The southern China sea is set to have the biggest Ocean Thermal Energy Conversion (OTEC) plant installed by a collaboration of Lockheed Martin and Reignwood Group. Although OTEC technology, which generates electricity from the difference in temperature between warm surface waters and cold deep waters of the sea, has been in existence for some time, there have been relatively few installations worldwide.
The planned OTEC plant is expected to produce the 10 MW of electricity sufficient to provide power for the net-zero energy resort to be built by Reignwood Group on the mainland.
The difference between OTEC and other sustainable energy sources like wind and solar is that OTEC produces electricity at all times in tropical climates whereas the other sources are more restricted. Explaining the fact that OTEC systems can be either be closed or open, Gizmag revealed that it is more likely that the planned plant would be the closed-cycle type system.
In this system, warm seawater is used to vaporize a low boiling point fluid like ammonia, which then turns a turbine to produce electricity. The gas is then cooled and condensed by cold seawater to begin the cycle once again.
Lockheed Martin will be hoping that their first proper venture into OTEC would be successful, considering the fact the plans for a similar plant in Hawaii did not bear fruit. Further, the technology is quite expensive as the construction would include putting up a platform on the open sea to pump up cold seawater. Lockheed, together with their collaborators will be hoping that the benefits of this prototype, which has the start of construction slated for next year, would more than cancel out the eventual cost.
Lockheed is planning even more OTEC plants over the next 10 years. These would be of commercial scale, and would have a capacities in the range of 10 MW to 100 MW. Focussing on the benefits to the environment, it is estimated that a 100 MW OTEC facility in one year can produce the same amount of electricity as 1.3 million barrels of oil, thus decreasing carbon emissions by about 500,000 tons.