Annual Report 2016

Task 11 - Ocean thermal Energy Conversion

In recent years, the United States, France, Korea, Japan and other countries have been developing a few OTEC demonstration projects aiming 1 MW - 10 MW range. In 2014, DCNS has obtained €72 million from the European Union for a 10 MW project in Martinique and have announced expected operation in 2018. There are great expectations for OTEC as compared to other renewable energies due to its stable power generation characteristics, multiple use (cooling, desalination, hydrogen production, etc.) and job creation.

OTEC requires very large economies of scale compared with other marine energy technologies. Economically, a 10 MW scale plant is expected to have an electricity cost of $200/MWh, while a 100 MW plant or larger is expected to cost $100/MWh, which would require a large project with initial investment in excess of $300 million. A 1 MW plant is expected to have an electricity cost of $300‐400/MWh, however, considering multiple use such as utilization of cold deep sea water and desalination, a cost of $200/MWh or less is expected.

In this way, the characteristics of cost evaluation and operation of OTEC are very different from other ocean energy technologies.


Yasuyuki Ikegami, Saga University, Japan

China, France, India, Japan, Republic of Korea, Singapore and The Netherlands


On the other hand, for the application and promotion of OTEC it is necessary to pay careful attention to the use of large amounts of seawater in terms of protection of the marine environment. Benefits such as significant carbon dioxide reductions and improvement of fishery resources through cold water use are expected, however, it is important to perform assessments such as the impact of nutrient enrichment on the ocean.

To investigate issues related to large scale OTEC development it is important to first understand the potential resource. Therefore, an initial task has been proposing aiming to study and understand the OTEC potential and status around the globe.


The overall work lead by Japan will be carried out by two groups addressing the following topics:

  1. Estimation of OTEC potential around the globe (lead by China)
  2. Present status and plans of OTEC projects (Lead by Korea)

A state-of-the art report of OTEC activities and projects around the globe will be produced as a first step to further define a full work program under Task 11. The identification of plans and new developments on OTEC in the various regions of the world would be important for the development of a future roadmap which is one of the goals of Task 11.