Ocean Thermal Energy PlantTerm PaperGroup members:

MOHIT NANDAN -20122004MOHD SHAMSHAD ALAM -20121070 ARCHIT KHANDELWAAL -20121093

Content LayoutHistoryIntroductionMotivationWorkingTypesPros and ConsUndergoing ProjectsFuture prospects

In 1881,Jacques Arsene d'Arsonval, a Frenchphysicist, proposed tapping the thermal energy of the ocean. D'Arsonval's student,Georges Claude, built the first OTEC plant, in Matanzas,Cubain 1930.The system generated 22kWofelectricitywith a low-pressureturbine. 1960s: American engineer J. Hilbert Anderson (a specialist in refrigeration and heat cycles) and his son James Anderson, Jr. begin studying ocean thermal energy.1980: India begins a long series of research studies into OTEC, currently led by itsNational Institute of Ocean Technology (NIOT).2008: Tamil Nadu Electricity Board is operating an experimental 1MW plant at Kulasekarapattinam, near Tiruchendur in the Tuticorin district

Key Moments in the History of OTECINTRODUCTIONOcean Thermal Energy Conversion (OTEC) is a technology for generating renewable energy that uses the temperature difference between the deep cold and relatively warmer surface waters of the ocean to generate baseload electricity.Since OTEC exploits renewable solar energy, recurring costs to generate electrical power are minimal.The distinctive feature of OTEC is the potential to provide base load electricity, which means day and night (24/7) and year-round. This is a big advantage for for instance tropical islands that typically has a small electricity network, not capable of handling a lot of intermittent power.Indian scenarioIn 2002, India tested a 1 MW floating OTEC pilot plant near Tamil Nadu. The plant was ultimately unsuccessful due to a failure of the deep sea cold water pipe.Government continues to sponsor research OTEC power generation trials have started, presumably on the Sagar Shakti research vessel, which is a 1 MW closed cycle plant.Tuticorin (South India): 1 MW Ammonia-based closed cycle plant was started in 2000.It was developed by Indian Government/ Indian Institute of Technology.

Basic Reasons OTEC Is Ready For The World:

A Clean Energy Source: OTEC delivers an environmentally friendly solution that produces electricity without the expense and price-volatility of fossil fuels.

Need For Potable Water: Large OTEC power plants can be designed to co-produce 120 million litres of fresh water per day. The OTEC power cycle moves about four cubic km of high-nutrient deep water per year (1 square km 11.5 meters deep each day, enough to grow 70 tons of shell fish meat per day)

Increased Awareness Of The Effects Of Climate Change: OTEC is carbon neutral and does not contribute to climate change by burning fossil fuels such as coal, gas and oil.TYPES

1. CLOSED CYCLE

Closed cycle OTEC was originally employed by DArsonval.

It employed a pure working fluid that would evaporate at the temperature of warm sea water. The vapor would subsequently expand and do work before being condensed by the cold sea water.

This series of steps would be repeated continuously with the same working fluid, whose flow path and thermodynamic process representation constituted closed loops hence, the name closed cycle.WORKING OF CLOSED CYCLE OTEC OPEN CYCLE

WORKING OF OPEN CYCLE OTECOpen Cycle OTEC was proposed by Claude.

It uses steam generated directly from the warm sea water as the OTEC working fluid. The steps of the Claude, or open cycle are:

flash evaporation of warm sea water in a partial vacuum;

(2) expansion of the steam through a turbine to generate power;

(3) condensation of the vapor by direct contact heat transfer to cold sea water; and

(4) compression and discharge of the condensate and any residual non-condensable gases.Arrangement for 1MW OTEC Plant

How To Improve The EfficiencyThe maximum efficiency of a thermodynamic system is the Carnots efficiency.

Since the maximum efficiency is limited by the temperature difference of the source and the sink .Since the temperature difference is less or equal to 20 C, hence the maximum efficiency is less than 10%, which means the actual efficiency is around 1-4%.

The actual efficiency of the system can be improved by following ways:

1. Use of mixtures as Working fluid.

2. Optimizing the flowrate of cooling seawater.

3. Increasing efficiencies of circulating pump, seawater pumps, and turbine generator.

Pros

If less than one-tenth of 1 percent of all the solar energy trapped in the oceans could be converted into electric power , it would supply more than 20 times the total electricity the United States consumes everyday,.

Unlike wind and solar power, OTEC can provide constant power that utilities can depend on any time of day. The electricity it produces could also be used to drive chemical reactions that generate fuel such as hydrogen, ammonia or methanol.ProsDepending on how OTEC plants are set up, they could provide copious amounts of drinkable freshwater, Penney said.

the deep seawater that OTEC plants suck upward is naturally loaded with nutrients from all the organic matter that sunk down from the surface, which could be used to benefit aquaculture farms..CONS1. It isnt a cost efficient technology right now.Ocean thermal energy conversion requires a lot of money up front since the devices are massive undertakings. The pipes have to be wide or else the deep seawater rushes up too fast, heating up as it rubs against the sides.

2. It is a location specific technology.Ocean thermal energy conversion requires a large location that has a close enough proximity to the shoreline.. With limited locations like this available, not every country may be able to effectively use this technology.CONS3. It requires expensive transportation options.Even when there is a location that is effective for OTEC, the logistics of transporting the energy that is created and removing the fresh water that is made as a side effect of the process can be quite expensive..

Although this technology may not be 100% sustainable right now for many countries, ocean thermal energy conversion gives us hope for the future. It is proof that we dont have to remain reliant on oil and fossil fuels if they are no longer found to be affordable or available

Major OTEC Projects in Development

India Tuticorin (South India): 1 MW Ammonia-based closed cycle plant was started in 2000.It was developed by Indian Government/ Indian Institute of Technology.

China: 10 MW On 13 April 2013,an agreement signed for development of a 10 MW land based OTEC installation on the Southern Coast of China, between Beijing Based Reign wood Group and Lockheed Martin.Although the density of energy is comparatively poor , the ocean provides us a huge amount of thermal energy. Today, the new OTEC technology made possible to extract the energy practically from the ocean realistically.

With proper cost of the electricity generation.. It is the OTEC, which has a potential to become powerful solution to three greatest global issues of Energy, Water and Food without vital harmful influence on irreplaceable earth environment. FUTURE PROSPECTS OF OTECReferenceshttp://wikipedia.orghttp://www.seasolarpower.comhttp://rclsgi.eng.ohio-state.edu/~kerechan/OTEC2.htmlhttp://www.nrel.gov/otec/what.htmlhttp://www.trellis.demon.co.uk/reports/otec_sites.htmlhttp://www.sprl.umich.edu/PHAYS/Chap_6/Chap_6_GIFShttp://starfire.ne.uiuc.edu/~ne201/1995/wantland/otec.htmlhttp://wsi-www1.cso.uiuc.edu/courses/GEOL105a/MODULES/lectures/resources/lect838737281.htmlhttp://hgea01.hgea.org/~daver/otecengy.htm

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