Ocean thermal energy conversion
Energy is one of our primary needs, and the most primary of all those needs is the need for an alternate source of energy that is nonpolluting and does not eat into our fossil fuel reserves. This is where these technologies come into play.
What exactly is Ocean thermal energy conversion?
The main line of thought behind OTEC or ocean thermal energy conversion is to utilize the solar energy that is trapped in the ocean into a useable source of energy. This energy that can be converted is usually found in the tropical oceans, where the temperature of the water is drastically different from the surface and the deep sea. The ocean surface by an average can be around 20 degrees hotter or cooler as compared to the deep sea temperature. This concept though is still in the experimental phase, even though it was conceived some 100 years back by the French engineer Jacques D’Arsonval as early as the year 1881. Over the past fifty years, three approaches have been created to work this facility. There three approaches are called
1) Open cycle OTEC
2) Closed cycle OTEC
3) Hybrid cycle OTEC
As of now, the world’s only functional OTEC plant is being hosted by the Natural Energy Laboratory of Hawaii.
1) Closed Cycle OTEC: in this cycle, a fluid with a low boiling point is used, as an intermediate fluid for e.g. ammonia or propane. The warm sea water is first pumped and the fluid is boiled using the energy in the water, the fluid that then turns to vapor which in turn further turns the turbine which then generates electricity. Cold sea water then cools down the fluid that is then again ready for use for a second round.
2) Open Cycle OTEC: in this no outside fluid is used, the fluid used is sea water itself and that steam from that only pushes the turbines.
3) Hybrid Cycle OTEC: this is the theoretical method still under experimentation, which aims at a combination of the two methods.
