Application of Titanium Dioxide Self-Cleaning Coatings on Photovoltaic Modules for Soiling Related Losses Reduction

Abstract

Several studies have assessed the influence of soiling deposition on Photovoltaic (PV) modules front-cover with regards to performance losses over time. In fact, soiling phenomena in PV systems are ascribed as responsible for medium and long-term yield reduction up to 16% over the first-year of outdoor exposure. Provided that PV technology is a low yield energy production source, maintaining module initial power output declared values is of the outmost importance to ensure that the return time of investment matches project calculations. The scope of this work was a detailed investigation on self-cleaning coating application as a viable retrofit option on already installed modules, or on newly built PV systems, to avoid soiling build-up on front-covers and guarantee threshold performance level in time. The aim is to provide system designers with a consistent alternative to manual cleaning, without losing effectiveness in terms of yield maintenance. The use of self-cleaning coating instead of acting on panels on a regular basis is more convenient in terms of operation and cost. These issues were analyzed through a set of experiments performed both on commercial size modules and laboratory assembled samples. Results prove product compatibility with PV components and its effectiveness in preventing soiling and dust deposition. Outcomes are presented in terms of maximum power output (P max ) variation according to measurements performed in Standard Test Conditions (STC) at different time steps. In addition, a parallel comparison with uncoated modules exposed to the same outdoor conditions is also proposed to allow for P max variation monitoring performed on a reference sample.

Utilization of Nano thin films for solar cell self-cleaning.

“…All measurements were made at a controlled ambient temperature of 20° C and relative humidity (79%). Placed at four different positions for the samples, and the average measurement has been estimated to be the final contact angle [14].…”

“…These factors can be optimized by choosing a suitable place for the panels and proper fitting with the environmentSelf -cleaning coatings reduce the maintenance costs, amount of water, and human resources, so it is a very effective process. Different types of coating depending on the application, their behavior to water as hydrophobic or hydrophilic, and their decomposition in organic compounds contain photocatalytic particles, as Nanocrystalline titanium dioxide in the form of Anatase phase [4]. Some of the panels are located in the sunny desert environment and this dry environment, and the presence of wind makes dust on PV panel's surface.…”