Japan’s IOES Adopts PreFS for Introduction of OTEC for Republic of Nauru

This article is an unofficial translation based on a press release in Japanese from Saga University: https://www.saga-u.ac.jp/koho/press/2021062821985


The Institute of Ocean Energy, Saga University, (IOES) together with the Overseas Environmental Cooperation Center (OECC), were selected as the implementing organizations for a project of the Climate Technology Center (CTCN), which is responsible for the technical mechanism of the United Nations Framework Convention on Climate Change (UNFCCC), regarding the Pre-FS (Pre-Feasibility Study) project on the introduction of OTEC power generation in the Republic of Nauru by UNIDO (United Nations Industrial Development Organization). This is the first time a Japanese Renewable Energy technology has been adopted for a CTCN project (other than green gas project *1).

The Government of Japan has contributed approximately US$4.6 million to CTCN.

The Republic of Nauru aims to have a renewable energy ratio of 100% by 2050, through the introduction of OTEC, etc.


IOES, together with the OECC, was selected for the FY2020 Pre-FS project on the introduction of OTEC, etc. in the Republic of Nauru, which was part of an open call internationally by CTCN (Climate Technology Center Network). This is the first Japanese renewable energy technology (other than a green gas project *1) to be adopted for a CTCN project. The Government of Nauru aims to increase the renewable energy ratio to 100% by 2050 through introduction of OTEC, etc. In May, an online conference was held with the Government of Nauru, CTCN, OECC, IOES, etc., where it was agreed to aim to the societal implementation of OTEC, etc., with the support of the GCF (Green Climate Fund). From May 2021, the Graduate School of Frontier Sciences, The University of Tokyo, is also participating in the project, and is evaluating and conducting analysis on the potential of OTEC etc., in the Republic of Nauru.  

Republic of Nauru:

It is an island country located in the southwestern Pacific Ocean with a population of about 13,000. It once flourished through the export of phosphorus ore. In the 1980s, TEPCO conducted empirical research on OTEC, but the technology at that time did not lead to commercialization. Currently, the power supply of the Republic of Nauru is almost 100% diesel power generation. Already, the introduction of solar power generation is progressing, but due to the intermittency (variability) and the limited installation space in island countries, expectations for OTEC are increasing again.  


It was established at COP16 (2010) as an implementation organization to promote technology transfer related to climate change, and has been in operation since 2013. It is an organization that provides support in line with the needs of each country based on requests from developing countries. Approximately US$51 million has been contributed, mainly from developed countries and the Global Environment Facility (GEF), of which approximately US$4.6 million has been contributed by the Japanese government.


An international fund that supports efforts by developing countries to reduce, reuse, and absorb (mitigate) GHG emissions and address (adapt) the effects of climate change. It provides support aimed at triggering a “paradigm shift” to enable developing countries to secure low emissions and resiliency to climate change. A total of 43 developed and developing countries have announced contributions to the GCF of approximately US$10.3 billion, while Japan has contributed US$1.5 billion.

Japan’s OTEC technology, where the following achievements in domestic and overseas research and development have been evaluated for more than 50 years, was adopted for this project through an international tender.

(1) At the FY2001 Council for Science and Technology Policy, among the four priority fields, in “Environment,” the “Research and Development of Ocean Energy” was cited. Saga University has been positioned as a core research center in this field, and academic research aimed at contributing to full-scale implementation was begun. The research equipment introduced at that time was evaluated as the world’s highest level research equipment (See “Renewable Energy White Paper”), and research results were obtained through the development of new heat cycles for power generation and high-performance heat exchangers.

(2) In 2013, a demonstration test facility for OTEC in Kume Island, Okinawa Prefecture, succeeded in generating the first electricity in the second phase of research and development worldwide, which has attracted international attention (more than 10,000 people from 67 countries have visited so far). The facility was the first ocean energy in Japan to be connected to a grid (Okinawa Electric Power). In addition, full-scale empirical research using this facility has been conducted by private companies since 2012 with support of the New Energy and Industrial Technology Development Organization (NEDO), which produced new research results and showed the possibility of implementation for society.

(3) The combined use of deep ocean water (DOW) based on OTEC in Kumejima Island, Okinawa Prefecture, is attracting national and international attention as the “Kumejima Model,” one of the effective social models for achieving the UN SDGs (goals 6, 7, 8, 9, 11, 13, 14, etc.).

(4) Saga University was selected for a FY2016 Science and Technology Research Partnership for Sustainable Development (SATREPS) project which is operated by the Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA). With the support of the program, it is promoting the social implementation of a new OTEC (H-OTEC) in Malaysia as well as developing human resources for young researchers. In this project, in order to promote renewable energy in Malaysia, we are contributing to the societal implementation of OTEC and building a “Malaysia Model” that makes the best use of the results of the “Kumejima Model.” During FY2021, we plan the export of a research facility for OTEC manufactured in Japan to Malaysia.

Demonstration OTEC in the Republic of Nauru in the 1980s