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Renewable Energy Sources unit I (2/3) as per Polytechnic syllabus

Renewable Energy Sources unit I (2/3) as per Polytechnic syllabus

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Res poly unit i (2)ppt Res poly unit i (2)ppt Presentation Transcript

  • RENEWABLE ENERGY SOURCES(22033)POLYTECHNIC SYLLABUSUnit I (2/3)FUNDAMENTALS OF ENERGY- C.CoomarasamyFormerly Professor, JRPC, Trichy(2012-2013)
  • UNIT I (2/3)-FUNDAMENTALS OF ENERGY Introduction to Energy-Energy consumption and standardof living-classification of energy resources-consumptiontrend of primary energy resources -importance of renewable energy sources-energy chain-common forms of energy-advantages and disadvantages ofconventional energy sources-salient features ofnonconventional energy sources-environmental aspects ofenergy -energy for sustainable development-energy density ofvarious fuels-availability of resources and future trends. Energy scenario in India – Overall production andconsumption-Availability of primary energy resources: Conventional, Non-Conventional-Estimated potential andachievement-Growth of energy sector and its planning inIndia – Energy conservation: Meaning and importance.2
  • 1.8 ADVANTAGES AND DISADVANTAGES OFCONVENTIONAL ENERGY SOURCESConventional energy sourcesNon-Conventional energy sources3
  • 1.8 ADVANTAGES AND DISADVANTAGES OFCONVENTIONAL ENERGY SOURCESFossil fuels, nuclear and hydro resources are considered asconventional sources.Their use has the following advantages and disadvantages.Advantages:1. CostAt present, these are cheaper than non-conventional sources.2. SecurityAs storage is easy and convenient, by storing a certainquantity, the energy availability can be ensured for certainperiod.3. ConvenienceThese sources are very convenient to use as technology f ortheir conversion and their use is universally available.4
  • 1.8 ADVANTAGES AND DISADVANTAGES OFCONVENTIONAL ENERGY SOURCESDisadvantages:1. Fossil fuels generate pollutants.Main pollutants generated in the use of these sources areCO, CO2, NOX, S OX, particulate matter and heat.These pollutantsdegrade theenvironment, pose health hazards andcause various other problems.CO2 is mainly responsible for global warming.2. Coal is also a valuable petro chemical and is used asraw material for chemical, pharmaceutical and paintindustries.From the long-term point of view, it is desirable to conservecoal for future needs.5
  • 1.8 ADVANTAGES AND DISADVANTAGES OFCONVENTIONAL ENERGY SOURCES3. Safety of nuclear plants isa controversial subject.The major problems with nuclear energy are the following:(a) The waste material generated in nuclear plants hasradioactivity quotients ofdangerous levels, it remains above thesafe limit for along period of time, and thus is ahealth hazard.Its safe disposal, which isessential to prevent radioactive pollution, is achallenging task.Also, the disposed radioactive waste is required to beguarded for a long period (till its radioactivity level comesdown to a safe limit) lest itgoes in wrong hands.6
  • 1.8 ADVANTAGES AND DISADVANTAGES OFCONVENTIONAL ENERGY SOURCES(b) There is possibility of accidental leakage of radioactivematerial from reactor.(c) Uranium resource, for which the technology presentlyexists, has a limited availability.(d) Sophisticated technology is required for using nuclearresources. Only few countries posses the technologyrequired to use nuclear energy.4. Hydroelectric plants are cleanest but large hydroreservoirs cause the following problems:(a) A large land area submerges into water leading todeforestation(b) Causes ecological disturbances such as earthquakes(c) Affects wildlife(d) Causes dislocation of a large population and theirrehabilitation.7
  • 1.9 SALIENT FEATURES OFNON-CONVENTIONAL ENERGY SOURCESMerits:1. Non-conventional sources are available innature free of cost.2. They produce no or very little pollution.Thus, by and large, they are environment friendly.3. They are inexhaustible.4. They have a low gestation period.Demerits:1. In general, the energy isavailable in dilute form from these sources.2. Though available freely in nature, the cost of harnessingenergy from nonconventional sources is generally high.3. Availability is uncertain; the energy flow depends onvarious natural phenomena beyond human control.4. Difficulty in transporting such forms of energy.8
  • 1.10 ENVIRONMENTAL ASPECTS OF ENERGY1.10.1 Trade-off between Energy and EnvironmentEnvironment literally means surroundings.Air, soil and water are the main constituents of environment.However, with passage of time, their quality is continuously beingdegraded due to various manmade reasons.The chief among them are a number of activities involvingenergy generation and its utilization.During every energy conversion process, some energy is expelled bythe energy conversion system into surroundings in the form ofheat.Also, some pollutants may be produced as a by-product of thisprocess.Both of these cause degradation of environment.Every step must be taken to conserve the environment.Therefore, while supplying the increased energy demand, effortsshould be made to adopt measures to minimize the degradationof environment.The present trend is to have a trade-off between the two.The future seems to be in favour of developing about environmentconservation. 9
  • 1.10 ENVIRONMENTAL ASPECTS OF ENERGY10
  • 1.10.2 ECOLOGY:Ecology deals with therelationship betweenliving organisms (man, animal, plants and vegetation) andthe environment.Normally, nature hasself-cleaning capability andrecycles (renews) its resources through variousprocesses, thusmaintaining a state of equilibrium.The water cycle,nitrogen cycle andcarbon cycle are the well-known examples of this.However, whenhuman interference exceeds natural limits, theecological balance gets disturbed.11
  • 1.10.3 GREENHOUSE EFFECTA greenhouse is an enclosure having transparent glass panes orsheets as shown in Fig.It behaves differently f orincoming visible (short wave) radiations andoutgoing infrared (long wave) radiations.It is transparent forincoming solar radiation,allows entry of sunlight andbecomes largely opaque forreflected infrared radiation from theearth‘s surface, thuspreventing theexit of heat.12
  • GREEN HOUSE13
  • 1.10.3 GREENHOUSE EFFECTHence, it maintains acontrolled warmer environment inside forgrowth of plants inplaces where theclimate is very cold.The CO2 envelope present around theglobe in theatmosphere behaves similar to aglass pane and forms a bigglobal greenhouse.This tends toprevent the escape of heat from the earth, which leads toglobal warming.This phenomenon is known asgreenhouse effect.14
  • 1.10.3 GREENHOUSE EFFECTNormal concentration of CO2in the atmosphere is 0.03%.It is due to this effect that the earthmaintains an average surface temperature of 15 C that ishospitable to life.In the absence of this layer, theearth would be a frozen planet at about –25 C (thetemperature of outer atmosphere).However, any further increase in the concentration of CO 2from the present level will upset the temperature balance .This would cause further warming of the globe, which mayhave disastrous consequences.Apart from CO 2, other harmful gases includemethane, nitrous oxide, hydro f louro carbons, sulphurhexafloride and water vapour.All these gases are known as greenhouse gases.15
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  • GREEN HOUSE EFFECT18
  • THE NATURAL GREEN HOUSE EFFECT19
  • 100 % GREEN GASOLINE.20
  • THE GREENHOUSE EFFECT21
  • .22
  • 1.10.4 CONSEQUENCES OF GLOBAL WARMINGGlobal warming is caused mainly due to theemission of excessive CO 2 due toburning offossil fuels in industry,burning of wood and also due toagricultural practices. (@ 0.2 degree C per decade)This trend isleading to the melting ofpolar snowcaps, which accounts for more than90% of the world‘s ice.Melting of the polar snowcaps would, in turn,increase the level of oceans and would possiblyredefine ocean boundariesinundating low-lying areas and smaller islands.23
  • 1.10.4 CONSEQUENCES OF GLOBAL WARMINGDuring the last 100 years, theearth‘s temperature has increased about1/2 degree Celsius andsea levels have risen 6 to 8 inches (15 to 20 cm).Experts have predictedmore frequent and severe heat waves,more intense tropical cyclones,change in rainfall patterns,melting of ice and glaciers at mountains,thus causing floods, followed bydecline of water supplies and anincreased incidence of vector-bornedeceases likemalaria. 24
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  • 1.10.5 POLLUTIONPollution is the introduction ofcontaminants into thenatural environment that cause adverse change.(a) Indoor PollutionIndoor pollution is mainly caused due to use ofconventional chulhas (stoves) in rural areas.Chemicals, cigarette smokes, gases, etc in urban areas.This requires the need of improved householdstoves and minimum and safety use toreduce indoor pollution.(b) Outdoor PollutionOutdoor pollution is mainly caused due touse of fossil fuels.Emissions from fossil fuel based plants degrade theenvironment and cause various other problems.Coal and oil are more pollutant than gas. 26
  • 1.10.5 POLLUTION-(A) INDOOR POLLUTION .27
  • 1.10.5 POLLUTION- (A) INDOOR POLLUTION28
  • 1.10.5 POLLUTION- (B) OUTDOOR POLLUTION .29
  • 1.10.5 POLLUTIONRemedy:1. Use of fossil fuels should be slowly curtailed.2. Less-polluting technologies should beemployed for use instead of fossil fuels, i.e.,gasified coal, which is less polluting, should be used inpower plants.3. Clean alternative fuels such ashydrogen should be used.Hydrogen is thecleanest fuel anddoes not cause pollution duringpower conversion.4. Electric vehicles orbattery-operated vehicles should beused in place ofIC-engine-based vehicles.30
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTS1. Particulate MatterThe presence of particulate matter•reduces sunlight•reduces visibility A level above 100µg/m 3(yearly average) results inrespiratory problems• A level above 300µg/m 3 (yearly average) results inbronchitis(inflammation of mucus membrane inside thebronchial tubes, branches of the wind pipe) The annual average permissible limit is 75µg/m.331
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTS2. CO 2:Carbon dioxide is ordinarily not considered a toxic gas.But increased concentration of CO2 adversely affects theglobal climate.Excess emission of CO2 in the atmosphere causes global warmingdue to greenhouse effect.The increasing CO2 level is mainly due to large-scale combustion offossil(a) fuels in coal fired thermal power plants all over theworld, and(b) felling of trees on a large scale (deforestation) forurbanization, agriculture, and industrialization, resulting inreduced photosynthesis process.32
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTS.Plants survive by extracting CO2from the air using magnesium atthe center of chlorophylland sunlight to convert itinto proteins and sugarsThe Environmental Protection Agency formally declared carbon dioxideand five other heat-trapping gases to be pollutants that threaten public healthand welfare, setting in motion a process that will regulate the gases blamedfor global warming. The E.P.A. said the science supporting its so-calledendangerment finding was ―compelling and overwhelming.‖The EPA believes that concentrations of these gases are very likelyresponsible for the increase in average temperatures even thoughglobal cooling is being reported as the sun cycles down for a period ofminimum activity. 33
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTS3. CO:Carbon Monoxide :is a colorless, odorless gas formed whencarbon in fuel is not burned completely.Motor vehicle exhaust contributes about 60 % of all CO emissionsnationwide (Latest Finding on National Air Quality 2002).Other non-road engines and vehicles (such as constructionequipment and boats) contribute about 22 % of all CO emissionsnationwide.Higher levels of CO generally occur in areas with heavy trafficcongestion.In cities, 95 % of all CO emissions may come from motor vehicleexhaust.Other sources of CO emissions include industrial processes (such asmetals processing and chemical manufacturing), residential woodburning, and natural sources such as forest fires.Woodstoves, gas stoves, cigarette smoke, and unvented gasand kerosene space heaters are sources of CO indoors.34
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTSThe highest levels of CO in theoutside air typically occur during the colder months of the yearwhen CO automotive emissions are greater andnighttime inversion conditions are more frequent.In inversion conditionsthe air pollution becomes trapped near the ground beneath alayer of warm air.CO is formed due to incomplete burning of carbon ininadequate air.It seriously impairs the oxygen-dependent tissues in thebody, particularly the brain, heart and skeletal muscles.CO concentration of100 ppm causesheadache, 500ppm causes collapse and1000 ppm is fatal.Smokers inhale CO concentrations of 400 to 450 ppm.35
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTS4. Sulfur Oxides (SOx) are colorless gases formed by burning sulfur.SOx gases are formed when fuel containing sulfur, such as coaland oil, is burned, and when gasoline is extracted from oilor metals are extracted from ore.Sulfur dioxide (SO2) is the criteria pollutant that is the indicator ofsulfur oxide concentrations in the ambient air.SO2 dissolves in water vapor to form acid, and interacts with othergases and particles in the air to form sulfates and other productsthat can be harmful to people and their environment.Over 65% of SO2 released to the air, or more than 13 million tons peryear, comes from electric utilities, especially those that burn coal.Other sources of SO2 are industrial facilities that derive theirproducts from raw materials like metallic ore, coal, and crude oil, orthat burn coal or oil to produce process heat.Examples are petroleum refineries, cementmanufacturing, and metal processing facilities.Also, locomotives, large ships, and some non road diesel equipmentcurrently burn high sulfur fuel and release SO2 emissions to the air 36
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTSS O x: The presence of SO 2 in the air is mainly due to manmadereasons involving combustion of fuels containing sulphur.The contribution from various sources is as follows:Power plants 70%, Industry 15%, Motor vehicles 8%, Solid wastedisposal 5%, others 2%SO 2 can further oxidize to form sulfur trioxide, which in turnforms sulphuric acid (H 2 SO 4) when absorbed in water.Harmful Effects(a) Causes respiratory deceases including asthma, and the irritateseyes and respiratory track(b) Causes acid rains, which are harmful toagriculture, forest ,vegetation, soil and stones (and thus tobuildings)(c) Causes corrosion of metals, deterioration of electricalcontacts, paper, textile, building stones, etc.The safe limit is 80 micro g/m 3 (annual average).37
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTS5.Nitrogen Oxides (NOx), is the generic term used to describe thesum of NO, NO2 and other oxides of nitrogen. NOx is a group of highly reactive gases that play a major role in theformation of ozone. Many of the nitrogen oxides are colorless and odorless. However, one common pollutant, nitrogen dioxide (NO2) alongwith particles in the air can often be seen as areddish-brown layer over many urban areas. Nitrogen oxides form whenfuel is burned at high temperatures, as in a combustionprocess. The primary sources of NOx aremotor vehicles, electric utilities, and otherindustrial, commercial, and residential sources that burnfuels.38
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTSOxides of nitrogen such asN 2O , NO, NO2,N2O3are commonly referred as NOxAbout 80% of nitrogen oxides in theatmosphere are produced due tonatural causes (biological reactions) andabout 20% due to manmade causes—mostly due to combustion process inair at high temperature.NOx is formed by the interaction ofnitrogen andoxygen athigh temperature.39
  • 1.10.6 VARIOUS POLLUTANTS AND THEIRHARMFUL EFFECTSManmade causes include:(a) Motor vehicles 7%(b) Industry 7%(c) Power plants 4%(d) Solid waste 2%Harmful Effects(a) Causes respiratory and cardiovascular illnesses(b) It deprives the body tissues of oxygen(c) It also forms acid in lungs and, therefore, is more toxicthan COThe safe limit is 100µg/m340
  • 1.10.7 GREEN POWERThe term green power is used to describe sources of energy whichare considered environmental friendly, non-polluting; andtherefore may provide a remedy to the systemic effects ofcertain forms of pollution and global warming.This is, in fact, the renewable energy sourced from the sun, thewind, water, biomass and waste.Green energy is commonly thought of in the context ofelectricity, heating, and cogeneration, and is becomingincreasingly available.Consumers, businesses, and organizations may purchasegreen energy in order to support further development, helpreduce the environmental impacts associated withconventional electricity generation, and increase their nation’senergy independence.Renewable energy certificates (green certificates, orgreen tags) have been one way forconsumers and businesses to support green energy.41
  • 1.10.8.GREEN HOUSE GAS DIAGRAM42
  • 1.10.8.GREENHOUSE GAS DIAGRAM KEY Reduce GHG emissions from farm buildings Reduce livestock methane emissions Lock up green house gases in soil and vegetation Reduce GHG emissions from farm machinery Help lock up green house gases in your land Reduce GHG emissions from crop production Produce renewable energy from your farm*****ENERGY IS MONERGY. LET US SAVE IT.43
  • 1.11 ENERGY FOR SUSTAINABLE DEVELOPMENTEnvironmental degradation cannot be singled out as anindependent matter among various global issues.Also important are the interactions among economicdevelopment, stable energy supplies, and globeenvironmental conservation.In the next few decades fossil fuels will continue to be theprincipal source of energy driving economicdevelopment.The source of fossil fuels is stable and their extraction isaffordable.Attempts to restrict the use of fossil fuels forenvironmental reasons are likely to have a negativeimpact on economic development and the overallavailability of energy.Thus the ‗three Es‘—environment, energy, and economicdevelopment are closely interrelated in a complexmanner.44
  • 1.11 ENERGY FOR SUSTAINABLE DEVELOPMENTThe strategy for mitigating ‘three Es’ issues are a strategy forenvironmentally sustainable economic development.Herman Daly, a famous ecological economist, laid down three conditions forsustainability:1. The consumption rate of renewable resources is not higherthan its recovery rate.2. The consumption rate of non-renewable resources is nothigher than the rate of increase in renewable resource supply.3. The emission of pollutants is within the absorption capacityof the environment.Unfortunately, these conditions have been violated for years.Examples of respective violations typically include deforestation, thedepletion of fossil fuels, and the increase in CO 2 concentration in theair.Such violations may be hard to reverse in the short term but, unless long-term remedial action is taken, present global development trends willnot be sustainable.In particular, a substantial reduction in resource consumption and emissionsof pollutants is essential for the development of a sustainable humansociety on this planet.45
  • 1.12 ENERGY DENSITY OF VARIOUS FUELS:Primary resource Energy densityCoal:Anthracite 32–34 MJ/kg Bituminous26–30 MJ/kg Coke29 MJ/kgBrown coal:Lignite (old)16–24 MJ/kg Lignite (new)10–14 MJ/kg Peat8–9 MJ/kgCrude petroleum45 MJ/kg Petrol51–52 MJ/kg Diesel45–46 MJ/kgNatural gas50 MJ/kg, (42 MJ/m3) Methane (85% CH4)45 MJ/kg, (38 MJ/m3)Propane50 MJ/kg, (45 MJ/m3) Hydrogen142 MJ/kg, (12 MJ/m3)W ood10–11 MJ/kgNatural uranium0.26–0.3 106 MJ/kg Enriched uranium2.6–3.0 106 MJ/kgU23383 106 MJ/kg U23582 106 MJ/kg Pu23981 106 MJ/kgTable: Energy densities/heating values of various 46