Dossier Océan et énergie - Énergie Thermique des Mers
Sommaire IOA News Letters
First IOA conference, brighton, UK,8-10 March, 1994
Don E. Lennard*
Ocean Thermal Energy Conversion Systems Ltd.
Technology as "one of the last great bargains". OI'94 was certainly that with over 400 exhibitors, nearly 5,000 delegates and many more visitors to the Exhibition. There was no doubt at all that the first IOA conference was a significant reason for the total number of attending conference delegates, with many of these being from the Pacific/Far East-an area which has not been fully represented at previous OI events.
As far as IOA is concerned, when has an organization had its first international conference made up of a full three-day set of papers, nearly all of a very high standard, and truly international? virtually every country which has been involved in OTEC and DOWA developments had a paper accepted by the Conference Committee. It was very clear that in selecting from the very large number of papers submitted for critical review, the Committee made an excellent choice. Indeed, based on this event, the scene is very well set for the future of IOA conference. The logic of co-locating the IOA event with another major Exhibition and Conference was shown to have very great benefits. Throughout the conference, there were two OI sessions running in parallel to the IOA event, and for many of us the topics being covered there had very relevant interests. For example Utilization and Sustainable Development of Ocean Resources, or Monitoring the Global Ocean are just two examples where cross-fertilization was very valuable. The same can be said in terms of the Exhibition. Many of the exhibitors were displaying services and equipment which would have relevance to OTEC/DOWA developments - although with the exception of the IOA's own stand, there were no examples of full-scale OTEC/DOWA designs on show. Nevertheless, this writer believes that there is much to be said for cooperation with erelevant other organizaions, and I hope that the IOA Governing Board may consider this option also for the future.
This report covers just the conference of the IOA the General Meeting in the afternoon of 9 March, and the Open Forum in the afternoon of 10 March are described elsewhere in this Newsletter.
With the key role that France has - having produced the initiator of OTEC - it was only right that the first IOA session was chaired by Michel Gauthier of IFREMER - and even more appropriate that he is presently located in South Pacific, in New Caledonia, now to be the legal home of the IOA. Accompanying him on the podium for this first session was Joseph Vadus of NOAA - who equally needed no introduction, and has been involved directly or indirectly in the US OTEC programme since its inception.
More recently, Taiwan has assumed growing importance in the OTEC scene, and as we heard later in the Conference, is now planning very seriously indeed for its first demonstrator plant. How appropriate then that the Conference Committee had chosen Dr. Jih-Chang Yang from Taiwan to give the Keynote address for this very first session with the title "OTEC for the 21st Century". Two key points stand out from this excellent paper: the first was the reference to Dr. C. Y. Li "It is without doubt his vision and leadership which have made IOA what it is today" said Dr. Yang. How true that is, and I think everybody present was totally in agreement. He concluded with a reference to the Blue Revolution - a term coined by Prof. Pat Takahashi from Hawaii for a report produced in 1992 which pointed up the crucial relevance of the oceans to us all, and within that highlighted OTEC as a benign source of power - and the provider of many more applications. Dr. Yang concluded "There are still a lot of challenges ahead of us. It is time to get started!" He was right; and we did!
The remainder of that morning session was then taken up with the overview papers for Europe, the United States, Japan and Taiwan. Those four papers repay very close attention to anyone who has an interest in OTEC/DOWA; in just over 60 pages there is a record which covers all the key OTEC activities to date, with references to take readers back who need to delve more deeply. One well-known face missing from this session was Dr. Paul Yuen from Hawaii, who had to cancel at the last moment due to an untimely spot of ill-health, but one of the other joint authors of the US paper - Carrie Matsuzaki - gave a refreshing presentation - indeed the only one from a lady in the whole IOA IOA Conference!
In the afternoon of 8 March, Dr. Karl Pan of ITRI, Taiwan, assumed the Chairman's role and presided over another 6 papers. Many paper studies of OTEC have been undertaken - as we all know - so it was particularly refreshing to hear Dr. Luis Vega describing the open-cycle OTEC facility which is built and operational at Keahole Point in Hawaii. As one of those who has been privileged to see this 210KW facility fired up from cold, and then generating net power the paper had a special significance. The importance of practical construction and testing was brought out by the paper where, among the successes, there were also descriptions of some of the less successful aspects - which is after what practical constructing and testing is all about. Too often it seems there are those in industry and government who forget that engineering is an inexact science and that, at the end of the day, practical development and fine-tuning has to be undertaken.
Later in the afternoon further experimental work was described in the paper by David Creber of Alcan and Dr. Alistair Johnson of GEC-Marconi. Heat exchangers are one of the key cost elements of an OTEC or OTEC/DOWA plant and some estimates have indicated their consumption of some 40% of the initial cost of the plant. Whether that or a lesser figure is correct, there is no doubt that improvement in heat exchanger efficiency has very considerable knock-on effects, both for land-based and floating OTEC plants. In the case of the latter, reduction in size of the heat exchangers will reduce the size of the overall plant, corresponding mooring loads, and with further iterative benefits. Initial test work was undertaken in the UK, with plans for further work at -yes you've guessed-Keahole Point.
Other papers in this session addressed points of detail whose understanding is absolutely necessary if we are to get anywhere near an optimised OTEC/DOWA plant. At the other end of the set of questions to be answered though is the key one "How do we get a commercially-sized OTEC power plant built?" This was the subject of the first paper in the session, by Dr. Tar-Zen Su from the National Taiwan Ocean University, who concluded that the overcome the various barriers-not least of which are the high capital investment necessary, and the relatively long period for calculating the "return on capital" - it was very much better to have an international joint venture project. Whilst the proposed Charter of the IOA very properly says that it will "refrain from venturing into commercial activities, sponsoring the execution of OTEC/DOWA commercial projects, or making financial arrangements to facilitate such projects" the draft charter also says under its Purpose, Mission and Objectives, that it "will promote international co-operation between government, industry and academia in basic and applied research for better understanding and utilization of the natural resources associated with deep ocean water. "This is, surely, a very important role for IOA.
On Wednesday morning, 9 March, this writer was chairing a session of the OI Conference - but felt very much at home since Michel Gauthier was talking there about marine resource assessment in the South Pacific, and Dr. Craig MacDonald of Hawaii was talking about its Ocean R&D industry-both significantly relevant to OTEC. However, this does mean that I had to rely on the text of the papers, and reports from friends and colleagues for this next session of the IOA conference. It was an extremely busy session - indeed the interest and discussions were such that it overran by an hour and concluded only 10 minutes before the afternoon session began! Chairing this session were Shinya Takeno of Mitsubishi (and OTECA, Japan), together with Dr. Pat Takahashi. The first paper, by Martin Brown from McDermott (Europe), took us back to the Carribean and produced some interesting financial figures for Net Present value and Internal Rate of Return, for a project which first examined potential sites and then looked at a whole range of Deep Ocean Water Applications - and in part for that reason was based on an hybrid OTEC cycle.
More practical work was described in the next paper, with authors from Japan (JAMSTEC) and the Deep Sea Water Lab. at the Kochi Artificial Upwelling Laboratory (KAUL). Here too it was demonstrated just how valuable and effective as a resoruce for mariculture, energy production, and other outputs is the deep sea water from an OTEC/DOWA plant.
Next came another well-known name. Takenobu Kajikawa, now Professor at the Shonan Institute of Technology in Japan, examined the opportunities for open-cycle OTEC with direct contact condensers for desalination purposes. A 1MW conceptual design was evaluated.
There were four remaining papers in this session and they all looked at deep ocean water utilisation. One was in terms of NELH in Hawaii, and a scenario paper sought to optimise OTEC for potable water - the former paper given by Tom Daniel of NELH, and the latter by Robert Flynn of OTEC Development. A further paper looked - also as a concept - at the use of warm water (too warm for the fish!) and deep ocean water, with its well-known nutrient rich properties; a very ambitious range of products was described. Finally in this session there was a paper by one of the (may I call him?) "Grand Old Men of the Oceans". That description is meant as kindly and complimentary, but as is well-known the British and the Americans are often described as "divided by a common language". So perhaps I should make a second attempt:" Dr. John P. Craven, Elder Statesman of the Ocean community" (Yes, that sounds a little better) gave us just the presentation that we would expect. Enthusiastic and embracing just about every option for OTEC/DOWA. Genuinely a tour D'horizon of the OTEC/DOWA scene.
The afternoon session consisted of just three papers, which were followed by the IOA General Meeting. A detailed paper on the specialised subject of shrimp growth by Prof. Miao and Dr. Tu from Taiwan followed a paper from Hawaii - also on modelling - but this time making use of wave energy to bring up nutrients from the deep ocean water. These two papers illustrated very well the broad additional benefits which can result from the fundamental and simple OTEC concept. The third paper was from the Netherlands and again looked at the range of products which could be obtained from an OTEC plant, and particularly at multi-stage flash evaporation for distillation of sea water.
The morning of 10 March saw the writer in the chair, and in terms of timing it was perhaps fortunate that two of the papers could not be presented due to the absence of their authors, although the written paper by Dr. Robert Cohen certainly seems to offer grand opportunities for OTEC applications.
The end of the morning saw a paper looking at trends for OTEC, but the first three papers of this session all related to pipeline systems, one from OTECA, and two from the National Taiwan Ocean University. Here were excellent examples of the depth of knowledge now being acquired within the detailed aspects for OTEC/DOWA and the design processes - which leads us back to that earlier suggestion from Taiwan that we need an international effort to draw all these together and to get a demonstrator scale plant built.
A further example of the detail which has just been referred to was a paper on Performance Analysis of OTEC using a new cycle with absorption and extraction processes, from Saga University and Shimonoseki University of Fisheries. This was clearly a paper that needed more time for discussion and explanation than the authors had at their disposal. The need to further improve the efficiency of OTEC power systems has been broadly accepted, and the Kalina cycle appears to offer just that. The authors detected a defect in that cycle and their new cycle seems to correct that. Their analysis indicates that their cycle is 10% better than Kalina and 30% better than Rankine. If the calculated results can be borne out in practical testing then I think we shall all be beating a path to their door.
Finally, there was an interesting paper from NOAA, USA - presented by Dr. Sylvia Earle in Bill Busch's absence. The key point here perhaps was the title of the author's position - Director of Emerging Technologies. The paper looked at alternative uses for offshore platforms, of which there is now a significant supply, with many coming to the end of their (original) useful life. It is certainly well worth exploring whether we can achieve economy for OTEC/DOWA by making use of these - although it has to be said that "the jury is certainly still out" in terms of "proof of concept" for this application.
And so to the last session - the afternoon of 10 March - chaired again by Joe Vadus and Pat Takahashi. Apart from the Open Forum there were just three papers. The last by Dr. William Avery of APL at the John Hopkins University, and by the co-chairs of the session. Another excellent review, which looks to benefit from "downsizing of defense expenditures" in the US, which are seen to provide an exciting opportunity to move OTEC into a commercial stage, the paper reviewing US 1970's and 1980's OTEC work, funded by the Department of Energy, where plants up to 400MW were under consideration. Reference is made to the NSF and NOAA Workshop "Ocean Resources 2000" and again to the Takahashi "Blue Revolution" proposals already mentioned - and which were first put forward at Pacon'92 in Italy.
The paper then went on to refer to OTEC for the Marshall Islands, where the US Government has sponsored a study for a 5-10MW multi-product OTEC plant. The conclusion is that we must take the opportunities offered to proceed to commercial demonstration of OTEC plants and plant ships in a range of sizes escalating from 5 to 400MW.
The penultimate paper was another by Luis Vega, which repays close attention on the economics of OTEC. It is summarised from a book published by the ASCE, but in its own right has considerable detail and interest.
I have left until last reference to the paper by Philip Chow of T. Y. Lin International, and Karl Pan of ITRI, on Commercial OTEC Power Plants for Taiwan. It was unfortunate that commercial confidentiality precluded more detail being given, since this is the project which it is hoped will lead to OTEC power in Taiwan. The Master OTEC Plant of the Republic of China (MOPR) seeks to saturate the territorial water within the 12-nautical mile limit along the east coast with closed-cycle OTEC plants. The Master Plan envisages a development programme of 20 years, the first 5 year phase of which will be devoted to a feasibility study leading to preliminary design of a 400MW commercial plant and the contract design of a 100MW commercial/demonstration plant. The three other phases then lead up to the construction, deployment and operation of up to eight 400MW plants.
In the question period it was clear that a number of people were disappointed that the Phase 1 feasibility study should be set to last 5 years. Whilst it does seem a long time, it should perhaps be put in the perspective of the 103 years which have elapsed since d'Arsonval first discovered "OTEC".
Dr. C. Y. Li
That paper - and the missing detail because of commercial confidentiality is certainly to be regreted - also takes us back in one respect to the opening Keynote Address on 8 March. Both papers refer to one man.
One says "Visionaries like Dr. C. Y. Li.....have long seen the rationality of this energy source....."; and the other says ".....a very special man - Dr. C. Y. Li. It is without doubt his vision and leadership.....".
I know of no one in the OTEC fraternity who would have anything other than support for those statements. It was a great shame that health considerations meant Dr. Li was unable to be with us all in Brighton on this occasion, but his name was constantly on our minds.
Conclusions. And a Challenge for IOA?
What would one conclude then, looking back over the whole of the first IOA conference? Firstly, it was an enormous success, attracting all the major players of OTEC/DOWA - internationally, Secondly - and very important - the IOA Conference papers bring the technology, economics and market prospects for OTEC/DOWA completely up to date. Here can be found - if the references are included - access to all relevant OTEC/DOWA knowledge. That embraces all options for OTEC/DOWA, from the traditional (if such a word is allowable for this technology) to the very new (enhanced working cycles for example). From this knowledge base it should be possible to go forward with feasibility studies/site specific designs/demonstrator construction. That last item is the one that cropped up again and again during the conference: We need to construct a demonstrator.
So that, it seems, is the principle aim to which we should all bend our efforts. And "all" presumably can be represented by the IOA. So there surely is a key role for the IOA to adopt: work hard to achieve a demonstrator - built and operational.
Just to finish off this report then, may this writer be permitted a personal view? We in fact have one demonstrator "on the way": in Taiwan as described by Philip Chow and Karl Pan. That is excellent. But engineering is an inexact science, and I have referred also to the feelings expressed that the time scale associated with the Taiwan MOPR was over long. Now, if I turn to my original discipline (aerospace) that too needed demonstrators, or prototypes, because it was always pushing hard against the current knowledge position. And, usually, two "competing" designs were chosen, and then built and flown as demonstrators. Each could then learn something from the other; if I just take two pairs of British examples; Vickers Viscount and Armstrong Whitworth Apollo airliners; or Avro Lancaster and Handley page Halifax bombers. Should the OTEC/DOWA community be looking to encourage the design, construction and operation of a second demonstrator - perhaps internationally supported? It could readily be a complement to the Taiwan MOPR, by being in the 5-10MW size bracket. I would go on to suggest the target date (which I believe to be realistic) for such a plant being "in the water" and operational should be the end of the millenium. A good target date surely, and something of an analogy to President Kennedy's man on the moon at the end of the '60s decade" challenge. The difference is that the OTEC/DOWA plant would be far, far less expensive and would be of far greater benefit to mankind in general.
As I say, that is just a personal view: but what, I wonder, do others think?