Participating Institutions:

National Institute of Ocean Technology, Chennai

c) Implementation Plans:Selection of working fluids, turbines, power plant components and experimental studies related with it.Implementation Plans:

1. Selection of working fluids, turbines, power plant components and experimental studies related with it.
2. Develop hydro-kinetic ocean current turbines to suit for power generation along Indian coast
3. Design and performance study of heat exchangers, turbines including Analytical modeling, numerical modeling, experimental comparison etc.
4. Design, Development and installation and commissioning of an improved power plant desalination technology in a coastal power plant for meeting the industrial and drinking water requirements.
5. Develop techno-economical solar desalination units for commercial implementation in coastal and rural areas of the country.
6. Material Studies for cold water pipe for desalination
7. The implementation, commissioning and operation and maintenance of the large scale floating desalination plant will be taken up in the XII Plan.

The prototypes of power modules for harnessing wave energy and developing turbines for power from thermal gradients will be designed and implemented in the field in the upcoming plan period.

After testing of scaled models, it would be a significant achievement to power the desalination plants using the power generated by these renewable ocean energies.

The programs will be implemented by NIOT availing scientific and technical manpower in regular as well as project mode. Wherever required, it is proposed to work in collaboration with academic institutes, research and development organizations.

The large scale floating desalination plant will be realized through partnership with industries and international organizations. Programs like solar desalination plants etc will be implemented with help of the local communities and authorities. Projects will be monitored as per the NIOT procedures.

Infrastructure facilities / Lab requirements

NIOT has gained a lot of experience in desalination due to several successes. However, for large scale production and commercialization, more optimization is required in the components related to the thermal cycle and vacuum systems. While the present campus does have a small laboratory, continuous data collection is not possible, since continuous flow of sea water is not possible. Locating the laboratory right at the sea shore will have the advantage of continuous flow of water. Thus the facility could house a desalination research laboratory drawing sea water continuously for long duration experiments on heat transfer, fouling, coatings for marine applications, development and performance of newer materials for heat exchangers, etc.

Research will be carried out on hybrid systems of wind / wave / solar energy. A wind turbine in a platform in the water can be installed, which could supply power to the seafront facility itself.

d) Deliverables:

1. Large scale Floating desalination plant
2. Floating wave powered device to power small loads or to meet the lighting requirements of small islands.
3. Current Turbines and wave turbines for power generation

e) Budget requirement : 365 crores.

(Rs. In crores)