reedg of the nternational otgraduate Conference on Engeerg (CE 1) 16-17 October 1, erli, alayia Effect of Solar rradiance and emerature on hotovoltaic odule Electrical Characteritic. rwanto *, Daut *,. Sembirg **, Ronazri B Ali *, S. Chamakeow *, and S. Shema * * Cluter ower Electronic and ache Deign, School of Electrical Sytem Engeerg, Univerity alayia erli (UniA), alayia Email: irwanto@unima.edu.my ** School of echatronic Engeerg, Univerity alayia erli (UniA), alayia Email: merdang@unima.edu.my Abtract he electrical characteritic of hotovoltaic () module are deendent on olar irradiance and temerature. t conit of hort circuit current, oen circuit voltage, imum ower, fill factor and efficiency. hi aer reent the effect of olar irradiance and temerature on module electrical characteritic. A mathematical modelg wa develoed to characterize the electrical characteritic of module ug Sice. A 6 W, 1, B SX 6 multi-crytalle ilicon module wa ued thi aer. Under contant olar irradiance and difference temerature or verely were teted to the module, it electrical characteritic hown. he reult how that if the olar irradiance i contant and the temerature creae will caue the oen circuit voltage, the imum ower and the efficiency decreae, if the temerature contant and olar irradiance creae will caue the hort circuit current, the oen circuit voltage, the imum ower and the efficiency creae. Keyword Solar irradiance; emerature; module; electrical characteritic 1. ntroduction he major factor which fluence the electrical deign of the module are olar irradiance, tilt angle of module, load matchg for imum ower and oeratg temerature [1]. he electrical characteritic of the module are generally rereented by the current veru voltage (i-v) curve. hey are fluenced by temerature and olar irradiance, and they fluence on the deign of module ytem []. emerature i an imortant conideration the oeration of module ytem [3]. At lower temerature, module ytem roduce more ower. For higher temerature, otimum oeration require modification of electrical load and removal of exce heat. At high temerature, two redomatg effect can caue efficiency to dro. A thermal energy creae, lattice vibration terface with the free ag of charge carrie and the junction beg to lo it ower to earate charge. he efficiency loe for ytem can be mimized the reence of temerature variation. n mot cae, good olution are a temerature-deendent charge controller or a imum ower tracker. Both device imrove the overall ytem efficiency at higher temerature where the erformance i oor [3]. A c-si module ha been tet to get it electrical characteritic by [4], 1 W / m of olar irradiance and temerature from 15 C to 65 C were fallen to the urface of the module. t electrical characteritic wa oberved, the reult hown that for olar irradiance wa contant and temerature creaed, it hort circuit current would be contant, oen circuit voltage and imum ower would decreae. Effect of temerature on electrical characteritic of a hotovoltaic module ha been teted by [], hown that for 975.4 W / m and temerature were 5.1 C, 45.9 C and 55.6 C reulted the imum ower were 44.98 W, 4.6 W and 38.11 W, reectively. he oen circuit voltage varie learly with temerature if the temerature were creaed [5]. he temerature of 5 C, the olar irradiance of 6 W / m, 8 W / m and 1 W / m (creaed olar irradiance) were teted to a c-si module by [4], the reult hown that the hort circuit current, oen circuit voltage, and imum ower would creae. he effect of olar irradiance on a hotovoltaic module erformance wa teted by [] SB 978-967-576-3-7
alo, hown that for the contant temerature of 37.7 C, the olar irradiance of 66 W / m, 831 W / m and 974 W / m reulted the imum ower were 8.7 W, 36.55 W and 41.85 W, reectively. Reearch by [5] hown that the hort circuit current creae almot lier, the fill factor i not ignificantly fluenced by the olar irradiance, the imum ower ot varie ub learly with olar irradiance. A behavioural model ha been develoed by [6] to characterize current, voltage and ower of the hotovoltaic module a function of temerature and olar irradiance. Calculated diagram are comared with diagram of two hotovoltaic module data heet. hi aer reent a mathematical modelg to oberve a module characteritic. A oly-crytal ilicon module wa teted with contant olar irradiance and varied temerature, alo with contant temerature and varied olar irradiance, both the module erformance oberved ug Sice oftware. he oberved module characteritic are the hort circuit current, the oen circuit voltage, the imum ower, the fill factor and the efficiency.. Data and ethodology.1. Data A 6 W, 1, B SX 6 multi-crytalle ilicon module wa ued thi aer. hi module conit of 36 olar cell configured erie trg. he comlete data of the module i hown able 1. able 1. Electrical arameter of oly-crytal ilicon module. athematical odellg of odule Characteritic he mot oular hotovoltaic module i a articular cae of a erie trg of olar cell. n terretrial alication the tandard module are comoed of a number olar cell connected erie. he number i uually 33 to 36 but different aiation are alo available. he module characteritic i the reult of the voltage calg of the ( ) characteritic of a gle olar cell. Conider the ( ) characteritic of a gle olar [7], [8]: L e + R n 1 e + R + R 1 Rh (1) Conider ome imlifyg aumtion, articular that the hunt reitance, R, of a olar cell i large and it effect can be neglected, and that the effect of the econd diode are alo negligible. So, aumg, equation (1) become and R h h + R n 1 c e () where ha alo been aumed. c L he calg rule of voltage, current and reitance when a matrix of olar cell i conidered are the followg: x (3) (4) c c (5) (6) where ubcrit tand for odule and ubcrit without tand for a gle olar cell. he calg rule of the erie reitance i the ame a that of an aiation of reitor: x
R R (7) Subtitutg equation (), c + R n 1( e 1) + R 1 (8) n ( e 1) (9) c oreover, from equation () oen circuit, can be written a: c (1) ( e n 1) Ug now equation (4) and (6) (11) ( e c n 1).3 emerature Effect Conider the electrical characteritic the -n te junction. n the ideal diode (with low level jection), the diffuion current i [3]: q q qd no qdnn k + k J J e 1 e 1 L Ln where (1) J i the aturation current denity, D i the diffuion coefficient and L i the diffuion length of D τ where τ electron or hole, which i equal to i the mority lifetime. he n and n rereent electron and hole denitie n-tye region and -tye region at thermal equilibrium. Alo, n i the tric carrier denity which ha the relationhi of n n n i. i he hort-circuit circuit tend to creae with creag temerature. When temerature creae, the diffuion coefficient diffuion D, the mority life time τ, the diffuion length L and the tric carrier denity will creae. he change of thee arameter will enhance diffuion, i.e, a larger D. he hoturrent generated by the olar cell i the um of electron diffuion current, hole diffuion current and domant generation current the deletion region. he generation current the ideal deletion region i deendent of temerature, o the creae of diffuion will reult an creae of hoturrent. he oen circuit voltage tend to decreae with creag temerature. he oen circuit voltage can be obtaed from the olar cell characteritic equation (1). k q h k + 1 ln q h ln (13) When temerature creae, the amount of aturation current will creae more than the amount of hoturrent and therefore make decreaed raidly..4 Solar rradiance Effect Alyg the oen circuit condition,, to the ( ) equation i given by [6]: 1 c e (14) he oen circuit voltage i given by : ln 1 + c (15) From equation (15), it can be een than the value of the oen circuit voltage deend, logarithmically on the / ratio. hi mean that under contant c o temerature the value of the oen circuit voltage cale logarithmically with the hort circuit which, turn cale learly with irradiance reultg a logarithmic deendence of the oen circuit voltage with irradiance. hi i alo an imortant reult dicatg that the effect of the irradiance i much larger the hort circuit current than the oen circuit value.
.5 hotovoltaic odule Characteritic n thi aer the hotovoltaic module characteritic are: 1. Short circuit current ( ) he hort circuit current ( imum current ( ) rereent to the ) that ae through the cell that correond to the hort circuit condition when the imedance i low. t cur at the begng of the wee when the voltage i zero. n an ideal cell, thi imum current value i the total current roduced the olar cell by hoton excitation., at. Oen circuit voltage ( ) he oen circuit voltage ( (16) ) i the imum voltage difference acro the cell, and it cur when there i no current ag through the cell., at (17) 3. aximum ower ( ) he ower roduced by the cell watt can be eaily calculated along the - characteritic curve Figure 5. At the and ot, the ower will be zero and the imum value for ower will cur between the two ot. he voltage and current at thi imum ower ot are denoted a and reectively. x (18) 4. Fill factor (FF) he Fill Factor (FF) i eentially a meaurement of quality of the olar cell. t i calculated by comarg the imum ower to the theoretical ower ( ) that would be outut at both the oen circuit voltage and hort circuit current together. FF can alo be terreted grahically a the ratio of the rectangular area, it larger deirable, and correond to an - characteritic curve Figure 5. yical fill factor range from.5 to.8. FF x (19) x 5. Efficiency (η ) Efficiency i the ratio of the electrical ower outut ( out ), comared to the olar ower ut ( ) to the cell. out can be taken to be ce the olar cell can be oerated u to it imum ower outut to get the imum efficiency. η η out () i taken a the roduct of the irradiance of the cident light, meaured W / m or un (1 W / m ), with the urface area of the olar cell ( m ). All rted material, cludg text, illutration, and chart, mut be ket with a rt area of 6-1/ che (16.51 cm) wide by 8-7/8 che (.51 cm) high. Do not write or rt anythg outide the rt area. All text mut be a two-column format. Column are to be 3-1/16 che (7.85 cm) wide, with a 3/8 ch (.81 cm) ace between them. ext mut be fully jutified. A format heet with the marg and lacement guide i available a both Word and DF file a <format.d> and <format.df>. t conta le and boxe howg the marg and rt area. f you hold it and your rted age u to the light, you can eaily check your marg to ee if your rt area fit with the ace allowed. 3. Reult and Dicuion 3.1. alidation of he athematical odellg Ug Sice o validate the mathematical modelg of module characteritic ug Sice, the data of module a hown able 1 wa imulated for condition of olar irradiance and temerature were 1 W/m and 5 C, reectively. he currentvoltage and ower-voltage curve are hown Figure 1 and.
Figure 1. Current-voltage curve of module -.19% and.75 %. hee ercentage error dicate that the mathematical modelg of module characteritic i conidered accetable. he negative ercentage error dicate tendency over-imulate to the data heet of module. he model decribed thi imulation i baed on Standard et Condition () defed with nomal olar irradiance level 1 W/m and nomal temerature 5 C of Air a (A) 1.5 G olar ectral content. hi accordg to the electrical characteritic of a module from the value of the ma magnitude available for a commercial module: hort circuit current, oen circuit voltage, imum ower and the number of cell connected. 3.. Solar rradiance effect Figure. ower-voltage curve of module he module characteritic for olar irradiance of 1 W/m of and temerature of 5 C are hown able. able. he module characteritic for 1 W/m of olar irradiance and 5 C of temerature Electric Characteritic Data Sheet Simulation Short circuit current (A) 3.87 3.87 Oen circuit voltage () 1 1.4 aximum ower (W) 6 59.55 he olar irradiance effect on electrical characteritic of module are imulated under olar irradiance of W/m, 4 W/m, 6 W/m, 8 W/m, 1 W/m and contant temerature of 5 C. he current-voltage and ower-voltage curve of module are hown Figure 3 and 4, reectively. he Figure 3 how that under contant temerature the value of the oen circuit voltage cale logarithmically with the hort circuit current which, turn cale learly with the olar irradiance reultg a logarithmic deendence of the oen circuit voltage with the olar irradiance. he olar irradiance effect on the electrical characteritic of module i much larger the hort circuit current than the oen circuit voltage. he value of the hort circuit current and the oen circuit voltage of each the olar irradiance can be een able 3. he module characteritic can be validated ug tatitical analyi, exactly ug ercentage error ( e ) [9]. A relative ercentage error between -1% and +1% i conidered accetable. Baed on electric characteritic a hown able 1, the ercentage error of the hort circuit current, the oen circuit voltage and the imum ower are %, Figure 3. Current-voltage curve of module with W/m, 4 W/m, 6 W/m, 8 W/m, 1 W/m of olar irradiance and 5 C of contant temerature
3.3. emerature effect Figure 4. ower-voltage curve of module with W/m, 4 W/m, 6 W/m, 8 W/m, 1 W/m of olar irradiance and 5 C of contant temerature Figure 4 how that under contant temerature, if the olar irradiance creae caue the imum ower of module will creae. he value of the module imum ower of each the olar irradiance can be een able 3. able 3 how that under contant temerature, if the olar irradiance creae caue the electrical characteritic of module (hort circuit current, oen circuit voltage, imum ower, and efficiency) will creae, the fill factor i fulfilled what dicued by [8]. able 3. he module characteritic with W/m, 4 W/m, 6 W/m, 8 W/m, 1 W/m of olar irradiance and 5 C of contant temerature he temerature effect on the electrical characteritic of module are imulated under contant olar irradiance of 1 W/m and temerature of 5 C, 35 C, 45 C, 55 C, 65 C. he current-voltage and ower-voltage curve of module are hown Figure 5 and 6, reectively. Figure 5 how that under contant olar irradiance and difference temerature, the oen circuit voltage and hort circuit current of module will be fluenced ignificantly and lightly, reectively. he oen circuit voltage tend to decreae with creag temerature. When temerature creae, the amount of aturation current will creae more than the amount of hoturrent and therefore make the oen circuit voltage decreaed raidly [3]. he hort-circuit circuit tend to creae with creag temerature. When temerature creae, the diffuion coefficient diffuion D, the mority life time τ, the diffuion length L and the tric carrier denity will creae. he change of thee arameter will enhance diffuion, i.e, a larger D. he hoturrent generated by the module i the um of electron diffuion current, hole diffuion current and domant generation current the deletion region. he generation current the ideal deletion region i deendent of temerature, o the creae of diffuion will reult an creae of hoturrent [3]. he value of the hort circuit current and the oen circuit voltage of each the temerature can be een able 4. Electrical Characteritic Solar irradiance (W/m ) 4 6 8 1 c (A).77 1.55.3 3.1 3.87 () 19.53.19.55.84 1.4 (W) 1. 4.38 36.49 48.3 59.55 FF.8.78.77.75.73 η (%) 4.63 6.8 8.38 99.5 Figure 5. Current-voltage curve of module under 1 W/m of contant olar irradiance and difference temerature
Concluion he electrical characteritic of module are deendent on olar irradiance and temerature. f the olar irradiance i contant and although the temerature creae will caue the hort circuit current till contant, if the olar irradiance i contant and the temerature creae will caue the oen circuit voltage, imum ower and efficiency decreae, if the temerature contant and olar irradiance creae will caue the hort circuit current, oen circuit voltage, imum ower and efficiency creae. Figure 6. ower-voltage curve of module under 1 W/m of contant olar irradiance and difference temerature Figure 6 how that under contant olar irradiance, if the temerature creae caue the imum ower of module will decreae. he value of the module imum ower of each the temerature can be een able 3. able 4 how that under contant olar irradiance, if the temerature creae caue the oen circuit voltage, imum ower, and efficiency of module will decreae, but the hort circuit current will creae, the fill factor i fulfilled what dicued by [8]. able 4. he module characteritic under temerature of 5 C, 35 C, 45 C, 55 C, 65 C and contant olar irradiance of 1 W/m Electrical Characteritic emerature ( C) 5 35 45 55 65 Reference [1] G. Cook, L. Billman, and R. Adck, hotovoltaic Fundamental, DOE/Solar Energy Reearch ntitute Reort o. DE91151, 1995. [] H.. El-Zayyat,. ahmoud, hotovoltaic ower Generator for Radio Communication Sytem Jordan, EE reedg, ol. 135, t.c, o.5, 1988. [3].J. Wu, E.J. imon and S.E. Watk, emerature Conideration Solar Array, EEE Exlorer,4. [4] J.. Roell,. banez, odellg ower outut hotovoltaic odule for Outdoor Oeratg Condition, Energy Converion & anagement, 5, 44-43. [5]. riedel,. Dyakonov, J. ari, L. Luten, D. anderzande, J.C. Hummelen, Current-oltage Characteritic of olymer- Fullerene Solar Cell, EEE Exlorer,,. 13-135. [6] B. Ulrick, A Simle odel of hotovoltaic odule Electric Characteritic, EEE Exlore. [7] L. Cataner, S. Silvetre, odellg hotovoltaic Sytem Ug Sice, John Wiley & Son, LD. [8]. rwanto,. Daut,. Sembirg, Electrical Characteritic of oly-crytal Silicon hotovoltaic odule ye 5(17) 8x541, Engeerg otgraduate Conference, 9. [9]. Daut,. Sembirg,. rwanto,. Syafawati, S. Haan, Hargreave odel For Etimatg Solar Radiation erli, nternational Conference: Electrical Energy and ndutrial Electronic Sytem EEES 9, 7-8 December 9, enang, alayia c (A) 3.87 3.89 3.9 3.94 3.96 () 1.4.3 19.39 18.6 17.8 (W) 59.55 56.48 53.55 5.61 47.68 FF.73.7.7.69.68 η (%) 99.5 94.13 89.5 84.35 79.47