About India OTEC

Stressing the importance of earth-friendly natural energy, Indian government has been vigorously tackling on, for example, utilization of wind power. The total capacity of their wind power generation as of today amounts to 940 MW, while here in Japan it is a meager 18 MW. Ocean energy is their next target resources for renewable energy. They put strong emphasis particularly on power generation by both OTEC technology and wave power technology. NIOT (abbr. National Institute of Ocean Technology, India ), the central organization in that country in charge of technical development of ocean energy, has long been pursuing roads for commercial application of the before-said two variations of ocean energy. As to the wave power technology is concerned, NIOT had first contacted our Prof. Setoguchi of Science & Engineering Dept. for his invention and currently they are conducting various experiments in Indian waters. In the meantime, their strenuous effort to make OTEC technology applicable for commercial operation is also striking. As we know, OTEC should generate most clean and renewable energy from seawater, which is available so abundant in the form of both quality and quantity. NIOT has predicted, as depicted in the drawing, some 1.5 x 10⁶km² of their coast lines should be technically good for total generation of 180,000 MW. They have decided to carry out experimental power generation off Indian coast and the specifications for the prototype experimental OTEC plant has been worked out (as introduced later). Seeking technical consultations, NIOT contacted us for our intellectual assets in this field. The intensive talks between the two parties since then had consequently lead to the signing of the 1997 agreement of technical collaboration. NIOT plans to, if things would turn positive as planned, construct some 1,000 OTEC power plants throughout Indian coast lines, according to their grand design.

■ Plan of the experimental OTEC plant

The said technical collaboration agreement cites a period of 3 years for the tests. Basic design, detailed design, procurement of materials from various sources, installation works on-board, test running and then finally they would commence experimental operation of the OTEC plant with the mode of Rankine Cycle. After careful evaluation of this experimental works, they are going to carry out the second round testing , this time with our Uehara Cycle. The experimental OTEC plant installed on-board a ship would be towed away to the testing site some 35km off Tiruchendur coast in south-east India. Conceptual drawing by NIOT of this plant is as per the attached.

■ Specification of the experimental OTEC plant A part of the specification as of Dec. 1999 is as shown in the following table.

Warm seawater temp.	29℃	Boiling point	23.9℃
Cold seawater temp.	7℃	Dew point	14.1℃
Pipe length of cold seawater pipe	1000m	Total heat transfer area of evaporator	3924m²
Inner diameter of cold seawater pipe	0.88m	Total heat transfer area of condenser	3610m²
Gross output capacity	1MW	No. of plate, evaporator	872
Net output capacity	493kW	No. of plate, condenser	900
Warm seawater pump	192kW	Warm seawater flow rate	7560t/h
Cold seawater pump	297kW	Cold seawater flow rate	5364t/h
Working fluid pump	18kW	Evaluation function	15.3m²/kW

1MW OTEC power plant, an experiment by Indian government

■ Feasibility in India of power generation by OTEC technology

■ Plan of the experimental OTEC plant

■ Specification of the experimental OTEC plant A part of the specification as of Dec. 1999 is as shown in the following table.

■ Photos of "Sagar Shakthi", the boat on which the OTEC plant is installed.