Optimizing Photovoltaic Efficiency in Isolated Areas: A Comparative Study of Fixed and Single-Axis Tracking Systems under Real Climatic Conditions

Abstract

This study presents an experimental simulation aimed at evaluating the performance of four photovoltaic (PV) subfields, each employing two mounting configurations: fixed-tilt and single-axis horizontal tracking systems with an east-west orientation. Two PV technologies, monocrystalline silicon (mc-Si) and polycrystalline silicon (pc-Si), were examined, with each subfield rated at a nominal capacity of 100 kW. All systems were installed at a tilt angle of 30°, optimized for solar energy capture at the experimental site in Ghardaïa, Algeria (32°34'43.79" N, 3°41'55.36" E). The study was conducted over four representative days, corresponding to different seasons.

System performance was evaluated using key indicators, including peak power output (kW), daily average power (KW), and the percentage increase in power based on daily averages(%). The impact of tilt angle and tracking mechanisms on solar energy capture was also assessed. Simulations were carried out using MATLAB-based PV design tools, and power output profiles were generated accordingly. High-resolution measurements recorded at four-minute intervals supported the simulation process and enabled real-time performance tracking.

The results demonstrated that single-axis tracking systems consistently outperformed fixed-tilt configurations, offering enhanced power generation and system efficiency throughout the day. On May 2nd, the mc-Si subfields with fixed and tracking structures achieved peak outputs of 95.96 kW and 92.06 kW, respectively, while the pc-Si equivalents reached 84.93 kW and 83.01 kW. Over the four study days, tracking systems exhibited superior performance in both power  production and solar irradiance utilization. Daily average power output were recorded on January 2nd , May 2nd , July 2nd , and October 2nd . The highest average daily power outputs for mc-Si and pc-Si tracking systems were observed on May 2nd, reaching 65.58 kW and 55.96 kW, respectively. Notably, on January 2nd, the tracking systems achieved the highest power gains of 19.30% (mc-Si) and 17.20% (pc-Si) compared to their fixed counterparts, underscoring the advantage of tracking technologies in maximizing daily energy yield.

In parallel, real-time solar irradiance measurements at a 30° tilt angle were obtained using a rooftop-mounted radiometric station. Three empirical models, Perrin de Brichambaut, Liu & Jordan, and Capderou, were assessed for their accuracy in estimating global tilted irradiance. Among them, the Perrin de Brichambaut model yielded the closest agreement with measured values on July 2nd, with a minimum root mean square error (RMSE) of 3.2261 W/m².