Fractal textured glass surface for enhanced performance and self-cleaning characteristics of photovoltaic panels

Photovoltaic (PV) modules face significant performance loss due to the reflection of solar radiation and dust accumulation on the PV glass cover. Micro- and nanoscale texturing of the PV panel glass cover is an effective means of reducing solar radiation reflection and providing surface hydrophobicity to reduce dust accumulation and ease cleaning. Considering multiscale surface texturing of PV panel glass cover, represented generically as fractal surfaces, the study comprehensively investigates the effect of texturing on the module’s optical, thermal, and overall performance, as well as the surface’s wettability characteristics. Numerical simulations over a range of fractal texturing parameters and geographical locations indicate that texturing reduces reflectance by over an order of magnitude and boosts the power output by as much as over 4 % depending on the fractal parameters, which is within 0.2 % of the theoretical maximum for an ideal case of zero reflectance on the glass cover. Complementing the power production enhancement, texturing is also shown to impart hydrophobicity or superhydrophobicity, which is essential for the surfaces to resist or easily remove soiling and dust accumulation. A design map for tailoring the fractal texture parameters so as to achieve the desired self-cleaning characteristic is derived from the study. The article elucidates, for the first time, a systematic fundamental understanding of texturing to enhance PV panel performance and provides information for designing texturing parameters for desired performance enhancement.