Dossier Océan et énergie - Énergie Thermique des Mers

Sommaire IOA News Letters

Introduction of IOA

By
Michel Gauthier, Chairman of IOA
IOA Secretariat

Since the concept of Ocean Thermal Energy Conversion (OTEC) was born more than one hundred years ago, a considerable world-wide body of experience, knowledge and lessons has been accumulated to develop the processes and the technology to harness the temperature gradient that exists between the cold water of the depth and the warm water in the surface layer of the tropical seas.   Also research on other practical uses of the properties of the deep ocean water has led to many Deep Ocean Water Applications (DOWA) and to the multiple products concept.   This contributed to reinforce the OTEC/DOWA economic potential.  During the 1970s and 1980s, the USA have spent over $250 million on OTEC Research and Development.   Japan and European countries, and more recently Taiwan have also spent substantial sums.  But despite most of the results of this work was available, no structure existed to permit world-wide and permanent exchange of relevant information.  This need for the establishment of such a structure for disseminating and promoting results of OTEC and DOWA R&D instigated the birth of the International OTEC/DOWA Association (IOA).

The IOA, established in 1989, was proposed by world-wide oceanology experts, including Dr. C. Y. Li from R.O.C. Because of his vision leadership, IOA plays a very important role promoting OTEC and DOWA among its members and educating the general public and governments via the Newsletter.

Objectives of IOA

The purpose of the International OTEC Association (IOA) is to provide a means for collection, coordination and dissemination of information as well as the cooperation of all parties interested in ocean thermal energy conversion and deep ocean water application (OTEC/DOWA).  The IOA is non-political, and dedicated to the full utilization of the renewable and non-polluting resources of the ocean--the thermal difference, the nutrients, the cleanness, the coldness.

This is a professional organization consisting of those who are involved with, or interested in development of OTEC/DOWA technology and closely related activities.  The Association invites all goverment agencies, companies, research organizations, academic entities and individuals concerned with this resource to participate and to discuss issues and problems of mutual interest.

The objectives of IOA are to:

1. Exchange and integrate scientific, technical and economic information among various OTEC/DOWA working groups.
2. Address the need for the development of OTEC/DOWA resoruces and emphasize the clean energy concept as well as the multi-product outputs possible with OTEC/DOWA.
3. Unite presently dispersed efforts on the promotion development and use of OTEC/DOWA resources.
4. Coordinate and support those OTEC/DOWA projects which require international cooperation and participation.
5. Enhance the development and application of sciences and technology related to both OTEC and DOWA.
6. Inform and advise governments and their agencies about the state of the art and economic development opportunities available with OTEC/DOWA as well as the requirements necessary to ensure effective progress.
7. Keep the public informed regarding OTEC/DOWA activities.

IOA Work Mission

At the first planning meeting of the International OTEC Association, held in Taiwan from December 11-16, 1989, the participants agreed that IOA should have a permanent secretariat and a product (the newsletter).

It was accepted, with appreciation, the offer of Taiwan R.O.C. to provide the secretariat and support for the editing, production and distribution of the newsletter.

The missions of IOA include:

1. IOA will strongly advocate the utilization of a extremely large, renewable resource, the deep ocean water, which can support power generation (OTEC), fresh water production, air conditioning, mariculture and agriculture.
2. IOA will be a strong proponent of deep ocean water applications.  Newsletters and announcements of seminars, conferences and other activities highlighting deep ocean water applications should be continued with wide dissemination.
3. IOA will promote multi-national collaboration for DOWA projects, with IOA members calling upon other members for assistance and sharing of their expertise.  A unified, dedicated organization like IOA is essnetial for this purpose.
4. IOA will promote and support DOWA projects such as an OTEC plant of sufficient scale to demonstrate that OTEC is a viable technology.  Such a plant is an investment for the future, built on behalf of the generations to come, providing economic and environmental benefits.

The Activities of IOA

To meet its objectives of IOA and foster its missions, the Association supports and promotes many related activities of OTEC/DOWA.  These activities include:

(1) The Newsletter

The IOA newsletter helps keeping its readers informed about OTEC/DOWA development throughout the world and helps
promote the Association to potential members and supporters.  It is a communication link among all those interested in
OTEC/DOWA.

The IOA newsletter is a quarterly publication by the IOA Secretariat.  With funds provided by the ROC government since
1989, the IOA Secretariat has published 29 newsletters over the past six years, with mailing to over 648 individuals and
companies in 50 nations.  The worldwide distribution of the newsletter is listed inTable 1.

(2) Conferences activities

The IOA coordinates the dates of its meetings and conferences with the dates of  other internationally established
organizations whose interests are synergistic with those of IOA.   This extents the IOA's interaction and promotes broader
awareness of OTEC/DOWA as well as stimulates attendance.

The IOA Secretariat has sponsored a number of planning meetings and International conferences, highlighting deep ocean
water applications.  IOA continues to advocate DOWA through wide publicity of upcoming events.

Table 1. Worldwide Distribution of Newsletter by Country

The Potential of OTEC/DOWA

(1) OTEC

The world is at the brink of a new century in which the environment will become an increasingly global concern.   The very
concept of sustainable development depends on balancing the need for development with the preservation of our natural
resources.  A crucial task will be satisfying our energy needs in a sustainable manner, and OTEC may become an
important part of the answer.

In the 1970's, development of OTEC technologies achieved a large measure of success.  In the eighties, progress was made
in improving the economics of OTEC.  And in the coming decade, OTEC needs to be made a true alternative among array
of existing and new energy options.

OTEC is a source of energy with many advantages:

• The OTEC is  a solar renewable resource.  It is widely distributed in the intertropical belt all around the world and is
  available 24 hours a day, all year around.  The potential for OTEC installed power plants exceeds probably several
  thousands of giga Watt.

• The OTEC technology and resouce are accessible to any nations.  Small onshore plants and medium size offshore plants
  could respond to the increasing demand for decentralized electric energy supply in coastal areas for many developing
  countries while large floating plant could graze OTEC resource of the open sea to produce fuel in a form that could be
  transported. The OTEC thus could contribute to provide some energetic independence for all nations.

• The OTEC would help decreasing thermal and GH gas pollution of the atmosphere.  The OTEC answers to the Zero
  Emission requirement initiative founded by the UN University in 1994.

• The OTEC plants can by-produce freshwater. Their nutrients rich effluents may contribute to stimulate primary production
  if properly dispersed in the sorrounding marine environment.

  What is needed is a global policy to encourage the use of renewable energy resources and a strategy that provides a sense of unity and direction at the world level and a framework for its implementation.

(2) Deep Ocean water Applications (DOWA)

The Deep Ocean Water (DOW) pumped from under the thermocline layer, because it is colder than tropical ocean surface water can also be used for air conditioning, sea water desalination, and for any industrial process that requires cooling. In most cases, for such processes, the DOW would appear as a much more efficient cooling fluid than warm air or water usually available in tropical coastal regions.   But the DOW is also rich in major nutrients and elements that are essential for the photosynthesis of photoplancton. In fact this property of the DOW is observed in the regions of the ocean where the DOW naturally upwell to the surface.  Upwelling regions of the ocean are known to account for some 80-90% of global ocean new production and have been known as rich fishing grounds for centuries.. Thus DOW can stimulate the primary production processes when properly discharged in marine location exposed to high rate solar radiation.  An important issue is to develop the relevant technology and expertise to maximize biomass production without negative impact on the environment.  The DOW also is biologically clean when compared with water in the surface layer.  Because of its properties the DOW is used in commercial marine cultures to improve their efficiency and the quality of products as fish, algae and other organisms that are cultivated as a source of high added value substances.

The ultimate approach for the DOW applications is to establish a cascade of processes in which the full potential of the DOW's properties is utilized exhaustively in a multiple products system that maximize benefits.  In addition, deep ocean water has a huge reserve of regenerative, inexhaustible carbon dioxide.  These resource characteristics can be adapted to a large variety of uses.   For example, low temperature water is an ideal cooling agent for air conditioning, for desalination, and for electric power generation.  Nutrients can be used as fertilizers. Biological cleanliness is essential in cultivation media for mariculture.   To sue these various resource characteristics of deep seawater, it is necessary to develop technology for an efficient and economical extraction and utilization scheme for deep seawater.

Experimental studies of primary productivity in nutrient-rich deep ocean water confirmed that biostimulation of phytoplanktonic activity is dependent on light availability.  This productivity enhancement occurs in the natural upwelling zones of the ocean where the combination of topography, winds and currents "upwells" the deep sea water to the surface.  Natural upwelling zones have been rich fishing grounds for centuries.

In summary, bringing DOW to the surface to produce electricity via OTEC also enables using DOW to produce freshwater, grow algae and cultivate fish.  But other Deep Ocean Water Applications (DOWA) are possible:   agricultural irrigation, air-conditioning coastal cities, cooling effluents for traditional plants (such as diesel power plants), or manufacturing ice.  For future DOW research and development, a crucial factor in the practical application of deep seawater is development of a method by which the nutrient resources of deep seawater can be concentrated and utilized.  One possible approach is to utilize the biological function of organisms, an approach that is highly efficient. Since deep seawater resouces can be utilized for production of living organisms; the hope is that deep seawater will be applicable to mariculture and the production of useful substances via living organisms.   Another approach is to establish a cascade system in which the nutrient resources of deep water are recovered and utilized exhaustively in a poly-culture system.

Table 3. The related IOA conference

An important issue is the effect of the discharged, utilized deep seawater on the natural environment.  Develop technology that assures minimum negative impact of discharged seawater on the ecosystem of the pertinent sea area is needed.  Utilization of a near-coast local upwelling sea area as the site for a deep seawater utilization station seems promising.  By modeling artificial upwelling areas after natural upwelling ecosystems, it should be possible to increase primary productivity, increase biomass, and even an increase in the carrying capacity of that sea area without negative impact.  Formation of an improved fishing ground may be expected.  To accomplish this, it is important to have a good understanding of the process of natural upwelling and related ecosystem processes to develop appropriate discharge technologies like these natural phenomena.

The General Trends of IOA Policy for Future

Promote economics studies

The OTEC will become a reality when pressure on traditional power generation builds up because of changing conditions in the oil market and increasing threats of environment changes.  The OTEC demand for the coming 25 years is probably over some tens of gigaWatt.  The first OTEC market lays in the insular countries of the Tropical Pacific region.  Leading initiatives for OTEC future development will come from countries with strong and diversified economies with significant concern for environment protection and near term energy and fresh water requirements.

The IOA shall contribute to the emergence of this market by promoting global economy studies and simulation model that permit a fair intercomparison of both the financial and social costs and benefits of OTEC and traditional energy sources.

Promote oceanographic research

Release of large quantity of DOW at the ocean surface will perturbate the local ecosystem surrounding the plant.  The perturbation does not appear to be a threat to the marine environment in the early stage of OTEC development.   For small OTEC plants built during this early stage,  the volume of the water discharged will induce negligible variation of parameters that probably could not be detected from natural seasonal variations. In the long term, it is acknowledged that not enough information is available to assess the overall impact of numerous large OTEC plants on the overall ecosystem.   The designers of an OTEC plant will have to carefully consider the site's geographic and oceanographic specific conditions to minimize its negative impacts and maximize its positive effects.

We shall contribute to develop and foster the necessary expertise by encouraging scientific research on relevant marine processes and marine ecosystem numerical modeling.

Promote OTEC/DOWA enterprises

It is difficult to anitcipate what is the best platform design for large OTEC floating plants since there are alternate solutions.  For example, the spare buoys moored platform made of light weight stressed concrete seems favored.  The same material could be considered as a candidate for the cold water pipe.  Serious consideration is recommended for the soft pipe and deep submerged pumps design.  Other uncertainties remain for mooring, power transmission, and heat exchanger components but these are not considered as fundamental technology gaps or major obstacles for the construction of OTEC power plants in the hundreds of MW size.

Experts suggest that establishing a pilot of a floating plant is the first step to promoting OTEC.  They favor a floating plant because it reduces the cost since no land needs to be purchased.  It can be constructed in an industrialized region and transported on the site for exploitation.  Also all the piping --  and especially the cold water's -- for a floating plant will be shorter than for on shore plant, and will not suffer the beaching constraints.  Large grazing OTEC plants could produce power at sea and convert it in a transportable fuel for shipment to land.  Most important is the open sea grazing plants offer to all nations the free access to the inexhaustible OTEC resource.

Onshore sittings better match the requirements for small OTEC plants associated with the multiple products concept.  The multiple products concept can be developed extensively together with activities related with education, tourism and health care.  Such fostering of activities in a Marine Park that responds to a well targeted local demand would contribute to the economy of the Marine Park enterprise while at the same time promoting OTEC/DOWA among public.  The equipment for a land based OTEC plant can also be built and assembled on a floating platform in an appropriate shipyard and then transported and sunk on site.

We shall promote the development of large OTEC floating plants as a long term ultimate objective and also the construction of DOWA multiple products on shore plants since their global benefits could be demonstrated in shorter term.

IOA contribution to the concept of a Sustainable Civilization

Historians agree to date the emergence of the market economy in Europe at the end of the 18^th century.  It contributed to the establishment of the modern capitalist system.  The profit oriented forces that run the system have demonstrated their tremendous efficiency to stimulate scientific and technical progresses and there are evidences that the past one hundred years have been an era of huge growth of the global world wealth and of a tremendous increase in the quantity and in the diversity of products and services offered to human consumption.  Modern technologies also contributed to quicker and easier exchanges of the products.  Today factories are established and markets are targeted anywhere to maximized the return of financial investment.  The whole world is open to industrial activities and to markets conquests and our master words in economy are efficiency, competition and globalization.

But historians also tell that the industrial era has been a period of tremendous growth of the world population. During the past century the population has been multiplied by 5 and we are almost 6 billion of human beings at the end of the 1990's.  In the late 1960's the Club de Rome's voice first questioned on the limits of this development. Since, with the report our common future in 1987,and more recently at the 1992 Rio de Janeiro conference, the United Nations fully acknowledge the difficulty to ensure a sustainable resource basis for future.

This difficulty can be demonstrated in the sectors of food and energy production, two sectors which are essential to development.  Because of the growth in population and the increase of industrial activities, and also because industrial development draw more and more people to live in big cities, the world energy consumption is predicted to jump from present value of 9 billion tones of oil equivalent to more than 13 billion tones in 2020.  Because there is still a considerable social resistance caused by the threat of nuclear major accidents and also questions concerning the management of nuclear waste, this energy demand will be mainly satisfied by burning oil and gas. Experts estimate oil and gas natural reserves are sufficient to satisfy that demand but this solution is obviously in contradiction with long term issues as it causes natural resources depletion and increase thermal and GH gas pollution that would create global changes of our ecosystem, with still impredictable consequences.  For the food sector the situation is worst.  In recent report, it is shown that the limits of food production from land and marine resources have been reached.  Deforestation to gain new agricultural lands and intensive use of fertilizer have disastrous consequence on environment.  Irrigation has to face the drying up of fresh water resource and fisheries suffer stocks depletion.  Unless still unforeseen new discoveries would permit a drastic increase of the yields the lack of food and fresh water might be the source of major conflicts and the main threat for peacc in future.

At this turn of the century it is thus widely acknowledge that the type of industrial development that led to what it was sometime referred in Europe as the Civilization of Consumers has severe drawbacks and evil effects.  Its profit oriented mechanisms that do not bear any moral or ethic vision of the future, naturally inclines to favor small risks investments and short term returns and thus tend to over-exploit natural resources until complete exhaustion. The system also demonstrated it was unable to neither self generate environment-conscious technologies nor to cure social decease as poverty, intolerance, racism and violence. The system, with the present situation of the world population and its predicted growth, shall not give to all human beings the right to live in a society that offers them a reasonable possibility to ameliorate the quality of their life and to perpetuate that possibility to their descendants.  Our modern industrial system - as a civilization model - will have no future if we do not respect that simple human right and if we cannot agree universally on few basic principles to transform it in a modern sustainable civilization.

The IOA by editing the newsletter, organizing conferences and acting to promote the benefits of exploiting OTEC/DOWA might modestly contribute to that transformation.