Miodrag Forcan

DOI Number
First page
Last page


Reduction of long-term degradation effects represents a long-time challenge in photovoltaic (PV) manufacturing industry. Modelling of long-term degradation types and their impact on maximum power of PV systems have been analysed in this article. Brief guidelines for PV cell-based modelling of PV systems have been illustrated. Special study case, PV string consisting of 12 PV modules, has been modelled in order to determine degradation and mismatch power losses. Modified methodology for prediction of annual energy production from PV string, based on horizontal irradiation and ambient temperature experimental measurements at the location of Belgrade, has been developed. Coefficient named “degradation factor” has been introduced to include and validate degradation power losses. Economic considerations have indicated evident money income reduction, as a consequence of lower annual energy production related to long-term degradation.


PV string, energy production, long-term degradation, degradation factor, mismatch losses

Full Text:



M. Forcan, “Prediction of Energy Production from String PV System under Mismatch Condition”, In Proceedings of the 2nd Virtual International Conference on Science, Technology and Management in Energy - eNergetics, 2016, pp. 3-9.

M. Jošt and M. Topič, “Efficiency limits in photovoltaics – case of single junction solar cells”, Facta Universitatis, Series: Electronics and Energetics, vol. 27, no 4, pp. 631 - 638, December 2014.

Y. Georgiev, G. Angelov, T. Takov, I. Zhivkov and M. Hristov, “The photovoltaic behavior of vacuum deposited diphenyl-diketo-pyrrolopyrrole polymer”, Facta Universitatis, Series: Electronics and Energetics, vol. 27, no 4, pp. 639 - 648, December 2014.

O. Perpinan, E. Lorenzo and M.A. Castro, “On the calculation of energy produced by PV grid-connected system”, Progress in Photovoltaics Research and Applications, vol. 15, issue: 3, pp. 265-274, 2007.

M. Brabec, E. Pelikán, P. Krč, K. Eben and P. Musilek, “Statistical modeling of energy production by photovoltaic farms”, In Proceedings of the IEEE Elect. Power Energy Conf. (EPEC), Aug. 2010, pp. 1-6.

O. Perpinan, “Statistical analysis of performance and simulation of two axis tracking PV system”, Solar Energy, vol. 83, issue 11, pp. 2074-2085, Nov. 2009.

S. Jiang, K. Wang, H. Zhang, Y. Ding and Q. Yu “Encapsulation of PV Modules Using Ethylene Vinyl Acetate Copolymer as the Encapsulant”, Macromol. React. Eng., 9, pp. 522–529, 2015.

T. Shioda, “Delamination failures in long-term field-aged PV modules from point of view of encapsulant”, Lecture presented at 2013 NREL PV Module Reliability Workshop, Denver.

D. C. Jordan, J. H. Wohlgemuth, and S. R. Kurtz, “Technology and Climate Trends in PV Module Degradation”, in Proceedings of the 27th European Photovoltaic Solar Energy Conference and Exhibition, 2012, pp. 3118-3124.

M. Kempe, “Modelling of rates of moisture ingress into photovoltaic modules”, Solar Energy Materials & Solar Cells, vol. 90, issue: 16, pp. 2720–2738, 2006.

M. Kempe, “Ultraviolet test and evaluation methods for encapsulants of photovoltaic modules”, Solar Energy Materials & Solar Cells, vol. 94, issue: 2, pp. 246–253, 2010.

A. Ndiaye, A. Charki, A. Kobi, C.M.F. Kébé, P.A. Ndiaye and V. Sambou, “Degradations of silicon photovoltaic modules: A literature review”, Solar Energy, vol. 96, pp. 140–151, 2013.

D. Sera, R. Teodorescu and P. Rodriguez, “PV panel model based on datasheet values”, In Proceedings of the IEEE International Symposium on Industrial Electronics, Vigo, Spain, 2007, pp. 2392–2396.

M. Forcan, Ţ. Đurišić, and J. Mikulović, “An algorithm for elimination of partial shading effect based on a Theory of Reference PV String,” Solar Energy, vol. 132, pp. 51–63, 2016.

M. Forcan, J. Tuševljak, S. Lubura and M. Šoja, “Analyzing and modeling the power optimizer for boosting efficiency of PV panel,” IX Symposium Industrial Electronics INDEL, Banja Luka, November 2012, pp. 193-198.

M. Forcan and Ţ. Đurišić, “The analysis of PV string efficiency under mismatch conditions,” in 4th International Symposium on Environment Friendly Energies and Applications - EFEA, 2016, pp. 1-6.

C. Schwingshackl, M. Petitta, J.E. Wagner, G. Belluardo, D. Moser, M. Castelli, M. Zebisch and A. Tetzlaff, “Wind effect on PV module temperature: Analysis of different techniques for an accurate estimation”, Energy Procedia, vol. 40, pp. 77–86, 2013.

S. Bensalem and M. Chegaar, “Thermal behavior of parasitic resistances of polycrystalline silicon solar cells”, Revue des Energies Renouvelables, vol. 15, pp. 171-176, 2013.

M.L. Priyanka and S.N. Singh, “A new method of determination of series and shunt resistances of silicon solar cells”, Solar Energy Materials & Solar Cells, vol. 91, pp. 137–142, Jan. 2007.

D. Macdonald and A. Cuevas, “Reduced fill factors in multicrystalline silicon solar cells due to injectionlevel dependent bulk recombination lifetimes”, Progress in Photovoltaics: Research and Applications, vol. 8, pp. 363–375, 2000.

MATLAB/Simulink. MathWorks, Inc. Natick. Massachusetts. United States.

PV module data sheet, available online at

R. Dubey, S. Chattopadhyay, V. Kuthanazhi, J. J. John, B. M. Arora, A. Kottantharayil, K. L. Narasimhan, C. S. Solanki, V. Kuber, J. Vasi, A. Kumar and O. S. Sastry “All India Survey of Photovoltaic Module Degradation 2013”, National Centre for Photovoltaic Research and Education, Mumbai, India, 2014, available online at

G. M. Masters, Renewable and Efficient Electric Power Systems. Hoboken, NJ: John Wiley & Sons, 2004, Chapters 7-8.


  • There are currently no refbacks.

ISSN: 0353-3670 (Print)

ISSN: 2217-5997 (Online)

COBISS.SR-ID 12826626