OCEAN THERMAL ENERGY CONVERSION
OceanThermal Energy Conversion
The ability to explore renewable sources of energy presents numerouschallenges as most of these sources of power are unable to producesufficient electricity for a large population. Ocean Thermal EnergyConversion offers a relatively new method that fosters electricityproduction. It relies on getting power from the difference intemperatures between the surface of the ocean and its deeper parts.OTEC is a renewable source of energy that doesn’t rely on land orhuman factors to generate electricity. It either uses land orsea-based plants to generate energy from its plants where each ofthese options presents some advantages to electricity production. Theenvironmental benefits that it gives to the population make itimpossible to adopt other sources of energy
Keywords: Energy,Power, OTEC, Plant, and Ocean
Ocean Thermal Energy Conversion
The need forbetter and more efficient energy prompts the exploration of othersustainable and renewable forms of generating power. The use of oilas a primary producer of electricity is often criticized due to itsinability to sustain itself in the future and the environmentaldegradation it causes (Panwar, Kaushik & Kothari, 2011 p.1515).According to Makai (2016 p.1), Ocean Thermal Energy Conversion (OTEC)provides a clean and renewable energy source that would curb theannual burning of 1.3 million barrels of oil. It would also produceoil at a reduced rate of $0.20KW/h while prevent carbon emissions ofabout half a million tons which is equivalent to that produced by100,000 cars (Makai, 2016 p.1). Global investment into thistechnology has surpassed $100 million which is spent on research anddevelopment (Makai, 2016 p.1). This source of energy can produce fourtimes the necessary power that the world requires.
Ocean ThermalEnergy Conversion is a source of energy that converts solar radiationin oceans to electric power. More than 70 percent of the earth iscovered by the oceans thus, making it a significant solar energycollector. Humanity depends on the exploitation of these forces ofnature to serve most of its needs. The main concept behind this formof energy collection is using natural solar collectors instead of theartificial ones such as solar panels.
According toFujita et al. (2012 p.463), hot water from the surface of the oceanis collected through the use of a warm water pipe and is subsequentlypumped to a boiler where some of this water heats the working fluid.The working fluid is usually propane or another liquid with similarproperties. Liquids with a lower boiling point such as Ammonia arepreferred in instances where the temperature is cooler. The vaporfrom the propane flows through a turbine, which is attached to agenerator that amasses electric power. Pumping of cold water from thedeep end of the sea to the condenser take place, and this assists inreturning the vapor to its initial liquid stage (Fujita et al., 2012p.464). This liquid then circulates back to the boiler, and theprocess repeats to produce electricity. The power harnessed from thepower plant is used to power the operations of the system and pumpwater, but a significant portion of this power is available as thenet generated power.
Landand Sea based Power Plants
The land basedpower plants consist of many buildings that house the heatexchangers, generators, turbines and other controls that contributeto electricity generation (Ahmadi, Dincer & Rosen, 2013 p.1799).It employs the use of several pipes to connect it to the ocean and amarine culture fish pond. The plant collects warm water through apipe that is close to the shore of the sea and another long tube thatreceives cold water in the deep parts of the ocean. It then generatespower and fresh water through the equipment on the plant. The usedwater will circulate into the large fish pond, and is laterdischarged into the ocean using the third pipe. The primary purposeof carrying this out is to ensure that the warm water used does notre-enter the power plant as it would lower the temperature difference(Makai, 2016 p.1).
The sea-basedpower stations work in the same way, but the key difference is thatit floats in the sea. Its primary advantage is that it does notrequire large pipes since it is in the middle of the ocean, making ita cheaper alternative to the land based plant.
Landand sea based plants (Makai, 2016 p.1)
Meritsand Limitations of Ocean Thermal Energy Conversion
OTEC presentsmany benefits that encourage its production. It uses the ocean as thethermal storage for power and whose capacity for production is notlimited by any environmental, land, human or water factors (Makai,2016 p.1). Unlike many other renewable sources of energy production,it can harness electric power for 24 hours. It is a stable form ofpower production as it generates baseload power that does not requirestorage during times of peak production unlike other forms ofrenewable energy such as solar and the wind. Furthermore, it providesa source of dispatchable power where the electricity levels caneasily be ramped up or down to compensate for fluctuating supply fromother sources of energy (Makai, 2016 p.1). It can thus be a suitablecomplementary source of power for other sources such as the wind andsolar energy. It is also clean and renewable which can cater formassive energy needs while presenting minimal risks to theenvironment.
However, it alsohas some demerits that influence its ability to generate power. Forexample, the initial investment for developing and maintain the powerplant is quite costly (Faizal & Rafiuddin Ahmed, 2011 p.1123).The small temperature differences between the water on the surface ofthe ocean and that on the deep parts of the ocean reduces itsefficiency. This inefficiency makes it unsuitable for uneconomicalfor small power plants (Faizal & vv Rafiuddin Ahmed, 2011p.1124).
Theinefficiencies and disadvantages of oil based power production promptthe need for cleaner and renewable sources of energy. The OceanThermal Energy Conversion presents a suitable way of generating cleanpower with little to no risks to the environment. It depends on thetemperature differences between water from the surface and in thedeep parts of the ocean. The ability to generate electricity at alltimes makes this one of the best energy harnessing methods.
Ahmadi, P., Dincer, I., & Rosen, M. A. (2013). Energy and exergyanalyses of hydrogen production via solar-boosted ocean thermalenergy conversion and PEM electrolysis. International Journal ofHydrogen Energy, 38(4), 1795-1805.
Faizal, M., &Rafiuddin Ahmed, M. (2011). On the ocean heat budgetand ocean thermal energy conversion. International Journal ofEnergy Research, 35(13), 1119-1144.
Fujita, R., Markham, A. C., Diaz, J. E. D., Garcia, J. R. M.,Scarborough, C., Greenfield, P., … & Aguilera, S. E. (2012).Revisiting ocean thermal energy conversion. Marine Policy,36(2), 463-465.
Makai, O. (2016). Ocean Thermal Energy Conversion | Makai OceanEngineering. Makai.com. Retrieved 28 September 2016, fromhttp://www.makai.com/ocean-thermal-energy-conversion/.
Panwar, N. L., Kaushik, S. C., & Kothari, S. (2011). Role ofrenewable energy sources in environmental protection: a review.Renewable and Sustainable Energy Reviews, 15(3), 1513-1524.