Solar Tracking Device for Photovoltaic Solar Energy System: A Review

Adewumi Hope Kofoworola¹, Adejumo Kehinde Ezekiel¹, Abiodun Ayodele Joshua², Oyetunji Emmanuel Oluwapelumi³, Oyeshola Hakeem Olayinka^1*, Oladimeji Azeez¹

¹Department of Pure and Applied Physics, Faculty of Pure and Applied Sciences, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
²Department of Physics, Faculty of Physical Sciences, Lead City University, Ibadan, Oyo State, Nigeria.
³Department of Physics, College of Science, The University of Texas, El Paso, United State.

DOI: 10.4236/oalib.1113070                

Abstract

In the face of the traditional fossil fuel energy crisis, solar energy stands out as a green, clean, and renewable energy source. Solar photovoltaic tracking technology is an effective solution to this problem. This review delves into the sustainable development of solar photovoltaic tracking technology, analyzing its current state, limiting factors and future trends. The adjustment of solar panel orientation using solar tracking technology to maximize energy generation efficiency has been widely implemented in various fields, including solar power plants. Currently, limiting factors for this technology include energy generation efficiency, costs and the complexity of various environmental conditions. In terms of sustainable development, this article emphasizes the importance of photovoltaic materials and manufacturing innovation, energy efficiency improvements, as well as the integration of smart and digital technologies. Future trends include higher precision, broader applications, and lower costs. Solar photovoltaic tracking technology will play a pivotal role in global energy production, fostering the realization of a clean and sustainable energy future.

Keywords

Solar, Tracking, Photovoltaic, Energy

1. Introduction

The majority of everyday activities in today’s world are greatly influenced by electricity. Such activities include daily operations in homes and businesses [1]. Many methods can be used to generate electricity from the public supply for consumers, such as using gas, water, wind, or steam energy to power a turbine [2]. Nuclear energy, solar energy, and generators are additional sources of electricity [3]. Solar energy holds incredible promises that renewable energy will meet the world’s already high and constantly increasing energy demand [4]. The conversion of solar energy into electricity is performed by both flat PV and concentrating solar power (CSP) systems [5] [6]. The output power generated by these devices depends on the quantity of solar energy they collect [7] [8]. Ideal ST allows PV panels and CSP systems to precisely point to the position of the sun and compensate for changes in daily altitude angle and seasonal latitude offset as well as changes occurring in the azimuth angle of the sun [9] [10].

With the advancement and progression of industrialization, the demand for energy has steadily climbed [11]. Traditional fossil fuels are gradually depleting, and their usage has adverse effects on the global climate. Solar energy derived from the Sun’s radiation, can be converted into electricity or thermal energy using solar panels [12]-[16]. It finds applications in electricity generation, heating, and various other energy needs. Solar energy is a clean and environmentally friendly source with vast potential [17]. It can reduce dependency on fossil fuels, decrease greenhouse gas emissions, and contribute to achieving sustainable energy goals [18]. The conversion of solar energy into electricity is accomplished through photovoltaic (PV) cells; with the output power of these cells depending on the amount of solar energy they collect [19]. The principle behind this process is that when sunlight strikes the solar panel, photons excite electrons within the semiconductor, causing them to move and generate an electric current [20] [21].

Scholars have carried out extensive research to further examine the effects of passive and active control on ST technology. Systems for passive tracking depend on the physical characteristics of substances like chlorofluorocarbons and shape memory alloys [22]. When photovoltaic panels are not oriented vertically toward the Sun, uneven heating on their sides causes expansion on one side and contraction on the other, aligning the panels as closely as possible with the Sun to achieve tracking objectives. Active tracking systems, on the other hand, employ microcontrollers, sensors, actuators, etc., to continuously track the Sun [23]-[26]. Typically, a signal is sent to the motor by the microcontroller or sensor when it detects the Sun’s movement, causing the solar panels to shift in order to track the Sun [27]. The purpose of tracking systems is to maximize the solar radiation received by the solar panels. Active tracking systems are further categorized into two types based on degrees of freedom: single-axis STS(s) and dual-axis STS(s) [28]. The motion mechanism of a single-axis tracking system usually offers one rotating degree of freedom. Its structure is simpler, and its control complexity is lower [29]. Considering the ground as a reference, the Sun’s movement relative to the ground can be divided into north-south and east-west motions, which mainly influence changes in elevation and azimuth angles [30]. Dual-axis tracking systems were introduced, featuring two mutually perpendicular rotational degrees of freedom [31]. Therefore, dual-axis tracking systems have more complex structures and control strategies [32].

1.1. Solar Energy

Solar energy is the total amount of energy that is captured by the sun’s rays. Many technologies, including solar heating, solar cells, solar thermal thermoelectric, solar architecture, and artificial photosynthesis, have a tendency to use radiant light and heat from the strong sun [33] [34]. Earth receives an estimated 1 KW/m² at high noon, but there has already been a direct conversion of photon energy to electricity, and solar power facilities are presently being established on a significant scale [35]. One advantage of solar energy over all other energy sources is that it doesn’t emit any noise and doesn’t reject heat, carbon dioxide, or radioactive particles. It is therefore the most environmentally friendly [36].

In remote areas and hilly regions of the planet, where power line transmission is sometimes expensive or extremely unlikely, solar energy provides a dependable energy source [37]. Additionally, urbanized electrification using photovoltaic panels to power street lighting is gaining traction. Contemporary electrical devices can also be powered by solar energy. These days, solar energy is being widely used in smart grid systems, electric cars, and building-integrated solar systems. There is no other source of energy available to spacecraft or satellites that are launched into space for an extended period of time except solar [38] [39].

1.2. Photovoltaic Cell

A PV system refers to a system that utilizes the PV effect of semiconductor materials to convert solar energy into electrical energy [40]. The key parameter for assessing the performance of PV cells is conversion efficiency, which refers to the ability of a PV cell to convert solar energy into electrical energy [41]. Conversion efficiency is closely related to the material characteristics of PV panels and can be categorized into four generations, which compare different materials used in PV cells [42]. The first-generation PV cell materials include monocrystalline silicon (m-Si), polycrystalline silicon (p-Si), and amorphous silicon (a-Si) [43].

The second-generation PV cells focus on thin-film technology, where cell materials are manufactured in the form of thin films [44] [45]. Materials in this category include cadmium telluride (CdTe), cadmium sulfide, copper indium selenide, and copper indium gallium selenide (CIGS) [46]. The third-generation photovoltaic cells incorporate organic materials and nanotechnology, building upon the previous generation [47]. This category includes photochemical solar cells, dye-sensitized solar cells (DSSCs), polymer solar cells, and nanocrystal solar cells [48]. The fourth-generation cells are characterized by flexibility and low cost [49]. These cells consist of stable and advanced inorganic nanostructures (such as metal nanoparticles and metal oxides) combined with organic nano-materials like carbon nanotubes, graphene, and their derivatives [50].

In 1948, Ohl utilized silicon as the material for PV cells; it marked the initiation of the era of PV power generation [51]. Until today, silicon remains the primary material for PV cells. Silicon, as the predominant material in PV cells, boasts advantages such as abundant resources, mature technology, high conversion efficiency, and reliability [52]. However, its band gap structure limits the absorption range of the solar spectrum, and its weight, resistance to light weighting, high energy consumption in the manufacturing process, and relatively elevated production costs are considered drawbacks [53]. Despite these challenges, silicon PV cells remain the current mainstream and reliable technology. Gallium arsenide (GaAs), as a material for PV cells, presents advantages such as high efficiency, temperature stability, and radiation tolerance, particularly excelling in broad-spectrum responsiveness and high-temperature environments [54].

The challenges persist in widespread commercial application due to high costs and the relative scarcity of gallium [55]. The application of thin-film technology in GaAs photovoltaic cells offers potential for flexible manufacturing, yet addressing cost and material supply issues is imperative for the extensive deployment of GaAs in the photovoltaic sector [56] [57]. Cadmium telluride (CdTe) serves as a prominent material for PV panels, showcasing several advantageous characteristics [58]. Demonstrating high-efficiency conversion, thin-film manufacturing techniques, relatively low production costs, and adaptability to high-light environments, CdTe PV cells excel in the realm of photoelectric conversion [59] [60]. Their inherent lightweight and flexibility, which are conducive to flexible design, afford increased versatility for diverse application scenarios. Simultaneously, the production process of CdTe is relatively environmentally friendly, mitigating adverse environmental impacts [61].

High photovoltaic conversion efficiency is exhibited by multifunction solar cells, which increase total efficiency by absorbing a wide range of sunlight wavelengths through various band gap designs [62]. In the realm of solar cells, graphene and its derivatives have attracted a lot of interest. An effective electrode material is graphene, which is renowned for its exceptional conductivity and transparency. Certain derivatives of graphene retain these qualities [63] [64]. Their adjustable optical properties help to increase the photoelectric conversion efficiency of the solar cell. These materials are appropriate for a range of solar applications due to their adaptability in design and capacity to modify electrochemical performance [65].

For example, graphene oxide has better electrical characteristics than graphene. The potential uses of carbon nanotubes in solar cells are exceptionally promising [66]. They are the perfect electrode material due to their remarkable electrical conductivity, which efficiently promotes electron transfer and improves solar cells’ overall efficiency [67].

1.3. Sun Path, Azimuth and Altitude Angle

The change of position of the moving sun varies at different times and season to season due to earth’s continuous and periodic rotation and revolution [68]. Consequently, it is now essential to determine the sun’s orientation at a specific time. The azimuth angle, elevation angle, sun pathways throughout time, and sunrise and sunset times were all described in a sun path diagram [69]-[71].

1.3.1. Declination Angle (δ)

The declination angle is the angle between the equator and a line drawn from the centre of the Earth to the centre of the sun [72] [73]. It is the angular distance of the sun’s position in the north or south of the earth’s equator. The declination angle, denoted by δ, varies seasonally due to the tilt of the Earth on its axis of rotation and the rotation of the Earth around the sun [74]-[77]. The declination would always be 0˚ if the Earth were not tilted on its axis of rotation. Nonetheless, the declination angle fluctuates by plus or minus the Earth’s 23.45˚ tilt. The declination angle is equal to 0˚ only at the spring and fall equinoxes [78]-[80].

$\delta ={\sin }^{-1}0.4\sin \left(360\frac{d_n-82}{365}\right)$ (1)

$\delta =-23.45\sin \left(360\frac{d_n+284}{365}\right)$ (2)

Where δ is the declination angle and dₙ is the number of days in a year.

1.3.2. The Altitude Angle or Elevation Angle (α)

It shows how high the sun appears in the sky. The angle is measured between an imaginary line between the observer and the sun and the horizontal plane the observer is standing on. The altitude angle is negative when the sun drops below the horizon [81].

$\alpha ={90}^{\circ }+\varnothing -{\delta }_{\alpha }$ (3)

1.3.3. Solar Azimuth Angle (γ_s)

This is the angle change from the south to the horizontal plane where beam radiation is projected. A position east of south is indicated by a positive solar azimuth angle, and a position west of south is indicated by a negative azimuth angle [82].

${\gamma }_s={\sin }^{-1}\left(\frac{sinhcos\delta }{\sin {\theta }_z}\right)$ (4)

Where ${\gamma }_s$ is the solar azimuth angle.

1.3.4. The Latitude (w or L)

A point or location is defined as the angle formed by the radial line that connects it to the earth’s centre and is projected onto the equatorial plane. At 90˚ latitude (the North Pole) and −90˚ latitude (the South Pole), the earth’s axis of rotation crosses the surface of the planet. The intersection of a longitude angle and a latitude angle can therefore be used to define any place on Earth’s surface [83] [84].

1.3.5. Angle of Incidence (θ_i)

This is the angle between the beam radiation on a surface and the normal to that surface [85]-[88].

${\theta }_i={\cos }^{-1}\left(\sin Lst\sin \delta +\cos Lst\cos \delta \cos ST\right)$ (5)

Where ${\theta }_i$ is the angle of incidence.

1.3.6. Hour Angle (${\omega }_s$ )

This is the angular displacement of the sun east to west of the local merridean due to rotation of the earth. On its axis at 15˚ per hour, morning is negative and afternoon is positive [89].

ℎ = 15˚ (solartime – 12 noon) (6)

${\omega }_s$ = ${\cos }^{-1}$ (tan L tan $\delta )$ (7)

where h and ${\omega }_s$ are the hour angle.

1.3.7. Zenith Angle (θ_z)

This is the angle between the vertical and the line to the sun, i.e., angle of incidence of beam radiation on a horizontal surface. That is, it is the angle between the sun and a line perpendicular to the earth’s surface. It is the complement of solar altitude [90].

1.3.8. Solar Attitude Angle (α_s)

This is the complement of the zenith angle, or the angle between the horizontal and the line to the sun. This represents the sun’s angular height as measured from the horizon. Positive is above the horizon, and negative is below. The solar altitude of the sun, which is situated in the center of the sky, is 90 degrees [91].

1.3.9. Surface Azimuth Angle (γ)

This is the projection of the site-to-sun line on the horizontal plane and the angle formed by the horizontal plane and due south. That is the sun’s direction from the observer, as indicated by the hour angle between the line’s north point and the intersection of the horizon and a vertical circle that passes through the sun [92].

1.3.10. Solar Irradiance

The measurement of sunlight’s power density is called solar irradiance. It is an instantaneous quantity with the unit W/m². The planet receives 1367 W/m² of irradiance from solar radiation [93]. The radiation becomes 1000 W/m² at the surface after being absorbed by the atmosphere and travelling through it. Solar radiation is a crucial component in this sector since it influences the performance of the solar cell’s output [94]. The energy that makes up sunlight has wavelengths that fall within a broad spectrum of electromagnetic waves. However, no solar cell is able to absorb all forms of energy. The primary purpose of a solar cell is to absorb a specific percentage of the entire spectrum of energy. The visible spectrum is the only wavelength that photovoltaic solar cells are intended to absorb [95] [96]. Solar irradiance is a parameter directly related to solar energy received by solar panels and maximum when rays are perpendicular to the panel plane. To achieve maximum solar energy it is necessary to rotate the panel face towards the sun. The device that is used for this purpose is called Solar Tracker [97].

2. Solar Tracking System

Solar tracking devices are essential for optimizing the efficiency of photovoltaic (PV) solar energy systems. These devices adjust the orientation of solar panels to follow the sun’s path, maximizing the amount of sunlight captured throughout the day. Advanced control algorithms play a crucial role in enhancing the performance of these tracking systems. However, the components of solar tracking system include; tracker mount, driver, sensors, motor, algorithm and microcontroller.

(1) Tracker mount: The structural support that holds the solar panel at the correct angle [98] [99].

(2) Driver: Controls the rotation of the motor shaft. Positioning system moves the solar tracker according to the preference of control unit [100]. It can be either electronic or hydraulic. Electrical systems utilize encoders and variable frequency drives or linear actuators to monitor the current position of the panel and move to desired positions [101]. The drive mechanism includes mechanical devices-rotary motors, linear actuators, linear drives, hydraulic cylinders, swivel drives, worm gears, planetary gears, and threaded spindles. These drives can be of different types according to design method [102].

(3) Sensors: Detects relevant parameters from the sun and provides output. Sensors are used to detect position of sun accurately [103]. For open-loop system light sensors are implemented to correct calculation and mechanical errors. Closed-loop system solely depends on several light sensing devices [104]. Light intensity detecting device includes photo resistor, photo-transistor, solar cell etc. Solar power based stations also use temperature, pressure, humidity, wind velocity, solar irradiance and other necessary parameters monitoring systems with trackers [105].

(4) Motor: Controls the movement of the tracker [106].

(5) Algorithm: Calculates the sun’s position using the time, date, and geographical location. Solar tracking can have open loop control algorithm or closed-loop control algorithm [107]. Open-loop control algorithm involves calculation of azimuth and altitude angle of sun on a purely mathematical platform based on astronomical references. The open-loop component is needed because the sun can be obscured by clouds, eliminating or distorting the feedback signals [108]. Closed-loop control algorithm includes detection of the position of sun by real-time light-sensing method and is needed to eliminate errors due to variability in installation, assembly, calibration, and encoder mounting [109]. These two methods can be combined together to keep balance between economic design and increased efficiency [110].

(6) Microcontroller: this can be programmed to generate internal interrupts. The control unit executes the sun tracking algorithm and necessary calculations. It can also coordinate the movement of the positioning system [111]. A microprocessor or a computer can be used as the centre of control unit. It normally has command input and data output mechanism for interfacing. For the trackers placed in remote region automatic tracking control mechanism is best suitable [112].

2.1. Types of Solar Tracking Systems

There are mainly two types of solar tracking systems: single-axis and dual-axis. Single-axis trackers follow the sun’s movement from east to west, while dual-axis trackers can also adjust the tilt angle to follow the sun’s elevation.

2.2. Control Algorithms

Advanced control algorithms are used to optimize the tracking performance. These algorithms can be categorized into:

a) Scheduled-based algorithms

These use pre-defined schedules based on the sun’s path.

b) Light-dependent algorithms

These use sensors to detect the sun’s position ireal-time.

c) Hybrid algorithms

These combine both scheduled-based and light-dependent approaches to improve accuracy and efficiency.

2.3. Performance Improvements

Studies have shown that dual-axis tracking systems can increase energy generation by more than 27% compared to stationary systems. Scheduled-based tracking systems have been found to enhance efficiency by 4.2% under diverse weather conditions compared to light-dependent resistor-based trackers.

2.4. Challenges and Advancements

Despite the benefits, there are challenges such as the initial cost, maintenance, and the need for precise control mechanisms. Recent advancements focus on improving the reliability and cost-effectiveness of these systems.

3. Solar Tracking System Technological Advancements and Classifications

3.1. Classification Based on Drive Mechanisms

3.1.1. Passive Tracking Systems

Unlike active tracking, passive tracking does not rely on sensors. A passive tracker responds to pressure imbalance between two locations at the tracker’s ends to move, rather than using sensors [113]. Heat from the sun generates gas pressure, and compressed pressure moves the structure, causing this pressure imbalance. This approach uses very little electricity to function and does not require electrical sensors. But in order to preserve accuracy, the mechanical design must be extremely important [114].

Relatively easy to use, passive solar tracking systems don’t need an external power source. Their goal is to increase solar panels’ exposure to sunlight in order to boost solar energy systems’ efficiency in producing energy [115]. Passive tracking systems, in contrast to active tracking systems, do not use motors or control systems to change the solar panels’ orientation. Rather, they make use of a number of material properties and physical concepts [116].

Usually employing shape memory alloys or chlorofluorocarbons, passive tracking systems take advantage of the physical characteristics of materials, such as thermal expansion and contraction [117]. In order to line the solar panels as vertically as possible with the Sun, one side of the panels expands while the other contracts due to uneven heating on both sides when they are not perpendicular to the Sun. Compared to fixed solar panels, Zomeworks 1969 introduction of the first commercial passive STS efficiently caught sunlight, increasing the output of electricity [118] [119].

3.1.2. Active Tracking System

Throughout the day, the sensors continuously determine the sun’s location. The sensor directs the motor or actuator to move such that the solar panel faces the sun at all times during the day [120]. With the aid of sensors, active tracking is precise. However, the primary issue arises on overcast days when the sensors are unable to distinguish between data and either miss the original trigger or produce a fake one. Devices like microcontrollers, sensors and actuators are used in an active tracking system to continuously monitor the Sun’s position [121].

By tracking variations in ambient light intensity, the solar tracking system uses LDRs as photosensitive parts to determine the Sun’s position [122]. In order to create a thorough model of the differences between the actual and predicted positions, the microcontroller reads the resistance values of LDRs with high accuracy and extensively compares them with the theoretical light intensity corresponding to the expected solar position [123]. The microprocessor uses the comparison results to run a complex algorithm for calculating errors, producing an electric signal that is proportionate to the variation in solar position [124]. To guarantee adherence to the accuracy and responsiveness specifications of the system design, this signal is carefully calibrated [125].

The microprocessor then sends the adjustment signal to the actuator, which precisely regulates the adjustment mechanism to align the solar panel with the Sun based on the signal properties (such as voltage and current) [126]. In order to maintain the solar panel’s orientation toward the Sun during ongoing monitoring, the actuator performs the adjustment movements. The system continuously senses changes in sun position, calculates errors, generates adjustment signals, and executes corrective operations in a persistent iterative loop [127]. This iterative procedure maximizes the efficiency of solar energy gathering by ensuring that the system responds to changes in the sun’s position promptly and accurately [128].

3.2. Classification Based on Degrees of Freedom

3.2.1. Single-Axis Solar Tracking System

A single-axis tracking system typically refers to a mechanism providing one rotational degree of freedom, and it can be classified into three types: horizontal single-axis, vertical single-axis, and tilted single-axis [129]. Tilted single-axis systems work well in mid-latitude areas; vertical single-axis tracking systems work well in high-latitude areas, and horizontal single-axis STS(s) work well in equatorial and low-latitude areas. There is enormous potential for the sustainable development of single-axis STS(s) [130] [131]. More sophisticated control systems, possibly including artificial intelligence and machine learning algorithms, will be used by future single-axis STS(s) to track solar positions and light levels in real time, allowing for accurate modifications of PV panel orientations [132].

By improving system response time, this development will guarantee that PV panels are constantly oriented toward the best possible positions. To minimize the impact on the environment and lessen reliance on finite resources, STS(s) shall be manufactured using ecologically benign and renewable materials [133]. In order to lower energy costs, future single-axis tracking systems might connect with alternative energy sources, such wind or energy storage systems. Furthermore, self-powering techniques may be incorporated into future single-axis STS(s). In conclusion, future single-axis STS(s) have the potential to be a significant technological advancement in the realm of sustainable energy due to their increased dependability and efficiency [134]. These developments will help lessen dependency on conventional energy sources, opening the door to a more sustainable and clean energy future [135].

Advantages of Single-Axis Solar Tracking System

The advantages of single axis tracking system are more reliable and long lasting, lower complexity so fewer maintenance issues, cheaper to purchase and operate, more efficient than stationary mounts and generate 15% - 16% more annual power than fixed panel [136] [137].

Disadvantages of Single-Axis Solar Tracking System

The disadvantages of single axis tracking system are producing less energy than dual-axis model during peak sunny times and limited technology upgrades capabilities [138].

3.2.2. Dual-Axis Solar Tracking System

Two degrees of rotation appear to be present in a dual-axis solar tracker. It might be able to follow the sun both vertically and horizontally [139]. This kind of tracker ensures optimal efficiency in using solar energy and may be used anywhere in the world [140]. Solar power structures and dish systems are examples of concentrated solar power (CSP) systems that use dual axis tracking [141]. Because the angle error matters for longer distances between the reflectors and the central receiver located in the tower structure, dual-axis tracking is extremely critical in solar power tower procedures. Compared to single-axis tracking, dual-axis tracking systems are more difficult to design and operate. Nonetheless, dual axis tracking is more cost-effective for large-scale solar energy generation [142].

The main elements affecting variations in tilt angle and azimuth angle are the Earth, which can be regarded as a reference, and the Sun’s movement with respect to the Earth, which can be separated into annual and daily motions [143]. Consequently, a dual-axis tracking system with increased tracking precision is introduced. Two rotating degrees of freedom that are perpendicular to one another make up a dual-axis tracking system. The dual-axis STS is a cutting-edge solar power generation system that continuously tracks the position of the Sun to optimize the energy collection efficiency of solar panels [144]. Usually, this system uses sensors and motors to track the Sun’s location and automatically reorient the solar panels [145].

Dual-axis STS(s) will become increasingly intelligent as machine learning and artificial intelligence continue to progress. These systems can maximize energy collecting efficiency by using machine learning algorithms to forecast the Sun’s position and make judgments in real time based on illumination and weather data [146] [147]. Furthermore, intelligent systems can save downtime by proactively managing maintenance and detecting faults. Dual-axis STS(s) will heavily rely on digital technologies. Real-time monitoring and gathering of enormous volumes of data, such as temperature, humidity, solar radiation, and other environmental parameters, will be made possible by sensor networks and Internet of Things technology [148] [149]. These data will be utilized for remote monitoring and system performance optimization. These systems can help reduce reliance on fossil fuels, decrease greenhouse gas emissions, and drive dual-axis STS(s) to become an integral part of sustainable development [150].

Advantages of Dual-Axis Solar Tracking System

The advantages of dual axis solar tracking system are maximize power output by continually following the sun, help manage grid power limitations, require less land area to produce more total energy and generate 45% - 50% more annual power than fixed panels [151] [152].

Disadvantages of Dual-Axis Solar Tracking System

The disadvantages of dual axis solar tracking system are more prone to technical glitches due to complexity, shorter life span and lower reliability and higher maintenance cost [153] [154].

3.3. Factors Limiting the Efficiency and Utilization of Solar Trackers

Generally, most of researchers have agreed that the solar trackers increase the overall efficiency of a PV panels and CSP systems [155]. However, clear indications should be provided indicating where, when and how maximum power efficiency can be achieved. Consistent with the aforesaid, many problems have been identified and each of these problems has been addressed individually including miss-tracking and failure of the control systems and/or the electronics of the trackers among others [156]. More importantly, the studies confirmed that most of the problems limiting the overall efficiency of both the fixed and tracking PV systems are similar. Moreover, different types of solar trackers present different advantages and challenges when considering their performance and efficiency, and studies have shown that tracking the sun position significantly increases the efficiency especially in cloudy days [157] [158]. For this reason, using ST could be the ideal way to boost up the efficiency and performance of both the PV panels and the CSP systems irrespective of what the weather looks like [159] [160].

3.3.1. Cost

Installing a solar tracking system necessitates the purchase of additional hardware, such as electric drives, sensors, controllers, and mechanical structures [161]. These parts are frequently very expensive to purchase, particularly for large solar fields or PV power plants. Compared to stationary solar systems, the installation of an STS or STSs is more complicated, and frequent maintenance is necessary to guarantee that the mechanical and electronic components are operating as intended [162]. Cleaning, lubrication, problem detection, and repairs are all part of this upkeep. It is anticipated that STS(s) technology will develop and grow throughout time [163]. Cost-effective sensors and electronic components, robust mechanical constructions, and more effective control systems might all be part of this. These developments in technology have the potential to lower the systems’ manufacturing costs [164] [165].

3.3.2. Geographical Environment and Climatic Conditions

The varying geographical locations on Earth result in significant disparities in both the intensity and trajectory of solar radiation [166]. For the majority of the year, places nearer the equator see comparatively high levels of sun radiation, which lessens the severity of STS(s). However, the solar trajectory gets more inclined at areas that are farther from the equator, particularly at higher latitudes [167]. As a result, in order to adapt to the Sun’s shifting position in the sky, STS(s) must be designed and controlled with greater sophistication. Geographical considerations also comprise topography and shading effects, which can impact the angle and intensity of solar radiation reaching a surface [168] [169]. Because of topographical factors like mountains and buildings, some areas may not receive direct sunlight at particular times, which reduces the effectiveness of solar energy systems [170] [171].

By monitoring the Sun’s movement, solar tracking systems in high-altitude areas help photovoltaic panels be oriented to maximize radiation reception [172]. This improves energy output by lessening the effect of complicated terrain and a sparse atmosphere on system performance. Climate factors that affect solar tracking systems’ effectiveness include temperature, wind speed, cloud cover, and seasonal fluctuations [173].

Solar tracking systems should be designed to adapt to various geographical environments, including high-latitude regions, deserts, mountains, coastal areas, etc [174]. In these locations, the trajectory of the Sun and climatic conditions may vary, requiring flexibility in tracking systems to accommodate diverse scenarios [175]. When facing extreme weather conditions, STS(s) need to possess features such as wind resistance, rain protection, and snow resistance. By continuously monitoring the Sun’s position and meteorological conditions, tracking systems can adjust the angles of solar panels in real-time to maximize solar radiation absorption or seek shelter [176] [177]. Similarly, the number of axes used to track the sun has a significant impact on the overall efficiency of the solar radiation harvested by the module. It studied the effect of tracking on the performance of PV modules based on the number of tracking axes for the system [178].

4. Conclusions and Prospects

The solar PV tracking system continuously adjusts the angle of solar panels to maximize energy collection throughout the day by tracking the Sun’s position. This article provides a comprehensive review of PV cells made from different materials, with a particular focus on comparing and analyzing their manufacturing processes, performance, and research trends. Based on driving mechanisms and degrees of freedom of motion, the low-cost cases, tracking strategies, control methods, and limiting factors of solar tracking systems are classified and reviewed. Advancements in tracking technology, including sophisticated sensor technology, intelligent control systems, and cloud computing, contribute to improving the performance and reliability of these systems. As economies of scale are realized, and technological costs decrease, the construction and maintenance costs of solar PV tracking systems are gradually decreasing, making solar energy more economically viable. Additionally, the development of more affordable, environmentally friendly, and efficient PV cell materials is a crucial research direction. Combining technological progress with the expansion of solar PV systems in the field of power generation can significantly reduce carbon emissions, contribute to addressing climate change, and mitigate global warming.

In the future, solar PV tracking systems will further enhance energy collection efficiency, including dual-axis tracking systems and systems employing advanced optical technologies. These systems will enable solar panels to track the Sun more accurately and perform exceptionally well under various lighting conditions. Simultaneously, tracking systems will become more intelligent and digitized. By utilizing artificial intelligence, big data analysis, and internet connectivity, the systems can achieve real-time monitoring, fault diagnosis, and remote operation. Solar tracking systems can be applied not only in electricity generation but also in various fields such as agricultural irrigation, water treatment, and integrated energy systems.

In conclusion, solar PV tracking system technology continues to play a crucial role in the field of sustainable energy, contributing to mitigating climate change, reducing energy costs, and promoting the transition to green energy. With ongoing technological advancements and the expanding market, solar PV tracking systems are expected to achieve broader applications and increased sustainability in the future.

Conflicts of Interest

The authors declare no conflicts of interest.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Guo, Z., Zhou, K., Zhang, C., Lu, X., Chen, W. and Yang, S. (2018) Residential Electricity Consumption Behavior: Influencing Factors, Related Theories and Intervention Strategies. Renewable and Sustainable Energy Reviews, 81, 399-412. https://doi.org/10.1016/j.rser.2017.07.046
[2]	Hassan, Q., Abdulateef, A.M., Hafedh, S.A., Al-samari, A., Abdulateef, J., Sameen, A.Z., et al. (2023) Renewable Energy-to-Green Hydrogen: A Review of Main Resources Routes, Processes and Evaluation. International Journal of Hydrogen Energy, 48, 17383-17408. https://doi.org/10.1016/j.ijhydene.2023.01.175
[3]	Kalair, A., Abas, N., Saleem, M.S., Kalair, A.R. and Khan, N. (2020) Role of Energy Storage Systems in Energy Transition from Fossil Fuels to Renewables. Energy Storage, 3, e135. https://doi.org/10.1002/est2.135
[4]	Lior, N. (2010) Sustainable Energy Development: The Present (2009) Situation and Possible Paths to the Future. Energy, 35, 3976-3994. https://doi.org/10.1016/j.energy.2010.03.034
[5]	Ju, X., Xu, C., Hu, Y., Han, X., Wei, G. and Du, X. (2017) A Review on the Development of Photovoltaic/Concentrated Solar Power (PV-CSP) Hybrid Systems. Solar Energy Materials and Solar Cells, 161, 305-327. https://doi.org/10.1016/j.solmat.2016.12.004
[6]	Islam, M.T., Huda, N., Abdullah, A.B. and Saidur, R. (2018) A Comprehensive Review of State-of-the-Art Concentrating Solar Power (CSP) Technologies: Current Status and Research Trends. Renewable and Sustainable Energy Reviews, 91, 987-1018. https://doi.org/10.1016/j.rser.2018.04.097
[7]	Parida, B., Iniyan, S. and Goic, R. (2011) A Review of Solar Photovoltaic Technologies. Renewable and Sustainable Energy Reviews, 15, 1625-1636. https://doi.org/10.1016/j.rser.2010.11.032
[8]	Kannan, N. and Vakeesan, D. (2016) Solar Energy for Future World: A Review. Renewable and Sustainable Energy Reviews, 62, 1092-1105. https://doi.org/10.1016/j.rser.2016.05.022
[9]	Nsengiyumva, W., Chen, S.G., Hu, L. and Chen, X. (2018) Recent Advancements and Challenges in Solar Tracking Systems (STS): A Review. Renewable and Sustainable Energy Reviews, 81, 250-279. https://doi.org/10.1016/j.rser.2017.06.085
[10]	Lorilla, F.M.A. and Barroca, R. (2022) Challenges and Recent Developments in Solar Tracking Strategies for Concentrated Solar Parabolic Dish. Indonesian Journal of Electrical Engineering and Computer Science, 26, 1368-1378. https://doi.org/10.11591/ijeecs.v26.i3.pp1368-1378
[11]	Gu, W., Zhao, X., Yan, X., Wang, C. and Li, Q. (2019) Energy Technological Progress, Energy Consumption, and CO2 Emissions: Empirical Evidence from China. Journal of Cleaner Production, 236, Article 117666. https://doi.org/10.1016/j.jclepro.2019.117666
[12]	Höök, M. and Tang, X. (2013) Depletion of Fossil Fuels and Anthropogenic Climate Change—A Review. Energy Policy, 52, 797-809. https://doi.org/10.1016/j.enpol.2012.10.046
[13]	Abas, N., Kalair, A. and Khan, N. (2015) Review of Fossil Fuels and Future Energy Technologies. Futures, 69, 31-49. https://doi.org/10.1016/j.futures.2015.03.003
[14]	Holechek, J.L., Geli, H.M.E., Sawalhah, M.N. and Valdez, R. (2022) A Global Assessment: Can Renewable Energy Replace Fossil Fuels by 2050? Sustainability, 14, Article 4792. https://doi.org/10.3390/su14084792
[15]	Hayat, M.B., Ali, D., Monyake, K.C., Alagha, L. and Ahmed, N. (2018) Solar Energy—A Look into Power Generation, Challenges, and a Solar-Powered Future. International Journal of Energy Research, 43, 1049-1067. https://doi.org/10.1002/er.4252
[16]	Yekinni, S., Asiata, I., Hakeem, O. and Mubarak, L. (2023) Solar Photovoltaic Energy System. In: Nanogenerators and Self-Powered Systems, Intech Open, 1-15. https://doi.org/10.5772/intechopen.108958
[17]	Panwar, N.L., Kaushik, S.C. and Kothari, S. (2011) Role of Renewable Energy Sources in Environmental Protection: A Review. Renewable and Sustainable Energy Reviews, 15, 1513-1524. https://doi.org/10.1016/j.rser.2010.11.037
[18]	Kumar, C.M.S., Singh, S., Gupta, M.K., Nimdeo, Y.M., Raushan, R., Deorankar, A.V., et al. (2023) Solar Energy: A Promising Renewable Source for Meeting Energy Demand in Indian Agriculture Applications. Sustainable Energy Technologies and Assessments, 55, Article 102905. https://doi.org/10.1016/j.seta.2022.102905
[19]	Singh, G.K. (2013) Solar Power Generation by PV (Photovoltaic) Technology: A Review. Energy, 53, 1-13. https://doi.org/10.1016/j.energy.2013.02.057
[20]	Solanki, C.S. (2015) Solar Photovoltaics: Fundamentals, Technologies and Applica-tions. PHI Learning Ltd.
[21]	Bayod-Rújula, A.A. (2019) Solar Photovoltaics (PV). In: Solar Hydrogen Production, Elsevier, 237-295. https://doi.org/10.1016/b978-0-12-814853-2.00008-4
[22]	Ya’u Muhammad, J., Tajudeen Jimoh, M., Baba Kyari, I., Abdullahi Gele, M. and Musa, I. (2019) A Review on Solar Tracking System: A Technique of Solar Power Output Enhancement. Engineering Science, 4, 1-11. https://doi.org/10.11648/j.es.20190401.11
[23]	Mousazadeh, H., Keyhani, A., Javadi, A., Mobli, H., Abrinia, K. and Sharifi, A. (2009) A Review of Principle and Sun-Tracking Methods for Maximizing Solar Systems Output. Renewable and Sustainable Energy Reviews, 13, 1800-1818. https://doi.org/10.1016/j.rser.2009.01.022
[24]	Prinsloo, G. and Dobson, R.T. (2015) Solar Tracking. Solar Books.
[25]	Singh, R., Kumar, S., Gehlot, A. and Pachauri, R. (2018) An Imperative Role of Sun Trackers in Photovoltaic Technology: A Review. Renewable and Sustainable Energy Reviews, 82, 3263-3278. https://doi.org/10.1016/j.rser.2017.10.018
[26]	Awasthi, A., Shukla, A.K., S.R., M.M., Dondariya, C., Shukla, K.N., Porwal, D., et al. (2020) Review on Sun Tracking Technology in Solar PV System. Energy Reports, 6, 392-405. https://doi.org/10.1016/j.egyr.2020.02.004
[27]	Abro, A.A., Bano, S., Tariq, U. and Shah, I.A. (2022) Sun Tracking and Control Design for PV Solar Energy System. International Journal of Innovations in Science and Technology, 4, 77-93. https://doi.org/10.33411/ijist/2022040507
[28]	Safan, Y.M., Shaaban, S. and Abu El-Sebah, M.I. (2018) Performance Evaluation of a Multi-Degree of Freedom Hybrid Controlled Dual Axis Solar Tracking System. Solar Energy, 170, 576-585. https://doi.org/10.1016/j.solener.2018.06.011
[29]	Oner, Y., Cetin, E., Ozturk, H.K. and Yilanci, A. (2009) Design of a New Three-Degree of Freedom Spherical Motor for Photovoltaic-Tracking Systems. Renewable Energy, 34, 2751-2756. https://doi.org/10.1016/j.renene.2009.04.025
[30]	Xu, L., Long, E., Wei, J., Cheng, Z. and Zheng, H. (2021) A New Approach to Determine the Optimum Tilt Angle and Orientation of Solar Collectors in Mountainous Areas with High Altitude. Energy, 237, Article 121507. https://doi.org/10.1016/j.energy.2021.121507
[31]	Alexandru, C. (2024) Simulation and Optimization of a Dual-Axis Solar Tracking Mechanism. Mathematics, 12, Article 1034. https://doi.org/10.3390/math12071034
[32]	Yao, Y., Hu, Y., Gao, S., Yang, G. and Du, J. (2014) A Multipurpose Dual-Axis Solar Tracker with Two Tracking Strategies. Renewable Energy, 72, 88-98. https://doi.org/10.1016/j.renene.2014.07.002
[33]	Zhou, H., Xu, J., Liu, X., Zhang, H., Wang, D., Chen, Z., et al. (2017) Bio-Inspired Photonic Materials: Prototypes and Structural Effect Designs for Applications in Solar Energy Manipulation. Advanced Functional Materials, 28, Article 1705309. https://doi.org/10.1002/adfm.201705309
[34]	Bhattacharjee, J. and Roy, S. (2024) Smart Materials for Sustainable Energy. Natural Resources Conservation and Research, 7, Article 5536. https://doi.org/10.24294/nrcr.v7i1.5536
[35]	Verma, B.D., Gour, A. and Pandey, M. (2020) A Review Paper on Solar Tracking System for Photovoltaic Power Plant. International Journal of Engineering Research & Technology, 9, 160-166.
[36]	Lorenzo, E. (2011). Energy Collected and Delivered by PV Modules. In: Handbook of Photovoltaic Science and Engineering, Wiley, 984-1042.
[37]	Shahsavari, A. and Akbari, M. (2018) Potential of Solar Energy in Developing Countries for Reducing Energy-Related Emissions. Renewable and Sustainable Energy Reviews, 90, 275-291. https://doi.org/10.1016/j.rser.2018.03.065
[38]	Jacobson, M.Z. and Delucchi, M.A. (2011) Providing All Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials. Energy Policy, 39, 1154-1169. https://doi.org/10.1016/j.enpol.2010.11.040
[39]	Munro, P.G. and Samarakoon, S. (2022) Off-Grid Electrical Urbanism: Emerging Solar Energy Geographies in Ordinary Cities. Journal of Urban Technology, 30, 127-149. https://doi.org/10.1080/10630732.2022.2068939
[40]	Nwaigwe, K.N., Mutabilwa, P. and Dintwa, E. (2019) An Overview of Solar Power (PV Systems) Integration into Electricity Grids. Materials Science for Energy Technologies, 2, 629-633. https://doi.org/10.1016/j.mset.2019.07.002
[41]	Venkateswari, R. and Sreejith, S. (2019) Factors Influencing the Efficiency of Photovoltaic System. Renewable and Sustainable Energy Reviews, 101, 376-394. https://doi.org/10.1016/j.rser.2018.11.012
[42]	Polman, A., Knight, M., Garnett, E.C., Ehrler, B. and Sinke, W.C. (2016) Photovoltaic Materials: Present Efficiencies and Future Challenges. Science, 352, aad4424. https://doi.org/10.1126/science.aad4424
[43]	Pastuszak, J. and Węgierek, P. (2022) Photovoltaic Cell Generations and Current Research Directions for Their Development. Materials, 15, Article 5542. https://doi.org/10.3390/ma15165542
[44]	Maalouf, A., Okoroafor, T., Jehl, Z., Babu, V. and Resalati, S. (2023) A Comprehensive Review on Life Cycle Assessment of Commercial and Emerging Thin-Film Solar Cell Systems. Renewable and Sustainable Energy Reviews, 186, Article 113652. https://doi.org/10.1016/j.rser.2023.113652
[45]	Singh, B.P., Goyal, S.K. and Kumar, P. (2021) Solar PV Cell Materials and Technologies: Analyzing the Recent Developments. Materials Today: Proceedings, 43, 2843-2849. https://doi.org/10.1016/j.matpr.2021.01.003
[46]	Ramanujam, J. and Singh, U.P. (2017) Copper Indium Gallium Selenide Based Solar Cells—A Review. Energy & Environmental Science, 10, 1306-1319. https://doi.org/10.1039/c7ee00826k
[47]	Lamont, L.A. (2013) Third Generation Photovoltaic (PV) Cells for Eco-Efficient Buildings and Other Applications. In: Nanotechnology in Eco-Efficient Construction, Elsevier, 270-296. https://doi.org/10.1533/9780857098832.2.270
[48]	Jasim, K.E. (2011) Dye Sensitized Solar Cells-Working Principles, Challenges and Opportunities. Solar Cells-Dye-Sensitized Devices, 8, 172Ā210.
[49]	Rehman, F., Syed, I.H., Khanam, S., Ijaz, S., Mehmood, H., Zubair, M., et al. (2023) Fourth-Generation Solar Cells: A Review. Energy Advances, 2, 1239-1262. https://doi.org/10.1039/d3ya00179b
[50]	Cao, X., Tan, C., Sindoro, M. and Zhang, H. (2017) Hybrid Micro-/Nano-Structures Derived from Metal-Organic Frameworks: Preparation and Applications in Energy Storage and Conversion. Chemical Society Reviews, 46, 2660-2677. https://doi.org/10.1039/c6cs00426a
[51]	Mehmood, H., Tauqeer, T. and Hussain, S. (2018) Recent Progress in Silicon-Based Solid-State Solar Cells. International Journal of Electronics, 105, 1568-1582. https://doi.org/10.1080/00207217.2018.1477191
[52]	Asim, N., Sopian, K., Ahmadi, S., Saeedfar, K., Alghoul, M.A., Saadatian, O., et al. (2012) A Review on the Role of Materials Science in Solar Cells. Renewable and Sustainable Energy Reviews, 16, 5834-5847. https://doi.org/10.1016/j.rser.2012.06.004
[53]	Huang, G., Curt, S.R., Wang, K. and Markides, C.N. (2020) Challenges and Opportunities for Nanomaterials in Spectral Splitting for High-Performance Hybrid Solar Photovoltaic-Thermal Applications: A Review. Nano Materials Science, 2, 183-203. https://doi.org/10.1016/j.nanoms.2020.03.008
[54]	Nowsherwan, G.A., Ali, Q., Ali, U.F., Ahmad, M., Khan, M. and Hussain, S.S. (2024) Advances in Organic Materials for Next-Generation Optoelectronics: Potential and Challenges. Organics, 5, 520-560. https://doi.org/10.3390/org5040028
[55]	Amano, H., Baines, Y., Beam, E., Borga, M., Bouchet, T., Chalker, P.R., et al. (2018) The 2018 Gan Power Electronics Roadmap. Journal of Physics D: Applied Physics, 51, Article 163001. https://doi.org/10.1088/1361-6463/aaaf9d
[56]	Wolden, C.A., Kurtin, J., Baxter, J.B., Repins, I., Shaheen, S.E., Torvik, J.T., et al. (2011) Photovoltaic Manufacturing: Present Status, Future Prospects, and Research Needs. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 29, Article 030801. https://doi.org/10.1116/1.3569757
[57]	Dallaev, R., Pisarenko, T., Papež, N. and Holcman, V. (2023) Overview of the Current State of Flexible Solar Panels and Photovoltaic Materials. Materials, 16, Article 5839. https://doi.org/10.3390/ma16175839
[58]	Artz, J., Müller, T.E., Thenert, K., Kleinekorte, J., Meys, R., Sternberg, A., et al. (2017) Sustainable Conversion of Carbon Dioxide: An Integrated Review of Catalysis and Life Cycle Assessment. Chemical Reviews, 118, 434-504. https://doi.org/10.1021/acs.chemrev.7b00435
[59]	Baraneedharan, P., Sekar, S., Murugesan, S., Ahamada, D., Mohamed, S.A.B., Lee, Y., et al. (2024) Recent Advances and Remaining Challenges in Perovskite Solar Cell Components for Innovative Photovoltaics. Nanomaterials, 14, Article 1867. https://doi.org/10.3390/nano14231867
[60]	Njema, G.G., Kibet, J.K. and Ngari, S.M. (2024) A Review of Interface Engineering Characteristics for High Performance Perovskite Solar Cells. Measurement: Energy, 2, Article 100005. https://doi.org/10.1016/j.meaene.2024.100005
[61]	Fthenakis, V., Athias, C., Blumenthal, A., Kulur, A., Magliozzo, J. and Ng, D. (2020) Sustainability Evaluation of CDTE PV: An Update. Renewable and Sustainable Energy Reviews, 123, Article 109776. https://doi.org/10.1016/j.rser.2020.109776
[62]	Li, H. and Zhang, W. (2020) Perovskite Tandem Solar Cells: From Fundamentals to Commercial Deployment. Chemical Reviews, 120, 9835-9950. https://doi.org/10.1021/acs.chemrev.9b00780
[63]	Olatomiwa, A.L., Adam, T., Gopinath, S.C.B., Kolawole, S.Y., Olayinka, O.H. and Hashim, U. (2022) Graphene Synthesis, Fabrication, Characterization Based on Bottom-Up and Top-Down Approaches: An Overview. Journal of Semiconductors, 43, Article 061101. https://doi.org/10.1088/1674-4926/43/6/061101
[64]	Xu, Y. and Liu, J. (2016) Graphene as Transparent Electrodes: Fabrication and New Emerging Applications. Small, 12, 1400-1419. https://doi.org/10.1002/smll.201502988
[65]	Zheng, Q., Li, Z., Yang, J. and Kim, J. (2014) Graphene Oxide-Based Transparent Conductive Films. Progress in Materials Science, 64, 200-247. https://doi.org/10.1016/j.pmatsci.2014.03.004
[66]	Kofoworola, A.H., Olayinka, O.H., Joshua, A.A., Kofoworola, A.M., Ayinde, A.G., Adeyemi, A.U. and Yekeen, S. Fabrication, Characterization and Applications of Multiwall Carbon Nanotubes-Aluminium Oxide (MWCNTs-Al₂O₃) Ceramic Com-posites. International Journal of Research Publication and Reviews, 5, 1990-1993.
[67]	He, M., Jung, J., Qiu, F. and Lin, Z. (2012) Graphene-Based Transparent Flexible Electrodes for Polymer Solar Cells. Journal of Materials Chemistry, 22, Article 24254. https://doi.org/10.1039/c2jm33784c
[68]	Sidorenkov, N.S. (2005) Physics of the Earth’s Rotation Instabilities. Astronomical & Astrophysical Transactions, 24, 425-439. https://doi.org/10.1080/10556790600593506
[69]	Kittler, R. and Darula, S. (2013) Determination of Time and Sun Position System. Solar Energy, 93, 72-79. https://doi.org/10.1016/j.solener.2013.03.021
[70]	Gaudino, E., Anacreonte, A., Caldarelli, A., Strazzullo, P., Musto, M., Bianco, N. and Russo, R. (2024) Impact of Collector Array Orientation on the Performance of a Flat Collectors Field for Middle-Temperature Applications. Energy Proceedings, 46, 1-7.
[71]	Jenkins, A. (2013) The Sun’s Position in the Sky. European Journal of Physics, 34, 633-652. https://doi.org/10.1088/0143-0807/34/3/633
[72]	Avila, R. and Syed, S.R. (2024) On the Elliptical Orbit of the Earth and Position of the Sun in the Sky: An Engineering Approach. The Nucleus, 61, 10-15. https://doi.org/10.71330/thenucleus.2024.1330
[73]	Karathanasis, S. (2019) Solar Radiation. In: Linear Fresnel Reflector Systems for Solar Radiation Concentration, Springer, 13-72. https://doi.org/10.1007/978-3-030-05279-9_2
[74]	Rueda, J.A., Ramírez, S., Sánchez, M.A. and Guerrero, J.D.D. (2024) Sun Declination and Distribution of Natural Beam Irradiance on Earth. Atmosphere, 15, Article 1003. https://doi.org/10.3390/atmos15081003
[75]	Nwokolo, S.C., Obiwulu, A.U. and Ogbulezie, J.C. (2023) Machine Learning and Analytical Model Hybridization to Assess the Impact of Climate Change on Solar PV Energy Production. Physics and Chemistry of the Earth, Parts A/B/C, 130, Article 103389. https://doi.org/10.1016/j.pce.2023.103389
[76]	Nfaoui, M. and El-Hami, K. (2018) Optimal Tilt Angle and Orientation for Solar Photovoltaic Arrays: Case of Settat City in Morocco. International Journal of Ambient Energy, 41, 214-223. https://doi.org/10.1080/01430750.2018.1451375
[77]	Senpinar, A. (2018) Optimization of Slope Angles of Photovoltaic Arrays for Different Seasons. In: Exergetic, Energetic and Environmental Dimensions, Elsevier, 507-521. https://doi.org/10.1016/b978-0-12-813734-5.00028-7
[78]	Yousef, B.A.A., Radwan, A., Olabi, A.G. and Abdelkareem, M.A. (2023) Sun Composition, Solar Angles, and Estimation of Solar Radiation. In: Renewable Energy-Volume 1: Solar, Wind, and Hydropower, Elsevier, 3-22. https://doi.org/10.1016/b978-0-323-99568-9.00023-6
[79]	González-Rodríguez, L., Pérez, L., Fissore, A., Rodríguez-López, L. and Jimenez, J. (2018) Tilt and Orientation of a Flat Solar Collector to Capture Optimal Solar Irradiation in Chilean Latitudes. In: Proceedings of the 2nd International Conference on BioGeoSciences, Springer, 215-228. https://doi.org/10.1007/978-3-030-04233-2_19
[80]	Naeimi, Y., Kooben, F. and Moallem, M.H. (2020) Calculation of the Optimal Instal-lation Angle for Seasonal Adjusting of PV Panels Based on Solar Radiation Predic-tion.
[81]	Hariri, N.G., AlMutawa, M.A., Osman, I.S., AlMadani, I.K., Almahdi, A.M. and Ali, S. (2022) Experimental Investigation of Azimuth-and Sensor-Based Control Strategies for a PV Solar Tracking Application. Applied Sciences, 12, Article 4758. https://doi.org/10.3390/app12094758
[82]	Obiwulu, A.U., Erusiafe, N., Olopade, M.A. and Nwokolo, S.C. (2022) Modeling and Estimation of the Optimal Tilt Angle, Maximum Incident Solar Radiation, and Global Radiation Index of the Photovoltaic System. Heliyon, 8, e09598. https://doi.org/10.1016/j.heliyon.2022.e09598
[83]	Qiu, Z. and Li, P. (2019) Solar Energy Resource and Its Global Distribution. In: Green Energy and Technology, Springer, 1-30. https://doi.org/10.1007/978-3-030-17283-1_1
[84]	Ozdemir, S. and Sahin, G. (2018) Multi-Criteria Decision-Making in the Location Selection for a Solar PV Power Plant Using AHP. Measurement, 129, 218-226. https://doi.org/10.1016/j.measurement.2018.07.020
[85]	Cuerno, R. and Kim, J.-S. (2020) A Perspective on Nanoscale Pattern Formation at Surfaces by Ion-Beam Irradiation. Journal of Applied Physics, 128, Article 180902. https://doi.org/10.1063/5.0021308
[86]	Cao, B., Liu, Q., Du, Y., Roujean, J., Gastellu-Etchegorry, J., Trigo, I.F., et al. (2019) A Review of Earth Surface Thermal Radiation Directionality Observing and Modeling: Historical Development, Current Status and Perspectives. Remote Sensing of Environment, 232, Article 111304. https://doi.org/10.1016/j.rse.2019.111304
[87]	Driemel, A., Augustine, J., Behrens, K., Colle, S., Cox, C., Cuevas-Agulló, E., et al. (2018) Baseline Surface Radiation Network (BSRN): Structure and Data Description (1992-2017). Earth System Science Data, 10, 1491-1501. https://doi.org/10.5194/essd-10-1491-2018
[88]	Barbón, A., Bayón-Cueli, C., Bayón, L. and Rodríguez-Suanzes, C. (2022) Analysis of the Tilt and Azimuth Angles of Photovoltaic Systems in Non-Ideal Positions for Urban Applications. Applied Energy, 305, Article 117802. https://doi.org/10.1016/j.apenergy.2021.117802
[89]	Raisal, A.Y. and Rakhmadi, A.J. (2020) Understanding the Effect of Revolution and Rotation of the Earth on Prayer Times Using Accurate Times. Ulul Albab: Jurnal Studi dan Penelitian Hukum Islam, 4, 81-101. https://doi.org/10.30659/jua.v4i1.10936
[90]	Wald, L. (2009) Solar Radiation Energy (Fundamentals). In: Encyclopedia of Life Support System (EOLSS), Eolss Publishers, 44-99.
[91]	Sampson, R.D. (2001) A Comparison of Photogrammetrically Determined Astronomical Refraction of Sunlight at High Zenith Angles with a Ray-Tracing Computer Model Employing Rawlinson Profiles.
[92]	Goswami, D.Y. (2017) Solar Energy Resources. In: Energy Conversion, CRC Press, 85-136. https://doi.org/10.1201/9781315374192-6
[93]	Stieglitz, R. and Platzer, W. (2024) Solar Radiation. In: Solar Thermal Energy Systems, Springer, 29-120. https://doi.org/10.1007/978-3-031-43173-9_2
[94]	Fouad, M.M., Shihata, L.A. and Morgan, E.I. (2017) An Integrated Review of Factors Influencing the Perfomance of Photovoltaic Panels. Renewable and Sustainable Energy Reviews, 80, 1499-1511. https://doi.org/10.1016/j.rser.2017.05.141
[95]	Balogun, S.W., Oyeshola, H.O., Ajani, A.S., James, O.O., Awodele, M.K., Adewumi, H.K., et al. (2024) Synthesis, Characterization, and Optoelectronic Properties of Zinc Oxide Nanoparticles: A Precursor as Electron Transport Layer. Heliyon, 10, e29452. https://doi.org/10.1016/j.heliyon.2024.e29452
[96]	Zwinkels, J. (2015) Light, Electromagnetic Spectrum. In: Encyclopedia of Color Science and Technology, Springer, 1-8. https://doi.org/10.1007/978-3-642-27851-8_204-1
[97]	El Hammoumi, A., Chtita, S., Motahhir, S. and El Ghzizal, A. (2022) Solar PV Energy: From Material to Use, and the Most Commonly Used Techniques to Maximize the Power Output of PV Systems: A Focus on Solar Trackers and Floating Solar Panels. Energy Reports, 8, 11992-12010. https://doi.org/10.1016/j.egyr.2022.09.054
[98]	Shang, H. and Shen, W. (2023) Design and Implementation of a Dual-Axis Solar Tracking System. Energies, 16, Article 6330. https://doi.org/10.3390/en16176330
[99]	Alexandru, C. and Pozna, C. (2010) Simulation of a Dual-Axis Solar Tracker for Improving the Performance of a Photovoltaic Panel. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 224, 797-811. https://doi.org/10.1243/09576509jpe871
[100]	Prinsloo, G.J. (2014) Automatic Positioner and Control System for a Motorized Parabolic Solar. Energy, 82, 462-470.
[101]	Bourogaoui, M., Sethom, H.B.A. and Belkhodja, I.S. (2016) Speed/Position Sensor Fault Tolerant Control in Adjustable Speed Drives—A Review. ISA Transactions, 64, 269-284. https://doi.org/10.1016/j.isatra.2016.05.003
[102]	Terniuk, M.E., Kryvosheia, A.V., Ustynenko, O.V., Krasnoshtan, O.M. and Tkach, P.M. (2022) Multiparameter Gears and Gear-Type Variators. In: Advances in Gear Theory and Gear Cutting Tool Design, Springer, 361-443. https://doi.org/10.1007/978-3-030-92262-7_12
[103]	Bernasconi, P.N., Rust, D.M. and Hakim, D. (2005) Advanced Automated Solar Filament Detection and Characterization Code: Description, Performance, and Results. Solar Physics, 228, 97-117. https://doi.org/10.1007/s11207-005-2766-y
[104]	Celikel, O. and San, S.E. (2009) Establishment of All Digital Closed-Loop Interferometric Fiber-Optic Gyroscope and Scale Factor Comparison for Open-Loop and All Digital Closed-Loop Configurations. IEEE Sensors Journal, 9, 176-186. https://doi.org/10.1109/jsen.2008.2011066
[105]	Borovic, B., Liu, A.Q., Popa, D., Cai, H. and Lewis, F.L. (2005) Open-Loop versus Closed-Loop Control of MEMS Devices: Choices and Issues. Journal of Micromechanics and Microengineering, 15, 1917-1924. https://doi.org/10.1088/0960-1317/15/10/018
[106]	Zi-Yi, L., Sew-Kin, W., Wai-Leong, P. and Chee-Pun, O. (2012) The Design of DC Motor Driver for Solar Tracking Applications. 2012 10th IEEE International Conference on Semiconductor Electronics (ICSE), Kuala Lumpur, 19-21 September 2012, 556-559. https://doi.org/10.1109/smelec.2012.6417207
[107]	Rubio, F.R., Ortega, M.G., Gordillo, F. and López-Martínez, M. (2007) Application of New Control Strategy for Sun Tracking. Energy Conversion and Management, 48, 2174-2184. https://doi.org/10.1016/j.enconman.2006.12.020
[108]	Lee, C., Chou, P., Chiang, C. and Lin, C. (2009) Sun Tracking Systems: A Review. Sensors, 9, 3875-3890. https://doi.org/10.3390/s90503875
[109]	de Rubeis, T., Ragnoli, M., Leoni, A., Ambrosini, D. and Stornelli, V. (2024) A Proposal for a Human-in-the-Loop Daylight Control System—Preliminary Experimental Results. Energies, 17, Article 544. https://doi.org/10.3390/en17030544
[110]	Mohamed, A.K.B., Mohamed, H. and Yacob, N.S. (2024) Solar Tracking Control Systems Design Strategies: A Review. AIP Conference Proceedings, Langkawi, 20-21 December 2021, Article 020046. https://doi.org/10.1063/5.0182413
[111]	Sidek, M.H.M., Azis, N., Hasan, W.Z.W., Ab Kadir, M.Z.A., Shafie, S. and Radzi, M.A.M. (2017) Automated Positioning Dual-Axis Solar Tracking System with Precision Elevation and Azimuth Angle Control. Energy, 124, 160-170. https://doi.org/10.1016/j.energy.2017.02.001
[112]	AL-Rousan, N., Isa, N.A.M. and Desa, M.K.M. (2018) Advances in Solar Photovoltaic Tracking Systems: A Review. Renewable and Sustainable Energy Reviews, 82, 2548-2569. https://doi.org/10.1016/j.rser.2017.09.077
[113]	Ferdaus, R.A., Mohammed, M.A., Rahman, S., Salehin, S. and Mannan, M.A. (2014) Energy Efficient Hybrid Dual Axis Solar Tracking System. Journal of Renewable Energy, 2014, 1-12. https://doi.org/10.1155/2014/629717
[114]	Zhou, B., Ahn, D., Lee, J., Sun, C., Ahmed, S. and Kim, Y. (2018) A Passive Tracking System Based on Geometric Constraints in Adaptive Wireless Sensor Networks. Sensors, 18, Article 3276. https://doi.org/10.3390/s18103276
[115]	Alippi, C. and Galperti, C. (2008) An Adaptive System for Optimal Solar Energy Harvesting in Wireless Sensor Network Nodes. IEEE Transactions on Circuits and Systems I: Regular Papers, 55, 1742-1750. https://doi.org/10.1109/tcsi.2008.922023
[116]	Racharla, S. and Rajan, K. (2017) Solar Tracking System—A Review. International Journal of Sustainable Engineering, 10, 72-81.
[117]	Tong, X.C. (2011) Advanced Materials for Thermal Management of Electronic Packaging (Vol. 30). Springer Science & Business Media.
[118]	Mushtaq, H., Khan, A. and Bhatti, H.N. (2024) Basics of Solar Energy Concentrators. Solar Energy Concentrators: Essentials and Applications, 1, 1-31.
[119]	Tilder, L. and Blostein, B. (2010) Design Ecologies: Sustainable Potentials in Architecture: Essays on the Nature of Design. Princeton Architectural Press.
[120]	Salgado-Conrado, L. (2018) A Review on Sun Position Sensors Used in Solar Applications. Renewable and Sustainable Energy Reviews, 82, 2128-2146. https://doi.org/10.1016/j.rser.2017.08.040
[121]	Chowdhury, M.E.H., Khandakar, A., Hossain, B. and Abouhasera, R. (2019) A Low-Cost Closed-Loop Solar Tracking System Based on the Sun Position Algorithm. Journal of Sensors, 2019, 1-11. https://doi.org/10.1155/2019/3681031
[122]	Dadi, V. and Peravali, S. (2020) Optimization of Light-Dependent Resistor Sensor for the Application of Solar Energy Tracking System. SN Applied Sciences, 2, Article No. 1499. https://doi.org/10.1007/s42452-020-03293-x
[123]	Chin, C.S. (2012) Model-Based Simulation of an Intelligent Microprocessor-Based Standalone Solar Tracking System. In: MATLAB—A Fundamental Tool for Scientific Computing and Engineering Applications-Volume 3, InTech, 251-278. https://doi.org/10.5772/46458
[124]	Solodovnik, E.V., Liu, S. and Dougal, R.A. (2004) Power Controller Design for Maximum Power Tracking in Solar Installations. IEEE Transactions on Power Electronics, 19, 1295-1304. https://doi.org/10.1109/tpel.2004.833457
[125]	Kumba, K., Upender, P., Buduma, P., Sarkar, M., Simon, S.P. and Gundu, V. (2024) Solar Tracking Systems: Advancements, Challenges, and Future Directions: A Review. Energy Reports, 12, 3566-3583. https://doi.org/10.1016/j.egyr.2024.09.038
[126]	Benzekri, A. and Azrar, A. (2014) FPGA-Based Design Process of a Fuzzy Logic Controller for a Dual-Axis Sun Tracking System. Arabian Journal for Science and Engineering, 39, 6109-6123. https://doi.org/10.1007/s13369-014-1213-5
[127]	Williams, B.C., Ingham, M.D., Chung, S.H. and Elliott, P.H. (2003) Model-Based Programming of Intelligent Embedded Systems and Robotic Space Explorers. Proceedings of the IEEE, 91, 212-237. https://doi.org/10.1109/jproc.2002.805828
[128]	Ray, S. and Tripathi, A.K. (2016) Design and Development of Tilted Single Axis and Azimuth-Altitude Dual Axis Solar Tracking Systems. 2016 IEEE 1st International Conference on Power Electronics, Intelligent Control and Energy Systems (ICPEICES), Delhi, 4-6 July 2016, 1-6. https://doi.org/10.1109/icpeices.2016.7853190
[129]	Musa, A., Alozie, E., Suleiman, S.A., Ojo, J.A. and Imoize, A.L. (2023) A Review of Time-Based Solar Photovoltaic Tracking Systems. Information, 14, Article 211. https://doi.org/10.3390/info14040211
[130]	Afanasyeva, S., Bogdanov, D. and Breyer, C. (2018) Relevance of PV with Single-Axis Tracking for Energy Scenarios. Solar Energy, 173, 173-191. https://doi.org/10.1016/j.solener.2018.07.029
[131]	Karabiber, A. and Güneş, Y. (2023) Single-Motor and Dual-Axis Solar Tracking System for Micro Photovoltaic Power Plants. Journal of Solar Energy Engineering, 145, Article 051004. https://doi.org/10.1115/1.4056739
[132]	Varadharajan, D.P., Kumarasamy, S., Murugesan, R., Muthuramalingam, A., Venkatesan, M. and Nachimuthu, L. (2024) A Comprehensive Review on Single Axis Solar Tracking System Using Artificial Intelligence. In: Advances in Computer and Electrical Engineering, IGI Global, 1-22. https://doi.org/10.4018/979-8-3693-3735-6.ch001
[133]	Demirdelen, T., Alıcı, H., Esenboğa, B. and Güldürek, M. (2023) Performance and Economic Analysis of Designed Different Solar Tracking Systems for Mediterranean Climate. Energies, 16, Article 4197. https://doi.org/10.3390/en16104197
[134]	Kazem, H.A., Chaichan, M.T., Al-Waeli, A.H.A.H. and Sopian, K. (2024) Dual Axis Solar Photovoltaic Trackers: An In-Depth Review. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 46, 15331-15356. https://doi.org/10.1080/15567036.2024.2420781
[135]	Ukoba, K., Olatunji, K.O., Adeoye, E., Jen, T. and Madyira, D.M. (2024) Optimizing Renewable Energy Systems through Artificial Intelligence: Review and Future Prospects. Energy & Environment, 35, 3833-3879. https://doi.org/10.1177/0958305x241256293
[136]	Vieira, R.G., Guerra, F.K.O.M.V., Vale, M.R.B.G. and Araújo, M.M. (2016) Comparative Performance Analysis between Static Solar Panels and Single-Axis Tracking System on a Hot Climate Region Near to the Equator. Renewable and Sustainable Energy Reviews, 64, 672-681. https://doi.org/10.1016/j.rser.2016.06.089
[137]	Sumathi, V., Jayapragash, R., Bakshi, A. and Kumar Akella, P. (2017) Solar Tracking Methods to Maximize PV System Output—A Review of the Methods Adopted in Recent Decade. Renewable and Sustainable Energy Reviews, 74, 130-138. https://doi.org/10.1016/j.rser.2017.02.013
[138]	Vykhnevych, Y. (2024) Improving Solar Energy Efficiency through Tracking Systems: Advantages and Challenges. Věda a Perspektivy, 8.
[139]	Riley, D. and Hansen, C. (2015) Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations. Journal of Solar Energy Engineering, 137, Article 031008. https://doi.org/10.1115/1.4029379
[140]	Lim, B., Lim, C., Li, H., Hu, X., Chong, K., Zong, J., et al. (2020) Industrial Design and Implementation of a Large-Scale Dual-Axis Sun Tracker with a Vertical-Axis-Rotating-Platform and Multiple-Row-Elevation Structures. Solar Energy, 199, 596-616. https://doi.org/10.1016/j.solener.2020.02.006
[141]	Zayed, M.E., Zhao, J., Elsheikh, A.H., Li, W., Sadek, S. and Aboelmaaref, M.M. (2021) A Comprehensive Review on Dish/Stirling Concentrated Solar Power Systems: Design, Optical and Geometrical Analyses, Thermal Performance Assessment, and Applications. Journal of Cleaner Production, 283, Article 124664. https://doi.org/10.1016/j.jclepro.2020.124664
[142]	Kuttybay, N., Mekhilef, S., Koshkarbay, N., Saymbetov, A., Nurgaliyev, M., Dosymbetova, G., et al. (2024) Assessment of Solar Tracking Systems: A Comprehensive Review. Sustainable Energy Technologies and Assessments, 68, Article 103879. https://doi.org/10.1016/j.seta.2024.103879
[143]	Schuh, H. and Böhm, S. (2021) Earth Rotation. In: Encyclopedia of Earth Sciences Series, Springer, 149-155. https://doi.org/10.1007/978-3-030-58631-7_177
[144]	Ismail, F.B., Rahmat, M.A.A., Kazem, H.A., Al-Obaidi, A.S.M. and Ridwan, M.S. (2024) Maximizing Energy via Solar-Powered Smart Irrigation: An Approach Utilizing a Single-Axis Solar Tracking Mechanism. Irrigation and Drainage, 73, 829-845. https://doi.org/10.1002/ird.2937
[145]	Shufat, S.A.A., Kurt, E. and Hancerlioğulları, A. (2019) Modeling and Design of Azimuth-Altitude Dual Axis Solar Tracker for Maximum Solar Energy Generation. International Journal of Renewable Energy Development, 8, 7-13. https://doi.org/10.14710/ijred.8.1.7-13
[146]	Forootan, M.M., Larki, I., Zahedi, R. and Ahmadi, A. (2022) Machine Learning and Deep Learning in Energy Systems: A Review. Sustainability, 14, Article 4832. https://doi.org/10.3390/su14084832
[147]	Ahmad, T., Madonski, R., Zhang, D., Huang, C. and Mujeeb, A. (2022) Data-Driven Probabilistic Machine Learning in Sustainable Smart Energy/Smart Energy Systems: Key Developments, Challenges, and Future Research Opportunities in the Context of Smart Grid Paradigm. Renewable and Sustainable Energy Reviews, 160, Article 112128. https://doi.org/10.1016/j.rser.2022.112128
[148]	Kosovic, I.N., Mastelic, T. and Ivankovic, D. (2020) Using Artificial Intelligence on Environmental Data from Internet of Things for Estimating Solar Radiation: Comprehensive Analysis. Journal of Cleaner Production, 266, Article 121489. https://doi.org/10.1016/j.jclepro.2020.121489
[149]	Othman, M.F. and Shazali, K. (2012) Wireless Sensor Network Applications: A Study in Environment Monitoring System. Procedia Engineering, 41, 1204-1210. https://doi.org/10.1016/j.proeng.2012.07.302
[150]	Mamodiya, U. and Tiwari, N. (2023) Dual-Axis Solar Tracking System with Different Control Strategies for Improved Energy Efficiency. Computers and Electrical Engineering, 111, Article 108920. https://doi.org/10.1016/j.compeleceng.2023.108920
[151]	Salam, A. (2024) Internet of Things for Environmental Sustainability and Climate Change. In: Internet of Things, Springer, 33-69. https://doi.org/10.1007/978-3-031-62162-8_2
[152]	Kishorebabu, V. and Sravanthi, R. (2020) Real Time Monitoring of Environmental Parameters Using IoT. Wireless Personal Communications, 112, 785-808. https://doi.org/10.1007/s11277-020-07074-y
[153]	Antonanzas, J., Arbeloa-Ibero, M. and Quinn, J.C. (2019) Comparative Life Cycle Assessment of Fixed and Single Axis Tracking Systems for Photovoltaics. Journal of Cleaner Production, 240, Article 118016. https://doi.org/10.1016/j.jclepro.2019.118016
[154]	Hernández-Callejo, L., Gallardo-Saavedra, S. and Alonso-Gómez, V. (2019) A Review of Photovoltaic Systems: Design, Operation and Maintenance. Solar Energy, 188, 426-440. https://doi.org/10.1016/j.solener.2019.06.017
[155]	Manisha, P., Kumari, M., Sahdev, R.K. and Tiwari, S. (2022) A Review on Solar Photovoltaic System Efficiency Improving Technologies. Applied Solar Energy, 58, 54-75. https://doi.org/10.3103/s0003701x22010108
[156]	Peharz, G. and Bett, A.W. (2010) High Concentration Fresnel Lens Assemblies and Systems. In: Solar Cells and Their Applications, Wiley, 331-335.
[157]	Kumar, M., Panda, K.P., Rosas-Caro, J.C., Valderrabano-Gonzalez, A. and Panda, G. (2023) Comprehensive Review of Conventional and Emerging Maximum Power Point Tracking Algorithms for Uniformly and Partially Shaded Solar Photovoltaic Systems. IEEE Access, 11, 31778-31812. https://doi.org/10.1109/access.2023.3262502
[158]	Sabiha, M.A., Saidur, R., Mekhilef, S. and Mahian, O. (2015) Progress and Latest Developments of Evacuated Tube Solar Collectors. Renewable and Sustainable Energy Reviews, 51, 1038-1054. https://doi.org/10.1016/j.rser.2015.07.016
[159]	Hafez, A.Z., Yousef, A.M. and Harag, N.M. (2018) Solar Tracking Systems: Technologies and Trackers Drive Types—A Review. Renewable and Sustainable Energy Reviews, 91, 754-782. https://doi.org/10.1016/j.rser.2018.03.094
[160]	GhaffarianHoseini, A., Dahlan, N.D., Berardi, U., GhaffarianHoseini, A., Makaremi, N. and GhaffarianHoseini, M. (2013) Sustainable Energy Performances of Green Buildings: A Review of Current Theories, Implementations and Challenges. Renewable and Sustainable Energy Reviews, 25, 1-17. https://doi.org/10.1016/j.rser.2013.01.010
[161]	Saravanan, C., Panneerselvam, M.A. and Christopher, I.W. (2011) A Novel Low Cost Automatic Solar Tracking System. International Journal of Computer Applications, 31, 62-67.
[162]	Marshall, G.J., Mahony, C.P., Rhodes, M.J., Daniewicz, S.R., Tsolas, N. and Thompson, S.M. (2019) Thermal Management of Vehicle Cabins, External Surfaces, and Onboard Electronics: An Overview. Engineering, 5, 954-969. https://doi.org/10.1016/j.eng.2019.02.009
[163]	Ajukumar, V.N. and Gandhi, O.P. (2013) Evaluation of Green Maintenance Initiatives in Design and Development of Mechanical Systems Using an Integrated Approach. Journal of Cleaner Production, 51, 34-46. https://doi.org/10.1016/j.jclepro.2013.01.010
[164]	Panagoda, L.P.S.S., Sandeepa, R.A.H.T., Perera, W.A.V.T., Sandunika, D.M.I., Siriwardhana, S.M.G.T., Alwis, M.K.S.D. and Dilka, S.H.S. (2023) Advancements in Photovoltaic (PV) Technology for Solar Energy Generation. Journal of Research Technology & Engineering, 4, 30-72.
[165]	Yang, Z. and Xiao, Z. (2023) A Review of the Sustainable Development of Solar Photovoltaic Tracking System Technology. Energies, 16, Article 7768. https://doi.org/10.3390/en16237768
[166]	Hathaway, D.H. (2015) The Solar Cycle. Living Reviews in Solar Physics, 12, Article No. 4. https://doi.org/10.1007/lrsp-2015-4
[167]	Lai, Y., Chou, M. and Lin, P. (2010) Parameterization of Topographic Effect on Surface Solar Radiation. Journal of Geophysical Research: Atmospheres, 115, D01104. https://doi.org/10.1029/2009jd012305
[168]	Olson, M. and Rupper, S. (2019) Impacts of Topographic Shading on Direct Solar Radiation for Valley Glaciers in Complex Topography. The Cryosphere, 13, 29-40. https://doi.org/10.5194/tc-13-29-2019
[169]	Liu, M., Bárdossy, A., Li, J. and Jiang, Y. (2012) GIS-Based Modelling of Topography-Induced Solar Radiation Variability in Complex Terrain for Data Sparse Region. International Journal of Geographical Information Science, 26, 1281-1308. https://doi.org/10.1080/13658816.2011.641969
[170]	Haigh, J.D. (2007) The Sun and the Earth’s Climate. Living Reviews in Solar Physics, 4, Article No. 2. https://doi.org/10.12942/lrsp-2007-2
[171]	Benton, E.R. and Benton, E.V. (2001) Space Radiation Dosimetry in Low-Earth Orbit and Beyond. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 184, 255-294. https://doi.org/10.1016/s0168-583x(01)00748-0
[172]	Kang, H., Kim, H., Hong, J., Zhang, R., Lee, M. and Hong, T. (2024) Harnessing Sunlight Beyond Earth: Sustainable Vision of Space-Based Solar Power Systems in Smart Grid. Renewable and Sustainable Energy Reviews, 202, Article 114644. https://doi.org/10.1016/j.rser.2024.114644
[173]	Aglietti, G.S., Redi, S., Tatnall, A.R. and Markvart, T. (2009) Harnessing High-Altitude Solar Power. IEEE Transactions on Energy Conversion, 24, 442-451. https://doi.org/10.1109/tec.2009.2016026
[174]	Gherboudj, I. and Ghedira, H. (2016) Assessment of Solar Energy Potential over the United Arab Emirates Using Remote Sensing and Weather Forecast Data. Renewable and Sustainable Energy Reviews, 55, 1210-1224. https://doi.org/10.1016/j.rser.2015.03.099
[175]	Yoneda, K., Suganuma, N., Yanase, R. and Aldibaja, M. (2019) Automated Driving Recognition Technologies for Adverse Weather Conditions. IATSS Research, 43, 253-262. https://doi.org/10.1016/j.iatssr.2019.11.005
[176]	Milidonis, K., Eliades, A., Grigoriev, V. and Blanco, M.J. (2023) Unmanned Aerial Vehicles (UAVS) in the Planning, Operation and Maintenance of Concentrating Solar Thermal Systems: A Review. Solar Energy, 254, 182-194. https://doi.org/10.1016/j.solener.2023.03.005
[177]	Yang, C., Sun, F., Zou, Y., Lv, Z., Xue, L., Jiang, C., et al. (2024) A Survey of Photovoltaic Panel Overlay and Fault Detection Methods. Energies, 17, Article 837. https://doi.org/10.3390/en17040837
[178]	Kelly, N.A. and Gibson, T.L. (2009) Improved Photovoltaic Energy Output for Cloudy Conditions with a Solar Tracking System. Solar Energy, 83, 2092-2102. https://doi.org/10.1016/j.solener.2009.08.009