Malaysia and Japan have since 2019 been cooperating on OTEC research and development though a Science and Technology Research Partnership for Sustainable Development (SATREPS) Program. The joint project includes a variety of fields and activities such as human resource development through onsite-training. In addition, the major component of the project is the development of a novel OTEC cycle, dubbed “hybrid-OTEC.”
The Facility sub-project objectives include design and demonstration of a 3kW Hybrid OTEC System, with jointly-designed equipment manufactured in Japan to be transported to a locally constructed facility at I-AQUAS at Universiti Putra Malaysia (UPM).
On March 10, 2021 project leaders Universiti Teknologi Malaysia (UTM) and the Institute of Ocean Energy, Saga University held the first SATREPS-OTEC forum, with flyer noted above. The flyer includes a photo of the completed portion of the demonstration equipment. More details on the project are available at https://www.utm.my/satreps/ and via a project leaflet.
Hybrid OTEC Cycle
The Hybrid OTEC cycle combines aspects of closed and open cycle OTEC systems. In closed OTEC cycles, a working fluid such as ammonia or other refrigerant are utilized with heat exchangers. The heat exchangers are often titanium to handle seawater conditions. Open OTEC produces fresh water with no working fluid through the use of a vacuum chamber to lower the boiling point of water, but requires very large turbines to take advantage of low-pressure steam. The Hybrid Cycle hopes to take advantage of the benefits of both systems. Surface seawater is vaporized in flash (vacuum) chamber. As salt and other components of seawater are left behind, lower-cost materials can be utilized in a heat exchanger to cool the vapor into desalinated water. To cool the vapor, a working fluid is used on the other side, and as it warms, the working fluid vaporizes, such as in a closed OTEC system. The vapor expands through a turbine, which drives a generator creating electricity. A final heat exchanger returns the vapor back into a liquid for reuse in the cycle though the cold-energy of deep ocean water. We look forward to the results of this research and demonstration project.