Degradation Effects in sc -­‐ Si PV Modules Subjected to Natural and Induced Ageing after Several Years of Field Operation

Abstract

This paper presents ageing effects observed in sc--Si PV modules operating in field conditions for 18 and over 22 years. The effects of both natural ageing processes and induced ageing by external agents, causing partial or total shading of cells for a prolonged period of time, are examined. Optical degradation effects observed through visual inspection include discoloration of the EVA, degradation of the AR coating, degradation of the interface between the cell and encapsulant, corrosion of busbars and fingers, and tears, bubbles and humidity ingress at the back surface of the modules. Thermal degradation effects examined via IR thermography reveal the existence of hot cells, hotspots on the busbars, and colder bubbles. Modules' power and performance degradation is assessed through I--V curve analysis. Results show naturally aged modules to exhibit milder ageing effects than modules subjected to induced ageing, an outcome also supported by their power degradation ratio.

Investigation of Operating Parameters and Degradation of Photovoltaic Panels in a Photovoltaic Power Plant

“…In our case, we have observed the rate of degradation (determined through the calculated efficacy) caused by age using a linear regression model, which is generally the accepted method [3]. The degradation rate is so low (in the order of 1 × 10 9 ) that it is impossible to determine because the changes in efficiency are within the statistical error and thus our results do not agree with the conclusions of the literature [5,8]. For midrange and polycrystalline PV panels, the degradation rates range from 0.3% to 2.9% per year [9].…”

“…Kaplani [8] have studied six modules from two different field producers for 18 years and over 22 years. The modules with over 22 years of operation time were exposed to natural field conditions, whereas modules with 18 years of operation, in addition to natural aging, were exposed to the strong effects of induced aging for several months.…”

An embedded microcontroller unit for PV module monitoring and fault detection

“…The effect may be temporary as in the case of transient shadows casted on the PV modules or permanent as in the case of corrosion, delamination, etc. In the latter case their impact may increase during the lifetime of the PV module, while the degradation and aging of the PV cells becomes a governing factor in the PV power performance [12][13][14].…”

Weeper Control Design based on Microcontroller for Photovoltaic Panel Cleaning System

“…Hence, a cleaning machanism to maintain the power performance by removing the dust from the solar panel surfaces is required [1,2,3]. The Moreover, disposals which cover continuously solar panel surfaces can damage any cell in a solar module [4]. Other pollutants such as ash can also reduce the power performance of a solar panels [5].…”