Final answer:
A disadvantage of ocean thermal energy conversion (OTEC) is the lack of cold water, which can affect the efficiency of OTEC plants.
Step-by-step explanation:
A disadvantage of ocean thermal energy conversion (OTEC) is that there may not be enough cold water available. OTEC works by using the temperature difference between warm surface water and cold deep water to generate power. If there is not enough cold water, the efficiency of the OTEC plants may be affected. Therefore, option (a) not enough cold water is a disadvantage of OTEC.
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