Advances in Mounting Structures for Photovoltaic Systems: Sustainable Materials and Efficient Design

Abstract

This article addresses the technical, aesthetic, and strategic problem of the limited attention paid to design and selection of materials in photovoltaic system (PSS) support structures despite their direct impact on the efficiency, durability and economic viability of these systems. As the costs of modules and electronic components continues to decrease, the structural elements acquire greater weight in the total cost and long-term performance. Our research comprehensively analyzes the mechanical, environmental, and regulatory factors influencing material selection and structural design in PV mounting systems. The PRISMA methodology was used to perform a systematic review of 122 articles published between 2018 and 2025, which were classified along two axes: materials (mild steel, galvanized steel, aluminum, polymers, and composites) and structural design (angle, orientation, loads, support typology, and adaptation to the environment). The results show that an adequate match between design and climatic conditions improves system stability, efficiency, and service life. With the support of digital modeling and advanced simulations, we identify trends towards modular, lightweight, and adaptive solutions, particularly in architectural applications (BIPV). This work provides a robust and contextualized technical framework that facilitates informed decision-making in solar energy projects, with direct implications for the sustainability, structural resilience, and competitiveness of the PSS sector in different geographical regions.

1. Introduction

Renewable energies, particularly solar photovoltaics (PV), are key to mitigating climate change and advancing sustainable production [1,2]. Declining costs have made PV highly competitive [3]; however, implementation faces challenges such as biodiversity loss and disposal of panels at the end of their lifespan. Additionally, climate change could impact renewable energy generation, with potential reductions of up to 40% in wind and hydroelectric power in certain regions [4]. Nevertheless, PV has the potential to decarbonize 90% of the electricity sector and reduce greenhouse gas emissions by 4.9 Gt by 2050, covering up to 25% of global electricity demand [5]. As prices of photovoltaic (PV) modules and related electronics have dropped significantly, the structural mounting system now accounts for an important share of the total system.

The most common problems in photovoltaic mounting system structures include several factors affecting their performance and durability. Limited access to proper panel cleaning can accelerate degradation, as moisture and pollutants negatively impact performance [6]. In floating photovoltaic installations, wave action and wind can cause structural deformation, revealing insufficient robustness in specific designs under harsh environments [7]. The use of low-quality components and absence of preventive maintenance increase the likelihood of early failures, particularly in critical elements such as inverters and batteries. Additionally, inadequate lightning protection can seriously damage the system [8]. Environmental factors such as lightning storms and high temperatures can compromise system performance, reducing efficiency and causing component failures [9].

Photovoltaic mounting structures are essential for solar energy systems and crucial in determining PV installations’ efficiency and environmental impact [10]. These structures support the PV modules and optimize their orientation while also influencing thermal regulation, shading, and overall system performance [11,12]. The aim of this review is to evaluate and optimize PV mounting structures in terms of their mechanical performance, durability, and cost-effectiveness, emphasizing improvements in structural integrity under diverse environmental conditions and minimization of balance-of-system (BOS) costs. This area remains a significant challenge, leaving numerous areas open for further research.

Shademan et al. [13] conducted an in-depth analysis of the relationship between the coefficients and the spacing between modules in solar panel structures, observing that an increase in this spacing leads to a reduction in the pressure difference between the windward and leeward sides. Similarly, Waqas et al. [14] applied the finite element method (FEM) to assess the structural strength and reliability of photovoltaic systems, finding that the joints located at the center and base of the structure experienced greater deformations under various horizontal wind loads. Previous research has focused exclusively on the effects of aerodynamic forces on the structural behavior of ground-mounted photovoltaic systems with different solar array configurations.

Polymer-based alternatives have gained significant attention in exploring innovative materials for structural applications in solar energy systems. Shweta et al. [15] studied structures made with polymeric materials, highlighting their potential as a strong alternative to traditional solar mounting designs due to their lightweight nature, high strength, and corrosion resistance. This paradigm shift leverages benefits of polymers such as their ease of manufacturing, low environmental impact, and design flexibility. This design approach supports the overarching goal of sustainable power generation by incorporating recyclable and eco-friendly components into systems alongside renewable solar energy. Zhiyu et al. [16] introduced an innovative concept for floating photovoltaic (FPV) systems that can withstand harsh environmental conditions, including extreme wave heights exceeding 10 m. The design employs lightweight and standardized semi-submersible floaters configured as individual modules made from circular sustainable materials. This concept demonstrates outstanding performance in terms of modular motion and offers promising potential for further research and development.

Resch et al. [17] reviewed various methods to prevent overheating of solar collection systems using polymer-based compounds. Kessentini et al. [18] conducted simulations and experimental studies on technologies for mitigating collector overheating by attaching a transparent insulation material (TIM) to the rear side of the glass in a flat-plate collector. Yue Wu et al. [19] studied flexible support structures for PV modules, highlighting advantages such as extensive span capability, rapid construction, speed and adaptability to complex environments. The authors proposed a novel support system based on a cable–truss structure, demonstrating excellent wind resistance performance. In summary, research on photovoltaic module structures has covered aspects ranging from aerodynamic design and structural resistance to using innovative materials and solutions tailored to complex environments and extreme conditions.

Recent developments in photovoltaic solar technology have focused on improving energy efficiency and optimizing the mechanical design and material selection for support structures. These decisions are increasingly influenced by the structural and climatic conditions of the installation sites, which can pose challenges such as high winds, heavy snow, corrosion, or seismic activity. Based on this, the following hypothesis is proposed: Environmental and structural conditions significantly determine the mechanical design strategies and material choices for photovoltaic support systems. From this hypothesis, three research questions emerge:

• How do specific climatic factors such as wind load, temperature variation, and humidity affect the performance and longevity of different support structures in photovoltaic installations?
• What recent innovations in mechanical design and materials have been most effective in enhancing the structural resilience of solar support systems across various environmental contexts?
• How can photovoltaic support structures be systematically adapted to different geographic regions in order to mitigate risks related to local environmental stressors (e.g., corrosion, seismic activity, and extreme weather)?

To answer these questions, in this research we aim to develop a systematic review following the PRISMA methodology that identifies, classifies, and analyzes the main advances in structural design and the selection of materials used in photovoltaic mounting systems. Technical, regulatory, and environmental variables are considered to establish a comprehensive analytical framework for understanding how design decisions affect these systems’ efficiency, durability, and adaptability. This approach seeks to guide the development and implementation of sustainable and technically viable solutions in varying geographical and architectural contexts.

The rest of this paper is structured as follows. Section 1 introduces the PRISMA methodology and reviews related work on mechanical design and material selection for support structures in photovoltaic systems. It also defines the research problem, emphasizing the need for a comprehensive understanding of how structural and climatic conditions influence the performance and reliability of solar systems. As this study addresses existing gaps by systematically analyzing the interaction between design strategies, material properties, and environmental demands, Section 1 additionally outlines the specific contributions of this work. Section 2 describes the PRISMA methodology and its application to engineering research, including the step-by-step procedure, inclusion and exclusion criteria, and rationale behind selecting relevant studies. Section 3 presents the research process, results, and a critical analysis of the key patterns and trends identified in the literature. Section 4 discusses the implications of the findings, proposes a classification framework for structural solutions based on environmental context, and compares this work with previous research. Finally, Section 5 concludes the article by summarizing the main findings and suggesting opportunities for future research on photovoltaic support systems.

2. Materials and Methods

A systematic review is a form of scientific research in which the object of analysis consists of original primary studies that address the same topic. In this case, the review focuses on identifying the main factors influencing the design of solar panel mounts and analyzing the relevant variables and their percentage ranges under different conditions. This review aims to provide a clear and precise answer to the previously posed research questions. The PRISMA review method allows us to obtain a comprehensive and reliable view of the subject while minimizing possible biases in the research [20,21].

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology offers a set of standardized guidelines to improve clarity, quality, and transparency when preparing systematic reviews and meta-analyses. Its primary purpose is to support researchers in conducting and presenting these types of studies in a more structured and complete manner, particularly in health contexts. The PRISMA methodology includes a checklist of 27 key elements to consider when writing a review along with a flowchart describing the process followed at each analysis stage. Implementing this methodology helps to increase scientific rigor, facilitate understanding of the results, and promote more transparent research practices [22,23].

2.1. Information Search

The most representative keywords related to the design and feasibility of support structures for solar photovoltaic systems were identified for this search. The Scopus database was used as the main source due to its extensive repository of scientific literature exceeding 75 million records and its advanced filtering functions that allows results to be refined according to different parameters. In addition, Scopus offers bibliometric indicators such as the h-index and CiteScore, which help to assess the relevance and impact of selected articles. The Scopus platform is continuously updated, which guarantees access to recent research in various areas of knowledge. The following set of key terms was used for the search: TITLE-ABS-KEY ((“solar photovoltaic system”) AND (“supports” OR “structures”)).

2.1.1. Selection of the Structure Type

The structural system anchors the photovoltaic panels to the rooftops or the ground. Its design depends on installation conditions, and can be classified as follows:

• Coplanar structures are installed directly on sloped roofs; they optimize available space and minimize visual impact, offering a discreet aesthetic.
• Triangular supports are used when the roof’s tilt or orientation is suboptimal. They adjust the panel angle to enhance solar exposure and improve energy yield.
• Tracking systems are equipped with one or two axes; these dynamic structures follow the Sun’s movement to maximize irradiance capture, boosting energy production by up to 30% in high-radiation zones. Common types include:

  –

  Dual-axis: Maintain panels perpendicular to sunlight throughout the day.

  –

  Polar axis: Align rotation with the Earth’s meridian containing the Sun.

  –

  Azimuthal axis: Rotate to track the Sun’s position on the local meridian.

  –

  Horizontal axis: Oriented north–south to follow the Sun across the sky.

• Fixed (static) structures contain panels arranged in a single optimized position. This is the most widely arrangement used due to its simplicity and its compatibility with rooftops and architectural settings.
• East–west gable structures feature panels facing both directions to extend daily solar utilization, which is especially useful in locations with variable sun paths.

2.1.2. Selecting the Module’s Angle of Inclination Concerning the Installation Surface

In photovoltaic installations, the generator should ideally face south in the northern hemisphere and north in the southern hemisphere. The tilt angle must balance optimal production during summer and winter. A common guideline is to set the tilt at about 10° less than the site’s latitude. Regardless of method, the inclination should not fall below 10° in order to ensure that rainwater can effectively clean dust and debris from the panels. For greater accuracy, Equation (1) can be applied using the tilt and latitude (in degrees) [24,25,26]:

$$B_o=3.7+0.69\times \left|\varphi \right|$$

(1)

where:

$B_o$ = the optimum angle of inclination.

$\varphi$ = the latitude of the installation site.

2.1.3. Determining the Azimuth of the Solar Modules

The azimuthal angle indicates the orientation of the modules. For locations in the northern hemisphere this is defined as the measured distance between the projection on the horizontal plane of the direction normal to the tilted surface and the south direction (in the southern hemisphere, the direction is due north) [27]. To determine the optimal azimuthal angle for solar panels, it is necessary to consider the latitude of the location, the orientation that receives the most sunlight, and the purpose of the solar installation.

Positive values of azimuthal angles tend to be oriented towards the west, while negative values tend to the east. Good results are obtained when the modules are oriented southeast or southwest with a deviation of up to 45 degrees from the south direction. A slight elongation of the module surface can compensate for larger deviations.

2.1.4. Structural Support Calculation

In addition to considering seismic activity, the structural design of photovoltaic support systems must account for several key factors: [28]:

• Structural self-weight.
• Panel weight.
• Beam loading.
• Wind-induced loads.
• Joint strength analysis.

Engineers employ specialized simulation tools to assess these loads and ensure structural integrity. Software such as Autodesk Inventor, SAP2000, STAAD.Pro, ANSYS Mechanical, and SolidWorks Simulation are frequently used to model static and dynamic effects, including the performance of joints, anchorage systems, and counterweights. These tools offer reliable 3D analysis capabilities and have been widely validated in renewable energy applications.

2.1.5. Weight of the Structure

The support system is critical in securing photovoltaic panels and ensuring long-term stability. A well-optimized structure improves operational safety and helps to reduce overall system costs. Current research in PV engineering focuses on achieving a balance between structural efficiency and cost-effectiveness. Common support designs suited to specific environmental and operational conditions include fixed, adjustable, and floating systems [29].

2.1.6. Weight of the Panels

The weight of photovoltaic panels varies depending on their type, size, and material. There are three types of material: monocrystalline, polycrystalline, and thin-film. Equation (2) computes the weight of the panels [30]:

$$P={\displaystyle \frac{P_p}{A}}$$

(2)

where:

P = specified weight.

A = area.

$P_p$ = solar panel weight.

2.1.7. Load on the Beams

Equation (3) computes the load on the beams:

$$N={\displaystyle \frac{P_{(p+a)}\times T_p}{L_v}}+W_c$$

(3)

where:

N = load on the beam.

$P_{(p+a)}$ = weight of the panel plus accessories.

$T_p$ = the total number of panels on the beam.

$L_v$ = length of the beams.

$W_c$ = linear weight of the conductor gauge.

2.1.8. Load Due to Wind Action

The wind speed acting on the front surface of the panels is determined by Equation (4):

$$V_f=V\times cos\left(\varphi \right)$$

(4)

where:

V = wind speed.

$\varphi$ = angle between the wind direction and the panel.

2.1.9. Wind Force on the Panels

Equation (5) uses the fluid–elastic model to determine the force exerted by the wind on the panels. In this equation, the air’s mass density and pressure coefficients remain unchanged. Calculating the wind force is necessary because the stress applied to the support structures increases as the wind increases [31]:

$$F=\rho \times C_d\times A\times {\displaystyle \frac{V_f^2}{2}}$$

(5)

where:

$\rho$ = air density at sea level.

$C_d$ = drag coefficient of flat surfaces.

A = projected area of the panel.

$V_f$ = frontal wind speed.

2.1.10. Calculation Method

Equations (6) and (7) provide the wind pressure on the panels and mounting structures:

$$q=q10\times C_t\times C_h\times C_s\times C_r\times C_f\times C_{ra}$$

(6)

$$q10={\displaystyle \frac{V_v^2}{1.6\times {10}^3}}$$

(7)

where:

$q10$ = basic characteristic wind pressure for a 25-year recurrence period.

$V_v$ = wind speed in the region.

$C_t$ = recurrence coefficient for 25 years.

$C_s$ = site coefficient considering an exposed site.

$C_h$ = height coefficient.

$C_r$ = gust coefficient.

$C_{ra}$ = area reduction coefficient.

$C_f$ = shape coefficient.

2.1.11. Calculation of Joint Strength

The methodology from Dobrovolski’s machine elements textbook calculates threaded joints in the panel support structure. The method applies to threaded joints without preloading during assembly.

In this case, the main failure mode is the bolt’s tensile failure. Equation (8) provides the strength condition:

$$d_1=\sqrt{{\displaystyle \frac{4P}{{\sigma }_a\times \pi }}}$$

(8)

where:

$d_1$ = bolt diameter up to the outer edge of the thread (nominal diameter).

P = axial load applied to the joint.

$\left[{\sigma }_a\right]$ = allowable tensile stress.

In addition to tensile failure, it is evident that other failure modes may occur, such as shearing of the bolt head, bolt thread, or nut thread as well as bending or crushing of the thread flanks.

Equations (9) and (10) provide the shear calculation of the bolt head to avoid failure along the cylindrical surface:

$${\sigma }_c={\displaystyle \frac{P}{0.5\times d_0\times h\times \pi }}<{\sigma }_a$$

(9)

where:

${\sigma }_c$ = shear stress.

$d_0$ = bolt diameter at the base of the thread.

h = height of the bolt head.

$\left[{\sigma }_a\right]$ = allowable shear stress.

The shear stress is determined by the following equation:

$${\sigma }_c={\displaystyle \frac{P}{0.5\times d_1\times H\times \pi \times \beta }}<{\sigma }_a$$

(10)

where:

H = thread height.

$\beta$ = thread height filling coefficient ($\beta$ = 1 for triangular threads).

The thread flanks are assumed to act as cantilever beams for this computation. The distributed load on the thread surface is replaced by a concentrated force ${\displaystyle \frac{P}{z}}$, where z represents the number of thread turns applied at the midpoint of the thread’s working height ($l={\displaystyle \frac{t_2}{2}}$), as seen in Equation (11):

$${\sigma }_f={\displaystyle \frac{3\times P\times t_2}{d_1\times \pi \times z\times b}}<{\sigma }_a$$

(11)

where:

${\sigma }_f$ = bending stress.

$t_2$ = half of the working height of the thread.

b = theoretical distance between thread flanks.

${\sigma }_a$ = allowable bending stress.

2.2. Criteria for Selection and Exclusion of Research

A systematic review must follow well-defined strategies and conditions to guarantee the reliability and precision of the findings. This type of study requires objectivity and methodological rigor both in qualitative and quantitative approaches as well as the application of specific tools that support data integration and the evaluation of study quality.

Despite their apparent simplicity, systematic reviews have gained popularity, especially among novice researchers, leading to inconsistencies in their quality. Although they have the potential to generate high-impact results, many such reviews are conducted without the necessary methodological rigor. The lack of universally accepted guidelines often compromises their reliability. Therefore, developing a clear and robust protocol is essential to ensure the transparency and credibility of the review process.

This research applied the following exclusion criteria:

• Keyword Selection: The main keywords were selected to identify studies focusing on solar photovoltaic structural supports and mounting systems (PSS).
• Timeframe Limitation: Only articles published from 2018 to 2025 were considered.
• Scope Restriction: Studies from unrelated disciplines, such as neuroscience, dentistry, agriculture and biochemistry, were excluded in order to maintain a focus on engineering and energy-related topics.
• Document Type: The selection process included only peer-reviewed research articles, excluding reviews and other publications such as conference review papers.
• Technical Relevance: The selection process excluded articles primarily focused on MPPT, DC–DC converters, electric vehicles, fuzzy logic, or energy storage systems, as these topics fall outside the specific scope of support structures for PSS.
• Energy System Focus: Studies centering on electric power distribution, transmission, inverters, battery systems, or microgrids were removed, as their focus diverges from the structural and mechanical design of photovoltaic support systems.
• Non-Relevant Keywords: Studies on fossil fuels, greenhouse gas emissions, or subjects unrelated to physical infrastructure (such as software control or electrical system protection) were excluded.
• Final Search Code: TITLE-ABS-KEY ((“solar photovoltaic system”) AND (“supports” OR “structures”)) AND PUBYEAR > 2018 AND (EXCLUDE (SUBJAREA,“NEUR”) OR EXCLUDE (SUBJAREA,“DENT”) OR EXCLUDE (SUBJAREA,“BIOC”) OR EXCLUDE (SUBJAREA,“AGRI”)) AND (EXCLUDE (DOCTYPE,“re”)) AND (EXCLUDE (EXACTKEYWORD,“MPPT”) OR EXCLUDE (EXACTKEYWORD,“DC-DC Converter”) OR EXCLUDE (EXACTKEYWORD,“Electric Vehicle”) OR EXCLUDE (EXACTKEYWORD,“Fuzzy Logic”) OR EXCLUDE (EXACTKEYWORD,“Vehicle-to-grid”) OR EXCLUDE (EXACTKEYWORD,“Maximum Power Point Tracking (MPPT)”) OR EXCLUDE (EXACTKEYWORD,“Electric Load Flow”) OR EXCLUDE (EXACTKEYWORD,“Gas Emissions”) OR EXCLUDE (EXACTKEYWORD,“Maximum Power Point”) OR EXCLUDE (EXACTKEYWORD,“Battery Storage”) OR EXCLUDE (EXACTKEYWORD,“Battery Energy Storage Systems”) OR EXCLUDE (EXACTKEYWORD,“Electric Power Distribution”) OR EXCLUDE (EXACTKEYWORD,“Electric Power Generation”) OR EXCLUDE (EXACTKEYWORD,“Secondary Batteries”) OR EXCLUDE (EXACTKEYWORD,“Electric Loads”) OR EXCLUDE (EXACTKEYWORD,“Electric Vehicles”) OR EXCLUDE (EXACTKEYWORD,“Microgrids”) OR EXCLUDE (EXACTKEYWORD,“Greenhouse Gases”) OR EXCLUDE (EXACTKEYWORD, “DC-DC Converters”) OR EXCLUDE (EXACTKEYWORD,“Electric Power System Control”) OR EXCLUDE (EXACTKEYWORD,“Electric Inverters”) OR EXCLUDE (EXACTKEYWORD,“Electric Power Transmission Networks”) OR EXCLUDE (EXACTKEYWORD,“Photovoltaic Cells”) OR EXCLUDE (EXACTKEYWORD,“Maximum Power Point Tracking”) OR EXCLUDE (EXACTKEYWORD,“Fossil Fuels”) OR EXCLUDE (EXACTKEYWORD,“Electricity Generation”) OR EXCLUDE (EXACTKEYWORD,“Carbon”) OR EXCLUDE (EXACTKEYWORD,“Electric Batteries”) OR EXCLUDE (EXACTKEYWORD,“Electric Power System Protection”) OR EXCLUDE (EXACTKEYWORD,“Microgrid”) OR EXCLUDE (EXACTKEYWORD,“Fossil Fuel Power Plants”))

2.3. Analysis Guide for Systematic Reviews

This study followed the structured multi-phase methodology illustrated in Figure 1. It began with an initial search in the Scopus database, which identified 510 articles. The refinement process adjusted the search to focus on the 2018–2025 period, reducing the selection to 354 articles. After applying the inclusion criteria, 122 relevant articles were identified and classified into two main analytical categories, designated Phase 3.1 and Phase 3.2.

2.3.1. Phase 3.1: Materials Used in Solar Panel Mounting Structures

In this phase (n = 33 articles), the focus was on materials used for mounting systems in photovoltaic solar panels. Key aspects included:

• Use of lightweight metals (e.g., aluminum, galvanized steel)
• Anti-corrosive coatings
• Innovations in composite materials
• Comparative evaluations of structural strength and durability
• Environmental factors influencing material selection (climate, humidity, solar exposure).

2.3.2. Phase 3.2: Structural Design Analysis of Photovoltaic Solar Panel Supports

This phase (n = 89 articles) analyzed the structural design criteria for support systems. The analysis identified key factors influencing the performance and efficiency of photovoltaic systems.

• Structural design: Panel orientation, tilt angle, support geometry
• Electrical configuration: Series/parallel connection, inverter placement
• Dynamic factors: Wind loads, seismic forces, thermal expansion
• Installation strategies: Use of solar tracking systems (single-axis, dual-axis)
• Compliance with structural design standards for solar energy systems.

2.3.3. Synthesis of the Analytical Framework

Both phases highlight how various interrelated factors (technological, design-related, and operational) influence the performance of photovoltaic solar systems. Material selection, appropriate structural design, and preventive maintenance all contribute to a system’s efficiency, durability, and sustainability. Additionally, emerging trends such as energy storage solutions, smart grid integration, and advanced processes for manufacturing and recycling reinforce the role of photovoltaic solar systems as a sustainable energy solution.

3. Results

This study used VOSviewer version 1.6.20 software to analyze current research trends related to PV systems. The analysis mapped key terms such as solar panels, performance, partial shading, machine learning, and sustainability, revealing a multidisciplinary approach integrating energy efficiency, artificial intelligence, and environmental sustainability. The results offer a clear perspective for the design of solar panel mounts, highlighting the need for structures that ensure mechanical strength, optimize solar gain, reduce shading, integrate smart technologies, and use materials with low environmental impact and high durability. Figure 2 shows the bibliometric analysis networks described above.

3.1. Materials Used in the Solar Panel Mounting Structure

Figure 3 shows the results of our term co-occurrence analysis related to materials used in the structure of solar panels. Visualizations generated with tools such as VOSviewer help to identify which concepts appear most frequently in the scientific literature and how they are interconnected.

Figure 3a presents the network of connections among the most significant terms. It identifies clusters of key terms, including “photovoltaic systems”, “solar panels”, “renewable energies”, “solar energy”, and “photovoltaics”, demonstrating their strong interrelation in the literature. These connections highlight the most extensively researched topics regarding materials for solar panel structures and illustrate the evolution of trends in this field.

Figure 3b shows the relationship between density and material. It shows a distribution of terms with different density levels, indicating the number of times they appear in the literature and their relevance in structural materials for photovoltaic systems. The higher the density in a specific image area, the more frequently these terms are used in the analyzed studies.

Mounting structures are crucial in supporting and stabilizing photovoltaic panels in solar energy systems. They provide the appropriate tilt and orientation to ensure optimal sunlight capture, directly enhancing the overall efficiency of the system. A well-engineered design and the selection of high-quality materials strengthen the performance of the panel, contributing to the longevity and structural integrity of the solar installation [32].

Various factors determine the performance of solar mounting structures, necessitating careful evaluation when selecting the appropriate materials. These elements directly shape the structural integrity, stability, and durability of the system, playing a vital role in ensuring the long-term efficiency and reliability of photovoltaic installations [33,34].

The selection of materials for solar mounting structures depends on the environmental conditions of the installation site. Several key factors influence this decision, ensuring the structure’s durability, stability, and efficiency in varying climatic conditions.

• Coastline (humidity and salinity): Proximity to the sea exposes the structures to corrosion. Chloride ions in air and seawater easily penetrate passive metal films such as stainless steel and aluminum, weakening them and promoting localized corrosion, pitting, and crevice corrosion. Thus, materials with high resistance to salinity and humidity are required in coastal areas [35,36].
• Tropical Zones (high winds): In areas with intense winds, the support structures of solar panels must be strong enough to withstand the forces exerted by the wind without compromising their stability. The wind load effect occurs when gusts impact the back of the photovoltaic modules, increasing the pressure on the installation. To reduce this impact and improve structural safety, choosing the right mounting system and type of mounting surface is crucial. Recent research has developed technologies that allow solar panels to automatically adjust their tilt based on simulations involving artificial intelligence and fluid dynamics, allowing the system to adapt to wind currents and reduce the risk of damage [37,38].
• Extreme weather (snow): In cold climates, the structure must withstand the weight of accumulated snow without compromising its stability or functionality. Aluminum is often an excellent choice in these cases due to its high strength and ability to withstand extreme weather conditions, ensuring long service life of the structure [39]. Unlike carbon steels and other metals, aluminum retains its ductility at low temperatures and does not transition from ductile to brittle. Although some steels can become brittle below $0^{\circ } \mathrm{C}$, aluminum maintains strength and toughness even in icy environments such as those used in cryogenic applications below −196 °C [40].

3.1.1. Mild Steel

Producing mild steel involves melting iron ore and coal in a furnace, which ensures the proper composition and properties required for various industrial applications. It also results in trace amounts of silicon and manganese, which aid in the deoxidation process, along with unavoidable impurities such as phosphorus, sulfur, and nitrogen. The carbon content remains low (typically below 0.25% by weight) and it has a relatively high melting point (between 1450 °C and 1520 °C). Mild steel typically has a density of approximately $7850{\mathrm{kg}/\mathrm{m}}^3$. Its capacity to conduct heat is about 50 W/m$·$K, while its specific heat capacity is approximately 510 J/g$·$K [41].

One of the most commonly used mild steels in the structural industry is Q235 (equivalent to ASTM A36).

Table 1. Typical characteristics for ASTM A36 mild steel.

Properties	Performance
Minimum Yield Strength	≈235 MPa
Ultimate Tensile Strength	≈430 MPa
Design Yield Strength (for thicknesses ≤ 16 mm)	≈215 MPa
Shear Strength	Roughly 60% of design yield strength
Axial Strength	≈405 MPa
Young’s Modulus	≈2 × 1011 MPa
Poisson’s Ratio	0.3
Coefficient of Thermal Expansion	1.2 × 10 −5 / °C

shows its main mechanical properties [28].

Mild steel is similar to iron in terms of its ease of moldability and workability. However, when the carbon content increases, the material becomes harder and stronger, losing some ductility and becoming more challenging to weld. Nonetheless, it is widely used for many reasons. Iron is plentiful in the crust of the Earth, mainly as Fe₂O₃, and converting this mineral into a usable metal requires relatively little energy. The manufacturing process also allows for adjustments to the microstructure, resulting in a wide range of mechanical properties suitable for various applications.

Despite the wide variety of specifications for different types of steel, carbon steel accounts for more than 90% of the total production due to its strength, flexibility, and low cost. Its adaptability to casting, forming, and machining processes makes it suitable for various applications [42].

Mild steel is not the primary material for solar panel installations; however, researchers incorporate it into lightweight structures, especially on roofs with restricted load-bearing capacity. Due to its low carbon content, it is highly flexible and easily machinable, making it suitable for shaping into different forms as needed [28,43]. Many studies support the use of mild steel in PV mounting structures [44,45,46,47,48]. While these studies provide valuable information on various aspects of solar panel mounting, they do not specifically address the advantages of mild steel in different installation contexts. Further research is needed to comprehensively evaluate the economic and structural benefits of mild steel in diverse solar panel mounting applications.

3.1.2. Galvanized Steel

Galvanized steel is extensively used in PV mounting systems structures because it offers superior protection against corrosion and maintains its strength in outdoor environments. In the industrial sector, engineers frequently apply galvanized steel surfaces to safeguard steel structures in outdoor or corrosive environments. These components are coated with a thin layer of zinc through hot-dip galvanizing, which effectively prevents degradation. Although modifying these surfaces to achieve superhydrophobic properties could offer highly beneficial functionalities, it is a challenging task, since preserving the delicate zinc coating remains a significant hurdle [49,50].

Immersing steel into liquid zinc creates a coating that protects the material from oxidation and improves its resistance to the elements. Of the various galvanizing methods, hot-dip galvanizing is the most common for modular mounting structures [51]. The selection of metals and alloys for coating steel using the continuous hot-dip process is restricted to those with sufficiently low melting points, ensuring that the steel can pass through the coating bath without breaking. Among the suitable coatings are zinc, zinc–iron alloys, aluminum, aluminum–silicon alloys, Zn–5Al alloys, and 55% Al–Zn alloys. In contrast, metals such as chromium and titanium are unsuitable for hot-dip coating due to their high melting points [52].

During hot-dip galvanizing, a multilayer coating is formed due to metallurgical reactions between iron (Fe) and zinc (Zn) when the material is introduced into a bath of molten zinc. This process is known as barrier coating because it provides complete coverage of the steel surface, effectively protecting it against corrosion. When the coating hardens, a surface layer composed exclusively of zinc is created, known as the $\eta$-phase (eta); this is followed by internal alloy layers incorporating various Fe–Zn intermetallic phases [53].

$\gamma$-phase (gamma): This reaction layer forms directly at the steel interface; although only about 100 nm thick, its high iron content (18–21 %wt) makes it an excellent insulating material and highly resistant.

$\delta$-phase (delta): This layer is distinguished by its dense structure, with a typical thickness ranging from 20 to 50 $\mathsf{\mu }$m; its hardness can reach up to 350 HV, exceeding that of the base material in the case of mild steel.

$\zeta$-phase (zeta): This phase enables the deposition of iron and zinc. It plays a key role in increasing the thickness of the zinc coating thanks to the resulting layer structure, which is rich in zinc and consists of hard zinc crystals containing (3.7–7.5 %wt) [54].

The optimal mechanical properties and coating hardness should range between 50 and 340 HV. Specifically, the eta ($\eta$) layer has a hardness of approximately 70 HV, the zeta ($\zeta$) layer is around 180 HV, the delta ($\delta$) layer is about 250 HV, and the gamma ($\gamma$) layer can reach up to 320 HV [55].

Hot-dip galvanizing is one of the most widely used protection methods. It provides a quick and cost-effective application solution and is versatile enough to adapt to various processes and production volumes [56].

Galvanized steel offers exceptional durability and is resistant to mechanical stress and environmental wear. Its zinc coating provides a protective barrier that prevents corrosion even under extreme conditions. This high lifetime is essential for PV mounting systems, which require stability and reliability for extended periods. Generally, galvanized steel can last more than 30 years in solar mounting applications, exceeding aluminum and other commonly used materials in terms of durability [57]. The widespread global production of galvanized steel guarantees a consistent and dependable supply, making it a practical and readily available choice for PV mounting structures. For these reasons, steel remains the preferred material for constructing various structure types where metal is the primary option. Although galvanized steel is heavier than aluminum, leading to higher handling and installation costs, its superior strength and durability often outweigh these challenges. Its robust nature ensures that mounting structures stay secure and stable even under heavy loads and harsh environmental conditions [44].

3.1.3. Aluminum

Aluminum is a remarkably lightweight metal, making it easier to handle and install. This characteristic is particularly advantageous in large-scale photovoltaic power plants, where material weight can significantly impact logistics and installation time. Extruded aluminum frames offer a strong and flexible solution, providing a more cost-effective alternative to steel in the long run, especially with optimized designs. The finish of aluminum elements can be enhanced through anodizing or powder coating, adding to their aesthetic appeal. Additionally, their corrosion and rust resistance ensure long-term durability with minimal maintenance. Aluminum has natural corrosion resistance, forming a protective oxide layer (Al₂O₃) when exposed to air; this enhances its durability even under harsh environmental conditions, ensuring that the mounting structures remain in good condition for many years without substantial degradation. Furthermore, aluminum offers a high strength-to-weight ratio, providing excellent structural support without adding unnecessary weight to the system [58,59].

Aluminum is the third most abundant element in the Earth’s crust, but is not found in a pure state due to its high reactivity. Its 2.7 g/cm³ density is much lighter than that of steel (7.85 g/cm³) due to its atomic mass of 27. Aluminum is ductile and has good electrical and thermal conductivity. Its ease of shaping is due the symmetry and stability of its FCC crystal structure and its high stacking fault energy, which allows it to deform without breaking. Aluminum’s melting point of 660 °C is a critical property influencing its structural behavior [60]. Aluminum alloys commonly incorporate copper, magnesium, zinc, manganese, silicon, and tin. These components play a vital role in modifying the microstructure and enhancing the overall properties of the alloys. The most commonly used aluminum extrusion alloys fall into the following series:

• 3000 series: Aluminum–Manganese (Al + Mn)
• 5000 series: Aluminum–Magnesium (Al + Mg)
• 6000 series: Aluminum–Magnesium–Silicon (Al + Mg + Si)
• 7000 series: Aluminum–Zinc–Magnesium (Al + Zn + Mg)

AL6005-T5 is a standard material used for structural components in solar panel mounting systems due to its high strength, corrosion resistance, and lightweight nature. It is commonly utilized in solar panel racking systems, ground-mounted frames, and rooftop supports, where it ensures durability and efficiency in renewable energy installations.

Table 2. Main characteristics of AL6005-T5 [61].

Properties	Performance
Anti-stress	216 N/mm2
Tensile Strength	216 N/mm2
Bending Resistance	216 N/mm2
Shear Strength	126 N/mm2
Young’s Modulus	72 GPa
Coefficient of Thermal Expansion	$13.1\times {10}^{-6}$ in./in. °F

shows the main mechanical properties of AL6005-T5.

3.1.4. Polymers

The solar support or mounting frame that holds and aligns the photovoltaic panels is an essential component for the efficient operation of PV systems. Historically, metals and alloys have been used to construct these supports; however, recent research on polymer-based designs has opened new avenues for developing solar energy infrastructure [15].

Polymeric materials offer a strong alternative for solar mounting design thanks to their light weight, high strength, and resistance to corrosion [15].

Most Commonly Used Types of Polymers in Photovoltaic Installations:

• Wood/Treated Wood [62,63]

  –

  Advantages: Wood and treated wood are being explored as alternative materials for PV racking systems, especially in agrivoltaic and small-scale solar applications. These systems reduce cost, increase sustainability, and provide practical solutions for farmers and DIY users while maintaining structural integrity and energy performance.

  –

  Applications: Wood-based polymers are well suited for agrivoltaic and small-scale applications, providing economic and functional benefits without compromising durability or energy output.

• Glass Fiber-Reinforced Polymer (GFRP) [64]

  –

  Advantages: Weather-resistant, non-corrosive, lightweight, and provides good electrical insulation.

  –

  Applications: Supports and frames for solar modules in humid or saline environments.

• Carbon Fiber-Reinforced Polymer (CFRP) [65]

  –

  Advantages: High mechanical strength and rigidity with lower weight than steel or aluminum.

  –

  Applications: High-tech structures or extreme conditions where low weight is critical.

• Basalt Fiber-Reinforced Polymer (BFRP) [66]

  –

  Advantages: Greater chemical and thermal resistance than fiberglass; more sustainable.

  –

  Applications: Alternative to GFRP for structures in areas with extreme temperatures.

• Ethylene Tetrafluoroethylene (ETFE) [67,68]

  –

  Advantages: PV–ETFE cushion roofs demonstrate structural stability under standard pressure and pre-stress conditions, with stress and strain remaining within safe limits; pressure has a greater impact on structural response than pre-stress, while factors and temperature distribution influence deformation patterns.

  –

  Applications: Integrating ETFE with PV technologies enables innovative solutions for building envelopes, roofs, and facades, supporting energy generation and architectural flexibility.

• Membranes (PVC) [69]

  –

  Advantages: Incorporating photovoltaic technology into textile materials is emerging as a novel strategy for developing sustainable and multifunctional building components. Polyester-reinforced PVC (PES-PVC) membranes are particularly notable for their mechanical strength, flexibility, and low production cost. Despite having a relatively limited service life of about 20 years, their ability to fulfill structural and energy-generating roles makes them a practical solution for building-integrated photovoltaic (BIPV) applications.

  –

  Applications: These composites maintain strong mechanical and electrical performance, supporting their use in innovative building and environmental applications. Advances in related membrane technologies could further enhance their potential for sustainable and multifunctional structures.

The use of high-performance polymers in photovoltaic structures has gained significant attention due to their lightweight properties, resistance to corrosion, and ease of manufacturing. These materials provide an alternative to traditional metals, offering advantages such as improved durability, thermal stability, and cost effectiveness in various environmental conditions.

Table 3. High-performance polymers for photovoltaic structures.

Type	Advantages	Applications
High-Performance Thermoplastics [70]
Polycarbonate (PC)	High impact resistance, good transparency, and light weight.	Protective covers for solar modules and glass replacement in some applications.
High-Density Polyethylene (HDPE)	Weather-resistant, high rigidity, and easy to manufacture.	Bases and supports in solar panel mounting systems.
Polyamides (PA-Nylon)	Good mechanical and thermal resistance with low friction.	Fastening components and structural connectors in photovoltaic systems.
Thermosets Used in Structural Components [71]
Epoxy Resins	High mechanical strength, strong adhesion, and good thermal performance.	Solar module encapsulants and adhesives in composite structures.
Polyester Resins	Low cost, good chemical and mechanical resistance.	Structural reinforcement in combination with fibers (GFRP and BFRP).

below categorizes the most commonly used thermoplastics and thermosets in photovoltaic applications, highlighting their key advantages and specific applications within solar panel structures.

3.1.5. Composite Materials

The use of composite materials in constructing solar panel structures has gained significant attention due to their light weight, high strength, and corrosion resistance. Unlike traditional materials such as aluminum and steel (Table 4), composites offer superior durability and mechanical properties, making them ideal for harsh environmental conditions [72].

These materials typically comprise a reinforcing fiber (e.g., glass, carbon or basalt) embedded in a polymeric matrix such as epoxy or polyester resin. This combination allows for an excellent strength-to-weight ratio, improved weather resistance, and reduced maintenance costs, making these materials a promising alternative for solar panel frames, supports, and mounting systems.

Adopting composites in PV structures contributes to the development of more sustainable and efficient solar energy systems by reducing the overall weight of installations and increasing their lifespan [73].

Table 4. Comparison of composite materials and metallic structures for solar panel frames.

Property	Composite Materials	Metallic Structures (Aluminum/Steel)
Durability	High resistance to environmental factors, longer lifespan [74].	Prone to oxidation and mechanical fatigue over time [75].
Cost	Higher initial cost but lower maintenance costs over time [76].	Lower initial cost but higher maintenance and replacement costs [75].
Density	Lower density, reducing structural weight [74].	Higher density, increasing load requirements [77].
Mechanical Properties	High strength-to-weight ratio, customizable stiffness [74].	High strength, but less adaptable in design [77].
Corrosion Resistance	Excellent resistance to corrosion and UV degradation [76].	Susceptible to corrosion, requiring protective coatings [77].

Table 4. Comparison of composite materials and metallic structures for solar panel frames.

Property	Composite Materials	Metallic Structures (Aluminum/Steel)
Durability	High resistance to environmental factors, longer lifespan [74].	Prone to oxidation and mechanical fatigue over time [75].
Cost	Higher initial cost but lower maintenance costs over time [76].	Lower initial cost but higher maintenance and replacement costs [75].
Density	Lower density, reducing structural weight [74].	Higher density, increasing load requirements [77].
Mechanical Properties	High strength-to-weight ratio, customizable stiffness [74].	High strength, but less adaptable in design [77].
Corrosion Resistance	Excellent resistance to corrosion and UV degradation [76].	Susceptible to corrosion, requiring protective coatings [77].

3.1.6. Textile-Integrated Photovoltaic Systems

Photovoltaic systems integrated into textile-based materials are gaining traction as a cutting-edge approach within building-integrated photovoltaics (BIPV). This emerging technology provides lightweight and versatile solutions that complement modern architectural demands while serving as functional energy-generating components [78,79]. Membranes such as ETFE (ethylene tetrafluoroethylene) and PES-PVC (polyester-reinforced polyvinyl chloride) are especially prominent among the commonly used materials. These fabrics act as part of the building envelope as well as substrates for photovoltaic integration [80].

ETFE cushions have proven capable of withstanding internal tensioning and external design loads without compromising their mechanical integrity. Their high transparency also makes them ideal for incorporating flexible solar technologies. In contrast, PES-PVC membranes are appreciated for their strength, affordability, and ease of manufacturing, although their operational life is typically limited to two decades. Such textiles open the door to novel structural concepts such as adaptable shading systems, membrane facades, and modular roofing for urban or temporary installations [81].

Ongoing research has highlighted the potential of these materials to simultaneously meet energy efficiency targets and aesthetic goals, especially when combined with semi-transparent PV or dynamic shading features. As innovations continue, textile-integrated PV solutions will become key components in developing resilient and energy-active building envelopes [82].

3.2. Photovoltaic Solar Panel Mounts: Types, Conditions, and Design Variables

The VOSviewer 1.6.20 tool analyzes the thematic relationships in a set of publications related to solar photovoltaic energy. Figure 4 was generated using VOSviewer as a visual representation of these connections. The first part of Figure 4a, entitled Network Visualization, shows the co-occurrence map of key terms; each node represents a recurring concept such as solar photovoltaic, renewable energy, or machine learning, while the lines connecting them indicate the frequency with which they appear together in the same documents. This visualization identifies related research clusters, facilitating a comprehensive understanding of the structural organization of topics within the field. On the other hand, the second part of Figure 4b, entitled Density Visualization, highlights the areas with the highest concentrations of terms using a color scale ranging from yellow (high density) to blue (low density). This representation facilitates the detection of central themes with the most significant impact on the dataset under analysis. Both figures complement the bibliometric analysis by providing a graphical view of the structure and thematic intensity of solar energy research.

In the context of photovoltaic solar energy utilization, one of the determining factors in the performance and durability of the systems is the proper selection of the type of support used to install the panels. Although often underestimated, this component plays a critical role in structural stability and the efficient use of solar resources [83,84].

3.2.1. Classification of Support Systems for Photovoltaic Solar Panels

Photovoltaic solar panel support systems are primarily classified based on their installation location:

• Roof-Mounted Systems [85,86]: These are the most common and utilize existing building rooftops.
• Ground-Mounted Systems [87,88]: These are installed directly on the ground and are common in large-scale projects or when roof space is limited or unsuitable.
• Pole-Mounted Systems [89,90]: These systems elevate the panels above ground level using one or more poles.
• Canopy/Carport Solar Systems [91,92]: Dual-purpose structures that provide shade while supporting solar panels.
• Building-Integrated Photovoltaics (BIPV) [93,94]: These systems include support structures that are integral to the building’s design and construction materials.
• Wall/Facade-Mounted Systems [95]: Photovoltaic panels are attached to the vertical walls of buildings.
• Solar Tracking Systems [96,97]: These are designed to follow the sun’s movement throughout the day in order to maximize energy capture.

Flexible and Lightweight Roof-Mounted Photovoltaic Systems

An emerging line of development within building-integrated photovoltaics (BIPV) involves the use of flexible and lightweight PV systems designed for rooftop installation. These systems are particularly relevant when retrofitting older buildings or structures with limited load-bearing capacity. Such systems enable quicker and more adaptable installations than conventional rigid modules, as they conform to curved or irregular surfaces without requiring complex support structures [78,98,99,100]. However, their deployment necessitates careful surface preparation, robust adhesion mechanisms, and protective measures against environmental exposure, as they are more susceptible to mechanical stress and variable weather conditions.

Regarding durability, flexible modules face challenges such as thermal degradation, moisture infiltration, and UV exposure, particularly those made from polymer-based materials. Although recent advances have led to extended operational lifespans, these systems generally have lower durability than traditional crystalline silicon modules [101]. Therefore, integrating multilayer encapsulation barriers and preventive maintenance strategies is essential for long-term reliability.

Due to material constraints, flexible PV systems deliver lower conversion efficiencies than rigid modules in terms of energy efficiency. Nevertheless, their ability to be integrated seamlessly into unconventional surfaces compensates for this limitation, particularly in dense urban settings where usable solar surfaces are scarce. Emerging technologies such as organic photovoltaics and copper–indium–gallium–selenide (CIGS) modules have progressively improved the energy yield and versatility of flexible solar solutions.

Analysis of Different Types of Structures

The increasing adoption of BIPV and wall-mounted systems reflects a trend toward enhanced architectural integration of solar technology, highlighting a growing emphasis on aesthetics alongside functionality in solar installations.

The distinction between fixed and tracking systems highlights a tradeoff between installation complexity and cost versus energy performance optimization, implying that project goals and economic considerations significantly influence system design.

The following comparative tables allow for a comprehensive analysis of the available support structures for photovoltaic solar panels, considering their technical characteristics and suitability for different environmental conditions.

Table 5. Comparative table of support structures for solar panels.

Support Type	Installation Cost	Maintenance	Adjustable Tilt	Avg. Energy Efficiency	Terrain Adaptability	Structural Requirements
Fixed Structure	Low	Low	No	Standard	Limited	Basic
Single-Axis Tracker	Medium	Medium	Yes	High	Good	Medium
Dual-Axis Tracker	High	High	Yes	Very High	Good	Complex
Tilted Roof Support	Low	Low	No	Standard	High	Moderate
Flat Roof Support	Medium	Medium	Yes	High	High	Moderate
Uneven Ground Support	Medium	Medium	Yes	High	High	High

shows that fixed structures stand out for their low cost and structural simplicity, making them ideal for applications with limited budgets or stable climatic conditions. However, they have limitations in energy efficiency and terrain adaptability. On the other hand, while single- and dual-axis solar trackers require higher initial investment and maintenance costs, they offer a considerable improvement in energy harvesting, which can translate into higher long-term profitability, especially in regions with high solar radiation.

In addition, specific roof supports—whether pitched or flat—offer practical solutions for urban environments, allowing for effective integration into existing buildings. Also noteworthy is their support for uneven ground, as their flexible design makes them suitable for rural areas and unleveled terrain, although requiring greater structural considerations.

Table 6. Environmental conditions vs. recommended support types.

Environmental / Topographic Condition	Recommended Support Type	Technical Justification
High Wind Zones	Reinforced Fixed Structure	Greater stability against gusts and lower mechanical complexity
High Solar Radiation	Single-Axis Tracker	Enables sun tracking with low maintenance
Rugged or Uneven Terrain	Uneven Ground Support or Single-Axis Tracker	Flexible anchoring and terrain adaptability
Regions with High Cloud Cover	Dual-Axis Tracker	Maximizes solar capture under variable conditions
Urban Installations (Flat Roofs)	Flat Roof Support with Adjustable Tilt	Efficient use of space and optimized tilt angle
Mountainous or Isolated Rural Areas	Fixed or Terrain-Adaptive Structure	Modular design facilitates assembly and reduces leveling costs

enhances this analysis by establishing a direct correlation between environmental and topographical conditions and the most suitable support type. This contextual approach emphasizes that no universally optimal solution exists, as each selection must be tailored to specific environmental factors. For instance, in regions experiencing strong winds, structural stability is ensured through reinforced fixed supports. In contrast, two-axis trackers optimize solar radiation capture in areas with frequent cloud cover.

3.2.2. Mounting Systems for Sloped Roofs

The accelerated deployment of PV technology on rooftops necessitates the use of optimized mounting systems that ensure structural safety and long-term performance. Selection of an appropriate support structure depends on roof type, slope, material, load-bearing capacity, and environmental conditions (see Figure 5). Inadequate mounting can lead to water leakage, structural damage, or reduced energy output [102,103,104]. This article presents a technical overview of mounting solutions for sloped and flat roofs, emphasizing their advantages and limitations.

Tile Roofs

The most common systems use L-brackets or elevated supports anchored to roof rafters, which are typically sealed to prevent water ingress. In the case of curved clay tiles, threaded rods are inserted through partial perforations. Proper waterproofing and adherence to roof warranties are both essential during installation.

Slate Roofs

Due to the brittle nature of slate, specialized hooks are screwed into the underlying structure after carefully lifting the tiles; this avoids direct perforation and minimizes the risk of material fracture.

Metal Roofs

Clamp-based systems are preferred for standing seam metal roofs, as they eliminate the need for drilling. Corrugated metal roofs use direct screw fixation with appropriate sealing. Coplanar mounting structures aligned with the slope of the roof are often employed to facilitate installation and solar exposure.

A thorough roof type and structure evaluation is crucial before installation to ensure mechanical stability and long-term performance.

Mounting Systems for Flat Roofs

Flat roofs offer flexibility in mounting configurations, which can be categorized by their attachment method.

Ballasted Systems

These systems utilize weight (ballast) to secure the panels without penetrating the roof surface, making them particularly suitable for preserving roof integrity. However, careful evaluation of wind loads and the structure’s load-bearing capacity is essential to ensure stability and optimal performance.

Anchored or Penetrative Systems

These involve direct attachment to the building structure using bolts or screws, typically with sealing elements to prevent leaks. They provide high structural resistance and are suited for areas with strong winds, although improper installation may compromise roof warranties.

Rail-Based Systems

Rails fixed to the roof provide a structural frame for mounting. Systems can use full rails or shared rails, which affects material usage and installation time. Rails also allow for flexibility in panel orientation and tilt.

Rail-Less Systems

These systems attach the modules directly to connectors anchored to the roof surface, reducing material costs and installation time.

Tilted Mounts on Flat Roofs

Panels can be tilted above the flat surface to optimize solar exposure. While this increases efficiency, it also increases wind load, necessitating careful structural design.

The widespread use of ballasted systems in commercial installations highlights a preference for non-penetrative solutions. Meanwhile, adopting rail-less designs reflects a trend toward reducing costs and accelerating installation times. Choosing between ballasted and anchored systems involves balancing rooftop protection with structural resilience based on site-specific environmental factors.

3.2.3. Mounting Systems for Flat Roofs and Ground Installations

The deployment of solar photovoltaic systems requires mounting solutions that adapt to the structural characteristics and environmental constraints of each site. This section summarizes the main types of mounting systems used for flat roofs and ground-mounted solar arrays, as shown in Figure 6, emphasizing the technical criteria involved in their selection and application [104,105,106].

Flat Roof Mounting Systems

Mounting systems for flat roofs fall into five primary categories:

• Ballasted Systems: Panels are held in place using weights, avoiding roof penetration. These systems are suitable for preserving waterproofing and are easy to install, although they require careful assessment of wind uplift and roof load capacity.
• Anchored (Penetrative) Systems: Panels are fixed directly to the roof structure using bolts or screws, often with waterproof seals. These offer strong resistance to wind loads, but must be carefully installed in order to avoid leaks and maintain roof warranties.
• Rail-Based Systems: Rails mounted on the roof serve as structural supports for the panels. These systems permit flexible orientations and tilts along with options for continuous or shared-rail setups, although they may impact material use and labor time.
• Rail-Less Systems: Modules are mounted directly to connectors attached to the roof, eliminating the need for rails, which reduces material costs and accelerates installation.
• Tilted Mounting Systems: Designed to raise panels at an angle on flat surfaces to enhance solar exposure, these systems offer improved energy yield but also increase wind load, requiring robust structural support.

Ballasted systems are particularly favored in commercial contexts for their non-invasive nature, while rail-less configurations reflect the industry’s push toward cost-efficiency and rapid deployment. Choosing between ballasted and anchored systems involves balancing rooftop protection and structural stability under site-specific environmental conditions.

Ground-Mounted Systems

Ground-mounted solar systems offer advantages in tilt optimization, maintenance access, and scalability. Common configurations include:

• Fixed-Tilt Systems: Panels are installed at a static angle optimized for annual solar gain.
• Tracking Systems: Single- or dual-axis trackers follow the Sun’s path, significantly increasing energy production but requiring higher investment and mechanical complexity.
• Pole-Mounted Systems: Panels are elevated using one or more poles, which is ideal for small-scale projects or uneven terrain.
• Ballasted Ground Systems: These systems use weights for stabilization when soil penetration is impractical or undesired.

Ground system foundations vary, including driven piles, concrete slabs, poured footings, helical piles, and weighted bases. Proper site preparation, soil analysis, and shading assessment are critical. The diversity of foundation types underscores the need for adaptability, while tracking systems highlight the potential for maximizing performance in suitable locations.

3.2.4. Design Variables and Technical Considerations

The structural design of solar panel support systems must be based on a detailed assessment of environmental, structural, and functional variables.

Table 7. Comparative table for the design of photovoltaic supports.

Variable	Influence	Design Considerations	References
Surface type	Determines anchoring method and structural support type.	Assess load-bearing capacity, surface material, and installation constraints.	[107,108,109]
Acting loads	Affects structural stability and safety.	Analyze wind, snow, and dead loads; follow local engineering standards.	[110,111]
Tilt and orientation	Directly impacts energy performance.	Optimize tilt according to latitude and reduce shading losses.	[112,113,114]
Type of support system	Affects installation time, cost, and durability.	Compare ballasted, anchored, rail-based, and rail-less systems.	[115,116]
Accessibility and maintenance	Impacts system lifespan and serviceability.	Ensure safe access for regular inspection and cleaning.	[117,118]

summarizes the primary variables, their influence on system performance, and relevant design considerations along with suggested references.

3.2.5. Advances in Autonomous BIPV Design Using 3D Modeling and Digital Technologies

In recent years, the design of building-integrated photovoltaic (BIPV) systems has transitioned towards automated data-driven approaches enabled by advanced 3D modeling, digital tools, and artificial intelligence (AI). Technologies such as UAV-based photogrammetry, LiDAR scanning, and semantic 3D modeling allow for highly accurate capture of architectural geometry, facilitating more realistic energy simulations from the early design stages [119,120,121].

This digitalization enables precise representation of building orientation, surface tilt, and environmental obstructions, thereby enhancing the accuracy of solar resource assessment and energy planning [122]. Detailed geospatial information also improves the structural design of PV support systems by optimizing load distribution, material usage, and architectural integration.

Autonomous design frameworks such as those proposed in Energy Reports (2024) incorporate optimization algorithms and geometric databases to automate key decisions regarding panel placement, orientation, and technology selection, resulting in reduced manual workloads and improved energy performance [123]. Machine learning techniques have been used to adapt solar facade designs based on historical, climatic, and architectural patterns [124].

Recent advances such as SolarGAN have introduced deep generative networks capable of synthesizing solar irradiance profiles on urban facades even with incomplete input data. This enables more robust and scalable predictive modeling [125].

Collectively, these developments signify a paradigm shift toward intelligent, autonomous, and adaptive BIPV design, with architectural integration, energy efficiency, and digital intelligence converging to deliver innovative and resilient solar solutions [124,126] (

Table 8. Summary of technologies supporting autonomous BIPV design.

Technology	Application in BIPV	Key Benefits
UAV Photogrammetry	Aerial capture of site geometry	High resolution, rapid data acquisition
LiDAR (Ground/Aerial)	Precise scanning of shapes and structures	High accuracy, suitable for complex environments
Semantic 3D Modeling	Classification and interpretation of architectural elements	Enables automated design decisions
Energy Simulation Tools	Performance evaluation and orientation optimization	Enhances efficiency and climatic adaptability

).

3.2.6. Climatic Trends and Design Strategies for Efficient Solar Structures

Local climatic conditions deeply influence the efficiency and design of support structures for PV panels. In arid and semi-arid climates, the performance of PV modules can be reduced by up to 30% despite abundant solar radiation due to extreme heat, dust accumulation, and high irradiance. This is especially the case for sensitive technologies such as thin-film modules [127]. In contrast, in humid subtropical regions such as Jordan, it has been demonstrated that panels installed on uninsulated roofs can reduce cooling loads by up to 5% annually thanks to their shading effect, offering both energy generation and thermal mitigation [128]. Meanwhile, in temperate and cold climates such as those in China, horizontally-mounted or tilted PV panels can help reduce heat loss in winter, thereby enhancing energy efficiency and indoor comfort. Given the diversity of environmental conditions, adopting adaptive design strategies that prioritize technologies resilient to specific environmental factors such as dust or humidity is essential. Moreover, holistic approaches must integrate electrical generation with the thermal impact on buildings by considering elements such as panel tilt and spacing in order to optimize ventilation and heat dissipation. Finally, maintenance should be tailored to local contexts, with frequency and cleaning methods adapted to regional dust, wind, and humidity patterns [129].

Table 9. Panel response by climate zone.

Climate Zone	Critical Condition	Optimal System Response	Reference
Arid	High temperatures and dust	Multicrystalline panels or HiT technology with good thermal dissipation and frequent cleaning.	[127]
Temperate	Mild seasonal variations	Roofs with adjusted tilt angle for annual balance between cooling and heating.	[129]
Humid Subtropical	High humidity and uninsulated roofs	Panels are used as shading devices to reduce thermal load.	[128]
Polar	Low temperatures and high irradiance	Technologies such as HiT can be efficient, but are not recommended for large-scale use.	[127]

shows some unique performance patterns observed in support structures with photovoltaic panels across different climate zones. Each region presents specific environmental challenges such as high temperatures, humidity, or variable irradiance that directly impact system efficiency. The table identifies the critical conditions affecting solar panel performance and proposes optimal design responses tailored to each environment, aiming to maximize energy efficiency and installation durability. This categorization can help to guide technical decisions for future projects based on local climate conditions.

4. Discussion

This section discusses the findings of the study and their relevance in different contexts, including residential and industrial applications. It also addresses the limitations of previous studies, pointing out possible biases or gaps in current knowledge. Finally, it discusses the practical implications of the findings and proposes future lines of research that may enrich the understanding and application of the studied factors in various scenarios.

4.1. New Perspectives in the Design of Supports for Solar Photovoltaic Systems

The present article analyzes publications from 2019 onward, focusing on the designs and materials used in solar panels. Our review identifies the main trends in the scientific literature during this period. As shown in Figure 7, there has been a significant increase in interest in panel structures since 2023, with a notable rise in research related to both design and materials. However, the trend suggests that the most significant innovations are centered on searching for more efficient materials, accounting for 57.6% of the total publications, with 32.2% concentrated between 2023 and 2024.

Although the overall increase in the number of studies between 2023 and 2024 was 4.6%, the development of new technologies in both materials and design continues to grow. In fact, 26.8% of the total number of publications recorded in 2024 have already been reported in the first three months of 2025 alone, representing a 1.6% increase. These results indicate a sustained growth trend.

One particularly noteworthy aspect is the increasing use of computational science and mathematics tools to optimize solar panel structures (see Figure 8). While the fields of engineering and energy still lead in terms of publication volume, the integration of these tools has been growing steadily since 2021. In 2022, their usage doubled compared to the previous year, and by 2023 their impact reached a level comparable to that of technological advancements in engineering and energy. This evolution aligns with global trends toward applying advanced algorithms and artificial intelligence in the energy sector.

4.2. Trends in the Design and Projection of Supports for Solar Photovoltaic Systems

Material selection considers essential aspects such as performance, cost, availability, and environmental impact. In addition, mechanical and physical properties such as strength, conductivity, manufacturability, and long-term reliability all play critical roles in determining suitability. ASTM International is widely recognized for developing technical standards to ensure the quality and safety of various materials, products, and industry processes. For this study, material selection was primarily guided by compliance with the following standards:

-

ASTM A36: Standard that specifies a carbon structural steel.

-

ASTM B209: Standard establishing requirements for sheets and plates of aluminum and its alloys used in structural applications.

-

ASTM D638: Test method used to determine the tensile properties of plastics.

The design of mounting structures for solar panels involves a comprehensive process that begins with the project definition phase, where key parameters such as installation type, panel specifications, and site location are established to guide subsequent decisions. The environmental and structural evaluation phase adapts the design to local conditions, including wind, snow, seismic activity, and corrosion risks, ensuring the structure’s safety and durability. During the materials and mechanical design phase, durable and recyclable materials such as galvanized steel and anodized aluminum are selected to prioritize modularity and ease of assembly. Additionally, these materials are chosen for their ability to accommodate thermal expansion, ensure proper drainage, and facilitate adequate ventilation. The electrical integration phase ensures efficient and safe cable routing, easy access for maintenance, scalability for future expansions, and compliance with relevant technical standards.

The compliance with norms and standards phase ensures that the design adheres to local and international codes such as NEC, CFE, IEC, and UL, preventing legal issues and ensuring safe system operation. Finally, the sustainability analysis and cost evaluation phase considers the long-term environmental impact and economic feasibility of the project by analyzing material choices, installation methods, maintenance needs, and return on investment (ROI). All of these stages are closely interrelated, and proper planning is essential for achieving an efficient, safe, cost-effective, and sustainable photovoltaic system. Figure 9 shows the recommended process to be followed for the design of structures for solar photovoltaic systems.

4.3. Comparative Table of Review Articles on Structures for Solar Photovoltaic Systems

Unlike other review articles focused on support structures for photovoltaic systems, the present work offers five key contributions that distinguish it from the current state of the art. First, previous studies have focused exclusively on energy efficiency or advances in materials; this article systematically integrates environmental and structural factors as critical variables in the design of support systems. This perspective enables a more comprehensive understanding of photovoltaic installations’ fundamental challenges under diverse geographic and climatic conditions.

Second, we employ the PRISMA methodology, which remains uncommon in applied engineering research. This approach reflects the methodological rigor and transparency of the literature selection and analysis process.

Third, in addition to reporting recent innovations, this study proposes a structured classification of technical solutions based on environmental context, facilitating their adaptation to various regions and extreme conditions.

Fourth, we conduct an integrated analysis of the interaction between mechanical design and material properties, which has generally been addressed in a fragmented or superficial manner by prior reviews. Finally, this study explicitly incorporates geographic adaptation criteria, considering environment-related risks such as corrosion, seismic activity, and extreme weather events that have often been excluded in other reviews on photovoltaic support systems.

These distinguishing elements are summarized in

Table 10. Comparison of this work against state-of-the-art reviews.

Works	Design Variables and Technical Considerations	Environmental Condition vs. Type of Structure	PV Structural Designss	Polymer Structures	Metal Structuress	Application of PRISMA Methodology	Period Search
[130]	X	X	X				–
[131]	X	X	X				2018–2024
[32]	X	X	X				2016–2022
[132]	X	X	X				2018–2020
[133]	X		X		X		–
[134]	X				X		–
Our Work	X	X	X	X	X	X	2019–2025

X: Contains.

, highlighting the topics addressed in this review that have gone uncovered in previous reviews. This table provides concrete evidence of the added value of this contribution in offering a more comprehensive, applied, and context-sensitive framework for the analysis and development of support structures in photovoltaic systems.

In contrast to previous reviews that have primarily focused on specific photovoltaic integration technologies such as building applications or flexible envelope systems, this study adopts a broader and more structured approach; rather than limiting our analysis to a single type of application or material, in this review we have systematically incorporated criteria for material selection, structural design variables, and environmental conditions that influence the performance of photovoltaic mounting systems across various contexts. By applying the PRISMA methodology, this review ensures a transparent, rigorous, and reproducible selection process that remains uncommon in applied engineering research. Furthermore, it introduces an analytical framework that categorizes technical solutions according to installation type, climatic conditions, and regulatory requirements, thereby offering a decision-making tool grounded in evidence. In addition to synthesizing existing knowledge, this work provides a practical reference for the design and implementation of photovoltaic systems, whether integrated into buildings or deployed in other configurations. As such, it provides a multidisciplinary and globally applicable guide for designing efficient, sustainable, and resilient structural solutions tailored to real-world project demands.

5. Conclusions

This review article systematically analyzes the key aspects involved in the design of mounting structures for photovoltaic solar systems, considering mechanical, environmental and regulatory criteria. The review emphasizes the importance of integrating early-stage elements such as project definition, environmental and structural evaluation, mechanical design and material selection, electrical integration, regulatory compliance, sustainability, and cost assessment. These stages are closely interrelated, and each is essential to ensuring an efficient, safe, and long-lasting solar installation.

Mechanical design plays a fundamental role, not only determining the structure’s resistance and stability against environmental loads such as wind, snow, or seismic activity but also guiding the selection of materials based on the installation type (ground-mounted, flat roof, or sloped roof) and ease of assembly. The criteria for selecting the materials must be carefully and precisely determined according to environmental conditions and structural demands.

For instance, mild steel is suitable for lightweight structures or rooftops with limited load capacity thanks to its flexibility and ease of machining. Due to its excellent corrosion resistance, galvanized steel is widely used in outdoor or industrial settings that are exposed to harsh climates. On the other hand, aluminum is advantageous in large-scale solar plants where the design must optimize both weight and ease of installation thanks to its exceptionally light weight. Proper integration between structural design and material selection is key to ensuring system durability, efficiency, and sustainability.

Current solar mounting system design trends are moving toward lighter, more modular, and more sustainable solutions that enable faster installation, lower environmental impact, and greater adaptability to diverse geographic and climatic conditions. There is also increasing interest in incorporating lifecycle analysis and return-on-investment considerations from the early design stages as well as ensuring adherence to international standards that support scalability in the global market. In this context, the present review provides a solid foundation that can guide future research and technological development towards addressing energy efficiency, climate resilience, and economic sustainability demands in photovoltaic projects.