PTE Academic Question Bank — Hit a 79+ score

Ocean thermal energy conversion (OTEC) represents a promising renewable energy technology that harnesses temperature differences between warm surface waters and cold deep ocean waters to generate electricity. Unlike solar and wind power, OTEC offers the significant advantage of providing continuous, baseload power generation regardless of weather conditions or time of day. The technology operates on a simple principle: warm surface water is used to evaporate a working fluid with a low boiling point, such as ammonia or propane. The resulting vapor drives a turbine connected to a generator. Cold water from depths of approximately 1,000 meters is then used to condense the vapor, completing the cycle. While OTEC facilities have demonstrated technical feasibility in several Pacific island nations, the high capital costs of underwater pipelines and the relatively low efficiency of the conversion process have limited large-scale implementation. Researchers continue to explore methods for improving OTEC's economic viability.