The temperature grade gift withinside the ocean is hired in a warmth device to activate strength. This is referred to as OTEC. Since the temperature grade is generally small, really withinside the tropical region, OTEC structures have generally low detail and elegantly excessive capital costs. There are 
introductory designs for OTEC structures.
1. Open cycle 
2. Closed cycle 
In this cycle, the seawater plays a multiple part of a warm temperature deliver, strolling fluid, coolant and heat Gomorrah. Warm face water enters an evaporator wherein the water is flash faded to brume under flyspeck vacuum. Low pressure is maintained withinside the evaporator with the useful resource of the usage of a vacuum pump. The low pressure so maintained removes thenon-condensable feasts from the evaporator. The brume and water admixture from evaporator moreover enters a turbine, the usage of it therefore generating electricity. The exhaust from the turbine is mixed with cold water from deep ocean in a proper away contact condenser and is discharged to the sea. The cycle is also repeated. Since the condensate is discharged to the sea, the cycle is calledopen .
Flash evaporation 
In the evaporator the pressure is maintained at a value slightly lower than the achromatism pressure of warmth face water at 27 . Hence, while the face water enters the evaporator, it receives ` superheated ` This. tremendous heated water undergoes ‚ amount boiling ‛ causing the water to incompletely flash to brume. 
Then, a separate strolling fluid similar as ammonia, propane or Freon is used further to water. The warmness face water is pumped to a boiler with the useful resource of the usage of a pump. This warmness water gives up its warm temperature to the secondary strolling fluid thereby losing its energy and is discharged again to the face of the sea. The vapours of the secondary strolling fluid generated withinside the boiler, pressure a turbine generating strength. The exhaust from the turbine is cooled in a face condenser with the useful resource of the usage of using cold deep seawater, and is also circulated again to the boiler with the useful resource of the usage of a pump. 
Figure OTEC – unrestricted cycle 
Advantages of OTEC 
1. Ocean is an horizonless warm temperature strain which receives solar prevalence in some unspecified time in the future of the time. 
2. Energy is freely available. 
Disadvantage of OTEC 
1. effectiveness is usually low, about2.5, in evaluation to 30- 40 effectiveness for conventional strength shops. 
2. Capital charge is usually immoderate.