Solar Array Design Research Articles

Mitigating the Impact of Partial Shading Conditions on Photovoltaic Arrays Through Modified Bridge-Linked Configuration

Global reliance on depleting energy resources is driving the urgent need for alternative solutions to address escalating energy demands. Solar energy, a prominent renewable resource, leverages various configurations and techniques to maximize power output, even under challenging environmental conditions. In photovoltaic (PV) arrays, partial shading conditions (PSCs) significantly hinder efficiency by reducing power extraction across solar panels. Traditionally, configurations such as series, parallel, series-to-parallel, and bridge-linked (BL) are employed to optimize power output; however, each has limitations under PSCs. Here, we introduce a modified bridge-linked (Modified BL) configuration designed to mitigate the adverse effects of partial shading on PV arrays. This approach allows for interconnected solar modules that reduce shading impact across an entire array, thus preserving efficiency by isolating shaded sections and minimizing power loss. The Modified BL configuration not only supports maximum power point tracking (MPPT) but also enhances resilience against shading, ensuring stable power output. Our simulation results underscore the critical influence of irradiance levels on PV electricity generation, suggesting that incorporating irradiance variability as a design parameter is essential in selecting optimal PV interconnection schemes under PSCs. This study contributes to advancing solar array design by providing a robust method to maintain power output in partial shading conditions, ultimately supporting broader efforts in renewable energy optimization.

Forage Biomass and Nutritive Value of Grasses and Legumes Grown Under Agrivoltaic Systems

Forage crops grown underneath ground-mounted photovoltaic systems (PV) may provide a feed source for livestock production. The objective was to evaluate forage biomass and nutritive value of crops, grasses and legumes grown under different PV conditions. Forages were planted underneath a 30-kilowatt PV site (30kW), a 50-kilowatt PV site (50kW) and one control site without PV (CON) in May 2022 with four replicates per site. Forage crops included alfalfa, field peas, meadow fescue, orchard grass, red clover, brown midrib sorghumsudan grass, white clover and 3 grass and legume mixes with either alfalfa, red clover, or white clover. Biomass samples were clipped at appropriate maturity levels for grazing. Samples were sorted for botanical composition and analyzed for nutrient value. Crop biomass, dry matter and nutrient values were analyzed with PROC Mixed of SAS with the fixed effects of site (30kW, 50kW, or Con), crop nested within site, and cutting (1st or 2nd) and the random effect of replicate nested within site. Forages produced less biomass at the 30kW (563.7 kg/ha) and 50kW (446.4 kg/ha) solar sites compared to CON (1099.7 kg/ha). The 50kW forages had greater crude protein on a dry matter basis (25.8%) than the 30kW (21.4%) and CON (20.9%). The 50kW (57.1%) forages also had greater total tract neutral detergent fiber (NDF) digestibility than the 30kW (52.5%) and CON (51.0%). Additionally, the 50kW forages had greater percent calcium (1.05%) compared to the 30kW (0.75%) and CON (0.84%). Forage biomass and nutrient values varied based on the solar array design and amount of sun exposure.

Self-Unfolding Properties of Smart Grid-Reinforced Membrane Origami

Origami-based membrane structures have shown great potential to revolutionize the construction of deployable and lightweight space structures in the future. However, the efficient unfolding mechanism puts forward major challenges to the practical realization of space-deployable structures. Here, a smart grid-reinforced membrane origami (SGRMO) is presented. The unfolding action hinges upon the application of forces facilitated by shape memory polymer composites (SMPCs). Subsequent locking action ensues through the restoration of the initial rigidity, accomplished via cooling mechanisms. This novel structure achieves the required lightweight and functionality by employing the grid design concept and effectively reduces the decline in unfolding extent caused by irreversible plastic deformation at the crease. Its recovery properties, including unfolding angle, distance, and surface precision, are experimentally and analytically investigated under different conditions. The results indicate that the structure can be reliably unfolded into the predefined shapes. In the case of Miura-SGRMO, the optimal surface precision is attained when the angle-ψ registers at 30°. The results of this study are expected to serve as the design of ultra-large flexible solar arrays and deployable antenna structures.

Receiving energy analysis and optimal design of crystalline silicon solar cell array on solar airship

The energy of solar airships comes from solar array, and the amount of solar radiation received by solar array determines airship endurance. Many studies optimize the solar array layout to receive more solar radiation. However, most of them are for flexible thin-film array. The influence of the size of the currently commonly used crystalline silicon panels on received energy is not considered. This paper establishes a solar irradiation model and a receiving energy model suitable for crystalline silicon arrays. The effects of array shape, array location, and module size on the energy received by crystalline silicon solar arrays are analyzed at different flight latitudes. Then, an improved genetic algorithm is designed to optimize the array geometric parameters. The results show that altering the size and layout of solar modules significantly influences energy capture, with opposing trends between regions of mid-low latitudes and high latitudes. Airships flying at mid-low latitudes should adopt larger solar modules, while airships flying at high latitudes should adopt smaller ones. After the optimization using the proposed algorithm, the received energy of solar array is further enhanced. The optimization resulted in a 2% improvement at mid-low latitudes and an 18% improvement at high latitudes over conventional optimization.

Parameter design of solar optical reflection lighting system array for shadowless lighting in threshold zone of short freeway tunnel

A solar optical reflection (SOR) lighting system has been developed to illuminate the threshold zone of short freeway tunnel in the premise of zero energy consumption. To improve the limited illumination performance of SOR lighting system due to the obstruction of moving vehicles on reflected sunlight rays, this study develops a fast and simple parameter design method for shadowless lighting based on an array of multiple SOR lighting systems that makes reflected sunlight emit to the threshold zone from different angles. The effectiveness of shadowless lighting is verified by the application on a two-lane freeway of Shaanxi Province, China. Results show that the shadowless lighting can significantly improve the illuminance in threshold zone, and the improvement rate is higher for the area farther from the tunnel entrance inside the tunnel. In order to achieve shadowless lighting avoid both the vehicle and inter-system blocking on reflected sunlight, the systems should be installed roadside in a staggered array that: 1) their heights descend and lateral distances from the curb shrink in turn from near to far from the tunnel entrance, with as small vertical and horizontal deflection angles of the reflectors as possible, or 2) their heights remain identical with a reduction in the vertical deflection angles of the reflectors from near to far from the tunnel entrance.

Design of solar array with sun position tracking system employing refrigerant

Renewable energy is quickly gaining relevance as a source of energy as the price of fossil fuels changes. As the need for electricity has risen in recent years, the power sector has played an increasingly important role in our daily lives. Solar power is one of the most important renewable energy sources on the planet, and it should be collected and exploited to its full potential. The proposed system is unique in that it uses the sun instead of the earth as a guiding source. Solar panels' energy conversion efficiency is determined on the amount of sunshine they receive. As a result, a tracker device must be designed to make sure that the solar panel's direction always follows the sun's location. As a result, we're attempting to design a solar array with a sun position tracking system that can provide or consume the most solar energy while maintaining a reasonable potency. There are a variety of ways to track the sun's location, but we prefer to utilize the passive method. Instead of using external energy to detect the sun's position, passive solar tracking employs refrigerant as a source. It operates on the concept that when the temperature rises, the refrigerant's vapour pressure rises as well. The transfer of high-pressure refrigerant from one canister to another generates an imbalance in the weights on the canisters, allowing them to track the position of the sun.

On‐Orbit Performance Analysis of Solar Array in Mars Orbit Based on Tianwen‐1 Orbiter

Herein, the on‐orbit performance of the solar array in Mars orbit based on the Tianwen‐1 Orbiter is analyzed. Different portions divided by the flight orbit and power output of the solar array are illustrated in detail, including Mars capture orbit, parking orbit, relay and survey orbit, and global reconnaissance orbit. Photogenerated currents generally exhibit dramatic variation ascribed to the Sun‐Orbiter distance. Radiation degradation of the solar array on Mars orbit is analyzed after calibrating by the incident light intensity and working temperature. The daily degradation coefficient of photogenerated current is calculated to be 10 000, indicating the friendly radiation environment on Mars orbit. Besides, current enhancement of about 0.32 A and temperature enhancement range 12.5–35.3 °C induced by Mars‐shine are observed since parking orbit. The temperature of the Mars orbit is also studied in this article. The ultralow temperature of −180 °C in shadow conditions proposes an enormous challenge for the solar array. The present work will be helpful to deepen the understanding of Mars orbit and provide reference to the solar array design for Mars exploration spacecraft.

Design and fabrication of Solar dish array and study it characterization

Designed and fabricated a (3.25m) solar dish array ,by using (52) plane mirror. These mirrors are level and fixed to reflect the radiation in one area (focus) and after distance (1.5 m). In addition, it was found that the heat concentration (217.79 W) the useful energy (1416.125W) and the center efficiency were55% at (400-700W/m2). The solar dish array is relatively suitable for solar thermal applications.

Extreme Wind Loading on Flat-Roof-Mounted Solar Arrays with Consideration of Wind Directionality

The assessment of extreme wind loading on solar arrays plays a significant role in ensuring their safe operation under strong winds. Therefore, this paper investigates the extreme wind loading on solar arrays mounted on a flat roof by taking into account the wind directionality effect. The estimation process is conducted by using in situ wind speeds obtained from meteorological stations and wind loading coefficients on solar arrays obtained from wind tunnel tests based on the joint probability distribution of multiple variables and their conditional probabilities. This allows a discussion regarding how the extreme wind loading of solar arrays would be affected by such factors as the uncertainty of wind loading coefficient, the structural orientation of buildings on which solar arrays are mounted, and the directional characteristics of wind speeds. Finally, a comparison among the proposed methods, considering the wind directionality in current wind loading codes, is performed. The extreme wind loading determined by multivariate extreme value theory is found to be comparable to the corresponding estimate calculated according to the independent assumption of directional extreme wind speed. The results of this study provide a valuable reference for the design of wind-resistant solar arrays that takes account of wind directionality effect.

A New Design of the 3D Deployable Solar Array in the Aerospace Field and Kinematic Analysis during Deployment

The paper focuses on a new design of the 3D deployable solar array for spacecraft and landers. Compared with existing solar array designs, the main advantage of this new design is the further increase in the area of the solar array. The principles of spatial rings and domes are used for this new design. This design consists of a large dome and four smaller rings. The model is constructed using Solidworks, and different configurations during the deployment are shown. The kinematic analysis shows that the length ratios of elements are independent of the input angle θ. It proves that this deployable structure has only one mobility. The configuration can be determined by a specific input angle. When the input angle θ increases, the top-view area of the structure increases, while the maximum height of the structure decreases. The volume of the increases and then decreases with the increasing θ. The maximum volume occurs at θ = 110°. In addition, the shape of the top-view geometry for a particular design is determined by two design parameters. It is found that the length ratios of elements increase with the increasing value of two design parameters.

Adaptive optics in the Arctic? A commentary on Fosbury and Jeffery.

Adaptive optics in the Arctic? A commentary on Fosbury and Jeffery.

Space deployable bistable composite structures with C-cross section based on machine learning and multi-objective optimization

A data-driven computational framework combining machine learning and multi-objective optimization is developed for the design of space deployable bistable composite structures with C-cross section. A C-cross section thin-walled deployable composite structure has bi-stability compared with other deployable structures, which has attracted many attentions thanks to its application prospects in roll-out solar array. In order to get the optimal geometric parameters of subtended angle, thickness, initial radius and longitudinal length, combination methods of finite element method, multi-objective optimization technique and experiment method for bistable composite structures with C-cross section are proposed in this article. The optimal Latin hypercube sampling algorithm is used to obtain the sample points of variables for the design of experiments. The surrogate models of the deployable structure will be obtained by response surface method and the non-dominated sorting genetic algorithm-II is used to obtain Pareto-optimal solution. The mechanical responses of the structure, which are set as optimization objectives are obtained by finite element simulation including the snap-through process and coiling process. Experimental results verify the accuracy and effectiveness of this optimization result. Furthermore, a parametric study of the geometric parameters is performed to determine the effect on the mechanical behavior and fully coiling-up stability. Lastly, the computational strategy proposed can be applied to different design problems in composite structures, which can also guide the design of roll-out solar array.

Mechanical Behaviors of the Origami-Inspired Horseshoe-Shaped Solar Arrays.

The importance of flexibility has been widely noticed and concerned in the design and application of space solar arrays. Inspired by origami structures, we introduce an approach to realizing stretchable and bendable solar arrays via horseshoe-shaped substrate design. The structure has the ability to combine rigid solar cells and soft substrates skillfully, which can prevent damage during deformations. The finite deformation theory is adapted to find the analytic model of the horseshoe-shaped structure via simplified beam theory. In order to solve the mechanical model, the shooting method, a numerical method to solve ordinary differential equation (ODE) is employed. Finite element analyses (FEA) are also performed to verify the developed theoretical model. The influences of the geometric parameters on deformations and forces are analyzed to achieve the optimal design of the structures. The stretching tests of horseshoe-shaped samples manufactured by three-dimensional (3D) printing are implemented, whose results shows a good agreement with those from theoretical predictions. The developed models can serve as the guidelines for the design of flexible solar arrays in spacecraft.

In‐Orbit Performance Analysis of Solar Array for Chang'e‐4 Relay Satellite in an Earth–Moon Lagrangian Point 2 Halo Orbit

Herein, the in‐orbit performance of the solar array for Chang'e‐4 Relay Satellite in an Earth–Moon Lagrangian point 2 (EML2) Halo orbit is analyzed. The daily degradation coefficient of the photovoltaic current is calculated to be 0.99989 independent of whether the relay antenna outspreads, indicating an annual degradation coefficient of 3.94%. However, due to the shading effect of the antenna and the electrical performance degradation, the output voltage of the solar array dissatisfies the requirement of the power controller on around the 700th day, resulting in an abrupt decrease of the photovoltaic current. In addition, the in‐orbit working temperature of the solar array for Chang'e‐4 Relay Satellite is also studied. The working temperature mainly ranges from 52.3 to 76.8 °C, while the working temperature decreases to the range of 0–25 °C once the relay antenna outspreads. The present work is helpful to a deepen the understanding of EML2 Halo orbit and provide reference to the solar array design for a deep space exploration aircraft.

Structural and dynamic analysis of a flexible solar array based on shape memory polymer composites

In recent years, shape memory polymer composites (SMPCs) have been gradually applied to space deployable structures owing to their shape memory characteristics and superior mechanical properties. This study investigated structural and dynamic analysis of an SMPC flexible solar array system (SMPC-FSAS). The SMPC-FSAS was designed to ensure the safety and reliability of the structure. In addition, the modal and swept sine vibration responses of the structure were studied by numerical simulations and experiments. The experimental results were consistent with the numerical simulation predictions, which verified the correctness of the numerical model. Subsequently, a series of dynamic tests verified that SMPC-FSAS has a favorable structural strength and rigidity. Notably, the SMPC-FSAS carried on the SJ-20 geostationary satellite was successfully launched into a geosynchronous orbit, which further verified its safety and reliability. The results of this study are expected to serve the design of ultra-large flexible solar arrays in the future.

Analysis of design of spacecraft solar arrays

Solar arrays supply electrical power to spacecraft equipment and also provide charging of electrochemical batteries used in the shadow sections of the orbit. Photovoltaic converters of light energy of solar radiation form the basis of the solar battery. Their principle of operation is based on the phenomenon of the photoelectric effect. The article provides an overview of the development of solar cells and the classification of modern designs of solar cells for spacecraft. The review considers stationary and deployable solar batteries used both on the first spacecraft and on space stations. The classification of solar cell designs is made taking into account their characteristic features. These features are the rigidity of the supporting structure, the method of placement in the starting position and the method of orientation towards the light source. The classification covered rigid panel solar arrays, flexible substrate solar panels, inflatable solar arrays, self-expanding solar arrays, and solar concentrator panels. In each design group of this classification, corresponding examples of solar cells are presented. The presented review and classification makes it possible to track trends in the development of solar array designs for spacecraft.

Preliminary Power Budget Analysis for Equatorial Low Earth Orbit (LEO) Communication Satellite

Satellite Technology Center – LAPAN would develop a constellation of 9 communication satellites in a low equatorial orbit. These satellites would perform as data collection platforms for many sensors that spread across the Indonesian territory. The data from the sensors will be downlink to Indonesia’s ground stations in real-time. This research aims to analyze the power budget of those satellites to decide how many solar panels and batteries are required to perform their mission. The method in this research began by calculating the power requirements of each mission per orbit period to estimate power consumption and calculate the power generated by the solar panels. The results of these calculations will be implemented to the power system design to find the satellite solar cells/ panels arrangement and battery capacity allocation. To minimize the development time and cost, the solar array design in this study considers the utilization of previous solar panel design of LAPAN-A series satellites as a design constraint. This study shows the configuration of 3 body-mounted solar panels and 2 deployable solar panels could support the mission operation of communication satellite in the low equatorial orbit. For energy storage, these satellites should be equipped with 28 V Li-ion in the 8Sx3P configuration.

An Analysis of Hybrid Energy Design for Yogyakarta International Airport (YIA)

The potential for solar and wind energy at YIA Airport is quite large so that it can be used as a renewable alternative energy source. Based on data obtained from BMKG of YIA, the average sun intensity at YIA Airport is 6.21 kWh/m2 while the average wind speed is 3.07 m/s. This potential can be used as solar and wind hybrid energy to meet some of the electricity demand at YIA Airport using photovoltaic modules and wind turbines. Design of the wind turbine refers to research conducted by Mihai Lates and Radu Velicu (2014), which implements a basic savonius type wind turbine with an aspect ratio (α) 2, diameter (D) 3.50 m, number of blades (n) 2. Solar array design uses an off-grid system, then will be hybridized with the wind turbine. Based on the calculation result shows that the required area of the solar array is 2282.87 m2 to produce 2574 kWh/day, while the number of turbines proposed is 143 units to produce 136.90 kWh/day. With this design and based on the calculation, electrical energy will be generated for 13.55% (2710.90 kWh/day) of the total electricity demand at YIA Airport.

Geostationary Communication Satellite Solar Array Optimization Using Gravitation Search Algorithm

The preliminary design of geostationary communication satellite solar array is presented in this work. Based on the power requirements, power margin requirements and performance requirements, the number of panels, strings and cells to be used on the solar array were defined. The main objective of this study was to optimize the power generated from the satellite solar array and the extraction of the parameters of a photovoltaic module, which is subject to the space environment and under a series of practical constraints, in order to extract the desired performance parameters for multiobjective functions, taking into account the solstice and equinox periods during temperature operation. A gravitational search algorithm based on the law of gravity and mass interactions was introduced. This algorithm has proved its effectiveness in optimizing system parameters in the literature. From the results obtained in this work, the total power of the optimized system was reduced by 181 W. The degradation and output power characteristics of the solar panels were calculated for different temperature values.

MONTHLY DESIGN DATA FOR MAXIMUM SOLAR RADIATION FALLING ON COLLECTOR ARRAYS IN BAGHDAD CITY

Increasing use of solar energy as a clean and free solution for energy demand necessitates proper use of its equipment, enhanced spatial planning and distribution of solar collectors, optimum directional facing and tilt angle to ensure maximum solar radiation falling, and decreasing as possible as the shading effects of panel arrays. Most existing references lack comprehensive data about shading effects that varied along the year and design of solar array. In the present work, enhanced theoretical design data of solar collector arrays were tabulated for each month in Baghdad. MATLAB program was used to calculate the maximum clear sky solar radiation per unit area per day. The tabulated data yields an economically saved design of solar field or rooftop collector systems. The results indicated that, the shading effect on panel arrays almost vanishes when the distance between two panel rows to panel height ratio is greater than 1 in summer and greater than 2 in winter.