A barrier to advancing the development of the massive ocean thermal energy conversion (OTEC) resource is its potentially adverse biological impact, but a new DOE-funded study carried out by Makai Ocean Engineering found the biological impact can be minimized.
This is expected to remove a significant regulatory obstacle to permitting pilot projects and clear the way for OTEC developers to move toward building 100-megawatt deep ocean power plants.
OTEC uses the higher temperature of the ocean’s surface water to turn liquefied ammonia, which has a very low boiling point, into a vapor that drives a turbine in the same way steam from water boiled by nuclear energy, fossil fuels or concentrated solar energy drives a turbine to generate electricity.
For a 100-megawatt plant on a floating platform much like a deep water drilling rig, tugboat-sized engines would pump the 25-degree-Celsius surface ocean water into an evaporator that vaporizes the ammonia. The vaporized ammonia then passes through the turbine, thereby compelling it to move, and is recaptured.