Ocean ThermalEnergy ConversionOtEC utilizEs thE wOrld’s largEstsolar radiation collector - theocean. The ocean contains enoughEnErgy pOwEr all Of thE wOrld’s OTEC is a way to generateelectrical needs. the temperature electricity using difference of sea water at different depth.
DISCOVERYIn 1881 JacquesArsene dArsonval, aFrench physicist, wasthe first to proposetapping the thermalenergy Arsonval In 1930 of the ocean. built an experimental open cycle OTEC system at Matazas Bay, Cuba.
WORKING PRINCIPLEOTEC utilizesthe OCEan’s20ºC naturalthermalgradientbetween thewarm surfacewater and thecold deep seawater(around
Oceans surfacewaters acts as heat sourceand the cold water at1,000 meters
5. Heatextraction from COLD DEEP 4. Expanding vapor drivecold-water sink to WATER the turbine, and electricitycondense the 5C is created by a generatorworking fluid inthe condenser. CONDENSER TURBINE 2. Fluid pump pressurizes and pushes working fluid to evaporator GENERATORWORKING FLUID(LIKE AMMONIA) EVAPORATOR 3. Heat addition from the hot-water source 1. Power input to used to evaporate the WARM SURFACE pumps to start WATER 28 C working fluid within process the heat exchanger (Evaporator)
OPEN CYCLE SYSTEMOpen-cycle OTEC uses the tropical oceans warm surface water to make electricity. When warm seawater is placed in a low-pressure container, it boils. The expanding steam drives a low-pressure turbine attached to an electrical generator. The steam, which has left its salt behind in the low- pressure container, isalmost pure fresh water. It is condensed back into aliquid by exposure to cold temperatures from deep- ocean water. OPEN CYCLE SYSTEM SYSTEM
CLOSED CYCLE SYSYTEMClosed-cycle systems( Rankine )use fluid with a low-boiling point, such as ammonia, to rotate a turbine to generate electricity. Heres how it works. Warm surface seawater is pumpedthrough a heat exchanger where the low-boiling-point fluid isvaporized. The expanding vaporturns the turbo-generator. Then, cold, deep seawater—pumped through a second heat exchanger—condenses thevapor back into a liquid, which is then recycled through the system. CLOSED CYCLE SYSTEM SYSTEM
ADVANTAGESi. Eco- friendlyii. Minimal maintenance costs compared to other power production plantsiii. Provide air conditioning to buildings within the OTEC plantiv. Fresh water - first by-product is fresh water. A small 1 MW OTEC is capable of producing some 4,500 cubic meters of fresh water per day, enough to supply a population of 20,000 with fresh waterv. Open cycle OTEC systems can produce desalinated water which is very important in third-world countriesvi. Chilled soil agriculture- cold seawater flowing through underground pipes, chills the surrounding soil. Thereby allowing many plants evolved in temperate to be grown in subtropics due to temp. difference in the plant roots in cool soil and plant leaves in warm air
ADVANTAGESVii. MineralExtraction : OTEC helps in miningocean water for 57 traceelements. Most economicanalyses have suggestedthat mining the ocean fortrace elements would beunprofitable as so muchenergy is required to pumpthe large volume of water
DISADVANTAGESi. OTEC-produced electricity at present would cost more than electricity generated from fossil fuels at their current costs.ii.OTEC plants must be located where a difference of about 20º C occurs year round. Ocean depths must be available fairly close to shore- based facilities for economiciii.No energy company will put money in this project because it only had
SUMMARY1. Based on Rankine cycle - Thermodynamic cycle which converts heat into work through a heat engine2. As with any heat engine , the greatest efficiency and power is produced with the largest temperature differences.3. Uses the vertical temperature gradient in the ocean as a heat
FUTUREThe fossil fuels will in the nearfuture be consumed, so we had to findsome alternative energy sources. OTECis a source, which uses the renewablesolar collector, the sea, instead of anartificial collector.The problem is that this investmentwill be more expensive than the fossilfuels power plants, and it will take along time before anyone will put some