OTEC - International Symposium 2013

Maritime academic facilties in Hawaii



The International OTEC Symposium

Honolulu Convention Center, Oahu September 9-10, 2013

1) Policies, Finance and Incentives

A distinguished panel of speakers from France, South Korea, Malaysia, Philippines, The Netherlands and the USA presented their vision as well as national frameworks to achieve the implementation of OTEC Plants.

2) Developers Perspective

In a unique format representatives from the major firms involved in the world-wide commercialization of OTEC plants presented their plans and held a round table discussion with audience participation

3) The Ocean Environment

Speakers from academic institutions and the private sector presented analytical work and computer modeling that has led to estimates of the ocean thermal resource for the sustainable global application of OTEC along with the potential environmental impact during operations. A field program designed by the University of Hawaii to monitor the ocean conditions prior and during operations of the Honolulu Sea Water Air Conditioning (SWAC) system was presented along with preliminary measurements.

4) Experimental Plants & OTEC Technology Lessons learned from the design and operation of OTEC experimental plants were presented. In addition, heat exchangers, turbines and working fluids for OTEC applications were discussed.

5) Other Applications

Uses of the seawater drawn from depths of about 600 m to 1,000 m for applications other than OTEC were discussed. In addition, designs of seawater conduits and pipes for OTEC and SWAC were presented.

6) Summary and Recommendations

A forum was held for open discussions and a historical summary of OTEC was presented  Vega bias USA OTEC History for Sep 2013 Symposium





Makai Ocean Engineering has received a $3.6 million contract from the Hawaii Natural Energy Institute and the Office of Naval Research for research and design on the marine renewable energy known as Ocean Thermal Energy Conversion, or OTEC. Makai will perform this work at their Ocean Energy Research Centre, located in Kona, Hawaii, which is the largest OTEC research facility in the world.

OTEC holds great promise because the tropical ocean is earth’s largest solar collector. According to Dr. Joseph Huang, a senior scientist at the U.S. National Oceanic and Atmospheric Administration, “If we can use one percent of the energy [generated by OTEC] for electricity and other things, the potential is so big. It is more than 100 to 1,000 times more than the current consumption of worldwide energy. The potential is huge. There is not any other renewable energy that can compare with OTEC.”1 OTEC is unique among renewables because it can provide large quantities of base load (constant) electricity. France, Korea, Japan, and China also have active OTEC development programs.

Makai will work on two initiatives to serve the ultimate goal of making commercial OTEC a reality: designing, manufacturing and testing an improved heat exchanger for OTEC, and connecting power from its OTEC plant to the electric grid on the Island of Hawaii.



P.I.: Assoc. Prof. Gerard Nihous, Department of Ocean and Resources Engineering

Objective: (i) Document the ocean thermal resource; and (ii) Analyze potential OTEC worldwide sustainable energy production.

One might ask: is OTEC renewable energy? The simple answer is that as long as the sun shines and, if and only if, deep-ocean cold water is provided by the thermohaline circulation the ocean thermal resource is renewable. A pertinent question, however, is: what is the worldwide power resource that could be extracted with OTEC plants without affecting the thermohaline ocean circulation? Our estimate is that the maximum steady-state OTEC electrical power is about 14 TW (Terawatts) corresponding to 250,000 plants of the kind described in the “OTEC Power Production” link below. These would be deployed throughout the OTEC region in the exclusive economic zone (EEZ) of ninety-eight nations. This power rating corresponds to 77% of the current worldwide annual energy consumption (Global OTEC Resources_2013).

Please use Google Chrome or Safari to view the links given below because Internet Explorer does not provide the display we intended.

Ocean Thermal Resource.- The temperature difference between 20 m and 1000 m water depths gives a good indication of available OTEC resources across tropical oceans. For example, values less than 18°C may not be economically viable for OTEC power generation. The NOAA National Ocean Data Center’s World Ocean Atlas (WOA) database (2005 version) was used to construct the link given below which shows the annual and monthly averages of the temperature difference (between 20 m and 1000 m depths) across the world oceans on a quarter-degree horizontal grid. The link TemperatureDifferentialWOA2005 provides the user with a color coded world map of the annual average temperature difference. The user can choose any region of interest defined by specific latitude and longitude ranges to view color-coded data of the annual average temperature difference as a function of latitude and longitude. Further, clicking on any location gives a plot of monthly averages of the temperature difference there.

OTEC Power Production.- An estimate of OTEC power production capabilities can be made with the temperature difference data available from the WOA database. The link PowerMaps gives annual and monthly averages of the power that would be produced by a single generic OTEC plant rated at 100 MW in standard conditions (seawater temperature difference of 20°C between 20 m and 1000 m depths, and seawater temperature of 300 K at 20 m depth). The standard conditions, along with other realistic assumptions are found in: OTEC Summary Aug 2012. The display is limited to a latitude band between 30°S and 30°N. The link provides the user with a color-coded distribution of OTEC power production from the generic 100 MW plant, in GWh per year. The user can choose any region of interest between 30°S and 30°N to view detailed values of annual average power. Further, clicking on any location provides the user with a plot of the monthly averages of net power there, in GWh per month.





Luis A. Vega, Ph.D. 

(808) 956-2335 (voice); 

(808) 956-2336 (fax) 












Staff & Lessons Learned

Challenges and Barriers

Licensing & Permitting

HINMREC Test Sites

Kaneohe Site


Projects at UH

Environmental Impact Studies

Hawai’i Marine Energy Resources

OTEC Thermal Resource

Corrosion Studies

Biofouling/Biocorrosion Studies

Wave Tank Studies

Wind Modeling as Input to Wave Forecasting

Advanced Wave Forecasting


Wave Energy References

OTEC References

OTEC Symposium-2013

















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