抄録
Energy, water, air and food are the essential requirements for the continuous evolution of mankind. However, mankind in the 21st century will face five important issues such as lack of energy, water and food, world wide environmental problems such as climate warming and rapid growth of world populations.
Ocean thermal energy conversion (OTEC) is a system to convert the thermal energy to the electricity by using temperature difference between warm surface seawater and cold depth seawater. The large amount of warm seawater and cold seawater are used to generate large electricity in OTEC plant. The fresh water can be obtained using warm and cold seawater used in OTEC and moreover, hydrogen is produced using fresh water and electricity. Depth seawater contains 0.2 ppm lithium. The lithium can be collected from depth seawater. Moreover, seawater mixed warm and cold seawater used in OTEC plant, desalination plant, etc. is flowed to ocean and is used in aquaculture to raise many types of fish and shellfish. We call it the complex OTEC used for multiple purposes as Integrated OTEC Systems (I-OTECS). In this paper, the present status and future of I-OTECS is presented.
