soalr pv info

8/11/2019 Soalr PV Info

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Solar panels

Issued M arch 1999

RS stock numbers 194-082, 194-098, 194-105, 194-111, 194-127, 194-133

194-149, 194-161, 194-183, 768-071, 768-087

Data Pack F

Data Sheet

A rang e o f com m ercial grade thin film am orphous silicon andind ustrial grade polycrystalline photovo ltaic m odules. The sepane ls are suitab le for charging both nickel cad m ium anddryfit batteries.

Principle of operationSolar panels w ork on the principle of the photovo ltaic e ffect.The photovoltaic e ffect is the conversion of sunlight intoelectricity. This occurs w hen the PV cell is struck by p hotons

(sunlight), freeingsilicon electrons to travel from the PVce ll, through electronic circuitry, to a load (Figure 1). Thenthey return to the PV ce ll, w here the silicon recaptures theelectron and the process is repeated .

Amorphous siliconSo larex thin film am orpho us silicon m od ules arem anufactured using autom ated processes sim ilar to thoseused for sem icond uctor m anufacturing . These processesresult in a m ono lithic m odule p recision-layered w ith

cond uctive and sem icond uctive film s. The se film s are laser-scribed, using a patented m ethod, into ind ividual solar ce lls.The lase rs ab ility to scribe cleanly and precisely p rod uce s asup erior product in several respects:

C ell d ivisions are very narrow , allow ing m ore m od ulesurface to b e d evoted to p ow er prod uction. Thus, am od ule o f g iven size gene rates m ore p ow er.V oltag e characteristics and ove rall perform ance at lowlight levels are im proved.

The series and parallel connections b etw ee n cells (w hichdeterm ine the m od ules voltage and current output) arecom pleted internal to the m odule (Figure 2), resulting in anultra-reliab le m odule w ithout solder joints.

Polycrystalline siliconPolycrystalline silicon ce lls are m anufactured using 99 .999%pure silico n feedstock nu ggets availab le to thesem icond uctor chip m anufacturers. The nug gets are m elteddow n in a vacuum furnace w ith a little boron and allow ed tocool very slow ly so that a p ure crystal lattice of P-typem aterial is form ed. The resulting b lock is quartered and the n

sliced into 0.2m m w afers using either a ho le saw or a w iresaw (Figure 3).

Fusedsilica

99.99%

Crusher withvibratory/screen

separation

Ball mill Mixer slip(with water)

Slip castings Ceramicvessels

UCP(silicon ingot)

Sizing(silicon brick)

Slicing(silicon wafers)

Silicon wafer(114mm sq 0.3mm)

Feedstock silicon

(crystal nuggets) 99.999%

Light source

Glass supastrateConductiveoxide

Metal Amorphoussilicon

+

Application

External circuit

Light(photons)

Negative layer Positive layer

Figure 1 Principle of operation

Figure 2 Module internal structure

Figure 3 Cell production process


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By a patented process the N -typ e m aterial is form ed as avery thin laye r on one face of each w afer by sp raying w ith aphosphorous com pound gas and baking . Th is is follow ed bythe addition of an anti-reflective filter coating to the uppersurface and cond uctive layers to both faces. The layer on thefront face is optim ised in the form of a g rid in order to allowthe m axim um am ount of light to p ass through to the N -typ em aterial w hilst d istrib uting the m axim um num b er ofelectrons (Figure 4).

C ells are then tested and m atched togethe r w ith cells ofsim ilar perform ance for build ing up into se ries and parallelm atrices to g ive the PV m od ule the desired electricalcharacteristics.

ConstructionA m orphous silicon solar plate ( RS stock no. 194-098)This am orphous solar plate is a m onolithic co nstructionconsisting of several layers of cond ucting and sem i-cond ucting m aterials dep osited onto a solar grad e g lasssup erstrate. Each plate com es unfram ed w ith integral flyingleads.

Low/Medium power amorphous modules(RS stock nos. 194-105 and 194-111)These am orphous silicon solar m od ules consist of seve rallayers of cond ucting and sem i-cond ucting m aterialsdep osited onto a solar grade glass superstrate. Each m od ulecom es co m plete w ith a low profile im pact reinforcedLEX A N fram e w hich protects the back and edg es of thepanel and 1.2m of 2 core 18aw g flying lead s.

Main features of the panels:

Full laser patterning: A patented p roce ss using aco m puter-co ntrolled lase r interconnects all solar ce lls.This m axim ises m od ule active area and cell current w hilem inim ising the area of the interconnects.

Laser isolation: The plate is encircled by a laser scribe toestab lish reliab le isolation. In the final unit, each part issurround ed by a thin, inactive borde r that acts as a barrierto edge corrosion.

Black appearance: A patented op tical coup lingtechno logy, com b ine d w ith a tightly controlledm anufacturing p rocess, creates un iform b lackappearance.

Tin-oxide glass coating: This patented process offers

exceptionally uniform cond uctivity and light ab sorption.

Polycrystalline panels

Low power modules(RS stock nos. 194-127 and 194-133)These m odules consists of high efficiency polycrystallinesilicon w afers bonded to an alum inium sub strate w hich islam inated betw ee n an e thylene vinyl acetate front sheet anda toug h EV A Ted larTM backsheet. Each m odule com escom plete w ith a b lack plastic fram e, an integral stand and0.8m flying lead s.

Medium/High power modules(RS stock nos. 194-149, 194-161, 194-183, 768-071and 768-087).These m od ules have the sam e b asic construction as the lowpow er m odules.Features of the se panels includ e:

Solarex Mega CellA dvanced polycrystalline technolog y11.4cm 11.4cm cell gene rates superior current.

Reliable outside bussingExtend s m od ule lifeResists electrical b reakd ow nA un ique , paten ted titanium d iox ide A R(anti-reflective) coating for optim um light ab sorptionand p ow er outputTem perature rang e 40C to + 90C or 40C to+ 85C at 85% relative hum idity.

Framed versions

Tempered low-iron glassH igh transm issivityH ail and w ind resistant to JPL b lock V standardsW ill w ithstand hailstone of 25.4m m diam eter at aterm inal velocity 52m ph.

Heavy-duty frameC orrosion resistant alum inium alloyA rchitectural grade b ronze anodised finishW ithstands 129m ph (208km /h).

Weatherproof junction box (20W, 32W and 53Wversions only)

N EM A 4X rated . U L rated term inal b lockInd ustry standard opening s and fittings.

Generous frame clearancePrevents electrical b reakdow nIm proves m odule reliab ility.

Unframed version

Low profile and lightweightThe unfram ed typ es have a low p rofile o fapproxim ately 9m m and are lightw eight, the 18Wversion w eighs only 1.49kg .

External circuit

Load

Electricity (Electrons)

Sunlight (photons)

Top electricalcontact redundantfingers or conductivefilm

Base contact conductive layer

Photosensitivesemiconductormaterial layers

Figure 4 Polycrystalline cell structure


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Simple photovoltaic systemA photovoltaic (PV ) system m ay have a m inim um of tw ocom ponents, the m od ule and the load to b e p ow ered. A nexam ple o f such a system w ou ld be a sim ple ventilation fandriven directly b y a m od ule during hot and sunny w eather.For tw enty-four hour a day operation a b attery and b lockingdiode are req uired , w hilst for UK all year round operationavoltage reg ulator is also recom m ended in order to p rotectthe battery from the effects of ove rcharge, typ ically duringthe sum m er.

Note: Th e solar regulator includ es a b locking diod e andthe refore a b locking diod e should on ly b e inco rporated ina system w hen the solar reg ulator is not being used.

Spectral sensitivity of silicon cellsFigure 6 show s the relative response o f crystalline siliconce lls to the ultra-violet, visib le and infra-red spectrum .Resp onse is fairly even to m ost of the visib le w avelengthsand the ne ar infra-red . A m orphous (thin-film ) silicon favoursthe b lue end of the spe ctrum .

The crystalline ce lls are m ad e from boron d op ed siliconw afers and are 12% efficient. The am orphous rang e o fm odules is m anufactured using autom ated thin film processes w here p recision laye rs of cond uctive and sem i-cond uctive m aterials are sprayed onto glass and laserscribed to prod uce ind ividual ce lls w ith an e fficiency o f 7% .A ll m od ules are optim ised for daylight operation w herecurrent is p rop ortional to light intensity and voltag e risesve ry quickly at low light intensities. Both the am orphous andpolycrystalline panels w ill operate in m ost U K daytim e

w eathe r cond itions.

Electrical specificationsStand ard test cond itions (ST C ) the pow er of a m od ule isgiven at ST C w hich is defined as follow s:1. A light intensity o f 1kW /m 2 (eq uivalent to full sun).2. A spectral distribution of A M 1.5 (AM A ir M ass = 1/cos

w here is the angle of the sun to the ve rtical).3. A cell tem perature of 25C .

The definition of air m ass is as follow s:A ir m ass, defined as 1/cosu (w here u is the ang le b etw eenthe sun and directly ove rhead ) is a useful quantity in d ealingw ith atm ospheric effects. A ir m ass indicates the relativedistance that light m ust travel through the atm osphere to agiven location. Because there are no effects due to airattenuation im m ediately outside the earths atm osphere, thiscond ition is referred to as air m ass zero (A M 0). A ir m ass one(A M 1) corresponds to the sun b eing directly overhead . A irm ass 1.5 (A M 1.5), how ever, is considered m orerep resentative of average terrestrial conditions and iscom m on ly used as a reference cond ition in ratingpho tovoltaic m od ules. Figure 7 show s the relative d istancethrough the earths atm osphere that the suns rays m ust pass

at tw o tim es d uring the day.

The value of air m ass at any given tim e and location can beeasily calculated using the relations show n on next pag e. Thehigher the value of air m ass, the greater the attenuating effectof the atm osphere.

Sun

Sun

Angle of incidence = 60

Air mass = 1.0Air mass = 2.0

Earths surface

Limit of atmosphereEarth

Directly overhead(zenith)

UV Visible IR100

R e

l . r e s p . %

300 500 700 900 1100

Wavelength, nanometer

PVarray

Solar shuntregulator

RS stock no.194-082

Blockingdiode

Battery

Load

+

+

RS stock no. 261-299

Figure 5 A simple photovoltaic system

Figure 6 Spectral response of siliconphotovoltaic cell

Figure 7 Suns angle of incidence versusdistance through atmosphere


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G uaranteed p erform ance all m od ules carry a lim itedw arranty covering perform ance :C rystalline products are guaranteed to p roduce at least90% of the specified m inim um pow er output for a period of 5years.A m orphous products are g uaranteed to p rod uce at least80% of the specified Im p (current at m axim um pow er) at STCw ith the voltag e fixed at V m p.

Electrical characteristics at STCSm all low pow er m odules

Medium to high power modulesThe m ed ium to high pow er m od ules (tab le b elow ) arelabelled detailing the individual characteristics of their actualpe rform ances at STC . The pow er outpu t of N O C T N orm alO perating C ell Te m perature at an am bient tem perature of20C is also p rinted on the lab el.N otes:1 . The 20W , 32W and 53W versions are suitab le for b oth 6

and 12V op eration and are user configurab le, seeinstallation details.

2. The M SX light series are the unfram ed versions.

Model MSX-005 MSX-01 SA-0640RS stock nos. 194-127 194-133 194-098Sp ecified lo ad vo ltag e (V ld ) 3.3V 7.5V 7.5VN om inal battery voltage 2.4V 6V 6VTypical cu rrent at V ld (Ild ) 150m A 150m A 45m A

O p en circuit voltag e (Voc) 4.6V 10.3V 12.0VShort circuit curre nt (ISC ) 160m A 160m A 54m ATem perature coefficient ofvoltage per C 16m V 37m V 30m VTem perature coefficient ofcurrent per C 0.15m A 0.15m A 0.05m A

Suns rays

Earth

Vertical

h = height

Shadow

S

Suns rays

A ir m ass = 1+ ( s )2h

A ir m ass = 1 cos

Legend: V PP V oltage at peak p ow erIPP C urrent at pe ak p ow erVO C O pen circuit vo ltag eISC Short circuit cu rrent

m V /C of V O C Tem perature co efficient of open circuit vo ltag eA /C of I SC Tem perature coefficient of short circuit current

N O C T N om inal O perating C ell Tem perature 49C (V LX M odules) 45C (M SX M odules)

M odel SA -1 SA -5 M SX -5 M SX -10 M SX -20 V LX -32 V LX -53RS stock nos. 194-105 194-111 194-149 194-161 194-183 768-071 768-087

V pp (V ) 17.5 17.5 17.5 17.5 17.1 17.2 17.2

Ipp (m A ) 80 20 270 580 1170 1860 3080

Voc (V ) 24.0 23.0 21.2 21.2 20.8 21.3 21.3

Isc (m A ) 110 340 290 600 1270 2010 3330

m V /C of V oc -65 -60 -72 -72 -73 -73 -73

A /C of I sc 10 300 275 500 1200 1500 2500

Pm ax @ 3.1 7.3 18.5 29.1 48.2N O C T - m A

Ipp @275.5 590 1194 1896 3140N O C T - m A


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Mechanical characteristicsWeight:RS stock no. 194-183 M SX -20 2.95kg

Dimensions: D im en sions in b rackets are centim etres.U nb racketed dim ensions are in inches.

Mechanical characteristicsWeight

RS stock no. 768-071 V LX -32 3.5kgRS stock no. 768-087 V LX -53 5.5kg

Dimensions: D im en sions in b rackets are centim etres.U nb racketed dim ensions are in inches.

Dim.A Dim.B Dim.C

V LX -32 23.28 19.72 18.38(RS stock no.768-071) (59.1) (50.0) (46.7)

V LX -53 36.88 19.72 18.38(RS stock no.768-087) (93.7) (50.0) (46.7)

0.30(0.75)

0.31(0.8)

0.33(0.85)

0.38(1.0)

0.89(2.3)

0.31(0.8)0.33

(0.85)0.67(1.7)

Section X-X

0.89(2.26)

1.97(5.0)

End view

Back view

Front view

C

A

X X

0.67(1.7)

B

Junctionbox

Dim. A Dim. B Dim. CM SX -20 16.5 0.75 8.29(RS stock no.194-183) (42.1) (1.9) (21.1)

19.76(50.2)

B

Junctionbox0.38 (1.0)dia mtgholes.

C

B18.38(46.7)

A

2.13(5.4)

0.437(1.1)

1.063(2.7)

1.968(5.0)

Section X-X

Back view

Side view

0.69(1.8)

Front viewX X


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Figure 12 Worldwide insolation availability maps These maps indicate worst case (wintertime) solar radiation based on a Solar Array tilted towards the sun atan angle equal to the latitude of the location +15.

4.5

4.5

4.5

4.5

4.0

4.0

4.5

4.04.0

4.5

3.53.5

3.0 3.0

2.02.0

3.5

4.0 4.0

4.5

4.5

4.0

4.0

4.5

5.0

3.53.5

3.03.0

2.5

2.5

15

0

10

20

30

40

50

60

3.5

60

50

40

30

15

0

1.5

2

2.5

3.03.5

4.04.55.0

5.56.0

6.05.5 6.5

7.0

6.0 7.0 7.5

6.0

4.0 3.5

3.53.0

2.52.01.5

0.8

0.60.4

4.0

3.5

5.0

4.0

4.5 5.05.5

5.5

5.0

4.54.0

3.5

3.53.0

6.55.0

6.5

7.0

7.5

3.0

5.5

Eastern hemisphere insolation map (winter)

Eastern hemisphere insolation map (winter)

Daily average insolation levels in theUnited KingdomThe follow ing tab les of m ean daily E SH (eq uivalent sunshinehours) m ay b e used to calculate the size of m od ule req uired :

Legend: O T O ptim um tilt angle (de grees fromhorizontal)H H orizontalV s V ertical south facingSo t Sou th facing at optim um tilt

(D ata taken from Climate in the UK ISBN 0 11 412301 2)Notes:

1. For areas of highe r or low er latitud e in the U Kap propriate insolation levels m ay be extrapolatedfrom the figures show n.

2. The d ata ab ove should be used w ith care as thesefigures w ere g ained from idealsites, p lease considerall the potential perform ance derating factors listedbelow .

3. If sizing a system outside the U K then an approxim ateguide to m ean daily w intertim e (w orst case) inso lationleve ls is given in the follow ing m ap s:

Equivalent sunshine hours kWhrs/m 2/day

Summer Winter Location (OT)mean for June mean for DecH Vs Sot H Vs Sot

Plym outh 65 5.56 2.85 4.20 0.69 1.35 1.40M anchester 68 5.17 2.80 3.86 0.46 0.88 0.91G lasgow 71 4.94 2.76 3.62 0.33 0.64 0.65

298-4578


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Module performance derating factorsIt is ap prop riate to consider the m any factors w hich cand erate the p erform anc e of a so lar m od ule p rior tocom pleting any sizing calculations:a) Tem perature as a guide the typ ical cell op erating

tem perature w ill be 20C to 25C higher than am bient.

b ) C leanliness the m od ules active area sho uld b e cleanedoff periodically to m aintain p erform ance .

c) Prod uction tolerances these are catered for w ith anap prop riate safety factor in the sizing calculation.

d) Reflection/Refraction if the m odule is m ounted behind

glass or som e othe r clear m ed ium then reflection andrefraction w ill typically account for losses of 20% .

e) Shadow ing during sunny conditions the possibility o fshad ow s falling across the m od ule should be reduced toa m inim um as the perform ance of all cells w ill bereduced to that w ith the low est output.

f) A zim uth and tilt ang le as an exam ple it w ill b e seenfrom the U K inso lation tab le ab ove tha t ho rizontalm ounting gives exce llent sum m er pe rform ance b utm inim al in w inter for b est all year round perform ancethe m od ule should be fixed at an ang le o f latitud e + 15,facing true south.

g) Spectral distribution o f light the perform ance of Solarexm od ules is op tim ised for daylight. Pe rform ance underartificial light sources m ust be found by m easurem ent.

Daily system loadIn order to ensure reliab le system operation all year round itis im p erative that the w orst case d aily load in w inter isknow n. It is also very im portan t to e nsu re that ad equateaccount is taken of quiescent load s, sw itching losses and if avo ltag e reg ulator is em p loy ed its ow n c on sum p tioncharacteristics.

Battery sizingThe b attery stores energy from the m od ule enab ling thesystem load to op erate day or night. D ue to the vag aries o fthe w ea the r w e m ust allow for lon g p eriod s of b elowaverage inso lation in orde r to ensu re reliab le operation. Ineffect this m eans that the battery size is calculated to allowfor a ce rtain nu m b er of d ays w itho ut en erg y inp ut, thesystem au tonom y. A t U K latitudes this should not b e lessthan 20 d ays.W e m ust also consider seve ral im portant points;a) that should this situation occur it is not ad visab le to allow

the battery to d ischarge to 0% cap acityb ) capacity red uces w ith tem peraturec) the effects of self d ischarge and charging efficiency m ay

be significantd) battery capacity is a function of discharge rate.Typ ically, therefore, do no t d ischarge the battery b elow its30% charge state and allow for a 10% cap acity red uction inw inter. Thus a system supp lying a load consum ing0.75A h/day w ou ld require a battery cap acity of:

0.75 20 1.3 1.1 = 21.45A hBattery choice T he RS D ryfit rang e of sealed lead acidbatteries is ideal for solar system s having high chargeefficiency, low self-discharge and goo d recovery from highdischarge.

Module sizingH aving determ ined the load req uirem ents and localinsolation the last step is to calcu late the size of m odulereq uired .

SA =L SF

ESH

SA = System A m ps (to be provided b y m odule)L = Load

SF = Safety factor (use 1.2)ESH = Eq uivalent sunshine hours

(kW hrs/m 2/day)Example: Thus for a system consum ing 0.75A h/day all yearround in the M anchester area w ith a m od ule facing truesouth, tilted at latitud e + 15 (= 68) and unshadow ed :

SA = (0.75 1.2)/0.91 = 0.99 A m psFrom the tab le of m od ule p erform ance characteristics w ew ill see that the M SX -18 m od ule has an I PP of 1.06 am ps. Thisis the correct choice as the sm aller M SX -10 only has an I PPof 0.58 A m ps.Note: A regulator w ou ld be required in this system thus the

daily load is inclusive of its pow er requirem ents.

15

0

20

30

40

10

50

60

4.5

5.0

5.5

5.55.04.54.0

3.5

3.02.5

2.01.5

1.01.0

1.5

2.02.5

3.0

3.5

4.0

4.5

4.5

60

50

40

30

15

0

0.31.5 1.0

1.5

2.02.5

1.5

1.52.02.5 3.5

4.0

4.0

5.0

5.05.5

5.55.5

5.5

5.5

4.5

4.03.5

1.8

2.6

5.5

1.1 0

1.4

5.0

3.0

1.3

Western hemisphere insolation map (winter)

Western hemisphere insolation map (winter)


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RegulationIn the U K w ith its high ratio of sum m er to w inter insolation it isalm ost alw ays essential for a solar system to be fitted w ith avo ltag e reg ulator to protect the battery against the effects ofove rcharge during the long sum m er days. A reg ulator w ouldno t b e req uired if d uring the p eriod of operation o f thesystem the d aily load w as m atche d to the m ean m od uleou tput. Reg ulators incorporate b locking diodes that preventb attery d ischarge throug h the m odule a t nig ht, so in anunregulated system a b locking diod e w ould be req uired . Asuitab le b locking diod e w ould be a 1N 5401 (RS stock no.261-299) 3A , 100V .

Shunt regulator ( RS stock no. 194-082)The perform ance specifications o f the shunt regulator are asfollow s:N om inal voltage ________________________________ 12.0VM axim um inpu t current __________________________ 6.0AShunt set point vo ltag e __________________________ 13.8VQ uiescent current ____________________________ < 1.0m ABlocking diod e voltag e drop ______________________ 0.4VTem p. coeff. of output vo ltag e ______________45m V /deg CThe three ou tput leads are co lour cod ed as follow s:RE D ____________________________ SO LA R M O D U L E + veBLAC K________________________________ C O M M O N veYELLO W________________________________ BATTERY +veEach 1.0m m 2 lead is 220m m in length and term inated w ith anM 4 spad e term inal.

Reg ulator status is ind icated by a sing le, green LE D w hich isillum inated w he n the set point vo ltag e of 13.8V is reache dand shunting of the m od ule o utpu t com m ences. W henbattery voltag e d rops to 12.8V the LE D is exting uished andthe m odule output is red irected to the battery.

The m atrix b elow provides g eneral guidelines for choosingeithe r a b locking diode or a regulator.

Glossary of solar termsAir mass A m easure o f distance that light trave ls throughthe earths atm osphere.

Ampere-hour A m easure of electrical charge.

Array A co llection of photovo ltaic m odules, electricallyw ired together and m echanically installed in their w orkingenvironm ent.

Block V M odule qualification tests designed and cond uctedby the Jet Propulsion Lab oratory. M odules und ergo e lectricalperform ance m easurem ents and m echanical tests, such astherm al cycling , hum idity-freezing , cyclic p ressure load ing ,hail-im pact and tw isted m ounting surface req uirem ents.

Blocking diode A device for preventing a reve rse flow ofcurren t through pho tovoltaic m od ules (also called a seriesdiode o r an isolation d iode).

Bypass diode A device p laced in p arallel w ith aphotovoltaic m od ule or group of m od ules allow ing a route forthe current und er cond itions of shad ing and ce ll failure (alsocalled a shunt diode).

Cell efficiency The ratio of the e lectrical ene rgy prod ucedby a p hotovoltaic cell (under full sun conditions) to theene rgy from sunlight falling upon the ce ll.

Design tilt The tilt of the array at w hich design and sizingcalculations are m ad e. O ften the design tilt is optim ised forenergy output under prescribed cond itions.

Diffuse radiation Sunlight received indirectly as a resu lt ofscattering due to clouds, fog, haze, dust or othe r substancesin the atm osphere.

Direct radiation Light that has travelled in a straight pathfrom the sun (also referred to as beam radiation ). A n ob jectin the p ath o f direct radiation casts as a shad ow on a clearday.

Fill factor The ratio of m axim um pow er to the p rod uct ofopen-circuit voltage and short-circuit current. Fill factor isthe squarenessof the I-V cu rve shap e.

Flat-plate array A photovo ltaic array in w hich the incidentsolar rad iation strike s a flat surface and no co ncentration o fsunlight is invo lve d.

Grid-connected A n energy p rod ucing system connectedto the utility grid (also called utility-interactive).

Grounding C onnection to a large cond ucting bod y (suchas the earth), w hich is used as a com m on return for anelectrical circuit and as an arb itrary zero potential.

Holes V acancies, w here electrons should norm ally be in aperfect crystalline structure.

Equivalent sunshine hours kWhrs/m 2/day

Summer Winter Location (OT)mean for June mean for DecH Vs Sot H Vs Sot

Plym outh 65 5.56 2.85 4.20 0.69 1.35 1.40

M anchester 68 5.17 2.80 3.86 0.46 0.88 0.91G lasgow 71 4.94 2.76 3.62 0.33 0.64 0.65

65.0

20.0

1.5

Green LED

RS Stock No.194-082

Solar ShuntRegulator

5.0

10.0

Dia. 4.5

40

220.0

( + ) S O L A R

( - ) C o m m

( + ) B A T T

37.0

40.0


12/12

298-4578

Hybrid system A pow er system consisting of tw o or m orepow er generating sub system s (e.g. the com bination of aw ind turb ine and a pho tovoltaic system ).

Insolation The am ount of sunlight reaching an area. U suallyexpressed in w atts per square m etre p er day.

Junction box A protective enclosure into w hich w ires orcab les are led and connected .

Load Electrical pow er being consum ed at any given

m om ent. The load that an e lectric g ene rating systemsup plies varies greatly w ith tim e o f day and to som e extentseason of year. A lso, in an electrical circuit, the load is anydevice or appliance that is using pow er.

Maximum power current (Imp) The co rrespond ingcurrent for the m axim um pow er point on an I-V curve.

Maximum power point (Pmax) The desired op eratingpoint on an I-V curve w here the prod uct of the current andvoltag e (pow er) is m axim ised .

Maximum power voltage (Vmp) The correspond ingvoltage for the m axim um pow er point on an I-V curve.

Module A num ber of photovo ltaic ce lls electrically w iredtogether, usually in a sealed unit of co nve nient size forhand ling and assem bling into p ane ls and arrays.Nominal operating cell temperature (NOCT) Thepho tovo ltaic ce ll junction tem perature correspond ing tono m inal operating cond ition s in a standard referenceenv ironm ent of 1kW /m 2 irrad iance , 20C am b ient airtem perature, 1m /s w ind , and electrically open circuit.

Open-circuit voltage (Voc) The voltag e ou tput of apho tovoltaic d evice w hen no current is flow ing throug h acircuit.

Panel A num ber of m od ules w ired tog ether, w hich in turn,can be w ired to o the r pane ls to form an array.

Parallel connected A m ethod of connection in w hich

positive term inals are connected togethe r and negativeterm inals are connected tog ether. C urrent output adds andthe voltage rem ains the sam e.

Peak sun hours The eq uivalent num ber of hours at peaksun cond itions (i.e. 1kW /m 2) that produces the sam e totalinsolation as actual sun conditions.

Photovoltaic cell The basic d evice that co nve rts light intodc electricity; the build ing b lock of photovo ltaic m odules.

p-n junction The junction form ed at the interface betw ee ntw o differently doped layers of sem icond uctor m aterial, onelayer being doped w ith a p ositive-typ e dopant, the othe r w itha negative -type dopant. A n electric field is estab lished at thep-n junction w hich give s direction to the flow of light-stim ulated electrons.

Series connected A m ethod of connection in w hich thepositive term inal of one d evice is connected to the ne gativeterm inal of another. the voltag es ad d and the current islim ited to the least of any device in the string.

Short-circuit current (Isc) The current flow ing free ly froma p hotovoltaic cell through an external circuit that has no loador resistance ; the m axim um current possib le und er norm aloperating cond itions.

Solar constant The rate at w hich ene rgy is received fromthe sun just outside the earths atm osphere on a surfaceperpe nd icular to the suns rays. A pproxim ately equal to1.36kW /m 2.

Standard test conditions (STC) Test conditions in a

stand ard reference environm ent of 1kW /m2

, 25C ce lltem perature, and 1.5 air m ass spe ctrum .

Thick cells C onventional ce lls, such as crystalline silico ncells, w hich are typ ically from 4 to 17m m thick. In contrast,thin-film ce lls are several m icrons thick.

Thin-film cells Photovoltaic cells m ade from a num ber oflayers of photo-sensitive m aterials. These layers are typicallyapplied using a chem ical vap our de position process in thepresence of an electric field.

Voltage regulator A device that controls the operatingvo ltag e of a p hotovo ltaic array.

Watt A m easure of electrical pow er or am ount of w orkdone in a unit of tim e. O ne A m p of curren t flow ing at apotential of one V olt prod uces one W att of pow er.

RS C om ponents shall not be liab le for any liab ility or loss of any nature (how soever caused and w he ther or not due to RS C om po nentsneg lige nce)w hich m ay result from the use o f any inform ation p rovided in RS tech nical literature

RS C om p onents, PO Box 99, C orby, N orthants, N N 17 9RS Telephone: 01536 201234A n E lectrocom ponents C om pany RS C om ponents 1998

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