Precise Solar Tracking Research Articles

Seven-Point Solar Tracking Control for a Fiber-Optic Daylighting System

Abstract A strategy for precise solar tracking has been developed using feedback signals from seven photosensors in conjunction with the operation of an active daylighting system. The tracking system was composed of a microcontroller, two stepper motors, photosensors, a grooves-in Fresnel lens concentrator, and a glass optical fiber cable. A robust control was implemented using cadmium sulfide (CdS) sensors to track the sun’s path precisely from sunrise to sunset. To avoid the cloud effect, two separate sensors were installed apart from the main tracking sensors. The control system was allowed to track the sun’s position if clouds covered the sky continuously for less than approximately 70 min. To analyze the performance of the solar tracker for daylighting applications, a series of experiments were performed in different weather conditions where the accuracy and effectiveness of the present solar tracking control were confirmed.

An automatic multi-axis solar tracking system in Ramadi city: design and implementation

In this paper, a complete design and implementation of an automatic Multi-Axis solar tracking system has been introduced. The main purpose of this system is to track Sun location and gain the maximum energy output of the solar panels. The system is Multi-axis using microcontroller and photocells to control the direction of the penal, whereas the penal is facing the sun at all times of the day. The system is a combination of hardware and software parts that work concurrently to achieve a precise angular Sun tracking. A Base, Penal Frame, Super Jack Motors, high-efficiency Solar Panel, Arduino Uno microcontroller, Relays, Rechargeable battery, Light Dependent Resistor (LDR) have been used for the system’s hardware part. These hardware parts need a high-level programming code, as a software part, to be embedded in the microcontroller to get an effective and precise solar tracking system. The results of the presented system were compared to a fixed direction system. The results show significant efficiency improvement of 24% over the static one. For a city like Ramadi, which has a high irradiance all over the year, it is very fruitful to use such tracking systems along with photovoltaic installation systems.<div align="center"> </div>

A fully planar solar pumped laser based on a luminescent solar collector

A solar-pumped laser (SPL) that converts sunlight directly into a coherent and intense laser beam generally requires a large concentrating lens and precise solar tracking, thereby limiting its potential utility. Here, we demonstrate a fully-planar SPL without a lens or solar tracking. A Nd3+-doped silica fiber is coiled into a cylindrical chamber filled with a sensitizer solution, which acts as a luminescent solar collector. The body of the chamber is highly reflective while the top window is a dichroic mirror that transmits incoming sunlight and traps the fluorescence emitted by the sensitizer. The laser-oscillation threshold was reached at a natural sunlight illumination of 60% on the top window. Calculations indicated that a solar-to-laser power-conversion efficiency could eventually reach 8%. Such an SPL has potential applications in long-term renewable-energy storage or decentralised power supplies for electric vehicles and Internet-of-Things devices.

Low-concentrated solar-pumped laser via transverse excitation fiber-laser geometry.

We demonstrate an extremely low-concentrated solar-pumped laser (SPL) using a fiber laser with transverse excitation geometry. A low concentration factor is highly desired in SPLs to eliminate the need for precise solar tracking and to considerably increase the practical applications of SPL technology. In this Letter, we have exploited the intrinsic low-loss property of silica fibers to compensate for the extremely low gain coefficient of the weakly pumped active medium. A 40m long Nd3+-doped fiber coil is packed in a ring-shaped chamber filled with a sensitizer solution. We demonstrated a lasing threshold that is 15 times the concentration of natural sunlight and two orders of magnitude smaller than those of conventional SPLs.

A comparative performance analysis on daylighting for two different types of solar concentrators: Dish vs. Fresnel lens

This study introduces the experimental work done to analyze the performance of active daylighting systems, which consist of small individually operated solar concentrators. Each system is capable of precise solar tracking thanks to the double axis solar tracker designed and constructed for lightness and easy operation. A solar tracking algorithm was implemented with AVR based on both closed and open loop control algorithms. Two different types of solar concentrators (developed for the system) were tested to assess their photometric characteristics in collecting and delivering solar rays to a deep plan office space for better lighting. To measure illuminance at different times of the day, a number of photo sensors were installed on the task planes at a height of 85 cm above the floor. The luminance values on different walls (including task planes) were also measured at a regular interval of 30 min to assess their variation with time and solar altitude. These photometric data enabled a systematic performance evaluation of the systems employed in the present study. The experimental results demonstrated the applicability of the daylighting systems employed in this work in bringing natural daylight to the interior, especially, to those spaces too deep for conventional daylighting apertures.

Design and optical analyses of an arrayed microfluidic tunable prism panel for enhancing solar energy collection

We present the design and optical analyses of an arrayed microfluidic tunable prism panel that enables wide solar tracking and high solar concentration while minimizing energy loss. Each of the liquid prism modules is implemented by a microfluidic (i.e. non-mechanical) technology based on electrowetting for adaptive solar beam steering. Therefore the proposed platform offers a low-cost, lightweight and precise solar tracking system while obviating the need for bulky and heavy mechanical moving parts essentially required for a conventional motor-driven solar tracker. In this paper, various liquid prism configurations in terms of design (single, double, triple and quad-stacked prism arrays) as well as optical materials are considered and their impact on optical performance aspects such as solar beam steering, reflection losses and beam concentration is studied. Our system is able to achieve a wide solar tracking covering the whole-day movement of the Sun and a reflection loss below 4.4% with a Rayleigh’s film for a quad-stacked prism configuration. Furthermore, an arrayed prism panel is proposed to increase the aperture area and thus allows for the collection of large amounts of sunlight. Our simulation study based on the optical design software, ZEMAX, indicates that the prism panel is capable of high solar concentration up to 2032× factor even without conventional solar tracking devices. We also deal with dispersion characteristics of the materials and their corresponding effect on concentration factor. The proposed microfluidic platform has a potential for high solar energy harvesting and is not only economically viable, but also reliable and practical for various solar power applications.

Ray-Trace Evaluation of a Fisheye Lens as Static Concentrator

The cost of electricity generated by photovoltaic panels is still far superior to that generated by conventional sources. This is mainly due to the high cost of solar cells and its low efficiency, which require the use large areas of solar panels for electricity generation. In order to reduce costs of infrastructure concentration photovoltaic systems (CPV) have been proposed, which require very precise solar tracking, which in turn limits the attainable cost reduction. To address this last point many different concentration systems that don’t require solar tracking are being developed in different parts of the globe.In this paper we evaluate the possibility of using a fisheye lens as static CPV. This type of lens is widely used in photography, having a wide acceptance angle. The evaluation is carried out using optical ray tracing CAD software, comparing the energy collected by a flat surface with that captured by a similar surface using arrangement of lenses. The evaluation is performed over an entire day, for different days throughout the year, including solstices and equinoxes. The energy concentration factor, using a lens with an acceptance angle of 60° is 1.75X to 1.6X depending on the time of year

Concentrating PV/T Hybrid System for Simultaneous Electricity and Usable Heat Generation: A Review

Photovoltaic (PV) power generation is one of the attractive choices for efficient utilization of solar energy. Considering that the efficiency and cost of PV cells cannot be significantly improved in near future, a relatively cheap concentrator to replace part of the expensive solar cells could be used. The photovoltaic thermal hybrid system (PV/T), combining active cooling with thermal electricity and providing both electricity and usable heat, can enhance the total efficiency of the system with reduced cell area. The effect of nonuniform light distribution and the heat dissipation on the performance of concentrating PV/T was discussed. Total utilization of solar light by spectral beam splitting technology was also introduced. In the last part, we proposed an integrated compound parabolic collector (CPC) plate with low precision solar tracking, ensuring effective collection of solar light with a significantly lowered cost. With the combination of beam splitting of solar spectrum, use of film solar cell, and active liquid cooling, efficient and full spectrum conversion of solar light to electricity and heat, in a low cost way, might be realized. The paper may offer a general guide to those who are interested in the development of low cost concentrating PV/T hybrid system.

Differential method of computing apparent places of stars for latitude work

The cost of electricity generated by photovoltaic panels is still far superior to that generated by conventional sources. This is mainly due to the high cost of solar cells and its low efficiency, which require the use large areas of solar panels for electricity generation. In order to reduce costs of infrastructure concentration photovoltaic systems (CPV) have been proposed, which require very precise solar tracking, which in turn limits the attainable cost reduction. To address this last point many different concentration systems that don’t require solar tracking are being developed in different parts of the globe.In this paper we evaluate the possibility of using a fisheye lens as static CPV. This type of lens is widely used in photography, having a wide acceptance angle. The evaluation is carried out using optical ray tracing CAD software, comparing the energy collected by a flat surface with that captured by a similar surface using arrangement of lenses. The evaluation is performed over an entire day, for different days throughout the year, including solstices and equinoxes. The energy concentration factor, using a lens with an acceptance angle of 60° is 1.75X to 1.6X depending on the time of year