Design, characterization and indoor validation of the optical soiling detector "DUSST"

TL;DR

This paper introduces DUSST, a low-cost optical sensor for detecting soiling on photovoltaic panels, with thermal characterization and validation showing less than 1.4% prediction error in real outdoor conditions.

Contribution

The study presents the design, thermal characterization, and outdoor validation of DUSST, a novel low-cost optical device for monitoring PV soiling losses.

Findings

Losses predicted with less than 1.4% error.

Successful outdoor validation with naturally soiled coupons.

DUSST offers an effective low-cost solution for PV maintenance.

Abstract

Nowadays, photovoltaic (PV) technology has reached a high level of maturity in terms of module efficiency and cost competitiveness in comparison with other energy technologies. As PV has achieved high levels of deployment, the development of devices that can help to reduce PV operation and maintenance costs has become a priority. Soiling can be cause of significant losses in certain PV plants and its detection has become essential to ensure a correct mitigation. For this reason, accurate and low-cost monitoring devices are needed. While soiling stations have been traditionally employed to measure the impact of soiling, their high cost and maintenance have led to the development of innovative low-cost optical sensors, such as the device presented in this work and named "DUSST" (Detector Unit for Soiling Spectral Transmittance). The thermal characterization of the components of DUSST and the methodology used to predict soiling transmittance losses are presented in this study. The results show that the losses can be predicted with an error lower than 1.4%. The method has been verified with an experimental campaign with naturally soiled coupons exposed outdoors in Ja\'en, Spain.