Ocean Thermal Energy Conversion Otec Environmental Sciences Essay

The oceans cover a little more than 70 per centum of the Earth surface. This makes it the universes largest solar energy aggregator and energy storage system. On an mean twenty-four hours, 60 million square kilometres if tropical seas absorb and sum of solar radiation equal in heat content to about 250 million barrels of oil. The history of world, have depended upon its ability to suppress the forces of nature, and to use these forces to function its demands. Energy engineering is surely one of the most of import factors in the outgrowth of world as the dominant species of this works. The innovation of the practical steam engine by James W, brought about development of big mills, steam ships and the steam engine. First wood was used, so coal. About the same clip, the usage of coal instigated progresss in metallurgy.petroleum from natural ooze has been used since ancient times for lighting, lubrication and sealing. The debut of boring for oil greatly increased the supply of oil. The industrial revolution switches in to high cogwheel. One job is that the natural ooze is limited and in a few old ages the elements will be used. The development of atomic power was touted as the replies to all world ‘s energy sufferings. It non turned out that manner. The riddance of authorities subsidies for atomic power workss has made them rather unaffordable. When it went so bad no insure in the universe will compose catastrophe for atomic power works

The construct of OTEC ( ocean thermal energy transition ) has existed for over a century as fantasised by Jules Verne in 1870 and conceptualised by Gallic physicist, Jacques arsene 500 arsonval in 1881. Despite this an operating OTEC power installation was non developed until the 1920 ‘s.

2.2 WHAT IS OTEC

OTEC, ocean thermic energy transition is an energy engineering that converts solar radiation to electric power. OTEC systems use the ocean ‘s natural thermic gradient, accordingly the temperature difference between the warm surface H2O and the cold deep H2O below 600 meters by about 20’c, an OTEC system can bring forth, a significantly sum of power. The oceans are therefore a huge renewable resource ; with the potency to assist us in the OTEC procedure is besides rich in foods and it can be used to civilization both marine being and works life near the shore or on land

The entire inflow of solar energy into Earth is of 1000s of clip as a great as world entire energy usage. All of our coal, oil and natural gas are the consequence of the gaining control of solar energy by life of the yesteryear. There have been, any undertakings for tackling solar energy, but most have non been successful because they attempt to capture the energy straight. The thought behind OTEC is the usage of all a natural aggregators, the Se, alternatively of unreal aggregator.

2.3 HOW OTEC WORKS

Warm H2O is collected on the surface of the tropical ocean and pumped by a warm H2O pump. The H2O is pumped through the boiler, where some of the H2O is used to heat the working fluid, normally propane or some similar stuff. The propane vapor expands through a turbine which is coupled to a generator that bring forthing electric power. Cold H2O from the underside is pumped through the capacitor, where the vapor returns to the liquid province. The fluid is pumped back into the boiler. Some little fraction of the power from the turbine is used to pump the H2O through the system and to power other internal operations, but most of it is available as net power.

There are two different sorts of OTEC power workss, the land based and the natation works. First, land based power workss, the land based pilot works will dwell of a edifice. This edifice will incorporate the heat money changers, turbines, generators and controls. It will be connected to the ocean via several pipes, and an tremendous fish farm ( 100 football countries ) by other pipes. Warm H2O is collected through a screened enclosure near to the shop. A long pipe laid on the incline collects cold H2O. Power and fresh H2O are generated in the edifice by the equipment. Used H2O if first circulated in to the marine civilization pool ( fish farm ) and so discharges by the 3rd pipe in to the ocean, downstream from the warm H2O recess. This is done so that the escape does non reenter the program, since rhenium usage of warm H2O would take down the available temperature difference. While, the other OTEC power workss is drifting power workss, the drifting power works works in the same manner as the land based the evident different is that the natation works is drifting.

Where really OTEC can be used, OTEC can be sited anyplace across about 60 million squares kilometers of tropical oceans anyplace there is deep cold H2O lying under warm surface H2O this by and large means between the tropic of malignant neoplastic disease and the tropic of Capricorn. Surface H2O is these parts, warmed by the Sun, by and large stys at 25 grades Celsius or supra. Ocean H2O more than 1000 metres below the surface is by and large at approximately 4 grades C.

2.4 TYPES OF OTEC

There are three types of OTEC designs: unfastened rhythm, closed rhythm and intercrossed rhythm.

Closed rhythm

Closed rhythm systems use unstable with a low boiling point, such as ammonium hydroxide, to revolve a turbine to bring forth electricity. Here how it works. Warm surface sea H2O is pumped through a heat money changer where the low boiling H2O point is vaporized. The spread outing vapor turns the turbo generator, so ball, deep saltwater pumped through a 2nd heat money changer condenses the vapor back into a liquid, which is so recycle through the system

Open rhythm

Open rhythm OTEC uses the tropical oceans warm surface H2O to do electricity. When warm saltwater is placed in a low force per unit area container, it boils. The spread outing steam drives a low force per unit area turbine attached to an electrical generator. The steam, which has left its slat behind in the low force per unit area container, is about pure fresh H2O. It is condensed back into a liquid by exposure to cold temperature from deep oceans H2O

Hybrid rhythm

Hybrid system combines the characteristic of both the closed rhythm an unfastened rhythm system. In a intercrossed system, warm saltwater enters a vacuity chamber where it is brassy evaporated into steam, similar to the unfastened rhythm vaporization procedure. The steam vaporizes a low boiling point fluid that drives a turbine to bring forth electricity

2.5 ADVANTAGES AND DISADVANTAGES OF OTEC

The advantages of OTEC is the utilizations OF OTEC is clean, renewable, its natural resource. Warm surface saltwater and cold H2O from the ocean deepnesss replace fossil fuels to bring forth electricity. Second, its appropriately designed OTEC workss will bring forth small or no C dioxide or other pollutant chemical

Third, OTEC system can bring forth fresh H2O every bit good as electricity. This is a important adapted in island countries where fresh H2O is limited, other there is adequate solar energy received and stored in the warm tropical ocean ‘s surface bed to supply most, if non all, of present human energy demands and last the usage of OTEC as a beginning of electricity will assist cut down the province about complete dependance on imported fossil fuels.

The disadvantages of OTEC is produced electric at present would be more than electricity generated from fossil fuels at theirs current costs. Second, OTEC workss must be located were a difference of about 20 ; degree Celsius occurs twelvemonth unit of ammunition. Ocean deepnesss must be available reasonably near to shore based installations for economics operation. Floating works ships could supply more flexibleness. Third, there is no energy company will set money in this undertaking because it merely has been tested in really smell graduated table and last, the building of OTEC workss and lying of pipes in coastal H2O may do localized harm to reefs and near shore Marine ecosystems.

2.6 ENVIRONMENTAL IMPACTS OF OTEC

OTEC systems are, for the most portion, environmentally benign. Although inadvertent escape of closed rhythm working fluids can present a jeopardy, under normal conditions, the lone wastewaters are the assorted saltwater discharges and dissolved gases that come out of solution when sea H2O is depressurized. Although the measures of outgassed species may be important for big OTEC systems, with the exclusion of C dioxide, these species are benign. Carbon dioxide is a nursery gas and can impact planetary clime ; nevertheless, OTEC systems release one or two orders of magnitude less C dioxide than comparable dodo fuel power workss and those emanations may be sequestered easy in the ocean or used to excite marine biomass production. OTEC assorted saltwater discharges will be at lower temperatures than sea H2O at the ocean surface. The discharges will besides incorporate high concentrations of foods brought up with the deep sea H2O and may hold a different salt. It is of import ; hence, that release back into the ocean is conducted in a mode that minimizes unintended alterations to the ocean assorted bed biology and avoids bring oning long-run surface temperature anomalousnesss. Analysiss of OTEC wastewater plumes suggest that discharge at deepnesss of 50-100 m should be sufficient to guarantee minimum impact on the ocean environment. Conversely, the nutrient-rich OTEC discharges could be exploited to prolong open-ocean Mari civilization