Japan Platform for Redesign: Sustainable Infrastructure (JPRSI)

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Ocean Thermal Energy Conversion (OTEC) & Multiple use of Deep Ocean Water

Technology / Service Summary

OTEC is renewable energy that generates electricity by using the temperature difference between the ocean's upper and lower layers. The deep ocean water can be reused for many industries as well.


While promoting the stable use of clean energy using deep ocean water, we aim to create a self-sustainable, circular society based on deep ocean water.


In tropical and subtropical regions the surface seawater temperature changes little throughout the year, and deep ocean water maintains a nearly constant temperature. Compared to wind and solar, this allows very stable power generation during the day and at night and is suitable as baseload supply. Also, OTEC takes up little space and has less impact on landscapes or from natural disasters. In addition, deep ocean water used for power generation can also be utilized for air conditioning in hotels and data centers, taking advantage of its low temperature of 5-7°C, as well as for aquaculture and agriculture due to its nutrient-rich and clean properties. Furthermore, minerals and other nutrients contained in deep ocean water are attracting attention in the fields of microalgae cultivation, beauty, and health.


New industries and jobs have already been created in Kumejima Town, with economic impact amounting to approximately 2.5 billion yen a year and more than 140 new jobs, making it a major industry for the island. We aim to expand the Kumejima Model, which combines OTEC with the use of deep ocean water, to other countries such as Mauritius, Malaysia, and Indonesia.

Controlled Substance

Applicable Regions / Countries

  • Japan
  • Southeast Asia
  • Central/South Asia
  • China/ East Asia
  • Middle East
  • Africa
  • Oceania
  • Europe
  • Central/South America
  • ASEAN countries

    Indonesia,Cambodia,Singapore,Thailand,Philippines,Brunei Darussalam,Viet Nam,Malaysia,Myanmar,Lao PDR

Related SDGs Goals

  • 7. Affordable and Clean Energy
  • 13. Climate Action

Ocean Thermal Energy Conversion (OTEC) & Multiple use of Deep Ocean Water