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A team of Algerian researchers has designed a new test bench and a novel acceleration law that takes into account both wind speed and sand density. The new methodology was tested on four photovoltaic modules and showed a lifespan of up to 47 years against sand impact. Algerian scientists have proposed a new accelerated aging testbed for photovoltaic modules and developed a novel acceleration law for sand erosion degradation. “Unlike existing models, our research introduces a law specifically tailored for sand erosion, incorporating both wind speed and sand density for a more accurate prediction of lifetime in desert environments,” corresponding author Abdelkader Elkharraz told pv magazine . “One of the most detrimental factors to the reliability of PV modules in desert environments is sand erosion. The constant bombardment of sand particles, driven by strong winds, can cause mechanical and optical degradation of the module surface. This degradation manifests itself in several ways, such as abrasion of the protective glass layer, scratching of the anti-reflective coating, and accumulation of dust and debris, all of which contribute to reduced light transmission and total power output.” The custom test rig designed by the team allows for control of parameters that influence sand erosion. It includes a sand feeding mechanism that regulates sand density, a variable speed fan to control wind speed, and a rotating stage that allows exposure from all sides. Sand from the desertification zone is used, characterized by larger, irregularly shaped grains, which causes more aggressive erosion. The team tested four monocrystalline silicon PV modules; two of them were brand new 100 W Dinel Solaire modules, while the other two were pre-used 80 W Visel modules. In test condition 1, they were sandblasted with a sand density of 5.8 g/m3 and a speed of 12 m/s; while in test condition 2, it was set at 10.3 g/m3 and 15 m/s, respectively. According to the team, condition 1 represented a “harsh acceleration environment,” while condition 2 represented “a more accelerated and harsh environment.” The new acceleration law, named after its creators, takes into account wind speed and sand density and ultimately calculates the mean time to failure (MTTF), which represents the average time until a system fails under specific operating conditions. Coupled with a fuzzy logic-based data analysis program, the model can then find the acceleration factor (AF). The AF quantifies the relationship between the rate of degradation under accelerated test conditions and under real-world conditions. The data collected was correlated with real wind data from a solar plant in Adrar, Algeria. This data set was then used to project a realistic lifetime of these modules under typical desert operating conditions, explains Professor Elkharraz. “Our model, coupled with a fuzzy logic program for data analysis, estimated a significantly longer service life for VISEL modules (46.8 years) compared to DINEL modules (31.6 years) in the Adrar region of Algeria. The lower annual degradation rates (0.64% vs. 1.38% for VISEL and DINEL, respectively) are consistent with existing literature and underline the potential of the model to accurately predict module service life in sand-prone regions.” Their findings were presented in “ A novel acceleration law for sand erosion degradation of photovoltaic modules,” published in Renewable Energy . The research was carried out by scientists from Ahmed Draia University in Adrar (Algeria), Medea University and the Centre for the Development of Renewable Energy (CDER). |
