Impact of dust on the photovoltaic (PV) modules characteristics after an exposition year in Sahelian environment: The case of Senegal

The objective of this paper is to find the effect of dust on the performance of photovoltaic modules. To this end, the International Center for Research and Training in solar energy at Dakar University and the Lasquo-ISTIA Laboratory of Angers University have put in place a research project in order to investigate the impact of Sahelian climatic conditions on the photovoltaic (PV) modules characteristics. Accordingly, monocrystalline silicon (mc-Si) PV module and a silicon polycrystalline (pc-Si) PV module are installed at Dakar University and monitored during one operation year without cleaning. We evaluate the variation depending on the dust of electrical characteristics such as I-V and P-V curves, open-circuit voltage(Voc), short-circuit current (Isc), maximum ouput current (Imax), maximum output voltage (Vmax), maximum power output (Pmax) and fill factor (FF). This work has highlighted theimpact of dust on the Current-Voltage (I-V) and Power-Voltage (P-V) characteristics of PVmodules (mc-Si and pc-Si) with the advent of the mismatch effect. Pmax, Imax, Isc and FF are the most affected performance characteristics by the dust deposits on the PV modules surface. The maximum power output (Pmax) loss can be from 18 to 78% respectively forthe polycrystalline module (pc-Si) and monocrystalline module (mc-si). Imax loss can varyfrom 23 to 80% for respectively pc-Si and mc-Si modules. However, the maximum voltage output (Vmax) and the open-circuit voltage (Voc) are not affected by dust accumulation for both technologies studied. The fill factor (FF) may decrease from 2% for the pc-Si module to 17% for the mc-Si module

Photovoltaic Platform for Investigating PV Module Degradation

Photovoltaic research is oriented more and further towards study on PV modules degradation. The objective is to understand the different degradation modes of PV modules and associated factors. This paper presents a platform for measures dedicated to do a study related to degradation of electrical characteristics of the photovoltaic modules. It is installed on the site at University of Dakar in Senegal. This work proposes a method for standardization of the direct measures of the short-circuit current (Isc) and the open-circuit voltage (Voc) of PV modules. The approach used for the assessment of degradation of Isc and Voc involves a comparison between baseline values given by manufacturer and those measured in real operating conditions brought back in the standard test conditions (STC). Findings presented on degradation of Isc and Voc photovoltaic modules cover the first ten months of measurements from Mars to January. Degradation of short-circuit current is about 13% for the three days. The degradation of open-circuit voltage measured during the three days is 8%

A Novel Method for Investigating Photovoltaic Module Degradation

This paper proposes a method for the detection and assessment of the degradation of the photovoltaic modules electrical characteristics such as short-circuit current (Isc), open-circuit voltage (Voc) and maximum output power (Pmax). This work presents a standardization method for measurements of these characteristics in real conditions. Standardization is bringing back the measurements in real conditions to the corresponding values in standard test conditions (STC). Thus the standardized values of short-circuit current (Isc,stc), the open-circuit voltage (Voc,stc) and the maximum output power (Pmax) are compared with reference values corresponding to the first putting service of module or the manufacturer\u27s data as in our case. The data collected on a platform of measurements installed at the University of Dakar in Senegal are used to validate our approach. A Period of one operation year of the PV module is considered. After one year of module operation, we note an average degradation of 10% for the short-circuit current, 2% for the open-circuit voltage. For the maximum output-power no degradation is yet detected at this stage

Degradations of silicon photovoltaic modules: A literature review

PV modules are often considered to be the most reliable component of a photovoltaic system. The alleged reliability has led to the long warranty period for modules up to 25 years. Currently, failures resulting in module degradation are generally not considered because of the difficulty of measuring the power of a single module in a PV system and the lack of feedback on the various degradation modes of PV modules. It should be noted that consumers are becoming more and more interested in the reliability and lifetime of their PV system considering economic issues. Reliability and lifetime of a PV system depend mainly on the energy performance of modules and their different degradation modes. Accordingly, research must more and more focus on photovoltaic modules degradation. This paper presents a review of different types of degradation found in literature in recent years. Thus, according to literature, corrosion and discoloration of PV modules encapsulant are predominant degradation modes. Temperature and humidity are factors of PV modules degradation in almost all identified degradation modes. However, despite the identification of PV modules degradation modes, it is still difficult to study them in real conditions. Indeed, there must be long periods feedback experiences to study the frequency, speed of evolution and impacts of various PV modules degradation modes on energy output. In this paper, models associated with the PV modules degradation are presented. These models can help to overcome the long-term experiments obstacle in order to study PV modules degradation under real conditions

Degradation evaluation of crystalline-silicon photovoltaic modules after a few operation years in a tropical environment

This paper presents an evaluation of the performance degradation of Photovoltaic modules after few operation years in a tropical environment. To this end, the International Center for Research and Training in solar energy at Dakar University and the Lasquo-ISTIA laboratory of Angers University have put in place a research project in order to investigate the impact of the tropical climatic conditions on the PV modules characteristics. Accordingly, two monocrystalline-silicon (mc-Si) PV modules and two polycrystalline- silicon (pc-Si) PV modules are installed at Dakar in Senegal and monitored during a few operation years: Module A (16 months), Module B (41 months), Module C (48 months) and Module D (48 months). After few operation years under tropical environment, the global degradation and the degradation rate of electrical characteristics such as I-V and P-V curves, open-circuit voltage (Voc), short-circuit current (Isc), maximum ouput current (Imax), maximum output voltage (Vmax), maximum power output (Pmax) and fill factor (FF) are evaluate at standard test conditions (STC). This study reports on data collected from 4 distinct mono- and poly-crystalline modules deployed at Dakar University in Senegal. The study has shown that Pmax, Imax, Isc and FF are the most degraded performance characteristics for all PV modules. The maximum power output (Pmax) presents the highest loss that can be from 0.22%/year to 2.96%/year. However, the open-circuit voltage (Voc) is not degraded after these few exposition years for all studied PV modules

International equatorial electrojet year : the African sector

International audienceThis paper presents the IEEY project in the African sector. The amount of our interpreted data is presently too short to allow proper scientific conclusions. Nevertheless, fist typical results illustrate our network possibilities. Some preliminary observations are briefly pre- , sented for their interest towards immediate research goals