Sand erosion of solar glass: Specific energy uptake, total transmittance, and module efficiency

Abstract

Summary Surface roughness, RZ, normal transmittance, ΤN, total transmittance, ΤT, and photovoltaic (PV) module efficiency, ηS, were measured for commercial solar glass plates and PV test modules identically sandblasted with different loads of quartz sand (200–400 μm), impact inclination angles, and sand particle speed. Measured data are presented versus the specific energy uptake during sand blasting, E (J/m2). Cracks, adhering particles, and scratch‐like textures probably caused by plastic flow phenomena could be observed after sand blasting. Their characteristic size was much smaller than that of sand particles. After blasting and subsequent cleaning, the glass surface was still covered with adhering glass particles. These particles, cracks, and scratch‐like textures could not be removed by cleaning. For sand blasting with α = 30° inclination angle and E = 30 000 J/m2, normal transmittance, total transmittance, and relative module efficiency decreased by 29%, 2% and ∽2%, respectively. This finding indicates that diffusive transmission of light substantially contributes to PV module efficiency and that the module efficiency decrease caused by sand erosion can be better estimated from total than by normal transmittance measurements.

Durability of Antireflective Sio2 Coatings with Closed Pore Structure

“…Unlike AR Aero and AR Roll , AR Etch exhibit numerous point defects and stuck grains of sand, seen as dark spots in the microscope (Fig. 7b), resembling observations of sand blasted solar glass [102]. The lack of visible grains of sand could indicate a better cleanability for AR Aero compared to AR Etch , as expected for the smoother surface [103], while the same is true relative AR Roll due to number of scratches.…”

“…The presented results suggest that the AR Aero coating could be highly competitive, particularly in tempered and arid climates, where resistance to temperature variations, moderate humidity and sand erosion are central. The niche of desert climates could be especially interesting considering the challenge of utilizing the abundance of solar irradiance due to soiling and irreversible sand erosion as the dominant degrading process [32,102]. Furthermore, primarily due to a better positioned transmittance peak than AR Etch , and better durability than AR Roll , and secondly due to the broadband antireflective behavior and closed porous surface (both originating from the hexagonal structure) [27], AR Aero would be superior for applications in photovoltaics [11].…”

Sand winds effect on the degradation of photovoltaic modules in desert environments - PART I: Simulator design and Database creating

“…The wind speed did not exceed 5 m/s for approximately 56% of the time, while the winds between 5 and 10 m/s lasted 33% of the time, and there were calm conditions for approximately 4% of this period. Figure (3) shows the wind direction we obtained from the previous data; it shows that the north-north-east is dominating at 14%, while the east and north-east are at 11% each. The lowest sector is the west-north-west direction with only 1%.…”