Ocean Thermal Energy Conversion (OTEC) is the latest in a long list of technologies that could “change the global energy game.” OTEC, though, is one of the more interesting ideas.
The oceans collect 80% of the energy the earth receives from the sun each day, the equivalent of 250 billion barrels of oil, which is three times more than current worldwide daily demand. If less than one tenth of one percent of this energy could be converted into electric power, it would provide twenty times the amount of energy used in the United States each day. As the surface of the ocean heats up each day, the depths of the ocean remain cold. This difference in temperature, known as the “thermal gradient,” is what OTEC exploits to produce power.
The process works when warm surface water is used to boil a fluid, producing steam. The steam turns a turbine producing electricity. Cold water from the ocean depths condenses the steam back into liquid completing the cycle.
US defense contractor Lockheed Martin has inked a deal with Chinese resort giant Reignwood Group to build a 10-megawatt power plant that will generate electricity from differences in ocean temperatures. Should the project be successful, it will undoubtedly lead to many multibillion-dollar projects worldwide.
Lockheed Martin developed the technology in the 1970s and the recent need to find new environmentally-friendly energy sources has brought the project off the shelves and onto the drawing board. OTEC systems are designed to provide around-the-clock power, clean drinking water and hydrogen for use in electric vehicles.
While there are no commercial scale projects yet, Lockheed Martin tested an OTEC plant for several months producing 50 kW of energy; the project was funded through a $12.5 million investment from the U.S. Navy.
The following video explains how OTEC works: