A Low-Cost Closed-Loop Solar Tracking System Based on the Sun Position Algorithm

Abstract

Sun position and the optimum inclination of a solar panel to the sun vary over time throughout the day. A simple but accurate solar position measurement system is essential for maximizing the output power from a solar panel in order to increase the panel efficiency while minimizing the system cost. Solar position can be measured either by a sensor (active/passive) or through the sun position monitoring algorithm. Sensor-based sun position measuring systems fail to measure the solar position in a cloudy or intermittent day, and they require precise installation and periodic calibrations. In contrast, the sun position algorithms use mathematical formula or astronomical data to obtain the station of the sun at a particular geographical location and time. A standalone low-cost but high-precision dual-axis closed-loop sun-tracking system using the sun position algorithm was implemented in an 8-bit microcontroller platform. The Astronomical Almanac’s (AA) algorithm was used for its simplicity, reliability, and fast computation capability of the solar position. Results revealed that incorporation of the sun position algorithm into a solar tracking system helps in outperforming the fixed system and optical tracking system by 13.9% and 2.1%, respectively. In summary, even for a small-scale solar tracking system, the algorithm-based closed-loop dual-axis tracking system can increase overall system efficiency.

Solar Tracking System with New Hybrid Control in Energy Production Optimization from Photovoltaic Conversion for Polish Climatic Conditions

“…The advantage of the tracking systems provided with a control system that includes positioning on two axes seems to be unquestionable in comparison with fixed systems. This issue is also confirmed by the authors of numerous papers [1,2,8,13,[17][18][19][20][21][22][23], who specify the energy gains that they achieved in their studies for the structures under consideration.…”

Solar Photovoltaic Tracking Systems for Electricity Generation: A Review

“…Therefore, they cannot correct the errors that occur during the tracking process. The closed-loop control system [90][91][92][93][94][95][96][97] is based on a feedback control system from sensors (light dependent resistors) and moves the axes of the PV tracking system after the sensor detects the position of the sun. The closed-loop control tracking systems are more expensive than open-loop because of the additional sensor devices.…”

A Review on the Sun Tracking Mechanisms for Pv Strings

“…Usually, the nowadays active tracking systems are based on planar or spatial linkages, gear mechanisms, chain or belt transmissions. The orientation of the photovoltaic panels with active solar trackers may increase the efficiency of the conversion system from 20% up to 50% [1,5,9,11,26].…”

“…Using as input data the location latitude and commonly available values of monthly irradiation, a relation between the latitude of the chose location and the most suitable solar tracker is established [41]. In reference [11] , there is developed an analysis model for comparing the energy capture between fixed tilt angle and sun tracking systems, in clear sky and mean sky conditions, using the Moon-Spencer and the Aste models. Specific software tools were developed in [27] for simulating the energy yield of PV systems as a function of the ground cover ratio, for different tracking cases.…”