| Work Detail |
An international research team studied the photovoltaic impact of emissions from a coal-fired power plant in the Atacama Desert and found that, after five months of exposure, dust deposited on co-located photovoltaic panels reached a maximum of 1.63 mg/cm2, with a 23% reduction in photocurrent. The accumulation at the co-located plant was three times greater than at nearby photovoltaic sites with similar coastal climate conditions. Aware of the operation and maintenance (O&M) costs of combating soiling of photovoltaic panels in arid, highly industrialized areas, a group of researchers from Chile and Spain investigated the impact of emissions from a coal-fired power plant on solar panels at three sites in the Atacama Desert, including a photovoltaic installation located within the coal-fired power plant. Dust adhesion mechanisms, composition, and effects on optical transmittance and current density reduction were studied, and scientists also briefly discussed specific cleaning and maintenance strategies to maintain system performance in photovoltaic plants located near coal-fired power plants. We observed a growing trend toward locating solar plants next to industrial facilities. This led us to question how emissions and byproducts from these industries affect the soiling of nearby PV systems compared to standard reference sites, Aitor Marzo, co-author of the study, explained to pv magazine . Additionally, a photovoltaic operator located several kilometers away contacted us to report unexpected soiling levels, explained Douglas Olivares, co-author of the study, adding that the operators observations differed from what was initially expected, prompting further investigation. We focused on how residues from the flue gas desulfurization process at a coal-fired power plant can create unusually tough dust crusts on photovoltaic modules, explains Marzo. By combining chemical analysis with performance testing, we demonstrated exactly how these byproducts adhere to panel surfaces. According to the research, the tests were conducted in Mejillones, a city known for hosting the highest concentration of coal-fired power plants in Chile. The researchers evaluated the transmittance losses of a 21.6 kW solar photovoltaic plant located on-site at a coal-fired power plant and examined dust accumulation on the panel surfaces over a five-month period, with a weekly frequency from September 21, 2022, to March 2, 2023. The photovoltaic glass samples lacked anti-fouling coatings and were installed facing north at a 20-degree tilt. The irradiance sensor results were compared with a clean glass sample. The impact of the coal-fired power plant on modules placed at the same location showed that, after five months of exposure, the deposited dust peaked at 1.63 mg/cm2, with a fouling rate up to six times higher than at other sites studied, resulting in a 23% reduction in photocurrent, the team noted. The results obtained were compared with three other sites in the Atacama Desert. Furthermore, our results indicate that the effects of the plants activity are perceptible up to 9 km away, becoming especially evident in areas with high humidity, where the solubility of the materials enhances the recrystallization and consolidation of dust on the surfaces of the modules, the researchers added. We were surprised by the extent of these desulfurization byproducts. They facilitated cementation in the modules even several kilometers away from the plant, something we didnt expect to see at that distance, said Olivares, noting that the calcite used in the plants sulfur gas reduction processes generates synthetic gypsum (FDG), which was found to facilitate dust cementation in the modules. The team noted that only optical transmittance and current density results were investigated in the study. Other measurements, such as output power and long-term degradation effects, remain to be investigated. The research is described in “ Impact of thermoelectric coal-fired power plant emissions on the soiling mechanisms of nearby photovoltaic power plants in the Atacama Desert,” recently published by Renewable Energy . The scientists came from the University of Antofagasta, the University of Chile, the Federico Santa María Technical University and the Millennium Nucleus of NanoBiophysics (NNBP), as well as the University of Granada, the University of Almería and Loyola University Andalucía. Since the studys completion, the research has generated considerable interest among photovoltaic plant operators, particularly in the Atacama Desert. Several companies sought our results to understand how local factors intensify soiling. They have since used this knowledge to optimize cleaning programs and maintenance strategies, explains Olivares. When asked about future research directions, Marzo responded, We plan to expand our work to broader industrial contexts, refine soil measurement methods, and develop localized soil maps to support PV design and maintenance in harsh environments. Additional research collaborations are also underway with teams in Europe, Spain, and Chile. |
