Lockheed Martin is progressing with Ocean Thermal Energy Conversion (OTEC), a technology that leverages the ocean’s natural thermal gradient to generate power.
Images © Lockheed Martin
The system generates electricity by leveraging the temperature difference between warm surface water and deep cold water.
“In geographical areas with warm surface water and cold deep water, the temperature difference can be leveraged to drive a steam cycle that turns a turbine and produces power.
Warm surface sea water passes through a heat exchanger, vaporizing a low boiling point working fluid to drive a turbine generator, producing electricity.”
Ocean Thermal Energy Conversion uses the temperature difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity. However, the temperature differential is small and this impacts the economic feasibility of ocean thermal energy for electricity generation.
The most commonly used heat cycle for OTEC is the Rankine cycle using a low-pressure turbine. Systems may be either closed-cycle or open-cycle. Closed-cycle engines use working fluids that are typically thought of as refrigerants such as ammonia or R-134a. Open-cycle engines use vapour from the seawater itself as the working fluid.
source lockheedmartin, wikipedia