PV Tracker System Net Gain Associated to the Local Climatic Conditions

Abstract

The optimization procedure on a photovoltaic system design implies the best compromise between energetic production (EP) and overall associated costs (OAC), which include economic and environmental. Both variables depend on the available solar radiation; strongly the EP and, in a lesser extent, the OAC. In this paper, the required conditions so that a PV tracking system produces a net gain with respect to a PV fixed system will be evaluated. This analysis is performed as function of the location's climatic conditions in terms of production and associated multidimensional costs, including EPBT and IRR. To avoid theoretical model dependences, the whole study has been carried out under real sun conditions on a medium irradiation region. For it, an 8-month historical monitoring data of a grid-connected PV field have been analyzed. The installation has two samemanufacturer polycrystalline arrays installed the same year, one of them with a 2-axis tracker and the other in fixed tilt position. As general result, a simple algorithm for tracker net gain evaluation as function of global and diffuse radiation is provided. Also, the net benefit limit value for a tracker system as function of the diffuse fraction is calculated. Keywords: PV design, Solar tracker, Multidimensional cost, Solar radiation, Diffuse fraction I. INTRODUCTIONIn the actual renewable energies paradigm, the selection of the most appropriate design for a given location relies on the best compromise between energy production and associated overall costs. Considering the solar photo voltaics, the energy production strongly depends on the climate and the PV system design (fixed tilt or solar tracker system). The associated overall costs consider not only economic but also the environment associated costs. The solar tracker installation optimizes a PV system in terms of energetic production. According to several authors, a 2-axis solar tracker provides between 12% and a 35% more gain in terms of production than a fixed tilt array. The wide spectrum of responses can be adjudicated to the high dependence on meteorological models, the limited historical databases and, of course, to the different climatic characteristics of the experimental setups location used for the analyses. Several studies regarding the energy production increase when installing 2-axis solar trackers have been developed. [8]. These studies tend to lead to the conclusion of the high profitability of installing a 2-axis solar tracking system. Nevertheless, other studies consider the solar tracking suitability in overcast conditions [9][10], concluding that overcast conditions lead to less production when considering tracking systems than fixed horizontal arrays. This dependence can be evaluated through the Clearness Index (KT). As this paper focus on directly measurable parameters [11], this variable will not be considered as it is obtained with mathematical models. Thus, the production as a function of directly measurable parameters should be assessed. To improve previous results,...

Design of actuator motor acceleration model in dual axis tracker movement for stand-alone PV system

“…Previously, a projection method was carried out using the PV position in flat conditions or at one point on the solar cell where this condition has not been able to produce optimal energy conversion in converting [18]- [21]. Then another problem that occurs is weather fluctuations that occur such as the movement of clouds in covering the sun so that the conversion produced by solar cells into electrical energy drops dramatically [22]- [24]. The solution is to focus on increasing the development and installation of a stand-alone PV system with the concept of using actuator motor technology with two linear motor drives so that the power generated by PV is maximized.…”