Research Article
Time Series Analysis of Rainfall Distribution in Gambella Meteorological Station
Issue:
Volume 12, Issue 1, February 2026
Pages:
1-8
Received:
11 December 2025
Accepted:
6 January 2026
Published:
27 January 2026
Abstract: This study conducted on this research on the Time Series Analysis of rainfall distribution in Gambella meteorological station. On this study, we try to see what the rainfall behavior of Gambella meteorological station seems like. In our study we have used time series model and focused on time series component, to deal variation and trend of rain fall distribution in Gambella metrological station, First, we have seen the actual data of rainfall in mm of the last ten years. The data shows a little change the year. When we see the trend value of the last ten years of the rain it is proportionally a little increasing. From the seasonal indices we have seen there was higher rainfall in the beginning of the years that means the earliest time and it shows proportionally decreasing except 2009 was higher rainfall. Lastly we seen the forecasted value for 2013 based on the rainfall of 2012 rainfall and the forecasted value of rainfall in Gambella meteorological is similar to that of its preceding years, but it will show a little decreasing at the beginning of the year and it will be constant.
Abstract: This study conducted on this research on the Time Series Analysis of rainfall distribution in Gambella meteorological station. On this study, we try to see what the rainfall behavior of Gambella meteorological station seems like. In our study we have used time series model and focused on time series component, to deal variation and trend of rain fa...
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Research Article
A Solar-position-based Analytical Algorithm with Seasonal Atmospheric Correction for Forecasting Bifacial PV Energy Yield in the Fergana Valley
Avazbek Abduraimov
,
Akmaljon Kuchkarov*
Issue:
Volume 12, Issue 1, February 2026
Pages:
9-24
Received:
11 May 2026
Accepted:
22 May 2026
Published:
5 June 2026
DOI:
10.11648/j.ajme.20261201.13
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Views:
Abstract: Accurate forecasting of photovoltaic energy generation is essential for preliminary system design, seasonal planning and reliable integration of solar power into electric-energy systems. This study proposes a solar-position-based analytical algorithm for estimating the seasonal and annual energy yield of a fixed-tilt bifacial photovoltaic system under the climatic conditions of Fergana city, Uzbekistan. The method combines solar-geometry calculations, monthly atmospheric correction factors, irradiance transposition onto an inclined surface, bifacial rear-side irradiance contribution and NOCT-based module-temperature correction within a unified hourly calculation framework. Monthly atmospheric coefficients were introduced to adapt theoretical clear-sky irradiation to the real seasonal radiation regime of the region. The algorithm was validated against PVsyst simulation results. The proposed method predicted an annual specific yield of 1860 kWh/kWp, while the PVsyst reference value was 1859 kWh/kWp, corresponding to an annual relative deviation of approximately 0.05%. Monthly deviations remained within 5.66%, and the mean absolute percentage error was 2.87%. The results also showed that summer thermal derating may reduce effective PV output by approximately 10–15%, whereas bifacial rear-side generation can increase annual yield by about 5–8%. The proposed algorithm provides a transparent and computationally efficient tool for preliminary photovoltaic energy-yield forecasting in regions with pronounced seasonal climatic variability.
Abstract: Accurate forecasting of photovoltaic energy generation is essential for preliminary system design, seasonal planning and reliable integration of solar power into electric-energy systems. This study proposes a solar-position-based analytical algorithm for estimating the seasonal and annual energy yield of a fixed-tilt bifacial photovoltaic system un...
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