![]() The temperature correction is almost similar in all versions, while the methods used to correct the spectral effects vary between the publications. Several researchers have developed correction methods that reduce the systematic errors of silicon sensors. They found that the monthly deviation between the solar irradiation measurements from both devices ranges between −4.8% in June to −0.7% in December. compared the Plane of Array irradiance data, measured at a tilt plan of 32° by a first-class thermopile sensor and a reference PV cell. ![]() They found that the daily solar irradiation deviation can amount up to 3% and that this deviation is highly variable over days, weeks, and months. considered the spectral effect and calculated the deviation of the two sensors in four different locations in the USA. They found the uncertainties in irradiance measurements to be in the order of ☒.4% for PV reference devices and ±5% for thermopile pyranometers. The calculations were performed for a fixed-tilt system under clear sky conditions. calculated typical measurement uncertainties for PV sensor and thermopile pyranometer measurements. Understanding these differences is important because PV system performance analysis often depends on accurate solar irradiance data, and sensors of different technologies may be used. Many studies have highlighted the differences between both sensors and evaluated the uncertainties for solar radiation measurements. The presented correction method shows promising results for a further improvement in the accuracy of silicon-based sensors. The difference in total annual irradiation decreased from 70 KWh/m 2 (6.5%) to 15 kWh/m 2 (1.5%) by the correction. The relative root mean squared difference (rRMSD) between the daily solar irradiation measured by both sensors decreased from 10.6% to 5.4% after applying the correction model, while relative mean absolute difference (rMAD) decreased from 7.4% to 2.5%. By applying the correction model on the measurements of the silicon-based sensor, the differences between sensor readings have been reduced significantly. The model separates measurements under a clear sky and cloudy sky by combining the clearness index and the solar zenith angle. Based on the analysis, a correction model is applied to the silicon sensors measurements. The analysis of the differences is based on evaluating four parameters that influence the sensor measurements, namely the temperature, cosine error, spectral mismatch, and calibration factor. In addition, their response time is much lower, and their spectral response is much closer to that of the PV systems. A major motivation to use silicon-based sensors for the measurements of irradiance is their lower cost. We present a method to correct the global horizontal irradiance measured by silicon-based sensors that reduces the difference to the standard thermopile sensor measurements. Silicon-based sensors are widely used for monitoring solar irradiance, in particular, in the field of Photovoltaic (PV) applications.
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