Operation and maintenance of grid-connected photovoltaic systems: thermographic inspection and cleaning of PV modules

Abstract

Photovoltaic systems (PV) are expanding in Brazil, accompanied by the implementation of good practices for the operation and maintenance (O&M) of photovoltaic plants. There is, however, a gap of knowledge in the field. Procedures for the identification and prevention of failures have helped in the search for the better performance, safety and availability of these systems. This paper presents methods for thermographic inspection and cleaning of PV modules, in addition to calculating generation losses. The study was conducted in the PV plants of the Federal Institute of Minas Gerais (IFMG), on the Betim and Congonhas campuses. The generation values were obtained from data acquisition systems at the plants. A qualitative thermographic inspection revealed that 12.7% of the Betim plant modules had hot spots. Through the cleaning of this system, generation losses of up to 22.25%, caused by the soiling of the modules, were estimated. In Congonhas, these losses reached 56.86%, possibly caused by air pollution. These results highlight the importance of preventive maintenance and monitoring of the systems, with the aim of achieving greater durability and energy performance of PV plants.

Keywords:
Photovoltaic solar energy; Operation and maintenance (O&M;. Thermography; Cleaning PV modules; Soiling of PV modules; Performance of PV systems