Dossier Océan et énergie - Énergie Thermique des Mers
Sommaire IOA News Letters
MORE OTEC/DOWA DEVELOPMENTS AROUND THE WORLD
A West German company can now produce a CWP pipe more than 6.5 feet in diameter, the size required for a 5.10 MWs plant. This pipe resembles the flexible plastic/metal ducting used in homes for venting laundry dryers. The CWP can be made in almost any continuous length and larger diameters. The length limit is now on how big a piece can be transported to the job site. This pipe forming process has been licensed to manufacturers in other countries, including Japan.
OTEC heat exchangers have been the major factor in the over-all cost estimate for the plant. However, new developments by GEC of Britain and the Aluminum Company of Canada have resulted in a low cost, highly efficient design. While not yet fully tested, the designers estimate that these heat exchangers will cost about 1000th less than conventional units of the same capacity.
GEC plans to test their heat exchangers at Hawaii's NELH. This laboratory is now developing the funding to build a 250-500 KWe power plant which will use the same coldwater supply that is being used for their multiproduct development at Kona. When completeed in a year or two, this will be the largest experimental OTEC plant built to date. Operational data from its operations will help in the planning and design of Taiwan's projected 5 MWe plant.
Finally, the Alsthom Group in France ( a sister company with GEC) has built and tested for a year a 7 MWe steam turbine that runs on very low pressure ammonia gas. Because of its lower temperature (compared to water) properties, ammonia will be the working fluid that will be used for closed cycle OTEC power plants.