Okinawa Prefecture

Post-OTEC Seawater Utilization Demonstration Project


The Mini Kumejima Model

One of the goals for OTEC is to integrate power production and deep seawater use in a system that efficiently uses the ocean resources available to increase the economics of the system as a whole. The "Kumejima Model" integrates larger scale OTEC and Seawater uses in a system that can provide small communities with energy, water, and food in a self-sufficient manner. Towards this goal, Okinawa prefecture is utilizing the existing OTEC facility and demand for seawater to test the Kumejima Model at small scale. The installation of new pipelines allows Post-OTEC deep seawater and surface seawater to be used by nearby industries for the first time anywhere in the world.

Project Details

Post OTEC DSW Use Map

The new pipelines were completed in FY2016, allowing for testing of use of Post-OTEC water to take place during FY2017-2018. As the OTEC facility currently only receives water capacity not in use by the ODRC and Industries, the new pipelines allow water currently used by industry to go to OTEC first, allowing more water for power generation. In addition, the sea grape farm will be able to utilize OTEC-cooled surface seawater, allowing more capacity of post-OTEC DSW to go to a new Oyster Hatchery recently completed.

New Pipes

Post OTEC DSW Use Map

3 pipes (DSW, SSW, Maintenance/Cleaning) x 200A x 680m

Current Surface Seawater Temperature


Current Deep Seawater Temperature


(Updated 7/30/2019)

©2013-2019 Okinawa Prefecture.