Comparison of Dust Deposition Reduction Performance by Super-Hydrophobic and Super-Hydrophilic Coatings for Solar PV Cells

Abstract

Dust deposition on solar photovoltaic (PV) cells will dramatically reduce the photovoltaic power output. Self-cleaning coating may be a novel method to decrease dust deposition problems. This paper compares self-cleaning performances and mechanisms of super-hydrophobic and super-hydrophilic coating on dirt deposition decrease for solar photovoltaic cells by experimental measurement. In the process of the deposition of dust on solar cells, covering glass, coated and uncoated, is conducted under natural settling conditions. Moreover, the dust removal efficiency of the glass samples with and without coatings is studied under water spraying conditions. The wettability of different surfaces, dust deposition mass, dust removal efficiency, self-cleaning mechanisms, and transmittance of glass samples are investigated and analyzed. Under natural settling conditions, the deposition mass reduction ratio by the super-hydrophilic coating is only 8.1%, while it can reach 85.8% by the super-hydrophobic coating because of surface micro-structures and low surface energy. However, after the water spraying process, the remaining dust mass ratio for the super-hydrophobic surface is only 16.5%, while it is 18.6% for the super-hydrophilic surface. The self-cleaning mechanism of super-hydrophobic coating is that most deposited particles of dust are removed from glass samples by the rolling of liquid droplets. However, the self-cleaning mechanism of super-hydrophilic coating is the breakup of the liquid film. Therefore, both coatings can effectively reduce dust deposition under water spraying conditions. The average transmittance of super-hydrophobic and super-hydrophilic coatings after the water spraying process is 91.1% and 86.4%, respectively, while it is only 61.1% for the uncoated glass sample.

Progress in Studies of Surface Nanotextures and Coatings with Nanomaterials on Glass for Anti-Dust Functionality

“…The results showed that the contact angle of the coating could approach 0°. Lu et al [ 159 ] mixed the prepared TiO 2 and SiO 2 sols and stirred them continuously for 4 h. Finally, the sols uniformly coated the bare glass samples, and the contact angle could reach 5°. After the water spray treatment, the remaining dust particles’ mass ratio of the superhydrophilic surface was 18.6%, which indicated the excellent cleaning function of the coating.…”

Exploration of Solar Panel Damage and Service Life Reduction Using Condition Assessment, Dust Accumulation, and Material Testing

“…These particles can be removed using wet cleaning if intervened at the right time. Cleaning can be facilitated by special coatings as proved by Lu et al [32]. In both cases, the transmittance of the solar cell decreases, and the proportion of reflected light increases.…”

“…These particles can be removed using wet cleaning if intervened at the right time. Cleaning can be facilitated by special coatings as proved by Lu et al [32].…”

Do Functional Coatings Work for Solar Panel Dust Mitigation?

“…The surface coating known as SPho achieves a self-cleaning effect by altering the surface with low-surfaceenergy molecules that reduce surface adhesion. 17 On the other hand, the SPhi coating uses its high porosity to lower the adhesion force between dust particles and the surface. The SPhi surface is mainly comprised of air due to its micro-and nanostructured design.…”

“…However, they have different self-cleaning mechanisms. The surface coating known as SPho achieves a self-cleaning effect by altering the surface with low-surface-energy molecules that reduce surface adhesion . On the other hand, the SPhi coating uses its high porosity to lower the adhesion force between dust particles and the surface.…”