The Ocean Thermal Energy Conversion (OTEC) is an innovation of energy usage lately. It was proposed by A French scientist, Jacques Arsene d’Arsonval in 1888. The principle of the technology is to absorb the sun’s warmth and to utilize the temperature differences of the surface and cold deep ocean waters to generate energy. At the moment, a heated debate about energy resources is rising in the international society: how long will oil resource support the human beings for living and producing? And where could we find another resources as a substitute of traditional energy – petroleum and natural gas? Ocean thermal energy seems to be a great choice in the prospect, for its high reserve, promised benefits in long term and environmental protection. Despite its disadvantages of high cost and strict requirements for technology and raw materials, OTEC is able to bring long-term benefits to the society and many scientists have considered it as a promising substitute for fossil oil. An unprecedentedly shortage of energy resources is of concern under the current situation. The research and development of ocean thermal energy is of vital importance.

The raw material of the OTEC is ocean water and sunshine, which can be unlimitedly obtained from the nature and recycling during the process. Ocean covers almost 71% of the surface on earth – the world’s largest solar energy collector and energy storage system. In spite of high storage, the efficiency of transferring the ocean thermal energy to the electricity is so high that it can definitely support people’s life and production in a long period. In the introduction part of “OTEC – Ocean Thermal Energy Conversion”, Maria Bechtel and Erik Netz say, “On an average day, 60 million square kilometers of tropical seas absorb an amount of solar radiation equal in heat content to about 250 billion barrels of oil. If less than one-tenth of one percent of this stored solar energy could be converted into electric power, it would supply more than 20 times the total amount electricity consumed in the United States (263 million inhabitants) on one day.” The statistics have implied that the energy extracted from the ocean is of great potential. Nowadays, people are in great demand for oil and gas resources. According to statistics in May 2015, there were 184 offshore rigs in the North Sea and even more in the rest of the world (Statista). Great consumption of energy resource causes concern to some environmentalists and energy administrations of desiring to solve this problem. Since Jacques put forward the concept of ocean thermal energy conversion in 1888, this innovative thinking has dramatically drown the attention of quite a few scientists, government energy programmers and commercial groups. In the past few years, people have spent a great deal of time and energy in this area and considerable evidences have proved that the technology of OTEC works with promised benefits to our society. As Kevin Joyce, a renewable energy consultant at Black & Veatch, stated in the New York Times that the OTEC technology could provide a more steady power, dwarfing most renewable energy resources. Besides, this technology is environmentally friendly and profitable in long term. Admittedly, the OTEC is not perfect at the moment and the opponents argue that it is unavailable to find out a suitable material for the pipeline, which is used to delivering seawater, and monitoring the temperature difference at a fixed rate is hard to reach under the current technical condition. Other than difficulties in technology, economical and political influence on the surrounding areas is of great concern as well. Based on the positions and conversations, we are in a dilemma about whether the OTEC technology would be worth trying and how it would influence people’s life in the future.

The primary factor for power supply is efficiency and cost. Due to costly Cold Water Pipelines and immaturity of technology in the process of operation, as well as regular maintenance later, it is difficult to spread the OTEC currently. However, as for these problems, Pacific Otec, the French Government-owned naval architect, is operating a feasibility study for a commercial OTEC plant in Tahiti with military shipbuilder (DCNS), as well as a Japanese specialist in desalination and thermal energy conversion technology Xenesys. The project aims to build an offshore OTEC platform to be connected with the Tahiti power grid, which could offer substantial electricity to satisfy 10 percent of island’s need by estimation. The experiment shows that with the advancement of technology, high efficiency could be achieved to meet the increasing demand of energy in the future. In addition, the project has received strong financial support from the French and French Polynesian governments, which respectively covers 50 percent and 18 percent of the total cost. Attracted by promised benefit of the OTEC, more and more commercial groups are going to invest in the exploitation of this technology. A video by OTEC International LLC (OTI) introduces a project of Kahe Point power plant in Hawaii and points out that the project is estimated to obtain great investment return. As the market leader in area of Ocean Thermal Energy Conversion, OTI is famous for its innovative techniques and competitive prices. Among the past few years, the company has gradually benefited from the early construction of ocean thermal conversion platforms and expected to gain higher profits in the future. With a strong financing background from enterprises and governments, Ocean Thermal Energy Conversion is continually developing in a fast race. Another video by Makai energy engineering also displays the world’s largest OTEC plant, which works 24 hours a day, 365 days a year, to support the residents in Hawaii. It is convincing that OTEC is an efficient power supply and it is worth trying. 

OTEC does not only supply substantial power for daily life and production, but also influence local employment and economy. The location of the OTEC platform is mostly selected in costal regions or on small islands, where People primarily earn their livings on fishing or shipping. Once a research group sets down a proper location to build the platform, they would generally employ residents in the surrounding areas. The construction of OTEC platform creates new job opportunities, thus increasing the employment rate and improving the employment structure. Furthermore, a new integration of development, called Ocean Technology Ecopark (OTEP), has been put forward based on OTEC studies. According to a research in “Beyond electricity: The potential of ocean thermal energy and ocean technology ecoparks in small tropical islands”, small islands are facing great challenges – reducing emissions and guarantying energy supply, decreasing freshwater resources, food security threats, as well as instability of economy and tourism. The researchers suggested that building an ocean technology ecopark is an integral solution for these issues and guarantying sustainable development. The construction of OTEC creates a new industry chain at the location and promotes the development of economy thoroughly.

Additionally, another outstanding characteristic of the OTEC technology is that, unlike traditional energy resources, it is environmentally friendly. Since the technology uses the temperature difference of surface water and deep ocean water to generate power, raw materials are recycling and few harmful byproducts were produced during this process. According to Kevin Joyce, as OTEC technology is more reliable and steady than other renewable, which means that it can operate the whole day uninterruptedly, therefore, it has more potential to reduce the discharge of CO2. It is a significant finding for environmentalists considering global warming and industrial emissions. Compared with fossil oil, ocean thermal energy resource can be converted into electricity in a more environmentally friendly way.

As we have mentioned above, the raw material of ocean thermal energy conversion is ocean water and it can be recycling. After going though one procedure of conversion, water can go back to ocean and there is no side effect on the emissions. The byproduct of energy conversion is water as well. In the “Beyond electricity”, a group of experts found out that there are many other properties of deep ocean water, in spite of generating electricity. For instance the low temperatures of deep ocean water can be used for refrigeration and air-conditioning and abundant nutrients in water are great materials for food-production. The OTEC is not solely a technology of power supply; however, it sets a baseline for an integral industry of development. Based on ocean thermal energy production and deep ocean water, entrepreneurs can broaden the production chain in varieties of areas, such as catering services of seafood, entertainment projects, and refrigeration industry. Such assumption has been under the experiments in Japan. At present, the largest Ocean Science and Technology Park is located in Hawaii, administered by the natural Energy Laboratory of Hawaii Authority (NELHA). After thirty year, this experiment has shown the evidence that the cold water has a wide range of utilities, including power supply, water, pharmaceuticals and mariculture. That might spark inspiration of a complete business system in other areas of the world.

On the other hand, considering that the OTEC is totally innovative and we are not completely proficient in mastering the technology and the consequence in long term is unclear, to widely use the technology into production is still being investigated. In the “Ocean Thermal Energy Conversion: Domestic Environmental Aspects”, Thomas B. Stoel states some underlying problems on the environment in those small islands. The byproducts will impact the local ecosystem and creatures unknowingly. Though some regulations decreed for the potential environmental issues, we are unsure of the consequences brought by technology and the countermeasures for the problems that could happen. In retrospect to Industrial Revolution, coal became the primary energy source in the first time, and petroleum took the place of coal in the second time. At the beginning when we used those natural resources, we have never conceived of image that happened today. The environment problems came out – such as global warming, acid rains, deforestation, and land erosion – and causes irreversible harm to the earth. Similarly, it is hard to imagine the consequence that the ocean thermal energy would cause in the future. In that case, OTEC is not an absolutely ideal solution.

In addition, energy issues have always caused new conflicts in the world. As Ann L. Hollick states in the “International Political Implications of Ocean Thermal Energy Conversion Systems”, the construction of OTEC will possibly cause “territorialization of what were formerly non-national areas” and generate new political conflicts of the geographical location. The topic about possible conflicts of OTEC with ocean space uses is furthered in the chapter “Spatial and Emerging Use Conflicts of Ocean Space” by Byron Washom. The use of ocean space, primarily for human land-based needs, will increase because of existing and emerging activities; OTEC serves as one emerging use and its normal operations may conflict with no less than seven other users, specifically with aspects of navigation, fishing, waste disposal, recreational boating, military operation, and offshore mining or exploration (95). A hot topic recently is about territorial sovereignty that several conflicts happen on the national boundaries. To fight for energy resources, a new round of competition could possibly take place. To avoid unnecessary conflicts, the locations of OTEC plant needs the corporations of countries, especially those with long seashores. The issues are taken seriously to avoid the potential negative effects, not only environmental aspects, but also political problems.

Albeit the ocean thermal energy conversion is of great concern in many factors, there are many companies and enterprises interested in this project and willing to pose investment into it. In the contemporary society, more and more investments have been put into this technology and quite a few achievements have been made. For instance, Makai Ocean Engineering launches the world’s largest operational OTEC power plant at the Natural Energy Laboratory of Hawaii Authority (NELHA). Duke Hartman, Makai Vice President of Development, notes that the construction of OTEC is going to widespread in the decades and more commercial groups will realize the long-term value of the technology. There are many similar examples in the world, and those experiments are increasing by year. It indicates a tendency that an industry is moving upward currently. Admittedly, we cannot neglect the fact that the OTEC is a promising technology, even though there are several concerns in it.

The society is constantly moving forward. During this process, innovations constantly come forth to propel our society to further development. Every time when a totally new stuff comes out, it challenges the public perception and gives fresh experience. While someone take interest in this stuff and can be willing to accept it, others suspect the function and usefulness, and object to this new stuff because they have been living a good life without it for a long time and they cannot notice its application in the future. However, creation is working for people’s need, but out of the current need. In the contemporary period, the energy issue has been a serious topic globally. Almost all of countries are trying their best to defend limited energy resources, thus further leading to conflicts in other aspects. Despite unknowing consequences of the OTEC, I firmly believe that the ocean thermal energy conversion brings benefits to human beings exceeding the disadvantages. What we should do is to develop the technology in an appropriate way and take experiments as many as possible to prevent underlying consequences that would do harm to people.

Based on the discussions about pros and cons of OTEC above, we need to take an objective attitude towards an innovative technology. It concludes with a quotation of Philippe Dubau, general manager of Pacific Otec, “We are in the same situation as the people who were making the first steam engine. There is still a very long and difficult road in front of us, but if we succeed, we can bring something interesting and relevant in terms of energy and water supply to the communities, so it is worth trying.” Hundreds of years ago, people could never imagine how profoundly the creation of the steam engine would impact the world. Similarly, we also cannot predict the influence of Ocean Thermal Energy Conversion to human beings in the prospect. However, no one could neglect the fact that the technological innovations promote the development of the society and the benefits overweigh the drawbacks.
