PV-soiling field-assessment of Mars™ optical sensor operating in the harsh desert environment of the state of Qatar

We report on the field assessment of the Mars™ optical soiling sensor performance for PV-soiling measurement under harsh conditions of a desert environment. Mars™ was installed in a hot, sunny, and dusty climate in the Outdoor Test Facility, managed by Qatar Environment & Energy Research Institute, located in Doha (state of Qatar). Mars™ is a compact system, easy to install at different geographical sites, and it is designed to allow an efficient and cost-effective PV-soiling measurement with lower labor and operation & maintenance requirements, compared to conventional soiling measurement requiring conventional clean/soiled reference module pair method. Despite some discrepancy in the soiling measurements that were more pronounced during certain periods of time than the others, overall, a good fit was noticed between the two methods. A mismatch of less than ∼ 0.1 %/day between the light transmission loss estimated by the Mars^TM sensor and from a PV array is identified, and results are discussed accordingly. We demonstrate thus the feasibility of Mars™ to be deployed in different geographical locations and it's potential in measuring wide range of PV-soiling in commercial-scale PV installations.