ENERGY YIELD OF TRACKING PV SYSTEMS IN JORDAN

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1 ENERGY YIELD OF TRACKING PV SYSTEMS IN JORDAN A. Al Tarabsheh, I. Etier, and A. Nimrat Hashemite University, Electrical Engineering Department, Zarqa, Jrdan. Abstract This paper analyzes the energy yield f phtvltaic (PV) mdules munted n fixed tilt, neaxis, and tw-axis tracking system twards maximizing the annual energy prductin. The perfrmance evaluatin f the prpsed design f the tracking systems is carried via simulating the glbal radiatin averages using METEONORM sftware and depicting the simulatin results in figures using MATLAB sftware. The ne-axis system is simulated by either fixing the azimuth angle while ptimizing the inclinatin angles r fixing the inclinatin angle while ptimizing the azimuth angles simulatin results shw an increase in energy yield f 5.87% and 20.12% cmpared t that f fixed tilt system respectively. In the tw-axis system ptimizatin f bth azimuth and inclinatin angles is carried simultaneusly which resulted in 30.82% imprvement in energy yield. Therefre, 30% imprvement in energy yield is directly reflected as saving in PV system cst due t reductin f the PV mdules surface area. Keywrds: PV, slar energy, tilt angle, MATLAB TM. 1. Intrductin The implementatin f sun-trackers maximizes the energy yield f phtvltaic (PV) systems by keeping the PV mdules pinting twards the maximum sun radiatin during the entire day [1-3]. The wrk in [4] validated the accuracy f the METEONORM 5.0 sftware [5], thus we used it here as simulatin tl. METEONORM 5.0 sftware is a cmprehensive meterlgical reference, incrprating a catalgue f meterlgical data and calculatin prcedures fr slar applicatins and system design at any desired lcatin in the wrld. It is based n ver 24 years f experience in the develpment f meterlgical databases fr energy applicatins. Nmenclature ζ θ PV g η Azimuth angle Inclinatin angle Phtvltaic Gain f the tracking system with respect t the fixed Efficiency f the PV mdules In this paper, we calculate the radiatin received frm the sun using the METEONORM 5.0 sftware fr different azimuth ( 90 ζ 90 ) (East-t-West) and inclinatin ( 90 θ 90 ) (Nrth-t-Suth) angles. A wide range f angles fr PV mdules are fund [6] as shwn in Figure 1. The tw-axis tracking cnfiguratin rtates abut tw axes maintaining the surface f the PV mdule always perpendicular t the sun t maximize the cllected radiatin and thus maximizing amunt f energy prductin. The rtatin abut the azimuth axis ranges frm ζ = 90 (east) t ζ = 90 (west) while the inclinatin angles range frm θ = 0 (hrizntal) t θ = 90 (vertical). 1

2 Fig. 1. One- (a) and tw-axis (b) tracking cnfiguratins where the PV mdules rtate abut the axes (inclinatin and azimuth) by a cntrllable gear. In this paper, we investigate nly the direct radiatin meterlgical data rather than the diffused radiatin because n sunny days, the direct sunshine accunts fr up t 90% f the ttal slar energy [1,7]. The study explres the ptential f slar energy generatin in the area f the Hashemite University in Jrdan. This wrk is rganized as fllws: Sectin 2 intrduces the energy yield f fixed ( ζ = 0, θ = 30 ) PV mdules which was ptimized in [8] assuming the efficiency f the PV mdules is η = 10% as a standard value. In sectin 3 ne-axis tracking system simulatin results are presented. in Sectin 4 the tw-axis system results are highlighted. Cnclusins are drawn in sectin Energy yield f fixed-tilt PV system We utilize with the finding f [9] by fixing the inclinatin angle at θ = 30 and the azimuth angle at ζ = 0 (i.e facing the suth) t cmpute the energy yield f a 10% efficient PV mdule frm 8 Am t 6Pm fr entire year as shwn in Figures 2 and 3. The maximum energy yield f the PV mdule ccurs at 12 O'clck n 6th April where the radiatin reaches 1100 W/m 2 and kwh/m2/ year. Fig. 2. Hurly slar irradiance frm 8 t 18 O'clck 2

Fig. 3. Energy yield f the PV systems, the energy yield is 227.1 kwh/m 2 / year. 3. Energy yield f ne-axis tracking PV system In this sectin simulatin results f ne-axis tracking system is presented and cmpared with energy yields f the PV system in previus sectin.

Fr each step, we calculate the energy yield f the PV system per hur frm 8Am-6Pm ver a cmplete year. The ptimized inclinatin angle θ results in a glbal maximum energy yield.

3 Fig. 3. Energy yield f the PV systems, the energy yield is kwh/m 2 / year. 3. Energy yield f ne-axis tracking PV system In this sectin simulatin results f ne-axis tracking system is presented and cmpared with energy yields f the PV system in previus sectin Fixing azimuth angle and varying inclinatin angle In this subsectin, we fixed the azimuth angle at ζ = 0 while the inclinatin angle varies frm θ = 0 t θ = 90. Fr each step, we calculate the energy yield f the PV system per hur frm 8Am-6Pm ver a cmplete year. The ptimized inclinatin angle θ results in a glbal maximum energy yield. Figure 4 shws the ptimal inclinatin angles fr each day f the year at different times. Therefre, t maximize the energy generated by PV mdules they have t be inclined at the angles shwn in Figure 4. F ig. 4. Optimal inclinatin angles θ fr different times in the day ver all the year while the azimuth angle is set t ζ = 0. 3

4 Figure 5 depicts the energy yields f bth fixed and ne-axis PV systems. Fixed system is fixed at θ = 30 and ne-axis system is inclined t ptimal angles. It is bvius that ne-axis system utperfrmed the fixed system by abut 5.87%. Fig. 5. Energy yield f fixed (fixing bth ζ and θ ) and ne-axis (fixing ζ and varying θ ) PV systems fr each mnth. The maximum energy yield ccurs in July fr bth lines. The gain f such tracking ver the fixed ne is 5.87%. The effect f tracking can be measured as "gain" g, which is defined as the rati f the energy prduced in deflected psitins t the energy prduced in the fixed psitin system [10], therefre the gain f the ne-axis system f fixed azimuth and varying inclinatin angles is g = 5.87% at ptimal inclinatin angles Fixing inclinatin and varying azimuth A secnd methd f ptimizing the ne-axis tracking system is by fixing the inclinatin angle at θ = 30 while the azimuth angle varies frm ζ = 90 t ζ = 90 (i.e frm east t west). The energy yield f this system is calculated n hurly basis during each day f the year. The azimuth angle ζ is ptimized t result in a glbal maximum energy yield. Figure 6 shws the ptimal azimuth angles fr every day in the year at the same times used in the last subsectin. The energy yields f this PV system and that f fixed system are shwn in Figure 7. The gain f fixing the inclinatin and varying azimuth give a g = % at ptimal azimuth angles cmpared t that f fixed system. 4

5 Fig. 6. Optimal azimuth angles ζ fr different times in the day ver all the year while the inclinatin angle is set t θ = 30. Fig. 7. Energy yield f fixed (fixing bth ζ and θ ) and ne-axis (fixing θ and varying ζ ) f PV systems fr each mnth. The maximum energy yield ccurs in als July fr bth curves. The gain f such tracking ver the fixed ne is 20.12%. 4. Energy yield f tw-axis tracking PV System In this sectin we ptimize the tw-axis tracking system by varying bth the azimuth angle ζ = 90 L90 and the inclinatin angle θ = 0 L90 simultaneusly. The energy yield f the PV systems is maximized fr each hur during the day ver the entire year by selecting the apprpriate angles that maximize the glbal energy yield. Figure 8 shws the ptimal inclinatin θ and azimuth ζ angles fr every day in the year at the same times used in the last subsectins. The energy yield f the tw-axis PV system, at ptimal azimuth and inclinatin angles against that f fixed system, is depicted in figure 9. 5

6 Fig. 8. Optimal azimuth ζ (dashed lines) and inclinatinθ (slid lines) angles are pltted fr different times in the day ver all the year. Fig. 9. Energy yield f fixed (fixing bthζ and θ ) and tw-axis (varying bth θ and ζ ) f PV systems fr each mnth. The maximum energy yield ccurs in als July fr bth lines. The gain f such tracking ver the fixed ne is 30.82%. The gain f this system is g = 30.82% which is superir t bth fixed and ne-axis systems better than the ne discussed befre. Frm thse results ne can say that the energy yield f PV systems depends n the effectiveness f the tracking methd used. In Figure 10 the energy yield f the three systems cnsidered in this wrk are pltted n the same graph. Frm this graph we ntice that the tracking abut azimuth r the inclinatin shws cmparable results in the winter mnths. Table 1 shws a brief cmparisn between the calculated gains fr the energy yields f tracking PV (ne- and tw-axis) systems. 6

7 Fig. 10. Cmparisn f the energy yield f the tw-axis (variable θ and ζ ) and the ne-axis (fixing ζ r θ ) tracking f PV systems. The tracking abut azimuth r the inclinatin shws cmparable results t each ther in the winter mnths. Tab. 1: Summary f the imprvements fr tracking PV systems ver fixed systems Case Gain, g Optimal azimuth angle, and variable inclinatin angles 5.87% Optimal inclinatin angle, and variable azimuth angles 20.12% Optimal inclinatin and azimuth angles 30.82% 5. Cnclusin In this paper we highlighted the ptential f the ne-axis and tw-axis tracking PV systems in imprving the energy prductin f slar system in the Hashemite University. The ptimized rtatin f the PV systems arund the inclinatin axis can increase the energy yield up t 5.87% cmpared t the fixed systems, while the ptimized rtatin f the PV systems arund the azimuth axis can increase the energy yield up t 20.12% and the ptimized rtatin abut bth the inclinatin and the azimuth axes simultaneusly culd increased the energy prduced by mre than 30% cmpared t fixed systems. Therefre, the mdules area can be reduced by 30% which cuts cst by same percentage. 6. References [1] Nelsn A. Kelly, Thmas L. Gibsn, "Imprved phtvltaic energy utput fr cludy cnditins with a slar tracking system", Slar Energy 83 (2009) pp [2] P. Rth, A. Gergiev, H. Budinv, "Cheap tw-axis sun fllwing device", Energy Cnversin and Management, 2005, 46, pp [3] Array Technlgies Inc., Wattsun Slar Trackers. Available frm: [4] Issa Etier, Anas Al Tarabsheh. Mhammad Ababneh, "Analysis f Slar Radiatin in Jrdan, Jrdan Jurnal f Mechanical and Industrial Engineering (JJMIE), Vlume 4, Number 6, pp ,

8 [5] Switzerland, Metetest: METEONORM Glbal Meterlgical Database fr Engineers, Planners and Educatin, Versin 5.0, Editin [6] A. Luque, S. Hegedus, Handbk f Phtvltaic Science and Engineering, P. 943, Jhn Wiley & Sns Ltd, [7] R. Hanitsch, I. Etier, N. Ertürk, K. Heumann, and M. Munschauer, "Simulatin and cmparisn f a tracked PV system with a mdel based n the measurement f the sky-irradiance distributin", EurSun98, 2nd ISES-Eurpe, Prtrz, Slvenia [8] Desmnd J. Higham, Nichlas J. Higham, MATLAB Guide, 2 nd Editin, 2005, ISBN [9] I. Etier, A. Tarabsheh, and M. Ababneh, "Investigatin f Slar Energy in the Hashemite University", Internatinal Cnference and Exhibitin n Green Energy & Sustainability fr Arid Regins & Mediterranean Cuntries Le Ryal Htel Amman, Jrdan, Nvember, (2009). [10] T. Tmsn, "Discrete tw-psitinal tracking f slar cllectrs", Renewable Energy 33 (2008), pp

SERC. A computer study of the improvement of PV panel monthly outputs when the panel azimuth is changed thrice daily. Eva Lindberg and Lars Broman

SERC. A computer study of the improvement of PV panel monthly outputs when the panel azimuth is changed thrice daily. Eva Lindberg and Lars Broman .. Centrum för slenergifrskning Slar Energy Research Center A cmputer study f the imprvement f PV panel mnthly utputs when the panel azimuth is changed thrice daily SERC Avdelningen för energi. miljö ch