Ocean thermal energy conversion (OTEC) uses the temperature difference between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce useful work, usually in the form of electricity.
Abiotic examples include things that are not alive but you will find in an ecosystem such as air, gases, water, sand, stones and rocks.
a nonliving condition or thing, as climate or habitat, that influences or affects an ecosystem and the organisms in it: Abiotic factors can determine which species of organisms will survive in a given environment.