A Comparative Investigation on Outdoor and Laboratory Test of the Degradation Rates for Different Types of Photovoltaic Modules with Different Exposure Periods
Keywords:PV modules, Outdoor tests, Laboratory tests, Degradation rates, Monocrystalline PV modules, Polycrystalline PV modules, Thin-film PV modules, Fill Factor.
Understanding field failure and degradation modes in solar photovoltaic (PV) modules is very important for various reasons especially for this widely used technology. The University of Applied Sciences Ostwestfalen-Lippe in Höxter owns photovoltaic-modules of different cell types, sizes and operation periods in German weather conditions. This paper presents a detailed degradation investigation and performance parameters analysis for chosen samples of polycrystalline, monocrystalline and thin film modules in the laboratory and outdoor test conditions after 10 years of exposure. The obtained measurements were standardized and then compared with the warranted values of the manufacturer’s datasheets for each module type. The real outdoor measurements for the larger units show that the maximum power Pmax after 10 years of exposure for polycrystalline, monocrystalline and amorphous thin film modules had declined by: 8.47%, 37.67%, and 19.05% respectively, which translates to an annual linear degradation rates of 0.652%, 3.67%, and 1.465% for each type respectively. While the maximum power output of the smaller units had declined by 19.05%, 19.36%, and 21.75% for polycrystalline, monocrystalline and amorphous thin film modules respectively, which also translated to annual linear degradation rates of 1.48%, 1.67%, and 0.6% for each type respectively. On the other hand, the laboratory tests for these modules show that there is a clear variation with the obtained outdoor results, where the Pmax for the same larger units had declined by 39.6%, 57.4%, and 82.5% for polycrystalline, monocrystalline and thin film modules respectively, While the Pmax output of smaller units had declined by 51.2%, 39.38%, and 9.39% for polycrystalline, monocrystalline and thin film modules respectively, The comparison of the efficiency and fill factor parameters for the obtained results with the manufacturer’s data shows that the outdoor measurements introduce close results than the laboratory results. The discoloration of the encapsulant is the most frequently occurring visually observable defects on the modules.
Schmela M, REN21, Renewables 2018 Global Status Report. REN21 Secretariat, Paris. 2018. Looking Back
Forth: Big Solar Surprises in 2017 & 2018. Solar Power. Europe. Available: http://www.solarpowereurope.org/newsletter/editorial-looki gback- forth-big-solar-surprises-in-2017-2018/ (accessed 17 May 2018).
Sustainable Energy for All (SEforALL), Our Mission - Going further, faster – together. Sustainable Energy for All, 2018. Available: https://www.seforall.org/ourwork> (accessed 3 May 2018).
International Electrotechnical Commission 60050 -191, Dependability and quality of service, 1990. renewable energy targets/ European Commission 2020 https://ec.europa.eu/energy/en/topics/renewable-energy.
Renewable energy in Germany, 2018. Available: https://en.wikipedia.org/wiki/Renewable_energy_in_Germany
Quansah DA, Adaramola MS. Comparative study of performance degradation in poly- and mono-crystalline-Si solar PV modules deployed in different applications. Int J Hydrogen Energy 43(6): 3092-3109. https://doi.org/10.1016/j.ijhydene.2017.12.156
Frankfurt School-UNEP Centre/BNEF. Global Trends in Renewable Energy Investment 2018. Frankfurt School of Finance & Management GmbH, Frankfurt.
Osterwald C, Adelstein J, del Cueto J, Kroposki B, Trudell D, Moriarty T. Comparison of degradation rates of individual modules held at maximum power. In: 4th IEEE World Conference on Photovoltaic Energy Conversion., 2006, Hawaii. https://doi.org/10.1109/WCPEC.2006.279914
Jordan DC, Kurtz SR, VanSant K, Newmiller Jeff. Compendium of photovoltaic degradation rates. Prog. Photovolt Res Appl 2016; 24(7): 978-989. https://doi.org/10.1002/pip.2744
Jordan DC, Kurtz SR. Photovoltaic degradation rates-an analytical review .2013. Prog. Photovolt. 12-29. https://doi.org/10.1002/pip.1182
Vikrant Sharma SS. Chandel, Performance and degradation analysis for long term reliability of solar photovoltaic systems: A review, Renewable Energy 89 (2016) 12e17). https://doi.org/10.1016/j.renene.2015.11.088
Malvoni M, Leggieri A, Maggiotto G, Congedo P, De Giorgi M. Long term performance, losses and efficiency analysis of a 960 kWp photovoltaic system in the Mediterran ean climate. Energy Conversion and Management 2017; 145: 169-81. https://doi.org/10.1016/j.enconman.2017.04.075
Jordan DC, Silverman TJ, Wohlgemuth JH, Kurtz SR, VanSant KT. Photovoltaic failure and degradation modes. Progress Photovoltaic. April 2017; 25: 18-26. https://doi.org/10.1002/pip.2866
Kraft L, Ajib S. Bbachelor's degree project (Comparative analysis of Performance characteristics of different types of PV modules at different operation periods based on laboratory and field measurements), 2018.Ostwestfalen – Lippe University of Applied Sciences /Germany.
PVSyst Software 6.7.0 Version. NASA Database, 2018, Support http://www.PVsys.com.
Volker. Q. 215. Regenerative Energy System, P.213, Text Book, ISBN: 978-3-446-44333-4.
Kaplanis S, Kaplani E. Energy performance and degradation over 20 years performance of BP c-Si PV modules.2011, Simul. Model. Pract. Theory 19, 1201–1211. https://doi.org/10.1016/j.simpat.2010.07.009
Jordan DC, Kurtz SR. Field experience: Degradation Rates, Lifetimes & Failures. PV Module Reliability Workshop: Lakewood, CO, USA, 2016).