PRELIMINARY ASSESSMENT OF DEGRADATION IN FIELD-AGED MULTI-CRYSTALLINE SILICON PV MODULES INSTALLED IN HOT-HUMID CLIMATE OF MID GHANA D. A. Quansah 1 *, M. S. Adaramola 1Δ and G. Takyi 2Λ 1 Renewable Energy Group, Department of Ecology and Natural Resources Norwegian University of Life Sciences (NMBU), Ås, NORWAY 2 Department of Mechanical Engineering Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, GHANA *david.ato.quansah@nmbu.no (Corresponding Author), Δ muyiwa.adaramola@nmbu.no, Λ gtakyi.soe@knust.edu.gh ABSTRACT: A multicrystalline solar PV installation in Kumasi Ghana, a hot humid climate, was studied for degradation in key performance characteristics after 18-years of exposure. An outdoor current-voltage (I-V) characteristization of the ASE-50-PWX-D the various modules was undertaken. The data was then translated to Standard Test Conditions (STC) and compared with the primary performance characteristics of the modules. The results showed a 0.9% - 1.6% average annual decline in peak power. Short-circuit current and open circuit voltage declined annually by 0.3%-0.6% and 0.1%-0.2% respectively. Decline in the fill factor was 0.3% - 1.2% p.a. resulting from 0.7%-1.1% and 0% - 0.8% loss in current and voltage at peak power. The module had a 10-year warranty and this data shows that it has met and exceeded warranty requirements. Keywords: Degradation, Multi-crystalline, Silicon, PV Module 1 INTRODUCTION The Solar PV industry has grown rapidly in recent years and is set to play an even more important role in the years ahead. Between 2010 and 2014, installations grew by almost 450% - from 40 GW to 177 GW [1]. Solar PV has been projected to supply 16% of global electricity consumption by 2050 [2]. New investments in renewable energy averaged $254 billion in the 5-year period 2010- 2014 [1]. As investment requirements grow, investors require assurances that modules will perform on field and last the 20-30 year periods that are typical of Solar PV project analysis. Manufacturers seek to assure investors by granting warranties on modules sold. Current module warranties range from 20 – 25 years [3], [4] [5] and promise a minimum of 80% peak power in this period. This requires that modules loose no more than 20% of peak power by the end of the 20 – 25 year period. This implies a maximum linear degradation of 0.8 - 1% of peak power annually. There are two problems that manufacturer warranties typically encounter. The first, is, there is insufficient field data to confirm that modules will perform as predicted when operated in the different climatic conditions of the world. Qualification tests as per IEC (International Electrotechnical Commission) Standards 61215 and 61646, for crystalline Si and thin films respectively [6], [7], serve as minimum requirements for market entry and has proven quite efficient in reducing infant mortality among PV modules. These tests, however, do not determine lifetime of modules. It may require up to 20 years of waiting to verify this. The second problem, is that, many companies hardly last the duration of the warranties they provide, making the warranties hardly enforceable. Between 2009 and 2013, over fifty (50) manufacturers closed or filed for bankruptcy with many more undergoing some kind of restructuring/merger/acquisition (see Figure 1) [8]. Figure 1: No. of Solar PV Companies Closing or Filing for Bankruptcy Data: GTM Research [8] While some manufacturers are moving to offer insurance- backed warranties [5], data on long-term performance of Solar PV technologies in the different climatic conditions of the world helps to minimize investor uncertainties and also provide feedback to manufacturing companies and research institutions involved in developing solar cell materials. There is, however, little information in the open literature on the long-term performance and degradation issues on PV systems in Africa [9] [10]. In this paper, we present results of our assessment of the performance of ten (10) multicrystalline modules installed in 1998 on the roofs of the Solar Energy Applications Laboratory (SEAL) at the Kwame Nkrumah University of Science and Technology (KNUST) in Kumasi Ghana, after 18-years of exposure. Kumasi, (located at latitude 6.7 o N, longitude 1.6 o W and elevation of 287 m) is a hot and humid climate with average daily temperature ranging from 24.4 o C – 27.8 o C and relative humidity of 65% - 83.5% [11]. 2 METHOD The installation under study (Fig. 2a and 2b) comprises fourteen (14) ASE-50-PWX-D modules (manufacturer - PHOTOWATT) with nominal power of 49 W (a total of 686 Wp). The modules were labelled as PWX1, PWX2, 10 5 38 3 0 10 20 30 40 2009-2010 2011 2012 2013 no . of companies Year 32nd European Photovoltaic Solar Energy Conference and Exhibition 2290