Key Factors and Innovations Driving Efficiency and Sustainability in Solar Photovoltaic Systems

Efficiency and Sustainability in Solar Photovoltaic Systems: A Review of Key Factors and Innovative Technologies

Abstract: Photovoltaic Solar Systems (PSS) are pivotal in the energy transition, and their efficiency is influenced by various interrelated factors. This study employs a systematic review based on the PRISMA methodology to identify four primary categories affecting performance: technological, environmental, design and installation, and operational factors. Noteworthy technological advancements, such as perovskites and emerging technologies like tandem and bifacial cells, significantly boost conversion efficiency, generating optimism in the field. Environmental aspects, including solar radiation, temperature, and contaminants, also play a crucial role in system performance. Design and installation factors are vital, especially concerning panel orientation, solar tracking systems, and the optimization of electrical configurations. Regular maintenance, material degradation, and advanced monitoring systems are essential for maintaining efficiency over time. This study reviews 113 articles, focusing on three key areas—materials, application of sizing technologies, and optimization—spanning from 2018 to 2025. It also delves into emerging trends such as energy storage systems and smart grid integration, which promise to enhance photovoltaic module (PM) performance. The findings underscore the significance of merging technological innovation, design strategies, and effective operational management to optimize PM systems, laying a robust foundation for future research and applications in residential, industrial, and large-scale settings.

Keywords: energy efficiency; system losses; solar photovoltaic systems; module technologies and materials; efficiency factors

1. Introduction

Technological advancements have led to the development of increasingly robust solar energy collection systems. Current challenges center on enhancing the efficiency of these systems by maximizing solar resource utilization while minimizing environmental impact. Research has also emphasized material selection in photovoltaic systems, as it significantly influences environmental sustainability. According to studies, the choice of material is critical because its degradation level can impact the environment. Research indicates the necessity for durable materials that can adapt to long-term environmental changes to sustain optimal panel performance.

In terms of efficiency, research has primarily focused on controlling the maximum power point in photovoltaic systems. Additional techniques, such as utilizing PVsyst software to assess installation effectiveness, evaluating system orientation, estimating CO2 emissions, and potentially saving up to 7.45 tons per year per household, have been explored.

Understanding efficiency losses under various conditions is fundamental to optimizing solar photovoltaic system performance across diverse applications. From a technological standpoint, solar cell conversion efficiency varies based on materials used—monocrystalline silicon, polycrystalline silicon, and advanced technologies like perovskites and tandem cells—each presenting unique thermal and optical loss rates. Design and installation parameters, including panel orientation, inclination, solar trackers, and electrical configurations, significantly influence energy capture and conversion, making it essential to assess associated losses for optimization. Operational aspects, including material degradation, inadequate maintenance, and lack of advanced monitoring systems, can lead to cumulative losses that compromise long-term performance. Addressing these factors through optimization and innovative management strategies is crucial for maximizing PM system efficiency and ensuring viability across residential, industrial, and large-scale applications.

Numerous variables must be considered for efficient installation, from energy demand to roof conditions suitable for housing a photovoltaic system. Installation location directly affects panel operating temperature, with ground installations experiencing losses of up to 27.95%. Various techniques influencing efficient photovoltaic system installation have been explored in the literature, yet limited research explicitly analyzes the relationship between material selection and installation methodologies. This systematic review aims to examine and assess the optimal conditions and material selection strategies documented in the literature to enhance photovoltaic system efficiency.

2. Materials and Methods

A systematic review is a scientific research method where the unit of analysis comprises original primary studies on a specific topic. In this case, the review focuses on the main factors affecting PSS efficiency, as well as variables of interest under different conditions. The objective is to answer a clearly defined research question, providing a comprehensive and reliable perspective while minimizing potential research biases.

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology is a standardized set of guidelines aimed at improving the transparency and quality of systematic reviews and meta-analyses. It assists researchers in conducting and reporting systematic reviews more clearly and comprehensively, particularly in healthcare. The methodology includes a 27-item checklist for authors to consider when writing their review, along with a flow diagram illustrating the progression of information through the different stages of a systematic review.

The preparation of this article involved an in-depth review of existing literature concerning factors and variables affecting PSS efficiency, using the PRISMA methodology as a reference. The steps followed were:

1. Define the objective: Establish the purpose of the systematic review or meta-analysis.
2. Develop a protocol: Design a protocol that includes research questions, inclusion/exclusion criteria, and analysis methods.
3. Conduct a comprehensive search: Search relevant databases to identify studies meeting the established criteria.
4. Select studies: Apply the inclusion/exclusion criteria to identified studies and select those to include in the review.
5. Extract data: Gather relevant information from selected studies, such as participant characteristics and results.
6. Evaluate study quality: Use appropriate tools to assess the risk of bias and methodological quality of included studies.
7. Analyze data: Perform statistical analysis, if possible, and present results.
8. Interpret results: Discuss findings in the context of existing literature and consider their implications.

2.1. Information Search

The main keywords describing the behavior and efficiency of PSS were selected. Scopus was chosen as the search engine due to its extensive database, which includes over 75 million scientific records and advanced search tools enabling filtering by various criteria. The following code was selected as keywords: TITLE-ABS-KEY ((“solar photovoltaic systems”) AND (“dust” OR “shadows” OR “materials” OR “photovoltaic arrays” OR “wiring” OR “types of modules” OR “climatic variables” OR “operating temperature” OR “orientation” OR “degradation” OR “installation”)).

Photovoltaic Panel Efficiency (η panel) is expressed as:

η panel = P out / P in × 100 

Where:
– P out: Electrical power generated by the panel (W).
– P in: Solar power incident on the panel (W).

Incident Solar Power (P in) is calculated as:

P in = G · A

Where:
– G: Solar irradiance (W/m²).
– A: Panel surface area (m²).

Photovoltaic System Efficiency (η system), representing the system’s efficiency in converting incident solar energy into useful electricity measured at the inverter output, is given by:

η system = E AC / (G · A · t) × 100

Where:
– E AC: Electrical energy measured at the inverter output (kWh).
– t: Solar exposure time (h).

Performance Ratio (P R) is expressed as:

P R = E AC / (G · A · t)

Total System Efficiency (η total) is defined as:

η total = η panel · P R

2.2. Criteria for Selection and Exclusion of Research

A systematic review requires adherence to essential strategies and conditions to ensure accuracy and reliability. This type of study demands objectivity and rigor in both qualitative and quantitative approaches, along with specific methodological tools that facilitate data integration while simultaneously assessing the quality of each study.

Although systematic reviews may appear straightforward, their growing popularity—especially among less experienced researchers—has led to variability in their quality. A well-defined protocol is essential to ensure the credibility of the review process.

For this research, the following exclusion criteria were applied:
– Keyword Selection: Main keywords were identified based on a review of relevant articles, focusing on evaluating and formulating equations for calculating the efficiency and size of PSS.
– Timeframe Limitation: The search was restricted to articles published between 2018 and 2025.
– Scope Restriction: Studies published in journals outside the research area were excluded.
– Technical Exclusions: Articles focusing on algorithms, simulations, mathematics, artificial intelligence (AI), MATLAB, optimization, and software were excluded, as these may artificially model PSS efficiency rather than reflect real-world performance.
– Economic and Financial Considerations: Studies focusing primarily on financial or economic aspects were excluded.
– Irrelevant Topics: Additional exclusions were made based on preliminary review rounds.

2.3. Analysis Guide for Systematic Review

The analysis framework considers the multiple interrelated factors influencing PSS efficiency. From a technological perspective, the materials used in solar cells, including monocrystalline and polycrystalline silicon, as well as emerging materials like perovskites, have contributed to improvements in energy conversion efficiency. Design and installation factors, such as panel orientation, tilt angle, the use of solar tracking systems, and component configuration, are critical for optimizing performance. Operational aspects, including predictive and corrective maintenance, material degradation, and advanced monitoring systems, are essential for ensuring long-term durability and efficiency.

3. Results

The efficiency of photovoltaic systems is crucial for maximizing performance and ensuring their economic and environmental viability in large-scale applications. Several technological, ecological, design, installation, and operational factors directly influence the systems’ ability to convert solar radiation into usable energy. Emerging technology trends, including innovations in materials, energy storage, and intelligent systems, are redefining performance standards. This section examines the key elements affecting photovoltaic system efficiency, along with the latest trends and technological developments shaping the future of this field.

A comprehensive literature analysis assesses relationships between keywords, trends in this research area, and the proportion of key variables influencing PSS efficiency. To analyze the first 113 articles related to PSS efficiency, VOSviewer software was used to construct keyword-based bibliometric networks.

3.1. Considerations for Photovoltaic System Design and Operation

Exclusion methods were applied to refine the search for relevant articles on photovoltaic systems. Irrelevant topics such as artificial intelligence, economics, maintenance, and simulation were excluded. Additionally, document types like reviews and conference papers were filtered out. Studies with undesired keywords such as “MATLAB” or “Wind Power” were eliminated to ensure a focused selection of studies.

Various environmental and design factors influence the performance and efficiency of photovoltaic systems. Optimizing system operation requires understanding how solar exposure, temperature fluctuations, and airborne pollutants impact energy production and system longevity. This section examines key environmental considerations and critical design and installation aspects.

Table 1. Estimated range of losses associated with various factors affecting photovoltaic systems is presented, outlining the scales of losses currently observed in installations.

To enhance advancements in photovoltaic materials and efficiency, search parameters can be refined by focusing on specific factors such as new material compositions, conversion efficiency, long-term stability, manufacturing techniques, and improvements in cells and modules.

3.2. Advancements and Technologies in Materials and Efficiency

The energy conversion efficiency of solar cells is closely linked to material properties and thermal conditions. Various materials have been utilized to achieve optimal efficiency. Among the most widely used is silicon, which exists in different forms. Monocrystalline silicon is known for its high efficiency and durability; however, high production costs limit its use. Amorphous silicon is cheaper but less efficient. Polycrystalline silicon is more efficient than amorphous silicon, though it has lost its previous economic advantage.

Other trends used to improve ultraviolet (UV) spectrum absorption are based on combining materials with different band gaps, which help reduce recombination losses and extend the lifespan of charge carriers.

Table 2. Advantages and disadvantages of materials used for the production of photovoltaic cells.

3.2.1. Nanomaterials

Integrating nanomaterials in photovoltaic cells presents a significant opportunity to enhance energy conversion efficiency. Due to their unique properties at the nanometric scale, nanomaterials can overcome the limitations of conventional materials.

3.2.2. Phase Change Materials

The efficiency of photovoltaic modules is affected by the choice of solar cell material and thermal conditions. Phase Change Materials (PCM) are specialized coatings applied to photovoltaic modules to regulate temperature through their physicochemical properties.

3.2.3. Future Technologies

Solar cell technology continues to evolve, enabling the efficient capture and conversion of solar energy. Large-scale solar panels are essential for harvesting sunlight, with the converted energy stored and utilized in various applications.

3.3. Technology Trends, Equipment, and Operations

The review study focuses on PSS operation, excluding research areas that do not align with its primary objective. Various technological advancements, including energy storage and management systems, are crucial for optimizing integration into power grids.

4. Discussion

This section interprets the findings of the study, analyzing their relevance across different contexts, including residential and industrial applications. It examines limitations of existing studies and identifies potential gaps in the literature.

4.1. New Perspectives on Solar Efficiency

The pursuit of clean and renewable energy has accelerated in recent years, aligning with global sustainability objectives. PM technology contributes significantly to the energy transition, with ongoing research focusing on innovative materials and operational strategies to enhance efficiency.

4.2. Trends in the Sizing and Projection of PSS

The proposed methodology for installing PSS considers the main factors affecting efficiency, ensuring both technical feasibility and economic viability. This approach prioritizes long-term energy efficiency and supports sustainable solutions.

4.3. Comparison Table of Review Articles on Solar Photovoltaic Systems

The comparative review highlights the distinct approaches of this study compared to existing literature, integrating technical performance, environmental impact, and technological advances.

5. Conclusions

One of the main challenges in photovoltaic systems is developing highly efficient and sustainable technologies. This systematic review emphasizes the importance of material selection and installation techniques to optimize efficiency. Despite advancements, gaps remain in the literature regarding the adaptation of PV systems to local conditions.

In summary, this study contributes to scientific knowledge by providing a comprehensive perspective on photovoltaic materials, evaluating design and operational variables, and exploring emerging technologies in solar energy solutions.