At the present time, despite the fact that OTEC systems have no fuel costs and can produce useful by-products, the high initial cost of building such power plants makes OTEC generated electricity more expensive than conventional alternatives.
As such, OTEC systems at the present time are restricted to experimental and demonstration units. Island nations which currently rely on expensive, imported fossil fuels for electrical generation are the most promising market for OTEC.
More experience in building OTEC power plants and standardized plant designs could bring OTEC costs down in the future. Heightened world concern over environmental issues such as global warming could also hasten the development of OTEC as a practical source of electricity.