Influence of Solar Position Calculation Methods Applied to Horizontal Single-Axis Solar Trackers on Energy Generation

Abstract

Photovoltaic systems have been explored as a solution to meet the growing demand for electricity from a clean and renewable source. However, the low energy conversion efficiency of photovoltaic panels is one of the critical factors that hinder the competitiveness of this energy source concerning the others. An effective way to improve the efficiency of photovoltaic systems is by using solar trackers. The tracking strategy most used in photovoltaic plants employs algorithms to calculate the Sun position. This work presents energy generation estimation applying six algorithms in horizontal single-axis solar tracking: the Solar Position Algorithm (SPA) and Grena 1–5 algorithms. The aim is to evaluate the influence of these algorithms on energy generation. For all simulated locations, comparing to an ideal scenario, the SPA presented the best energy generation results. However, the other algorithms showed negligible differences between themselves, which allows us to conclude that any of the algorithms can be used without implying significant energy losses. Thus, Grena 1–2 can be highlighted for easier implementation.

Efficiency Enhancement of Tilted Bifacial Photovoltaic Modules with Horizontal Single-Axis Tracker—The Bifacial Companion Method

“…(6) Reflector energy efficiency η en : according to Iqbal Model C and ASHRAE Model C [41], the direct solar radiation intensity (DNI) is approximately proportional to the solar elevation angle, i.e., DN I ∝ sin el. Then, the energy weight of optical efficiency η sum can be obtained as follows:…”

“…Basic parameters of the calculation model. Solar position parameters of the global coordinate system Introducing time parameters (T, N), in the astronomical geocentric celestial coordinate system (see Figure5a), the approximate equation[41] is used to calculate the solar hour angle ω = 15 o × (T − 12), declination angle δ = 23.45 o × sin[ 360 o 365 × (N + 284) at any time, where T is the true solar time and N is the serial number of a day in a year. The solar elevation angle el and azimuth angle az are expressed as follows:…”