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Disclaimer
T0s &ocu-ent &oes not c"0- n$ or0#0n"0t$ n& cnnot !e use& s su!st0tute 3or
4rescr0!e& te5t!oo6s. Te 0n3or-t0on 4resente& ere 0s -ere"$ co""ect0on !$ te co--0ttee
-e-!ers 3or te0r res4ect07e tec0n# ss0#n-ents. Vr0ous sources s -ent0one& t te en&
o3 te &ocu-ent s we"" s 3ree"$ 70"!"e -ter0" 3ro- 0nternet were consu"te& 3or
4re4r0n# t0s &ocu-ent. Te owners04 o3 te 0n3or-t0on "0es w0t te res4ect07e utors
or 0nst0tut0ons. Furter, t0s &ocu-ent 0s not 0nten&e& to !e use& 3or co--erc0" 4ur4ose n&
te co--0ttee -e-!ers re not ccount!"e 3or n$ 0ssues, "e#" or oterw0se, r0s0n# out o3
use o3 t0s &ocu-ent. Te co--0ttee -e-!ers -6e no re4resentt0ons or wrrnt0es w0t
res4ect to te ccurc$ or co-4"eteness o3 te contents o3 t0s &ocu-ent n& s4ec030c""$
&0sc"0- n$ 0-4"0e& wrrnt0es o3 -ercnt!0"0t$ or 30tness 3or 4rt0cu"r 4ur4ose. Te
co--0ttee -e-!ers s"" !e "0!"e 3or n$ "oss o3 4ro30t or n$ oter co--erc0" &-#es,
0nc"u&0n# !ut not "0-0te& to s4ec0", 0nc0&ent", conse8uent0", or oter &-#es.
S$""!us
NON9CONVENTIONAL ENERGY SOURCES /+9(9*2MODULE9I /(* HOURS2
Energy Scenario: Classif ication of Energy Sources, Energy resources (Conventional andnonconventional, Energy needs of !ndia, and energy consumption patterns" #orld$ide %otentials of these sources" Energy eff iciency and energy security" Energy and its environmental impacts,Distri&uted generation"Solar Energy: Solar thermal Systems: Types of collectors, Collection systems, eff iciency
calculations, applications"
%hoto voltaic (%V technology: %resent status, solar cells, cell technologies, characteristics of %V
systems, e'uivalent circuit, array design , &uilding integrated %V system, its components , siing
and economics" %ea) po$er operation" Standalone and grid interactive systems"
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MODULE9II /(* HOURS2
#ind Energy: #ind speed and po$er relation, po$er e*tracted from $ind, $ind distri&ution and $indspeed predictions" #ind po$er systems: system components, Types of Tur&ine, Tur&ine rating"Choice of generators, tur&ine rating, electrical load matching, Varia&le speed operation, ma*imumpo$er operation, control systems, system design f eatures, stand alone and grid connectedoperation" Small +ydro SystemsMODULE9III /(* HOURS2
Energy storage and hy&rid system conf igurations: Energy storage, Battery types, e'uivalent circuit,performance characteristics, &attery design, charging and charge regulators" Battery management"-ly$heel.energy relations, components, &enef its over &attery" -uel Cell energy storage systems"Ultra Capacitors" Bio./ass and Bio.-uels"
MODULE9IV /(* HOURS2
0rid !ntegration: Stand alone systems, Concept of /icro.0rid and its components, +y&rid systems
hy&rid $ith diesel, $ith f uel cell, solar.$ind, $ind hydro systems, mode controller, load
sharing, system siing" +y&rid system economics, !nterface re'uirements, Sta&le operation,
Transient.saf ety, 1perating limits of voltage, fre'uency, sta&ility margin, energy storage, and load
scheduling" Eff ect on po$er 'uality, harmonic distortion, voltage transients and sags, voltage
f lic)ers, dynamic reactive po$er support" Systems stiff ness"
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ENERGY SCENARIO
INTRODUCTION
2ny physical activity in this $orld, $hether carried out &y human &eings or &y nature, is cause
due to flo$ of energy in one form or the other" The $ord3energy4 itself is derived from the 0ree)
$ord 3en.ergon4, $hich means 3in.$or)4 or 3$or) content4" The $or) output
depends on the
energy input"
Energy is one of the ma5or inputs for the economic development of any country" !n the case of thedeveloping countries, the energy sector assumes a critical importance in vie$ of the ever.increasing energy needs re'uiring huge investments to meet them"
Energy can &e classif ied into several types &ased on the follo$ing criteria:
•
%rimary and Secondary energy• Commercial and 6on commercial energy
• 7ene$a&le and 6on.7ene$a&le energy
• Conventional and 6on.conventional energy
(.( Pr0-r$ n& Secon&r$ Ener#$
-ig8"8" /a5or %rimary and Secondary sources
%rimary energy sources are those that are either found or stored in nature" Common primary energysources are coal, oil, natural gas, and &iomass (such as $ood" 1ther primary energy
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sources availa&le include nuclear energy from radioactive su&stances, thermal energy stored in
earth9s interior, and potential energy due to earth9s gravity" The ma5or primary and secondary
energy sources are sho$n in -igure 8"8
%rimary energy sources are costly converted in industrial utilities into secondary energy sources
for e*ample coal, oil or gas converted into steam and electricity" %rimary energy can also &e useddirectly" Some energy sources have non energy uses, for e*ample coal or natural gas can &e used as afeedstoc) in f ertilier plants"
(.: Co--erc0" Ener#$ n& Non Co--erc0" Ener#$
Co--erc0" Ener#$
The energy sources that are availa&le in the mar)et for a def inite price are )no$n as commercialenergy" By far the most important forms of commercial energy are electricity, coal and ref inedpetroleum products" Commercial energy forms the &asis of industrial, agricultural, transport andcommercial development in the modern $orld" !n the industrialied countries, commercialied f uels
are predominant source not only for economic production, &ut also for many household tas)s of general population"
E*amples: Electricity, lignite, coal, oil, natural gas etc"
Non9Co--erc0" Ener#$
The energy sources that are not availa&le in the commercial mar)et for a price are classif ied as non.commercial energy" 6on.commercial energy sources include f uels such as f ire$ood, cattle dung andagricultural $astes, $hich are traditionally gathered, and not &ought at a price used especially inrural households" These are also called traditional f uels" 6on.commercial energy is often ignored inenergy accounting"
E*ample: -ire$ood, agro $aste in rural areas solar energy for $ater heating, electricitygeneration, for drying grain, f ish and f ruits animal po$er for transport, threshing, lif ting $ater forirrigation, crushing sugarcane $ind energy for lif ting $ater and electricity generation"
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(.+ Renew!"e n& Non9Renew!"e Ener#$
7ene$a&le energy is energy o&tained from sources that are essentially ine*hausti&le" E*amples of
rene$a&le resources include $ind po$er, solar po$er, geothermal energy, tidal po$er and
hydroelectric po$er (See -igure 8";" The most important f eature of rene$a&le energy is that it can&e harnessed $ithout the release of harmf ul pollutants"
6on.rene$a&le energy is the conventional fossil f uels such as coal, oil and gas, $hich are
li)ely to deplete $ith time"
-igure 8"; 7ene$a&le and 6on.7ene$a&le Energy
(.; Con7ent0on" n& Non9con7ent0on" ener#$ resources'
Con7ent0on" Ener#$
Conventional energy resources $hich are &eing traditionally used for many decades and $ere incommon use around oil crisis of 8 are called conventional energy resources, e"g", fossil f uel,nuclear and hydro resources"
Non9con7ent0on" ener#$
6on.conventional energy resources $hich are considered for large scale use af ter oil crisis of
8, are called non.conventional energy sources, e"g", solar, $ind, &iomass, etc"
Ener#$ Consu-4t0on n& Stn&r& O3 L070n#'
The energy consumption of a nat
ion can &e &road
ly d
ivided
into the follo$ing areas or sectors depend
ing on
energy.related activities" These can &e further su÷d into su§ors:
• Domestic sector (houses and off ices including commercial &uildings
• Transportation sector
• 2griculture sector
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• !ndustry sector
Consumption of a large amount of energy in a country indicates increased activities in these sectors" This
may imply &etter comforts at home due to use of various appliances, &etter transport f acilities and more
agricultural and industrial production" 2ll of this amount to a &etter 'uality of lif e" Therefore, the per capita
energy consumption of a country is an inde* of the standard of living or prosperity (i"e" income of the
people of the country"
(.< G"o!" Pr0-r$ Ener#$ Reser7es=
Co"
The proven glo&al coal reserve $as estimated to &e milliontonnes &y end of ;>" The US2 had the largest share of the glo&alreserve (;A"@ f ollo$ed &y 7ussia (8A"" (1ne &arrel of oil is appro*imately
8 liters
Gs
The glo&al proven gas reserve $as estimated to &e 8= trillion cu&ic metres &y the
end of ;>" The 7ussian -ederat
i
on had thelargest share of the reserve $
ithalmost ;="
(Source: B% Statistical 7evie$ of #orld Energy, Fune ;@
G"o!" Pr0-r$ Ener#$ Consu-4t0on
The glo&al primary energy consumption at the end of ;> $as e'uivalent to
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Ener#$ &0str0!ut0on !etween &e7e"o4e& n& &e7e"o40n# Countr0es
2lthough ? percent of the $orld9s population
lies in the developing countries (a four. f old
population increase in the past ;A years, their
energy consumption amounts to only @
percent of the $orld total energy consumption"
The high standards of living in the developed
countries are attri&uta&le to high energy
consumption levels"F0#. (.;' Ener#$ D0str0!ut0on Between
De7e"o4e& n& De7e"o40n# Countr0es
2lso the rapid population gro$th in the developing countries has )ept the per capita energy
consumption lo$ compared $ith that of highly industrialied developed countries" The $orld
average energy consumption per person is e'uivalent to ;"; tones of coal" !n industrialied
countries, people use four to five times more than the $orld average and nine times more than the
average for the developing countries" 2n 2merican uses >; times more commercial energy than an
!ndian"
(.> In&0n Ener#$ Scenr0o
Coal dominates the energy mi* in !ndia, contri&uting to AA of the total primary energy pro.duction" 1ver the years, there has &een a mar)ed increase in the share of natural gas in prima. ry
energy producti
on from 8 in 8
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
!ndia is the fourth largest producer of coal and lignite in the $orld" Coal production is
concentrated in these states ( 2ndhra %radesh, Uttar %radesh, Bihar, /adhya %radesh,
/aharashtra, 1rissa, Fhar)hand, and #est Bengal"
O0" Su44"$
1il accounts for a&out > of !ndia4s total energy consumption" !ndia today is one of thetop ten oil.guling nations in the $orld and $ill soon overta)e Horea as the third largestconsumer of oil in 2sia af ter China and Fapan" The country9s annual crude oil production ispea)ed at a&out >; million tonne as against the current oil consumption &y end of ;= ise*pected to reach 8> million tonne(/ T, of $hich domestic production $ill &e only >@/ T" !ndia $ill have to pay an oil &ill of roughly IA &illion, assuming a $eighted average priceof IA per &arrel of crude" !n ;>.@, against total e*port of I@ &illion, oil imports accountedfor I;8 &illion" !ndia imports = of its crude needs mainly from gulf nations" The ma 5ority of !ndia9s roughly A"@ &illion &arrels in oil reserves are located in the Bom&ay +igh, upper 2ssam,Cam&ay, Hrishna.0odavari" !n terms of sector $ise petroleum product consumption, transportaccounts for @; f ollo$ed &y domestic and industry $ith ;@ and ;@ respectively" !ndia spent
more than 7s"8,8, crore on oilimports at the end of ;@"
Ntur" Gs Su44"$
6atural gas accounts for a&out ?"< per cent of energy consumption in the country" The currentdemand for natural gas is a&out 8st /ay ;@, consisting of ;?,? /#. hydro, ==,8 /#. thermal
and ;,=; /#. nuclear and 8,?< /#. $ind (/inistry of %o$er"
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
Nuc"er Power Su44"$
6uclear %o$er contri&utes to a&out ;"@ per cent of electricity generated in !ndia" !ndia has tennuclear po$er reactors at five nuclear po$er stations producing electricity" /ore nuclear reactors
have al
so &een approved for constructi
on"H$&ro Power Su44"$
!ndia is endo$ed $ith a vast and via&le hydro potential for po$er generation of $hich only
8A has &een harnessed so f ar" The share of hydropo$er in the country9s total generated units hassteadily decreased and it presently stands at ;AC as on >8st /ay ;BB@" !t is assessed thate*ploita&le potential at BC load factor is ?@, /#"
F0n" Ener#$ Consu-4t0on
-inal energy consumption is the actual energy demand at the user end" This is the diff erence
&et$een primary energy consumption and the losses that ta)es place in transport, transmission
J distri&ution and ref inement" The actual final energy consumption (past and pro5ected is given
in Ta&le8";"
T2BKE 8"; DE/26D -17 C1//E7C! 2K E6E70L -17-!62K C16SU/%T!16 (B2U SCE6 27!1
Source Un0ts (@@;9@< :**(9*: :**>9*) :*((9(:
Electricity Billion Units ;?@""@=
Kignite /illion Tonnes @"?A 88"< 8"; 8
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Sector 0se Ener#$ Consu-4t0on 0n In&0
The ma5or commercial energy consuming sectors in thecountry are classif ied as sho$n in the -igure 8"A" 2s seen fromthe f igure, industry remains the &iggest consumer of commercial energy and its share in the overall consumption is@
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
Ener#$ Intens0t$
Energy intensity is energy consumption per unit of 0D%" Energy intensity indicates thedevelopment stage of the country" !ndia9s energy intensity is >"= times of Fapan, 8"AA times of US 2,8"@= times of 2sia and 8"A times of #orld average"
F0#ure (.) Per C40t Ener#$ Consu-4t0on
(. Lon# Ter- Ener#$ Scenr0o 3or In&0
Co"' Coal is the predominant energy source for po$er production in !ndia, generating appro*imate. ly= of total domestic electricity" Energy demand in !ndia is e*pected to increase over the ne*t 8.8A years although ne$ oil and gas plants are planned, coal is e*pected to remain the dominant f uel forpo$er generation" Despite signif icant increases in total installed capacity dur. ing the last decade,the gap &et$een electricity supply and demand continues to increase" The resulting shortf all has had anegative impact on industrial output and economic gro$th" +o$ever, to meet e*pected f uturedemand, indigenous coal production $ill have to &e greatly e*panded" %roduction currently stands ataround ;" C during the plan period" Domesticcrude oil production is li)ely to rise marginally from >;"> million tonnes in;8.; to >>"
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has consistently declined from in the As to > currently" Same is e*pected to go do$n to ? &y;;" 2s sho$n in the f igure 8"?, around
Diesel: ?@;=; ;A,88 8,8
2dditional capacity
(;8.;8;
A>,>>> ;,@? ? >;,=> 88A,=
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(.@ Ener#$ Pr0c0n# 0n In&0
%rice of energy does not ref lect true cost to society" The &asic assumption underlying eff iciency of mar)et place does not hold in our economy, since energy prices are undervalued and energy $astages arenot ta)en seriously" %ricing practices in !ndia li)e many other developing countries are inf luenced &ypolitical, social and economic compulsions at the state and central level" /ore often than not, this has&een the f oundat
ion for energy sector po
licies in !nd
ia" The !nd
ian energy sector offers many e*amp
lesof cross su&sidies e"g", diesel, K%0 and )erosene &eing su&sidied &y petrol, petroleum products forindustrial usage and industrial, and commercial consumers of electricity su&sidiing the agricultural anddomestic consumers"
Co"
0rade $ise &asic price of coal at the pithead e*cluding statutory levies for run.of .mine (71/ coal aref i*ed &y Coal !ndia Ktd from time to time" The pithead price of coal in !ndia compares f avora&ly $ithprice of imported coal" !n spite of this, industries still import coal due its higher calorific value and lo$ash content"
O0"
2s part of the energy sector reforms, the government has attempted to &ring prices for many of thepetroleum products (naphtha, furnace oil, KS+S, KD1 and &itumen in line $ith international prices" The most important achievement has &een the lin)ing of diesel prices to international prices and areduction in su&sidy" +o$ever, K%0 and )erosene, consumed mainly &y domestic sectors, continue to&e heavily su&sidied" Su&sidies and cross.su&sidies have resulted in serious distortions in prices, asthey do not ref lect economic costs in many cases
Ntur" Gs
The government has &een the sole authority for fi*ing the price of natural gas in the country" !t has also&een ta)ing decisions on the allocation of gas to various competing consumers" The gas prices variesfrom 7s A to 7s"8A per cu&ic meter"
E"ectr0c0t$
Electricity tariff s in !ndia are structured in a relatively simple manner" #hile high tensionconsumers are charged &ased on &oth demand () V 2 and energy ()#h, the lo$.tension (K Tconsumer pays only for the energy consumed ()#h as per tariff system in most of the electricity&oards" The price per )#h varies signif icantly across States as $ell as customer segments $ith. in a State" Tariffs in !ndia have &een modif ied to consider the time of usage and voltage level of supply" !naddition to the &ase tariff s, some State Electricity Boards have additional recovery f rom customers inform of f uel surcharges, electricity duties and ta*es" -or e*ample, for an industrial consumer thedemand charges may vary from 7s" 8A to 7s" > per ) V 2, $hereas the energy charges may varyany$here &et$een 7s" ; to 7s" A per )#h" 2s for the tariff ad 5ustment mechanism, even $hensome States have regulatory commissions for tariff revie$, the decisions to effect changes are stillpolitical and there is no automatic ad5ustment mechanism, $hich can ensure recovery of costs for theelectricity &oards"
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(.(* Ener#$ n& En70ron-ent
The usage of energy resources in industry leads toenvironmental damages &y polluting the atmosphere"-e$ of e*amples of air pollution are sulphur
dio*ide (S1;, nitrous o*ide (61O and car&on
mono*ide (C1 emissions from &oilers and f urnaces,Chlorof luro car&ons (C-C emissions f rom
ref rigerants use, etc" !n chemical and f ertiliers
industries, to*ic gases are released" Cement plants
F0#ure (.(* In4uts 1 Out4uts o3 Process
and po$er plants spe$ out particulate matter" Typical inputs, outputs, and emissions for a typicalindustrial process are sho$n in -igure"
A0r Po""ut0on
2 variety of air pollutants have )no$n or suspected harmf ul effects on human health and theenvironment" These air pollutants are &asically the products of com&ustion from fossil f uel use" 2irpollutants from these sources may not only create pro&lems near to these sources &ut also can causepro&lems far a$ay" 2ir pollutants can travel long distances, chemically react in the atmosphere toproduce secondary pollutants such as acid rain or oone"
E7o"ut0onr$ Tren&s 0n Po""ut0on Pro!"e-s
&oth developed and rapidly industrialiing countries, the ma5or historic air pollution pro&lem hastypically &een high levels of smo)e and S1; arising from the com&ustion of sulphur.containingfossil f uels such as coal for domestic and industrial purposes"
Smogs resulting from the com&ined effects of &lac) smo)e, sulphate G acid aerosol and fog have&een seen in European cities until fe$ decades ago and still occur in many cities in developing$orld" !n developed countries, this pro&lem has signif icantly reduced over recent decades as a result of changing f uel.use patterns the increasing use of cleaner f uels such as natural gas, and theimplementation of eff ective smo)e and emission control policies"
!n &oth developed and developing countries, the ma5or threat to clean air is no$ posed &y traff icemissions" %etrol. and diesel engine motor vehicles emit a $ide variety of pollutants, principally
car&on mono*i
de (C1, o*i
des of nit
rogen (61*
,
vol
atil
e organi
c compounds (V1Cs andparticulates, $hich have an increasing impact on ur&an air 'uality"
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!n addition, photochemical reactions resulting from the action of sunlight on 61; and V1Cs f romvehicles leads to the f ormation of oone, a secondary long.range pollutant, $hich impacts in rural areasoften far from the original emission site" 2cid rain is another long.range pollutant inf luenced &y vehicle61* emissions"
!ndustrial and domestic pollutant sources, together $ith their impact on air 'uality, tend to &e steady. stateor improving over time" +o$ever, traff ic pollution pro&lems are $orsening $orld.$ide" The pro&lem may&e particularly severe in developing countries $ith dramatically increasing vehicle population,inf rastructural limitations, poor engineGemission control technologies and limited provision formaintenance or vehicle regulation"
The principle pollutants produced &y industrial, domestic and traff ic sources are sulphur dio*ide,nitrogen o*ides, particulate matter, car&on mono*ide, oone, hydrocar&ons, &enene, 8,>. &utadiene,to*ic organic micro pollutants, lead and heavy metals"Brief introduction to the principal pollutants are as f ollo$s:
Su"4ur &0o50&e is a corrosive acid gas, $hich com&ines $ith $ater vapourin the atmosphere to produce acid rain" Both $et and dry deposition have &eenimplicated in the damage and destruction of vegetation and in the degradationof soils, &uilding materials and $atercourses" S1; in am&ient air is alsoassociated $ith asthma and chronic &ronchitis" The principal source of this gasis po$er stations and industries &urning fossil f uels, $hich contain sulphur"
N0tro#en o50&es are formed during high temperature com&ustion processesfrom the o*idation of nitrogen in the air or f uel" The principal source of nitrogen o*ides . nitric o*ide (61 and nitrogen dio*ide (61;, collectively)no$n as 61* is road traff ic" 61 and 61; concentrations are greatest inur&an areas $here traff ic is heaviest" 1ther important sources are po$er stationsand industrial processes"
6itrogen o*ides are released into the atmosphere mainly in the form of 61, $hich is then readily o*idied to 61
;&y reaction $ith oone"
Elevated levels of 61* occur in ur&an environments under sta&le meteorological conditions,
$hen the air mass is una&le to disperse"
6itrogen dio*ide has a variety of environmental and health impacts" !t irritates the respiratorysystem and may $orsen asthma and increase suscepti&ility to inf ections" !n the presence of sunlight, itreacts $ith hydrocar&ons to produce photochemical pollutants such as oone"
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6itrogen o*ides com&ine $ith $ater vapour to form nitric acid" This nitric acid is in turnremoved from the atmosphere &y direct deposition to the ground, or transf er to a'ueous droplets (e"g"cloud or rain$ater, there&y contri&uting to acid deposition"
Ac0&030ct0on 3ro- SO: n& NO5
2cidif ication of $ater &odies and soils, and the conse'uent impact on agriculture, forestry andf isheries are the result of the re.deposition of acidifying compounds resulting principally from theo*idation of primary S1; and 61; emissions from fossil f uel com&ustion" Deposition may &e &yeither $et or dry processes, and acid deposition studies often need to e*amine &oth of theseacidif ication routes"
2ir&orne 4rt0cu"te -tter varies $idely in its physical and chemical composition, source andparticle sie" %/8 particles (the f raction of particulates in air of very small sie (P8B µm are of ma5orcurrent concern, as they are small enough to penetrate deep into the lungs and so potentially posesignif icant health ris)s" !n addition, they may carry surface.a&sor&ed carcinogenic compounds into thelungs" Karger particles, com&ustion, $here transport of hot e*haust vapour into a cooler e*haust pipecan lead to spontaneous nucleation of Qcar&onQ particles &efore emission" Secondary particles aretypically formed $hen lo$ volatility products are generated in the atmosphere, f or e*ample theo*idation of sulphur dio*ide to sulphuric acid" The atmospheric lif etime of particulate matter isstrongly related to particle sie, &ut may &e as long as 8 days for particles of a&out 8mm in diameter"
Concern a&out the potential health impacts of %/8 has increased very rapidly over recent years"!ncreasingly, attention has &een turning to$ards monitoring of the smaller particle f raction %/;"Acapa&le of penetrating deepest into the lungs, or to even smaller sie f ractions or total particlenum&ers"
Cr!on -ono50&e (C1 is a to*ic gas, $hich is emitted into the atmosphere as a result of com&ustion processes, and from o*idation of hydrocar&ons and other organic compounds" !n ur&anareas, C1 is produced almost entirely (
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H$&rocr!ons
There are t$o main groups of hydrocar&ons of concern: volatile organic compounds (V1Cs andpolycyclic aromatic hydrocar&ons (% 2+s" V1Cs are released in vehicle e*haust gases either asun&urned f uels or as com&ustion products, and are also emitted &y the evaporation of solvents andmotor f uels" Benene and 8,>.&utadiene are of particular concern, as they are )no$n carcinogens"1ther V1Cs are important &ecause of the role theyplay in the photochemical f ormation of oone in the atmosphere"
Benene is an aromatic V1C, $hich is a minor constituent of petrol(a&out ; &y volume" The main sources of &enene in the atmosphere are
the distri&ution and com&ustion of petrol" 1f these, com&ustion &y petrolvehicles is the single &iggest source (= of total emissions
$hilst the ref ining, distri&ution and evaporation of petrol from vehicles accounts f orappro*imately a further 8 of total emissions" Benene is emitted in vehicle e*haust not onlyas un&urnt f uel &ut also as a product of the decomposition of other aromatic compounds"Benene is a )no$n human carcinogen"
(,+9!ut&0ene, li)e &enene, is a V1C emitted into the atmosphereprincipally from f uel com&ustion of petrol and diesel vehicles" Unli)e&enene, ho$ever, it is not a constituent of the f uel &ut is produced &y thecom&ustion of olef ins" 8,>.&utadiene is also an important chemical incertain industrial processes, particularly the manufacture of syntheticru&&er" !t is handled in &ul) at a small num&er of industrial locations"1ther than in the vicinity of such locations, the dominant source of 8,>.&utadiene in the atmosphere are the motor vehicles" 8,> Butadiene is also a)no$n, potent, human carcinogen"
TOMPs /To50c Or#n0c M0cro 4o""utnts2 are produced &y the incomplete com&ustion of f uels" They comprise a comple* range of chemicals some of $hich, although they are emitted invery small 'uantities, are highly to*ic or and carcinogenic" Compounds in this category include:R % 2+s (%oly 2romatic +ydrocar&onsR %CBs (%olyChlorinated BiphenylsR Dio*insR -urans
He7$ Met"s n& Le&
%articulate metals in air result from activities such as fossil f uel com&ustion (includingvehicles, metal processing industries and $aste incineration" There are currently no emissionstandards for metals other than lead" Kead is a cumulative poison to the central nervous system,particularly detrimental to the mental development of children"
Kead is the most $idely used non.ferrous metal and has a large num&er
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
of industrial applications" !ts single largest industrial use $orld$ide is in the manufacture of &atteries and it is also used in paints, glaes, alloys, radiation shielding, tan) lining and piping"
2s tetraethyl lead, it has &een used for many years as an additive in petrol $ith theincreasing use of unleaded petrol, ho$ever, emissions and concentrations in air have reducedsteadily in recent years"
C"0-t0c Cn#e
+uman activities, particularly the com&ustion of fossil f uels, have made the &lan)et of green.house gases ($ater vapour, car&on dio*ide, methane, oone etc" around the earth thic)er" Theresulting increase in glo&al temperature is altering the comple* $e& of systems that allo$ lif e tothrive on earth such as rainf all, $ind patterns, ocean currents and distri&ution of plant and animalspecies"
Greenouse E33ect n& te Cr!on C$c"e
-ig 8"88 The green house eff ect
Kif e on earth is made possi&le &y energy from the sun, $hich arrives mainly in the form of visi&lelight" 2&out > percent of the sunlight is scattered &ac) into space &y outer atmosphere and the&alance = percent reaches the earth9s surface, $hich ref lects it in form of inf rared radiation" The escape of slo$ moving inf rared radiation is delayed &y the green house gases" 2 thic)er&lan)et of greenhouse gases traps more inf rared radiation and increase the earth9s temperature(7efer -igure 8"88"
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
0reenhouse gases ma)eup only 8 percent of the atmosphere, &ut they act as a &lan)etaround the earth, or li)e a glass roof of a greenhouse and )eep the earth > degrees $armer than it$ould &e other$ise . $ithout greenhouse gases, earth $ould &e too cold to live" +uman activitiesthat are responsi&le for ma)ing the greenhouse layer thic)er are emissions of car&on dio*ide fromthe com&ustion of coal, oil and natural gas &y additional methane and nitrous o*ide fromf arming activities and changes in land use and &y several man made gases that have a long lif e inthe atmosphere"
The increase in greenhouse gases is happening at an alarming rate" !f greenhouse gasesemissions continue to gro$ at current rates, it is almost certain that the atmospheric levels of car&on dio*ide $ill increase t$ice or thrice from pre.industrial levels during the ;8st century"
Even a small increase in earth9s temperature $ill &e accompanied &y changes in climate. suchas cloud cover, precipitation, $ind patterns and duration of seasons" !n an already highly cro$dedand stressed earth, millions of people depend on $eather patterns, such as monsoon rains, tocontinue as they have in the past" Even minimum changes $ill &e disruptive and diff icult"Car&on dio*ide is responsi&le for percent of the Qenhanced greenhouse effectQ" +umans are&urning coal, oil and natural gas at a rate that is much f aster than the rate at $hich these f ossil f uels$ere created" This is releasing the car&on stored in the f uels into the atmosphere and upsetting thecar&on cycle (a precise &alanced system &y $hich car&on is e*changed &et$een the air, theoceans and land vegetation ta)ing place over millions of years" Currently, car&on dio*ide levelsin the atmospheric are rising &y over 8 percent every ; years"
Current E70&ence o3 C"0-t0c Cn#e
Cyclones, storm, hurricanes are occurring more f re'uently and f loods and draughts are moreintense than &efore" This increase in e*treme $eather events cannot &e e*plained a$ay as randomevents"
This trend to$ard more po$erf ul storms and hotter, longer dry periods is predicted &ycomputer models" #armer temperatures mean greater evaporation, and a $armer atmosphere is a&leto hold more moisture and hence there is more $ater alof t that can f all as precipitation" Similarly,dry regions are prone to lose still more moisture if the $eather is hotter and hence this leads tomore severe droughts and desertif ication"
Future E33ects
Even the minimum predicted shif ts in climate for the ;8st century are li)ely to &e signif icant anddisruptive" %redictions of future climatic changes are $ide.ranging" The glo&al temperaturemay clim& from 8"@ to A"? degrees C the sea level may rise from < to ?? cm" Thus, increases in sealevel this century are e*pected to range from signif icant to catastrophic" This uncertainty ref lectsthe comple*ity, interrelatedness, and sensitivity of the natural systems that ma)e up the climate"
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Se7ere Stor-s n& F"oo&0n#
The minimum $arming forecast for the ne*t 8 years is more than t$ice the B" degree Cincrease that has occurred since 8
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man and his ancestors migrated in response to changes in ha&itat" There $ill &e much less room formigration in f uture"
0lo&al $arming almost certainly $ill &e unf air" The industrialied countries of 6orth 2merica and #estern Europe, and other countries such as Fapan, are responsi&le for the vastamount of past and current greenhouse.gas emissions" These emissions are incurred for the highstandards of living en5oyed &y the people in those countries"
Let those to suffer most from climate change $ill &e in the developing $orld" They havefe$er resources for coping $ith storms, $ith f loods, $ith droughts, $ith disease out&rea)s, and $ithdisruptions to food and $ater supplies" They are eager for economic development them. selves, &utmay find that this already diff icult process has &ecome more diff icult &ecause of climate change" The poorer nations of the $orld have done almost nothing to cause glo&al $arming yet is moste*posed to its eff ects"
Ac0& R0n
2cid rain is caused &y release of S1O and 61O from com&ustion of fossil f uels, $hich then mi*
-ig 8"8; 2cid 7ai
n$ith $ater vapor in atmosphere to form sulphuric and nitric acids respectively (7efer -igure8"8;"
The effects of acid rain are as f ollo$s:S 2cidif ication of la)es, streams, and soils
S Direct and indirect effects (release of metals, -or e*ample: 2luminum $hich $ashes a$ayplant nutrients
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S Hilling of $ildlife (trees, crops, a'uatic plants, and animals
S Decay of &uilding materials and paints, statues, and sculpturesS +ealth pro&lems (respiratory, &urning. s)in and eyes
(.(( Ener#$ Secur0t$
The &asic aim of energy security for a nation is to reduce its dependency on the importedenergy sources for its economic gro$th"
!ndia $ill continue to e*perience an energy supply shortf all throughout the forecast period" This gap has $idened since 8
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
t 0s Ener#$ Conser7t0on
Energy Conservation and Energy Efficiency are separate, &ut related concepts" Energyconservation is achieved $hen gro$th of energy consumption is reduced, measured inphysical terms" Energy Conservation can, theref ore, &e the result of several processes ordevelopments, such as productivity increase or technological progress" 1n the other handEnergy eff iciency is achieved $hen energy intensity in a specif ic product, process or area of production or consumption is reduced $ithout aff ecting output, consumption or comfortlevels" %romotion of energy eff iciency $ill contri&ute to energy conservation and is there.fore an integral part of energy conservation promotional policies"
Fig 1.13 Fig 1.14
Energy eff iciency is often vie$ed as a resource option li)e coal, oil or natural gas" !t pro.
vi
des additi
onal econom
i
c val
ue &y preservi
ng the resource &ase and reduci
ng poll
uti
on" -ore*ample, replacing traditional light &ul&s $ith Compact -luorescent Kamps (C-Ks meansyou $ill use only 8G@th of the energy to light a room" %ollution levels also reduce &y thesame amount (ref er -igure 8"8@"
6ature sets some &asic limits on ho$ eff iciently energy can &e used, &ut in most cases ourproducts and manuf acturing processes are still a long $ay from operating at thistheoretical limit" Very simply, energy eff iciency means using less energy to perform thesame f unction" 2lthough, energy eff iciency has &een in practice ever since the f irst oilcrisis in 8, it has today assumed even more importance &ecause of &eing themost cost.eff ective and relia&le means of mitigating the glo&al climatic change"7ecognition of that potential has led to high e*pectations for the control of f utureC1; emissions through even more energy eff iciency improvements than haveoccurred in the past" The industrial sector accounts for some @8 per cent of glo&alprimary energy demand and appro*imately the same share of C1; emissions"
(.(+ Ener#$ Strte#$ 3or te Future
The energy strategy for the future coul
d &e cl
assi
f i
ed i
nto i
mmedi
ate, medi
um.term andlong. term strategy" The various components of these strategies are listed &elo$:I--e&0te9ter- strte#$'
S 7ationaliing the tariff structure of various energy products"S 1ptimum utiliation of e*isting assets
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S Efficiency in production systems and reduction in distri&ution losses, includingthose in traditional energy sources"
S %romoting 7JD, transf er and use of technologies and practices f orenvironmentally sound energy systems, including ne$ and rene$a&le energysources"
Me&0u-9ter- strte#$'
Demand management through greater conservation of energy, optimum f uel mi*,structural changes in the economy, an appropriate model mi* in the transport sector,i"e" greater dependence on rail than on road for the movement of goods and passengersand a shif t a$ay from private modes to pu&lic modes for passenger transportchanges in design of diff erent products to reduce the material intensity of thoseproducts, recycling, etc"
There is need to shif t to less energy.intensive modes of transport" This $ouldinclude measures to improve the transport inf rastructure vi" roads, &etter design of vehicles, use of compressed natural gas (C60 and synthetic f uel, etc" Similarly,&etter ur&an planning $ould also reduce the demand for energy use in thetransport sector"
There is need to move a$ay from non.rene$a&le to rene$a&le energy sources vi" solar,$ind, &iomass energy, etc"
Lon#9ter- strte#$'
Eff icient generation of energy resources
S Eff icient production of coal, oil and natural gas
S 7eduction of natural gas f laring
!mproving energy inf rastructure
S Building ne$ ref ineries
S Creation of ur&an gas transmission and distri&ution net$or)
S /a*imiing eff iciency of rail transport of coal production"
S Building ne$ coal and gas f ired po$er stations"Enhancing energy eff iciency
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S !mproving energy eff iciency in accordance $ith national, socio.economic, andenviron. mental prioritiesS %romoting of energy eff iciency and emission standards
S Ka&eling programs for products and adoption of energy eff icient technologies inlarge industriesDeregulation and privatiation of energy sector
S 7educing cross su&sidies on oil products and electricity tariff sS Decontrolling coal prices and ma)ing natural gas prices competitive
S %rivatiation of oil, coal and po$er sectors for improved eff iciency"!nvestment legislation to attract f oreign investments"
S Streamlining approval process for attracting private sector participation in po$ergeneration, transmission and distri&ution "
Bureu o3 Ener#$ E330c0enc$ /BEE2'
The mi
ssi
on of Bureau of Energy Efficiencyi
s toi
nsti
tuti
onali
e energyeff iciency services, ena&le delivery mechanisms in the country and provideleadership to energy eff iciency in all sectors of economy" The primary o& 5ective$ould &e to reduce energy intensity in the !ndian Economy"
The general superintendence, directions and management of the aff airs of theBureau is vested in the 0overning Council $ith ; mem&ers" The Council isheaded &y Union /inister of %o$er and consists of mem&ers represented &ySecretaries of various line /inistries, the CE1s of technical agencies under the/inistries, mem&ers representing e'uipment and appliance manuf acturers,industry, architects, consumers and five po$er regions representing the states" TheDirector 0eneral of the Bureau shall &e the e*fficio mem&er.secretary of theCouncil"
The BEE $ill &e initially supported &y the Central 0overnment &y $ay of grantsthrough &udget, it $ill, ho$ever, in a period of A.= years &ecome self .suff icient" !t$ould &e authoried to collect appropriate fee in discharge of its f unctionsassigned to it" The BEE $ill also use the Central Energy Conservation -und andother funds raised from various sources for innovative f inancing of energyeff iciency pro5ects in order to promote energy eff icient investment"
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(.(;(.(; DDIISSTTR R IBIBUUTTEE DD
GGEENNEERARATITIOONN
(.* D0str0!ute& Genert0on Bs0cs
t 0s D0str0!ute& Genert0on
Distri&uted generation (or D0 generally refers to small.scale (typically 8 )# A /#electric po$er generators that produce electricity at a site close to customers or that are tiedto an electric distri&ution system" Distri&uted generators include, &ut are not limited tosynchronous generators, induction generators, reciprocating engines, micro.tur&ines(com&ustion tur&ines that run on high.energy fossil f uels such as oil, propane, natural gas,gasoline or diesel, com&ustion gas tur&ines, f uel cells, solar photo.voltaic, and $indtur&ines"
A44"0ct0ons o3 D0str0!ute& Genert0n# S$ste-s
There are many reasons a customer may choose to install a distri&uted generator" D0 can&e used to generate a customer4s entire electricity supply for pea) shaving(generating a portion of a customer4s electricity onsite to reduce the amount of electricitypurchased during pea) price periods for stand&y or emergency generation (as a &ac)up to#ires 1$ner9s po$er supply as a green po$er source (using rene$a&le technology or forincreased relia&ility" !n some remote locations, D0 can &e less costly as it eliminates theneed for e*pensive construction of distri&ution andGor transmission lines"
Bene30ts o3 D0str0!ute& Genert0n# S$ste-s
D0str0!ute& Genert0on'
+as a lo$er capital cost &ecause of the small sie of the D0 (although the investmentcost per )V2 of a D0 can &e much higher than that of a large po$er plant" /ay reduce theneed for large inf rastructure construction or upgrades &ecause the
D0 can &e constructed at the loadlocation"
!f the D0 provides po$er for local use, it may reduce pressure on distri&ution andtransmissionlines"
#ith some technologies, produces ero or near.ero pollutant emissions over its usef ul lif e (not ta)ing into consideration pollutant emissions over the entire product
lifecycleie" po
llut
i
on produced during the manuf actur
ing, or af terdecommissioning of the D0 system"
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
So lar Energ y:
Intro&u ct0 on '
Solar energy is an important, clean, cheap and a&undantly availa&le rene$a&le energy" !t is received on Earth in cyclic, intermittent and dilute form $ith very lo$ po$er density to 8)#
Gm;"So
l
ar energy recei
ved on the groundl
evel i
s affected &y atmospheri
c cl
ari
ty, degreeof latitude, etc" -or design purpose, the variation of availa&le solar po$er, the optimum tilt angle of solar f lat plate collectors, the location and orientation of the heliostats should &ecalculated"
Un0ts o3 so"r 4ower n& so"r ener#$'!n S! units, energy is e*pressed in Foule" 1ther units are angley and Calorie $here
8 angley 8 CalGcm;"day8 Cal @"8? F
-or solar energy calculations, the energy is measured as an hourly or monthly or yearlyaverage and is e*pressed in terms of ) FGm;Gday or ) FGm;Ghour" Solar po$er is e*pressedin terms of #Gm; or )#Gm;"
Essent0" su!s$ste-s 0n so"r ener#$ 4"nt'
8" So"r co""ector or concentrtor: !t receives solar rays and collects the energy" !t may &eof follo$ing types:
a -lat plate type $ithout f ocusing& %ara&olic trough type $ith line f ocusingc %ara&oloid dish $ith central f ocusingd -resnel lens $ith centre f ocusinge +eliostats $ith centre receiver f ocusing
;" Ener#$ trns4ort -e&0u-: Su&stances such as $aterG steam, li'uid metal or gas areused totransport the thermal energy from the collector to the heat e*changer or thermal storage" !nsolar %V systems energy transport occurs in electrical f orm"
>" Ener#$ stor#e: Solar energy is not availa&le continuously" So $e need an energy storagemedium for maintaining po$er supply during nights or cloudy periods" There are three ma5ortypes of energy
storage: a Thermal energy storage & Battery storage c %umped storage hydro.electricplant"
@" Ener#$ con7ers0on 4"nt: Thermal energy collected &y solar collectors is used f orproducing steam, hot $ater, etc" Solar energy converted to thermal energy is fed to steam.thermal or gas.thermal po$er plant"
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A" Power con&0t0on0n#, contro" n& 4rotect0on s$ste-: Koad re'uirements of electricalenergy vary $ith time" The energy supply has certain specif ications li)e voltage, current,fre'uency, po$er etc"
The po$er conditioning unit performs several f unctions such as control, regulation,conditioning,protection, automation, etc"
-ig Su&systems in solar thermal energy conversion plants
" A"ternt07e or stn&!$ 4ower su44"$: The &ac)up may &e o&tained as po$er f romelectricalnet$or) or stand&y diesel generator"
Ener#$ 3ro- te sun'
The sun radiates a&out >"? * 8; # of po$er in all the directions" 1ut of this a&out 8"= *88= # isreceived &y earth" The average solar radiation outside the earth4s atmosphere is 8">A)#Gm; varying from 8"@> )#Gm; (in Fanuary to 8">> )#Gm;(in Fuly"
Solar thermal energy (STE is a form of energy and a technology f or
harnessing so
l a r e n e rg y to generate th e r m a
l e n er gy or e
lectr
ica
l energy for use in
industry,
Department of Electrical Engineering, Veer Surendra Sai University of Technology Burla Page 31
thermosiphon
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
and in the residential and commercial sectors" The f irst installation of solar thermal
energy e'uipment occurred in the S ahara Dese rt appro*imately in 8A@ /#, also inthe /o5ave, as $ell as the So l n o v a S o l ar % o $ e r S tati o n (8A /#, the 2n d a so l so l ar p o $ er stati o n (8A/#, and E* tr e s o l S o l a r % o $ e r i o n (8 /#, allin Spain"
The f irst three units of So ln o va in the foreground, $ith the t$o to$ers of the %S8 and %S ; solar po$er stations in the &ac)ground"
2 solar thermal collector system gathers the heat from the solar radiation and gives it to
the heat transport f luid" The heat.transport fluid receives the heat from the collector and
delivers it to the thermal storage tan), &oiler steam generator, heat e*changer etc" Thermal
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storage system stores heat for a fe$ hours" The heat is released during cloudy hours and at
night" Thermal.electric conversion system receives thermal energy and drives steam
tur&ine generator or gas tur&ine generator" The electrical energy is supplied to the
electrical load or to the 2C grid" 2pplications of solar thermal energy systems range f rom
simple solar coo)er of 8 )# rating to comple* solar central receiver thermal po$er plant
of ; /# rating"
SOLAR COLLECTORS
Solar thermal energy is the most readily availa&le source of energy" The Solar energy is mostimportant )ind of non.conventional source of energy $hich has &een used since ancienttimes, &ut in a most primitive manner" The a&undant solar energy availa&le is suita&le forharnessing for a num&er of applications" The application of solar thermal energy systemranges from solar coo)er of 8 )$ to po$er plant of ;/#" These systems are groupedinto lo$ temperature (P8AoC, medium temperature (8A.>oC applications"
Solar C oll ect ors
Solar collectors are used to collect the solar energy and convert the incident radiations intothermal energy &y a&sor&ing them" This heat is e*tracted &y flo$ing fluid (air or $ater ormi*ture $ith antif reee in the tu&e of the collector for further utiliation in diff erentapplications" The collectors are classif ied as 6on concentrating collectorsS Concentrating (f ocusing collectors
N on C oncentrating C oll ect ors
!n these collectors the area of collector to intercept the solar radiation is e'ual to thea&sor&er plate and has concentration ratio of 8" -lat %late Collectors (0lae Type -latplate collector is most important part of any solar thermal energy system" !t is simplest indesign and &oth direct and diff use radiations are a&sor&ed &y collector and converted intousef ul heat" These collectors are suita&le for heating to temperature &elo$ 8oC" The mainadvantages of f lat plate collectors are: !t utilies the &oth the &eam as $ell as diff use radiation for heating"S 7e'uires less maintenance"
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Disadvantages
S Karge heat losses &y conduction and radiation &ecause of large area" 6o trac)ing of sun"S Ko$ $ater temperature is achieved"
The constructional details of f lat plate collector is given &elo$
(a !nsulated Bo*: The rectangular &o* is made of thin 0"! sheet and is insulated f rom sidesand &ottom using glass or mineral $ool of thic)ness A to ? cm to reduce losses f romconduction to &ac) and side $all" The &o* is tilted at due south and a tilt angle depends onthe latitude of location" The face area of the collector &o* is )ept &et$een 8 to ; m;"
(& Transparent Cover: This allo$s solar energy to pass through and reduces theconvective heat losses from the a&sor&er plate through air space" The transparenttampered glass cover is placed on top of rectangular &o* to trap the solar energy andsealed &y ru&&er gas)ets to prevent the lea)age of hot air" !t is made of plasticGglass &ut glassis most f avoura&le &ecause of its transmittance and lo$ surface degradation" +o$ever$ith development of improved 'uality of plastics, the degradation 'uality has &eenimproved" The plasticsare availa&le at lo$ cost, light in $eight and can &e used to ma)etu&es, plates and cover &ut are suita&le for lo$ temperature application =.8;oC $ith singlecover plate or up to 8AoC using dou&le cover plate" The thic)ness of glass cover > to @mm is commonly used and 8 to ; covers $ith spacing 8"A to > cm are generally used&et$een plates" The temperature of glass cover is lo$er than the a&sor&er plate and is a gooda&sor&er of thermal energy and reduces convective and radiative losses of s)y"
(c 2&sor&er %late: !t intercepts and a&sor&s the solar energy" The a&sor&er plate is made of copper, aluminum or steel and is in the thic)ness of8 to ; mm" !t is the most important part of collector along $ith the tu&es products passing the li'uid or air to &e heated" The platea&sor&s the ma*imum solar radiation incident on it through glaing (cover plate and transf ersthe heat to the tu&es in contact $ith minimum heat losses to atmosphere" The plate is &lac)painted and provided $ith selective material coating to increase its a&sorption and reducethe emission" The a&sor&er plate has high a&sorption (?.
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Copper and aluminum are li)ely to get corroded $ith saline li'uids and steel tu&es $ithinhi&itors are used at such places"
7emoval of +eat: These systems are &est suited to applications that re'uire lo$temperatures" 1nce the heat is a&sor&ed on the a&sor&er plate it must &e removed f ast anddelivered to the place of storage for further use" 2s the li'uid circulates through the tu&es, ita&sor&s the heat from a&sor&er plate of the collectors" The heated li'uid moves slo$ly andthe losses from collector $ill increase &ecause of rise of high temperature of collector and$ill lo$er the eff iciency" -lat.plate solar collectors are less eff icient in cold $eather than in$arm $eather" -actors aff ecting the %erformance of -lat %late Collector" The diff erent factors aff ecting the performance of system are:
(a !ncident Solar 7adiation: The eff iciency of collector is directly related $ith solarradiation falling onit and increases $ith rise in temperature"
(& 6um&er of Cover %late: The increase in num&er of cover plate reduces the internalconvective heat losses &ut also prevents the transmission of radiation inside the collector"/ore than t$o cover plate should not &e used to optimie the system"
(c Spacing: The more space &et$een the a&sor&er and cover plate the less internal heatlosses" The collector eff iciency $ill &e increased" +o$ever on the other hand, increase inspace &et$een them provides the shading &y side $all in the morning and evening andreduces the a&sor&ed solar flu* &y ;.> of system" The spacing &et$een a&sor&er andcover plate is )ept ;.> cm to &alance the pro&lem"
(d Collector Tilt: The f lat plate collectors do not trac) the sun and should &e tilted at angleof latitude of the location for an average &etter performance" +o$ever $ith changingdeclination angle $ith seasons the optimum tilt angle is )ept V 8Ao"
The collector is placed $ith south f acing at northern hemisphere to receive ma*imumradiation throughout the day"
(e Selective Surf ace: Some materials li)e nic)el &lac) (W B"?
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(f !nlet Temperature: #ith increase in inlet temperature of $or)ing fluid the lossesincrease to am&ient" The high temperature fluid a&sor&ed the less heat from a&sor&er plate&ecause of lo$ temperature diff erence and increases the top loss coeff icient" Theref ore theeff iciency of collector get reduced $ith rise in inlet temperature"
(g Dust on cover %late: The eff iciency of collector decreases $ith dust particles on thecover plate &ecause the transmission radiation decreases &y 8" -re'uent cleaning isre'uired to get the ma*imum eff iciency of collector"
Concentrt0n# Co""ectors
Concentrating collector is a device to collect solar energy $ith high intensity of solarradiation on the energy a&sor&ing surface" Such collectors use optical system in the f orm of ref lectors or ref ractors"
These collectors are used for medium (8.>o C and high.temperature (a&ove >oCapplications such as steam production for the generation of electricity" The hightemperature is achieved at a&sor&er &ecause of ref lecting arrangement provided f orconcentrating the radiation at re'uired location using mirrors and lenses" These collectors are &est suited to places having more num&er of clear days in a year"
The area of the a&sor&er is )ept less than the aperture through $hich the radiation passes, toconcentrate the solar f lu*" These collectors re'uire trac)ing to follo$ the sun &ecause of optical system" The trac)ing rate depends on the degree of concentration ratio and needsfre'uent ad5ustment for system having high concentration ratio" The eff iciency of thesecollectors lies &et$een A.=" The collectors need more maintenance than -%C &ecause of its optical system" The concentrating collectors are classif ied on the &asis of ref lector usedconcentration ratio and trac)ing method adopted"
FPC w0t Re3"ectors
The mirrors are placed as ref lecting surface to concentrate more radiations on -%Ca&sor&er" The fluid temperature is higher &y >oC than achieved in -%C" Thesecollections utilie direct and diff use radiation"
Lens Focus0n# T$4e
The f resnel lenses are used to concentrate the radiation at its focus" The lo$er side of lenses is grooved so that radiation concentrates on a focus line"
Co-4oun& Pr!o"0c Co""ectors
These collectors are line f ocusing type" The compound para&olic collectors have t$opara&olic surfaces to concentrate the solar radiation to the a&sor&er placed at &ottom"
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These collectors have high concentration ratio and concentrator is moving to trac) the sun"
C$"0n&r0c" Pr!o"0c Co""ectors
The troughs concentrate sunlight onto a receiver tu&e, placed along the f ocal line of thetrough" The temperature at the a&sor&er tu&e is o&tained at nearly @o C" The a&sor&er inthese collectors is moving to receive the ref lected radiations &y ref lector, $hile theconcentrators (trough remains f i*ed" Because of its para&olic shape, it can focus the sun at> to 8 times its normal intensity (concentration ratio on a receiver" The heat transf ermedium carries the heat at one central place for further utiliation"Pr!o"0c D0s Co""ector
The collectors have mirror.li)e ref lectors and an a&sor&er at the f ocal point" Thesecollectors are point f ocusing type" The concentrating ratio of these collectors is 8 andtemperature of the receiver can reach up to ;o C" These collectors have highereff iciency for converting solar energy to electricity in the small.po$er plant" !n some systems,a heat engine, such as a Stirling engine, is connected to the receiver to generate electricity"Center 7eceiver Type (Solar %o$er To$er These collectors are used to collect the large solar energy at one point" This system uses8.8 of f lat trac)ing mirror scaled heliostats to ref lect the solar energy to centralreceiver mounted on to$er" The energy can &e concentrated as much as 8,A times thanthat of the energy coming in, from the sun" The losses of energy from the system are
mi
ni
mi
ed as sol
ar energyi
s &ei
ng di
rectl
y transf erred &y ref l
ecti
on from the heli
ostats toa single receiver $here the sun4s rays heat a fluid to produce steam"
2dvantages of concentrating collector over f lat collector The sie of the a&sor&er can &e reduced that gives high concentration ratio"
S Thermal losses are less than -%C" +o$ever small losses occur in the concentratingcollector &ecause of its optical system as $ell as &y ref lection, a&sorption &y mirrors andlenses" The eff iciency increases at high temperatures"
!n these collectors the area intercepting the solar radiation is greater than the a&sor&er area" These collectors are used for high.temperature applications"S 7ef lectors can cost less per unit area than f lat plate collectors"
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S -ocusing or concentrating systems can &e used for electric po$er generation $hen notused for heating or cooling
S Kittle or no anti freee is re'uired to protect the a&sor&er in a concentrator system$hereas the entire solar energy collection surface re'uires anti freee protection in a f latplate collectorDisadvantages
1ut of the &eam and diff use solar radiation components, only &eam component iscollected in case of f ocusing collectors &ecause diff use component cannot &e ref lectedand is thus lost" !n some stationary ref lecting systems it is necessary to have a small a&sor&er to trac) thesun image in others the ref lector may have to &e ad 5usta&le more than one position if yearround operation is desired in other $ords costly orienting systems have to &e used to trac) thesun"
S 2dditional re'uirements of maintenance particular to retain the 'uality of ref lectingsurface against dirt, $eather, o*idation etc" 6on unif orm flu* on the a&sor&er $hereas flu* in f lat.plate collectors in unif orm"
S 2dditional optical losses such as ref lectance loss and the intercept loss, so theyintroduce additional factors in energy &alances"S +igh initial cost"
So"r A0r Heters
2ir stream is heated &y the &ac) side of the collector plate in f lat plate collector" -insattached to the plate increase the contact surface" The &ac) side of the collector is heavilyinsulated $ith mineral $ool or some other material" !f the sie of collector is large, a&lo$er is used to dra$ air into the collector and transmit the hot air to dryer"
The most f avora&le orientation of a collector for heating only is f acing due south at aninclination angle to the horiontal e'ual to the latitude plus 8A" The use of air as the heattransport fluid eliminates &oth f reeing and corrosion pro&lems and small air lea)s are of lessconcern than $ater lea)sDisadvantages:
8" 6eed of handling larger volumes of air than li'uids due to lo$ density of air as$or)ing su&stance";" Thermal capacity of the air is lo$"
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
eff iciency cannot &e improved" Too many surfaces and too much restriction to air flo$ $illre'uire a larger fan and a larger amount of energy to push the air through" The energy re'uiredfor this cancels out saving from using solar energy, particularly if fan is electrical and if theamount of energy $hich is &urned at the po$er plant to produce the electrical energy isincluded"
The solar air heating utiliing a transpired honey com& is also f avora&le since the flo$ crosssection is much higher" Crushed glass layers can &e used to a&sor& solar radiation and heatthe air" 2 porous &ed $ith layers of &ro)en &ottles can &e readily used f or agriculturaldrying purposes $ith minimum e*penditure" The overlapped glass plate air heater can &econsidered as a form of porous matri*, although overall flo$ direction is along the a&sor&erplates instead of &eing across the matri*" 2pplications of Solar air heatersS +eating &uildings"S Drying agricultural produce and lum&er"S +eating green houses"S 2ir conditioning &uilding sutiliing desiccant &eds or a a&sorption ref rigeration process"S +eat sources for a heat engine such as a Brayton or Stirling cycle"
F"t 4"te co""ector'
-lat plate collector a&sor&s &oth &eam and diff use components of radiant energy" Thea&sor&er plate is a specially treated &lac)ened metal surface" Sun rays stri)ing thea&sor&er plate are a&sor&ed causing rise of temperature of transport f luid" Thermalinsulation &ehind the a&sor&er plate and transparent cover sheets (glass or plastic prevent lossof heat to surroundings"
2pplications of f lat plate collector:
8" Solar $ater heating systems for residence, hotels, industry"
;" Desalination plant for o&taining drin)ing $ater from sea $ater"
>" Solar coo)ers for domestic coo)ing"
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@" Drying applications"
A" 7esidence heating"
Kosses in f lat plate collector:
8"Shadow e
ff ec
t : Shado$s of some of the ne
i
gh&or panel f a
ll on the surface of the
collector $here
the angle of elevation of the sun is less than 8Ao(sun.rise and sunset"
Shado$ factor surface of the collector recieving light
Total surface of the collector
Shado$ factor is less than B"8 during morning and evening" The eff ective hours of solar
collectors
are &et$een " R e fl ec ti v e l oss f a c t or: The collector glass surface and the ref lector surface collect dust,
dirt, moisture etc" The ref lector surface gets rusted, deformed and loses the shine" +ence, theeff iciency of the collector is reduced signif icantly $ith passage of time"
M0ntennce o3 3"t 4"te co""ector'
8" Daily cleaning
;" Seasonal maintenance (cleaning, touch.up paint
>" Learly overhaul (change of seals, cleaning af ter dismantling
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Pr!o"0c trou# co""ector'
%ara&olic trough $ith line f ocusing ref lecting surface provides concentrati n ratios f rom
> to A" +ence, temperature as high as >oC can &e attained" Kight is focused on a
central line of the para&olic trough" The pipe located along the centre line a&sor&s the heat
and the $or)ing fluid is circ
Pr!o"o0& &0s co""ectors'
lated trough the pipe"
The &eam radiation is ref lected &y para&oloid dish surface" The point focus is o&tained
$ith C7 (a&ove 8 and temperatures around 8oC"
Bse& on te te-4erture'
• Ko$ temperature collector
• /edium temperature collector
• +igh temperature collector
Low temperature coll ect or :
Ko$.temperature collectors\edit] ain article: Solar thermal collector
0laed solar collectors are designed primarily for space heating" They re.circulate &uildingair through a solar air panel $here the air is heated and then directed &ac) into the &uilding" These solar space heating systems re'uire at least t$o penetrations into the &uilding andonly perform $hen the air in the solar collector is $armer than the &uilding roomtemperature" /ost glaed collectors are used in the residential sector"
o
u
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Unglaed, QtranspiredQ air collector
Unglaed solar collectors are primarily used to pre.heat ma)e.up ventilation air incommercial, industrial and institutional &uildings $ith a high ventilation load" They turn&uilding $alls or sections of $alls into lo$ cost, high performance, unglaed solarcollectors" +eat conducts from the a&sor&er surface to the thermal &oundary layer of air8 mm thic) on the outside of the a&sor&er and to air that passes &ehind the a&sor&er" The&oundary layer of air is dra$n into a near&y perf oration &efore the heat can escape &yconvection to the outside air" The heated air is then dra$n from &ehind the a&sor&er plateinto the &uilding9s ventilation system"
2 Trom&e $all is a passive solar heating and ventilation system consisting of an airchannel sand$iched &et$een a $indo$ and a sun.f acing thermal mass" During theventilation cycle, sunlight stores heat in the thermal mass and $arms the air channelcausing circulation through vents at the top and &ottom of the $all" During the heatingcycle the Trom&e $all radiates stored heat"Solar roof ponds are uni'ue solar heating and cooling systems developed &y +arold +ay inthe 8
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&uilt &y +o r ac e de S a u ssu r e in 8==" 2 &asic &o* coo)er consists of an insulatedcontainer $ith a transparent lid" These coo)ers can &e used eff ectively $ith partiallyovercast s)ies and $ill typically reach temperatures of A8 ^C" Concentrating solarcoo)ers use ref lectors to concentrate solar energy onto a coo)ing container" The mostcommon ref lector geometries are f lat plate, disc and para&olic trough type" These designscoo) f aster and at higher temperatures (up to >A ^C &ut re'uire direct light to f unctionproperly" The Solar Hitchen in 2u r o vill e , !n di a uses a uni'ue concentrating technology)no$n as the so l a r & o $ l " Contrary to conventional trac)ing ref lectorGf i*ed receiversystems, the solar &o$l uses a f i*ed spherical ref lector $ith a receiver $hich trac)s the focusof light as the Sun moves across the s)y" The solar &o$l9s receiver reaches temperature of 8A ^C that is used to produce steam that helps coo) ;, daily meals"
+igh temperature collector#here temperatures &elo$ a&out
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storage"\ ; ] #ith current technology, storage of heat is much cheaper and more eff icient thanstorage of electricity" !n this $ay, the CS% plant can produce electricity day andnight" !f the CS% site has predicta&le solar radiation, then the CS% plant &ecomesa relia&le po$er plant" 7elia&ility can further &e improved &y installing a &ac).upcom&ustion system" The &ac).up system can use most of the CS% plant, $ thecost of the &ac).up system" ich decreases
CS% f acilities utilie high electrical conductivity materials, such as copper, in f ield
po$er ca &l e s , grounding net$or)s, and m o t o r s for trac)ing and pumping f luids, as $ell as inthe main generator and high voltage tr a n s f o r m e r s "#ith relia&ility, unused desert, no pollution, and no f uel costs, the o&stacles for largedeployment for CS% are cost, aesthetics, land use and similar factors for the necessaryconnecting high tension lines" 2lthough only a small percentage of the desert is necessary tomeet glo&al electricity demand, still a large area must &e covered $ith mirrors or lenses too&tain a signif icant amount of energy" 2n important $ay to decrease cost is the use of aS !/ % K E design"#hen considering land use impacts associated $ith the e*ploration and e*tractionthrough to transportation and conversion of foss il f u e ls , $hich are used for most of ourelectrical po$er, utility.scale solar po$er compares as one of the mostenergy resources availa&le"S$ste- &es0#ns
land.eff icient
During the day the sun has diff erent positions" -or lo$ concentration systems (and lo$temperatures trac)ing can &e avoided (or limited to a fe$ positions per year if non.im a g in g o p tic s are used" -or higher concentrations, ho$ever, if the mirrors or lenses do notmove, then the focus of the mirrors or lenses changes (&ut also in these cases no n . im a g in g op ti c s provides the $idest a c ce p t a n c e a ng l e s for a given concentration" Therefore itseems unavoida&le that there needs to &e a trac)ing system that follo$s the position of thesun (for solar ph o to v o l ta i c a so l ar t rac ) e r is only optional" The trac)ing system increases thecost and comple*ity" #ith this in mind, diff erent designs can &e distinguished in ho$ theyconcentrate the light and trac) the position of the sun"Parabolic trough designs
P ara b o lic t r o u gh power plants use a curved!irrored trough which re"ects the direct solarradiation onto a glass tube containing a "uid#also called a receiver absorber or collector$running the length o% the trough positioned atthe %ocal point o% the re"ectors. &he trough isparabolic along one a'is and linear in theorthogonal a'is. For change o% the dail( positiono% the sun p e r p e nd ic u lar to the receiver the
trough tilts east to west so that the directradiation re!ains%ocused on the receiver. )owever seasonal changes in the in angle o%sunlight p arall e l to thetrough does not re*uire ad+ust!ent o% the !irrors since thelight is si!pl(
concentrated
elsewhere on the receiver. &hus the trough design does not re*uire trac,ingon a second a'is. &he receiver !a( be enclosed in a glass vacuu! cha!ber.
&he vacuu! signi%icantl( reduces convective heat loss.
h
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2 para&olic solar dish concentrating the sun9srays on the heating element of a Stirlin g en gine" -resnel ref lector
CS%.Stirling is )no$n to have the highest eff iciency of all so la r te c hn o lo g ie s around >compared to solar %V appro*imately 8A, and is predicted to &e a&le to produce thecheapest energy among all rene$a&le energy sources in high scale production and hot areas,semi deserts etc" 2 dis h S tirli n g system uses a large, ref lective, pa r a &o li c dish (similar inshape to satellite television dish" !t focuses all the sunlight that stri)es the dish up onto asingle point a&ove the dish, $here a receiver captures the heat and transforms it into a usef ulform" Typically the dish is coupled $ith a Sti r li n g en g i n e in a Dish.Stirling System, &ut alsosometimes a s t ea m en g i n e is used" These create rotational )inetic energy that can &e convertedto electricity using an el e c tr i c g e n e r a to r "
Fresneltechnologies
2 linear -re s n e l re f le c to r po$er plant uses a series of long, narro$, shallo$.curvature (or evenf lat mirrors to focus light onto one or more linear receivers positioned a&ove the mirrors" 1ntop of the receiver a small para&olic mirror can &e attached for f urther f ocusing the light" These systems aim to offer lo$er overall costs &y sharing a receiver &et$een several mirrors(as compared $ith trough and dish concepts, $hile still using the si m p l e line.f ocus geometry$ith one a*is for trac)ing" This is similar to the trough design (and diff erent from centralto$ers and dishes $ith dual.a*is" The receiver is stationary and so fluid couplings are notre'uired (as in troughs and dishes" The mirrors also do not need to support the receiver, sothey are structurally simpler" #hen suita&le aiming strategies are used (mirrors aimed atdiff erent receivers at diff erent times of day, this can allo$ a denser pac)ing of mirrors onavaila&le land area"7ival single a*is trac)ing technologies include the relatively ne$ linear -resnel ref lector(K-7 and compact.K-7 (CK-7 technologies" The K-7 diff ers from that of thepara&olic trough in that the a&sor&er is f i*ed in space a&ove the mirror f ield" 2lso, theref lector is composed of many lo$ ro$ segments, $hich focus collectively on an elevatedlong to$er receiver running parallel to the ref lector rotational a*is"%rototypes of -r e s n e l l e n s concentrators have &een produced for the collection of thermalenergy &y !n te r n a ti o n a l 2 u to m a te d S y s t e m s " 6o f ull.scale thermal systems using -resnellenses are )no$n to &e in operation, although products incorporating -resnel lenses incon 5unction $ith photovoltaic cells are already availa&le"\@8]
Micro-CSP
/icro.CS% is used for community.sied po$er plants (8 /# to A /#, for industrial,agricultural and manuf acturing 9process heat9 app l i c a ti o n s, and $hen large amounts of hot$ater are needed, such as resort s$imming pools, $ater par)s, large laundry f acilities,steriliation, distillation and other such uses"Enclosed parabolictrough
The enclosed para&olic trough solar thermal system encapsulates the components $ithin anoff .the.shelf greenhouse type of glasshouse" The glasshouse protects the components fromthe elements that can negatively impact system relia&ility and eff iciency" This protectionimportantly includes nightly glass.roof $ashing $ith optimied $ater.eff icient off .the.shelf automated $ashing systems"\ @;] Kight$eight curved solar.ref lecting mirrors
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+eat storage ena&les solar thermal plants to produce electricity during hours $ithoutsunlight" +eat is transf erred to a thermal storage medium in an insulated reservoir duringhours $ith sunlight, and is $ithdra$n for po$er generation during hours lac)ing sunlight" Thermal storage mediums $ill &e discussed in a heat storage section" 7ate of heat transf er isrelated to the conductive and convection medium as $ell as the temperaturediff erences" Bodies $ith large temperature diff erences transf er heat f aster than &odies $ithlo$er temperature diff erences"+eat transport refers to the activity in $hich heat from a solar collector is transported to theheat storage vault" +eat insulation is vital in &oth heat transport tu&ing as $ell as the storagevault" !t prevents heat loss, $hich in turn relates to energy loss, or decrease in the eff iciency of the system"
2s solar po$er has lo$ density ()#Gm;, theref ore large area on the ground is covered &ycollectors" -lat plate collectors are used for lo$ temperature applications" -or achievinghigher temperature of transport f luid, the sun rays must &e concentrated and f ocused"Concentrt0on Rt0o /CR2'
CR =solar radiation surfaces()#Gm;
solar radiation at focus on surfaces of collector()#Gm ;
C7 -or f lat plate collectors, C7 8" Using heliostats $ith sun.trac)ing in t$o planes,
$e o&tain C7 of the order of 8" C7 up to 8 can &e achieved &y using para&olic
trough collectors $ith sun trac)ing in one plane"
The performance of a collector is evaluated in terms of its collector eff iciency $hich isgiven as constant solar radiation ()#Gm;, the collector eff iciency decreases $ith theincreasing diff erence &et$een the collector temperature and the outside temperature"
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PageDepartment of Electrical Engineering, Veer Surendra Sai University of Technology Burla
PHOTO VOLTAIC TECHNOLOGY'
The Hyoto agreement on glo&al reduction of greenhouse gas emissions has promptedrene$ed interest in rene$a&le energy systems $orld$ide" /any rene$a&le energytechnologies today are $ell developed, relia&le, and cost competitive $ith the conventionalf uel generators" The cost of rene$a&le energy technologies is on a f alling trend and ise*pected to f all further as demand and production increases" There are many rene$a&le
energy sources such as &iomass, solar, $ind, mini.hydro, and tidal po$er" 1ne of theadvantages offered &y rene$a&le energy sources is their potential to provide sustaina&leelectricity in areas not served &y the conventional po$er grid"
The gro$ing mar)et for rene$a&le energy technologies has resulted in a rapid gro$thin the need for po$er electronics" /ost of the rene$a&le energy technologies produceDC po$er, and hence po$er electronics and control e'uipment are re'uired to convert theDC into 2C po$er"
!nverters are used to convert DC to 2C" There are t$o types of inverters: stand. aloneand grid.connected" The t$o types have several similarities, &ut are diff erent in terms of control f unctions"
2 stand.alone inverter is used in off .grid applications $ith &attery storage" #ith&ac)up diesel generators (such as % Vdiesel hy&rid po$er systems, the inverters may haveadditional control f unctions such as operating in parallel $ith diesel generators and
&idirectional operation (&attery charging and inverting" 0rid.interactive inverters mustfollo$ the voltage and fre'uency characteristics of the utility.generated po$erpresented on the distri&ution line" -or &oth types of inverters, the conversion eff iciency is avery important consideration" Details of stand.alone and grid.connected inverters for %V and$ind applications are discussed in this chapter"
The density of po$er radiated from the sun (ref erred to as the 33solar energyconstant44 at the outer atmosphere is 8">=>)#Gm;" %art of this energy is a&sor&edand scattered &y the earth4s atmosphere" The final incident sunlight on earth4s surf acehas a pea) density of 8)#Gm; at noon in the tropics" The technology of photovoltaic
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2 simplif ied e'uivalent circuit of a solar cell consists of a current source in parallel $ith a
diode as sho$n in -ig" ;a" 2 varia&le resistor is connected to the solar cell generator as a
load" #hen the terminals a
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