Dossier Océan et énergie - Énergie Thermique des Mers

Sommaire IOA News Letters

NEW WAYS ON DEEP SEA-WATER APPLICATION FOR ENERGY CONSERVATION

by
Bino Fortuin, Tebodin; and
Peter Kortekaas and Charles Vos, Delta Marine Consultants bv
The Netherlands

It is well known that in tropical areas energy can be generated through the use of the temperature difference between the surface of the ocean and the ocean water at greater depths.  However, the present energy cost level does not allow the application of the OTEC energy conversion principle.

On the other hand, it can be extremely advantageous to pump water from the deep ocean, from a depth of 300 to 500 meter, in order to make use of this cold sea water, having a temperature of 8 to 13¢XC in the Carribean, for improving the efficiency of the following energy conversion processes:

    -  Electricity generation in thermal power plants
    -  Water production in sea-water distillation plants
    -  Production of cold in refrigeration and air conditioning units.

Through a number of calculations carried out on representative cases for islands in the Carribean area, it was found that under favourable conditions with respect to the coastal slope, substantial fuel savings may result from the deep sea-water pipeline.  The low cooling water temperature reduces the specific fuel consumption in existing thermal power plants by up to 5%, whereas the specific potable water output of a sea-water distilling plant may increase by up to 30%.  When also other, spin-off, projects can be included, like refrigeration and e.g. salmon and lobster breeding, the economic prospects of a deep ocean pipeline construction can be quite interesting.  This advantage is, of course, fully realised in the case of newly designed plants, where also a large capital saving as a result of the more economically operating equipment can be effectuated.

The paper will conclude with a summary of our views for implementation within national and international mechanisms.