OREANDA-NEWS. July 20, 2012.   Yokogawa Electric Corporation announces that IHI Plant Construction Co., Ltd. (IHI), Xenesys Inc. (Xenesys), and Yokogawa have been jointly selected by Okinawa Prefecture for its fiscal year 2012 Experimental Deep Seawater Power Generation Project. This OTEC pilot plant project, which will be conducted at the Okinawa Prefectural Deep Sea Water Research Center on Kumejima Island, is one of the efforts that are underway to develop multiple uses of deep seawater and surface water.

An OTEC system utilizes the temperature differences between warm surface seawater and cold deep seawater to generate electricity. A low-boiling-point working fluid such as ammonia is pumped into an evaporator, where the transfer of heat from warm surface seawater to the working fluid causes the fluid to vaporize. The vapor drives the turbine and generates electricity through the attached generator. Then, the vapor is transferred to a condenser where it is returned to a liquid state as the result of the transfer of heat to the cold deep seawater in the condenser. This OTEC technology is regarded as one of the most effective methods for utilizing the ocean’s thermal energy, and it is most suitable in tropical and sub-tropical regions, where the temperature differences between deep seawater and surface seawater is the greatest.

In this project, the construction of an OTEC pilot plant is underway and is expected to be completed by March 2013. This OTEC pilot plant will be utilized to study methods for the reduction of power generation costs and examine the feasibility of operating floating commercial OTEC plants off the Okinawan coast. Here, IHI is handling facility design and construction, Xenesys is designing and manufacturing the power generation unit and the heat exchangers, and Yokogawa is designing, manufacturing, and engineering the monitoring and control system for the power generation unit and the electronics for the interconnected power system *.

With their respective expertise in plant engineering, OTEC technology, and monitoring and control systems, IHI, Xenesys, and Yokogawa will work together to make this Experimental Deep Seawater Power Generation Project a success and achieve progress toward the goal of a sustainable society with renewable OTEC energy in the near future.