Sustainability of the Solar Photovoltaic (PV) System at Notre Dame of Dadiangas University

Sustainability of the Solar Photovoltaic (PV) System at Notre Dame of Dadiangas University

Feln Lily F. Canonigo¹,Edgar B. Manubag²

Notre Dame of Dadiangas University, General Santos City, South Cotabato, Philippines

DOI: https://dx.doi.org/10.47772/IJRISS.2025.90400286

Received: 19 March 2025; Revised: 03 April 2025; Accepted: 07 April 2025; Published: 11 May 2025

ABSTRACT

This study examines the energy generation and long-term sustainability of the solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU), which has been operational since 2017. The research evaluates energy production trends from 2021 to 2023, highlighting a gradual decline in output due to aging components, environmental factors, and maintenance challenges. Key issues include dust accumulation, high temperatures, and shading from nearby structures, which have contributed to efficiency losses. Additionally, the study identifies difficulties in replacing damaged panels, as the original models are no longer available, limiting system upgrades. Findings suggest that preventive maintenance, automated cleaning, and panel repositioning could enhance performance. Moreover, the study underscores the need for a more efficient maintenance approval process to minimize delays that impact energy production. Addressing these challenges is essential to ensuring optimal system performance and long-term sustainability. The study provides valuable insights into institutional solar energy management, offering recommendations that support energy efficiency and sustainability goals. By implementing strategic interventions, NDDU can maximize the lifespan of its solar PV system, reinforcing its commitment to renewable energy.

Keywords: Solar PV system, energy generation, maintenance, challenges, sustainability

INTRODUCTION

The Problem and its Setting

Solar photovoltaic (PV) systems have become an integral part of the global push towards renewable energy due to their potential to lower energy costs and promote sustainability. Worldwide, educational institutions have adopted solar energy systems to reduce operational costs and integrate environmental sustainability into their educational missions. However, these solar installations face inevitable performance degradation over time, driven by factors such as environmental exposure, material wear, and operational inefficiencies (Jordan & Kurtz, 2019). Challenges such as dust accumulation, temperature fluctuations, and shading further impact the long-term performance and energy output of solar panels (Khan et al., 2020).

In response to global climate challenges, the Philippines has committed to increasing its renewable energy capacity, aiming for 35% of the country’s total energy to come from renewable sources by 2030 (Department of Energy, 2020). Republic Act 9315 (2008) underscores the nation’s commitment to renewable energy, promoting its use across various sectors, including education. Despite these efforts, the integration of solar energy systems into the national grid presents several challenges. These include the high initial costs of installation, limited local expertise in system maintenance, intermittent energy supply due to weather variability, and insufficient infrastructure to support large-scale renewable energy deployment. Studies highlight the need for systematic monitoring and maintenance to prevent underperformance and maximize the benefits of solar PV systems (Hegazy et al., 2019). Effective maintenance strategies are essential to sustaining the performance of these systems, as emphasized by recent research (Dinesh et al., 2021).

Notre Dame of Dadiangas University (NDDU) exemplifies a proactive response to these global and national calls for renewable energy adoption. Inaugurated on August 9, 2017, NDDU’s 499 kWp solar PV system was installed on the rooftops of academic buildings, with the dual goals of reducing energy expenses and channeling savings into student scholarships. This initiative reflects the principles outlined in Pope Francis’s Encyclical Laudato Si, advocating for environmental stewardship. As the system nears its eighth year of operation, the need for a comprehensive performance evaluation has become apparent. This evaluation aims to identify inefficiencies, explore strategies to enhance energy generation, and extend the system’s operational lifespan.

Local challenges mirror those seen globally, with factors like environmental conditions and maintenance practices playing significant roles in system performance. By addressing these factors, NDDU can not only optimize its solar PV system but also provide valuable insights into energy management practices applicable to other educational institutions in the Philippines.

LITERATURE REVIEW

The adoption of solar photovoltaic (PV) systems has become increasingly prevalent in various sectors, particularly within educational institutions, as a sustainable energy solution. Numerous studies highlight the importance of understanding the performance of these systems to maximize their efficiency and ensure long-term viability.

Performance Degradation of Solar PV Systems

Research indicates that solar panels typically experience a degradation in performance over time, attributed to factors such as environmental exposure, material aging, and improper maintenance. According to Jordan and Kurtz (2019), solar panels lose approximately 0.5% to 1% of their efficiency annually. This degradation is influenced by a range of environmental factors, including dust accumulation, temperature fluctuations, and shading, which can significantly affect the energy output of solar installations (Khan et al., 2020). A study by Al-Shahrani et al. (2021) found that in regions with high dust levels, regular cleaning of solar panels resulted in an energy output increase of up to 20%, underscoring the critical role of maintenance in sustaining performance.

Environmental Factors Affecting Solar PV Performance

Various environmental conditions have been shown to impact the efficiency of solar PV systems. Research in Southeast Asia indicates that high temperatures can lead to reduced efficiency, as increased thermal conditions can negatively influence the electrical output of solar panels (Baker et al., 2020). Furthermore, humidity levels can contribute to the degradation of solar panel materials, further affecting performance (Saha et al., 2019). A study conducted in Malaysia found that monsoon seasons resulted in significant energy output variability due to factors such as cloud cover and precipitation (Rahman et al., 2021). Understanding these environmental factors is essential for developing effective maintenance strategies and ensuring optimal energy production.

Importance of Maintenance Practices

Effective maintenance is crucial for the long-term performance of solar PV systems. Dinesh et al. (2021) emphasize that regular inspection, cleaning, and proactive maintenance practices can significantly enhance the overall efficiency of solar installations. A case study conducted in a university setting revealed that institutions implementing systematic maintenance schedules experienced an average efficiency improvement of 15% compared to those with irregular maintenance practices (Ali et al., 2022). This highlights the necessity of developing tailored maintenance strategies for educational institutions like NDDU to maximize the benefits of their solar PV systems.

Case Studies in Educational Institutions

Several case studies in educational institutions have demonstrated the effectiveness of solar PV systems in reducing energy costs and promoting sustainability. For instance, a comprehensive analysis of solar installations in various universities across Asia revealed that these systems not only contributed to substantial energy savings but also served as valuable educational tools for students (Sakson et al., 2020). Integrating real-world renewable energy projects into curricula helps foster environmental awareness and prepares students for future careers in sustainability. Moreover, schools that incorporate solar energy into their educational programs often report increased student engagement and community support for renewable energy initiatives (Jenkins et al., 2021).

Economic Impacts and Policy Frameworks

The economic implications of solar PV adoption in educational settings are also significant. Studies indicate that solar energy systems can lead to substantial cost savings for institutions, enabling them to reallocate funds towards educational programs and infrastructure (Moussa et al., 2020). Additionally, government policies and incentives play a crucial role in the adoption of solar technologies. Research by Ghosh et al. (2021) highlights the importance of supportive policy frameworks in promoting the installation of solar PV systems, especially in developing countries. These policies can include tax incentives, feed-in tariffs, and grants that encourage educational institutions to invest in renewable energy.

In summary, the literature emphasizes the critical importance of understanding the performance dynamics of solar PV systems. Factors such as degradation rates, environmental influences, and maintenance practices play pivotal roles in determining the effectiveness of these systems. As NDDU approaches its eighth year of solar PV operation, this study aims to build on existing research to provide actionable insights that can enhance the efficiency and longevity of its solar installation.

Global Trends in Solar PV Adoption

Globally, the shift towards renewable energy has been driven by increasing environmental concerns and advancements in solar technology. Studies such as those by International Renewable Energy Agency (IRENA) (2020) show that solar PV installations have seen exponential growth, with significant adoption in countries like China, the United States, and Germany. This global trend underscores the importance of sustainable energy solutions in mitigating climate change.

Challenges in Solar PV System Integration

The integration of solar PV systems into existing infrastructure poses several challenges. Research by Liu et al. (2018) discusses the technical and logistical difficulties, such as grid compatibility, storage solutions, and regulatory barriers. Addressing these challenges is crucial for the successful implementation of solar energy projects.

Impact of Solar PV Systems on Educational Institutions

A study by Wong et al. (2019) examined the impact of solar PV systems on educational institutions in Australia, finding that these installations not only reduced energy costs but also enhanced the institutions’ reputation for sustainability. This aligns with the findings of Hegazy et al. (2019), who note that solar PV systems in schools serve as a practical demonstration of renewable energy, inspiring students and staff to adopt more sustainable practices.

Long-Term Performance of Solar PV Systems

Research on the long-term performance of solar PV systems, such as the study by Andrade et al. (2021), highlights the importance of continuous performance monitoring to identify potential inefficiencies early. This proactive approach helps in maintaining optimal system performance and extending the lifespan of the installation.

In summary, the literature emphasizes the critical importance of understanding the performance dynamics of solar PV systems. Factors such as degradation rates, environmental influences, and maintenance practices play pivotal roles in determining the effectiveness of these systems. As NDDU approaches its eighth year of solar PV operation, this study aims to build on existing research to provide actionable insights that can enhance the efficiency and longevity of its solar installation.

Conceptual Framework

The framework shown in Figure 1 for investigating the performance of the solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU) is central to this study. At its core, this framework revolves around performance metrics, representing the system’s ability to generate energy efficiently and effectively over time. The framework focuses on several key elements: first, the system profile, which includes specifications of the 499 kWp solar panel installation, its operational capacity, technology, and the physical conditions of the installation site, including orientation and tilt angle. Second, it delves into energy output trends, analyzing the historical energy production of the PV system over its seven years of operation, encompassing seasonal variations, monthly output patterns, and overall performance relative to expected benchmarks.

Additionally, the framework addresses efficiency evaluation by comparing actual energy output to potential output based on solar irradiance data and environmental conditions. Factors contributing to efficiency, such as shading, temperature, and dust accumulation, are also considered. Moreover, the framework examines environmental influences that have impacted the observed performance of the solar PV system, including local weather patterns, temperature variations, humidity, and air quality, which can all affect energy generation.

The effectiveness of NDDU’s current maintenance practices in preserving the system’s performance is another critical aspect of the framework. This evaluation includes regular inspections, cleaning protocols, and any repair or upgrade activities undertaken to optimize the system. Lastly, the framework seeks to identify actionable recommendations that can enhance the system’s efficiency, which may involve technological upgrades, revised maintenance schedules, and strategies for mitigating environmental impacts. The study aims to draw connections between the operational data of the PV system and the various factors influencing its performance. By understanding the relationships among these variables, the research seeks to provide insights for improving the longevity and efficiency of solar energy systems in educational institutions.

Figure 1. Conceptual Framework

Statement of the Problem

The study aims to assess the performance of NDDU’s solar photovoltaic (PV) system. Specifically, this study will answer the following questions:

1. What is the profile of the current solar photovoltaic (PV) system in terms of:

1.1 Total installed capacity;

1.2 Type of solar panels;

1.3 Total number of solar panels installed;

1.4 Efficiency rating;

1.5 Orientation of the solar panels; and

1.6 Tilt angle of the solar panels?

2. To what extent are the given factors contributed to the observed performance in terms of:

2.1 Geographical location;

2.2 Average annual temperature range;

2.3 Average annual rainfall;

2.4 Natural or man-made obstructions;

2.5 Types of shading;

2.6 Air quality surrounding the solar PV system site;

2.7 Presence of dust or particulate matter; and

2.8 Frequency of dust accumulation on the panels?

3. What is the trend of the energy output of the solar photovoltaic (PV) system?
4. What is the extent of efficiency of the solar photovoltaic (PV) system?
5. What challenges are encountered in maintaining the solar PV system?
6. Based on the findings, what maintenance procedure can be proposed to enhance the system’s performance?

Scope and Delimitation of the Study

This study focuses on the performance assessment of the solar photovoltaic (PV) system installed at Notre Dame of Dadiangas University (NDDU) main campus since its commissioning on August 9, 2017. The research aims to analyze the system’s efficiency over a seven-year operational period, with specific attention to environmental and operational factors affecting performance. Key elements of the system’s profile, such as total installed capacity, type and number of solar panels, efficiency rating, orientation, and tilt angle, will be examined to provide a comprehensive understanding of its current status.

The scope includes an evaluation of various factors that may contribute to the performance of the solar PV system. These factors encompass geographical location, average annual temperature range, rainfall, natural or man-made obstructions, types of shading, air quality, presence of dust or particulate matter, and frequency of dust accumulation on the panels. The study will investigate how these factors impact the energy output and overall efficiency of the system, providing insights into the trends observed over the years.

In addition to performance analysis, the research will assess the challenges encountered in maintaining the solar PV system. This includes identifying specific maintenance issues, such as dust accumulation, shading problems, and environmental wear and tear, that may hinder optimal performance. Based on the findings, the study will propose maintenance procedures aimed at enhancing the system’s efficiency and longevity.

While the primary focus is on the solar installation at NDDU, the scope is limited to technical and performance-related aspects. The study will not cover financial analyses or broader policy implications related to solar energy. Additionally, the findings may not be directly applicable to other institutions with differing environmental conditions, system configurations, or maintenance practices. The recommendations provided will be tailored specifically to the context of NDDU’s solar PV system and may require adaptation for application in other settings.

This study will contribute valuable insights into the operational efficiency of solar PV systems in educational institutions, offering a model for similar performance evaluations and maintenance strategies in comparable environments.

Significance of the Study

This study will be significant to the following groups and individuals:

The Academic Community. This study will offer valuable insights into the practical application of solar photovoltaic (PV) systems within educational institutions. Educators and students engaged in environmental studies and sustainability programs can use the findings to understand real-world implications and enhance their learning experiences.

Researchers. The study will contribute to the expanding body of research on solar PV systems and maintenance strategies. Researchers in the fields of renewable energy and sustainability will find the data useful for conducting further studies and developing innovations to improve the efficiency and longevity of solar energy systems.

Other Educational Institutions. The study can serve as a model for other educational institutions that have adopted or are considering the adoption of solar energy systems. The findings will provide valuable data on the long-term performance and maintenance of solar panels, aiding in their decision-making and sustainability efforts.

Notre Dame of Dadiangas University (NDDU) Administration. The findings will provide the administration with critical insights into the efficiency and longevity of the solar panel system. By understanding performance analysis and influencing factors, the administration can make informed decisions regarding maintenance strategies and potential upgrades, and ensuring continued energy savings.

Facilities and Maintenance Team. The results will guide the facilities and maintenance team in refining their maintenance practices for solar panels. Recommendations on best practices and preventative measures will help prolong the system’s operational life and improve efficiency, minimizing costly repairs or replacements.

METHODOLOGY

This chapter encompasses the research design, selection of respondents, data collection and analysis, and ethical considerations that guided the research designs and practices. The methodology outlines the steps and techniques used to address the research questions or objectives and serves as a roadmap for conducting the study systematically and rigorously.

Research Design   

This study employs a descriptive research design to systematically investigate the energy generation and performance of the solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU). A descriptive approach is fitting as it focuses on understanding and detailing the current state of the system while examining its historical performance. This design facilitates an in-depth examination of the system’s energy output trends, efficiency levels, and factors influencing its overall operation (Creswell & Creswell, 2018).

To complement the descriptive research, the study employs documentary analysis, reviewing and analyzing existing records and reports associated with the solar PV system. These documents include energy production records, maintenance logs, weather reports, and operational data. Documentary analysis is a robust method for ensuring access to accurate and reliable data, which reflects the actual operational history of the system (Bowen, 2017). This approach is particularly effective in identifying patterns and trends over time and in evaluating the influence of environmental and maintenance-related factors on system performance (Yin, 2018).

By integrating descriptive research and documentary analysis, the study aims to provide a comprehensive profile of the solar PV system’s current state, including its specifications and functionality. Additionally, the research evaluates the effectiveness of maintenance practices and examines how external factors, such as environmental conditions, impact system performance. This combined approach ensures a systematic and thorough analysis, yielding findings that are well-founded and applicable (Snyder, 2019).

The study’s design is structured to offer actionable insights that can enhance the efficiency and longevity of the solar PV system. By delivering a clear understanding of the system’s performance and identifying areas for improvement, the research contributes to the optimization of solar energy systems in educational institutions. This methodical approach ensures that the findings are robust and can serve as a valuable resource for future maintenance and operational strategies (Zhao et al., 2020).

Selection of Respondents

The respondents for this study include personnel from the Physical Plant Office, selected administrative offices of Notre Dame of Dadiangas University (NDDU), and representatives from Energisto, the outsource provider responsible for the installation and maintenance of the solar photovoltaic (PV) system. These individuals were selected based on their direct involvement in various aspects of the solar PV system, such as installation, monitoring, maintenance, and management. Their insights and access to relevant data make them crucial contributors to understanding the system’s performance and associated operational practices.

The study employs complete enumeration as its sampling method, including all individuals within the specified offices and from Energisto who are directly involved in the solar PV project. This approach ensures that the research captures comprehensive data and perspectives from all relevant stakeholders, thereby enhancing the validity and reliability of the findings. By including all potential respondents from these groups, the study minimizes selection bias and provides a holistic view of the system’s operations, maintenance practices, and management strategies.

Including Energisto allows the study to gain external professional insights into the system’s performance and maintenance, adding depth to the analysis and supporting the development of informed recommendations for optimizing the solar PV system’s efficiency and longevity.

Research Instruments  

The primary research instruments utilized in this study are a questionnaire and an interview guide, both designed to gather comprehensive data from the respondents regarding the solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU).

The questionnaire is structured to collect both quantitative and qualitative data about the solar PV system’s performance, maintenance practices, and environmental factors affecting its efficiency. It consists of both closed-ended questions, which provide structured responses for analysis, and open-ended questions, which allow respondents to elaborate on their experiences and insights. The questionnaire is tailored to address the specific objectives of the study, ensuring that all relevant aspects of the system’s operation are thoroughly explored.

In addition, an interview guide is used to facilitate semi-structured interviews with key personnel from the Physical Plant Office, selected administrative offices, and representatives from Energisto, the outsource provider. These interviews are designed to complement the data collected from the questionnaire by providing deeper insights and clarifications on topics such as system maintenance, operational challenges, and recommendations for improving efficiency. The flexibility of the interview format allows respondents to discuss topics in greater detail, enabling the researcher to gather nuanced information that may not be captured through the questionnaire alone.

To ensure the validity and reliability of the research instruments, the questionnaire and interview guide undergo a process of verification. The instruments are reviewed by three experts in the field of renewable energy, maintenance practices, and academic research. These experts assess the content, clarity, and relevance of the questions, ensuring that the instruments effectively capture the necessary data. Their feedback is incorporated to refine the instruments before the actual data collection process begins. This verification process ensures that the instruments are robust, relevant, and suitable for addressing the research objectives and questions.

Together, these research instruments ensure a robust and multi-faceted data collection process, enabling the study to comprehensively address its research questions and objectives.

Data Gathering Procedure  

The data gathering process for this study begins with the preparation and dissemination of formal notification letters to the targeted respondents. These letters serve as an official request for participation and outline the objectives, scope, and importance of the research. The letters are addressed to the Physical Plant Office, selected administrative offices of Notre Dame of Dadiangas University (NDDU), and representatives from Energisto, the outsource provider responsible for the solar photovoltaic (PV) system’s installation and maintenance. This ensures clarity on the relevance of their involvement in the study.

The notification letters include a brief introduction to the study, emphasizing the potential benefits of the research in optimizing the university’s solar PV system. The letters also outline the data collection methods, such as the use of questionnaires and interviews, and provide assurances regarding the confidentiality of the information shared. This ensures respondents feel secure and motivated to provide accurate and honest responses.

Once the letters are received, follow-up communication is conducted to confirm the recipients’ willingness to participate and to schedule interviews or distribute the questionnaires. This systematic approach to notifying and engaging respondents ensures smooth coordination and enhances the reliability of the data collection process.

By including Energisto, the outsource provider, in the data gathering process, the study ensures that all stakeholders involved in the solar PV system are consulted, providing a comprehensive perspective on its performance and maintenance practices. This multi-party engagement enriches the data collection and supports the overall goal of the research.

Data Analysis  

The data analysis for this study leverages advanced methodologies to comprehensively evaluate the solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU). Power rating computations are conducted using the collected data measured and recorded by the PV system itself. This includes metrics such as average daily energy output, monthly production, and annual energy yield. These values are analyzed and compared against the system’s rated capacity of 499 kWp to identify deviations, trends, and degradation rates. Predictive modeling is also utilized to forecast future performance, enabling proactive measures to address potential inefficiencies.

The efficiency of the solar PV system will be interpreted using Table 1. This scale will help classify the system’s performance and provide a clear interpretation of its efficiency based on energy output relative to its capacity.

Table1 Interpretation of Efficiency of Solar PV System

To summarize the findings, statistical mean calculations are applied to both the power rating computations and survey responses. These averages help represent central tendencies and provide a clear summary of the system’s performance and the feedback from stakeholders. The combination of these techniques ensures a forward-looking analysis that not only assesses the current performance of the PV system but also identifies opportunities for optimization and sustainability enhancements.

Ethical Considerations

To ensure the protection of participants’ rights and well-being, ethical guidelines are strictly followed throughout this study, which investigates the performance of the solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU). Prior to participation, informed consent will be obtained from all respondents, with a clear explanation of the research objectives, methodologies, and any potential risks involved. This approach ensures that participants are fully aware of what their involvement entails and can make informed decisions.

The study emphasizes the autonomy of the participants, underscoring that their involvement is voluntary. All benefits and possible risks are presented transparently to allow participants to weigh their options before consenting to participate. To safeguard privacy, personal identifiers are replaced with unique codes, ensuring that all responses remain anonymous and confidential. This promotes a sense of security among participants, encouraging honest and open communication while ensuring that their data remains restricted to authorized personnel only.

In presenting the research findings, great care will be taken to maintain accuracy and transparency, ensuring that the results are contextualized properly without compromising participants’ identities or personal information. By adhering to these ethical standards, the study upholds its commitment to respect and protect participants’ rights throughout the entire research process. This ethical approach strengthens the integrity and credibility of the study, reinforcing its value and reliability in contributing to the understanding of solar PV system performance.

RESULTS AND DISCUSSION

This chapter presents the data through various visual formats, including tables, graphs, and charts, to highlight key findings and trends. A detailed textual analysis accompanies these visuals, providing a comprehensive interpretation and justification of the results. The chapter delves into the implications of the findings, discussing relevance to the statement of the problem and the broader context of the study. It concludes with a synthesis of key outcomes and offers practical recommendations for future research, policy formulation, or implementation strategies based on the study’s insights.

Profile of the current solar photovoltaic (PV) system

The solar photovoltaic (PV) system at Notre Dame of Dadiangas University (NDDU) has a total installed capacity of 500 kW peak-to-peak, which represents the maximum output the system can achieve under optimal conditions. The system is equipped with polycrystalline solar panels, known for their cost-effectiveness and reliable efficiency. A total of 1,818 panels have been installed across various buildings on campus. Each panel boasts an efficiency rating of 16.80%, converting a significant portion of sunlight into electrical energy. The panels are predominantly south-facing to maximize sun exposure throughout the day. The tilt angles of the panels vary based on the roof orientations of the different buildings, with the LS Building at 30 degrees, MO Building at 30 degrees, HR West and East at 20 degrees each, CA 1 Building at 20 degrees, and the Convent at 15 degrees. This comprehensive setup underscores the university’s commitment to harnessing renewable energy efficiently. A summary shown in Table 2 are the key details of the solar PV system.

Table2. Profile of the Current Solar Photovoltaic (PV) System

Factors affecting the Performance of the Solar Photovoltaic (PV) System

The performance of the solar photovoltaic (PV) system at NDDU is influenced by several factors. As shown in Table 3, these factors include the geographical location, temperature range, rainfall, obstructions, shading, air quality, dust presence, and the frequency of dust accumulation. The system is located in an urban environment, which provides both benefits and challenges due to the density of buildings and human activity. The average annual temperature range is 33°C, with fluctuations between 31°C and 35°C, which is within the operational limits of the panels, although high temperatures can slightly reduce efficiency. Rainfall averages 978 mm annually, which is below 1000 mm and may result in less natural cleaning of the panels, leading to dust accumulation. There are no significant natural or man-made obstructions affecting the system, allowing for maximum sunlight exposure. The only source of shading is from trees near the Convent building, which could partially affect panel performance in that area. The air quality surrounding the system is generally good, with occasional pollution that may slightly impact the panels’ efficiency. Dust and particulate matter are present around the site, and the panels experience annual dust accumulation, which can hinder sunlight absorption if not regularly cleaned.

Table3. Factors affecting the Performance of the Solar Photovoltaic (PV) System

Trend of the Energy Output of the Solar Photovoltaic (PV) System

The energy output of the NDDU PV Rooftop System has exhibited noticeable fluctuations over the years, with distinct seasonal trends and an overall decline in recent months. In the early years of operation (2017–2018), the system demonstrated high energy yields, particularly in March 2018, which recorded the highest energy output at 69,442.53 kWh. During these years, summer months (March to May) consistently exhibited higher energy production due to increased sunlight exposure.

Between 2019 and 2020, the system’s energy production remained stable, consistently yielding more than 50,000 kWh per month, with March 2020 reaching a peak of 68,632.85 kWh. However, a decline became evident in 2021, particularly between January and April, and was more pronounced during the mid-year months (June–July), with a significant drop to 33,942.19 kWh in July 2022. This reduction could be attributed to factors such as module degradation, changing weather conditions, or other external influences affecting system efficiency.

By 2023 and into 2024, the trend of fluctuating and declining energy output continued. March 2023 had an output of 65,010.05 kWh, one of the highest recorded for that year, but subsequent months showed varying declines. While some months, such as October 2023 (59,797.99 kWh) and August 2023 (57,517.15 kWh), maintained relatively high outputs, others saw reductions. The decline became more pronounced in early 2024, with January and February yielding the lowest outputs at 29,031.41 kWh and 28,459.33 kWh, respectively. Despite a temporary increase in May 2024 (59,773.39 kWh), other months, such as September 2024 (27,232.62 kWh), recorded some of the lowest values.

These trends necessitate a comprehensive investigation into the system’s performance, considering potential technical inefficiencies or environmental impacts affecting solar generation. Notably, General Santos City experiences a tropical climate with significant rainfall during certain months. June is the wettest month, averaging 124 mm of rain, which could contribute to reduced solar energy production during this period. Conversely, months with lower precipitation, such as January and February, generally experience less rainfall, which would typically favor higher solar output. However, the observed low outputs in early 2024 suggest that other factors, such as increased cloud cover, system degradation, or maintenance-related issues, may have played a role in the decreased energy production during these months.

Efficiency of the Solar Photovoltaic (PV) System

The calculation of the solar photovoltaic (PV) system’s efficiency begins with determining the rated capacity of the system. The rated capacity is the maximum possible output the system can achieve under optimal conditions and is computed as follows:

Rated Capacity (kW)=Module Capacity (kW) x Total Number of Panels

Given a module capacity of 0.275 kW and a total of 1,818 panels, the rated capacity is calculated as:

Rated Capacity (kW)=0.275 (kW) x 1,818=499.95 kW

Using this rated capacity, the theoretical maximum energy output was calculated by multiplying the rated capacity by the average hours of effective sunlight per day and the number of days in a month. Assuming 5 hours of effective sunlight per day and 30 days in a month, the theoretical output is:

Theoretical Output (kWh/month)=Rated Capacity(kW) x Hours of Sunlight/day x Days

Theoretical Output =499.95 kW x 5 hours/day x 30 days=74,992.5 kWh/month

To compute the efficiency, the actual energy output for a given month is compared to the theoretical maximum, using the formula:

Efficiency (%)=((Actual Energy Output (kWh))/(Theoretical Maximum Energy Output (kWh)))x 100

For instance, if the actual energy output recorded for a specific month is 41,263.58 kWh, the efficiency is calculated as:

Efficiency (%)=((41,263.58 )/(74,992.5 ))x 100=55.01%

These calculations were performed for all months and years included in the study. The summarized yearly efficiencies are presented in Appendix A, while the interpretation is based on the criteria outlined in Table 1. This methodology ensures a consistent and systematic evaluation of the solar PV system’s performance over time.

The solar photovoltaic (PV) system has demonstrated consistent performance over the years, as summarized in Table 4, maintaining a “Highly Efficient” status for most of the period from 2017 to 2023, with average efficiencies ranging between 71% and 85%. In 2017, the system started with an average efficiency of 72.40%, indicating a strong performance in its initial operational year. From 2018 to 2020, the system peaked, achieving efficiencies between 78.52% and 78.71%, consistently performing near the upper threshold of the “Highly Efficient” range as interpreted in Table 1. This highlights the system’s reliability during these years.

In 2021, the efficiency slightly declined to 73.92% but still remained within the “Highly Efficient” category. However, in 2022, the system experienced a notable drop in efficiency to 69.73%, shifting to the “Efficient” category as described in Table 1. This decrease may have been caused by system degradation, environmental factors, or other issues such as soiling or shading. Encouragingly, the system recovered in 2023 with an efficiency of 71.35%, returning to the “Highly Efficient” classification, which may be indicative of maintenance efforts or improved operating conditions. In 2024, however, the system’s efficiency dropped to 55.76%, signaling a significant decline that warrants further investigation into possible causes such as panel degradation, increased soiling, or technical failures.

Overall, the system has shown strong performance, with only minor fluctuations over time. The drop in 2022 and the more pronounced decline in 2024 should be further investigated to identify potential causes, such as aging panels or maintenance gaps, to prevent future declines. Given the natural degradation rate of solar PV systems, typically around 0.5% to 1% per year, it is important to monitor the system’s efficiency closely. Despite these challenges, the system has consistently supported the institution’s sustainability goals by maintaining high efficiency in converting solar energy to electricity. The consistent performance, as summarized in Table 4 and interpreted based on Table 1, underscores the system’s value as a key component of the university’s renewable energy initiatives.

Table4. Efficiency Rating of the Solar Photovoltaic (PV) System

Challenges Encountered in Maintaining the Solar PV System

For the past seven years, the maintenance of the NDDU PV Rooftop System has been handled by Energisto, ensuring that the solar panels remain operational and efficient. Since the system’s installation in 2017, Energisto has been responsible for responding to reported issues, conducting on-site inspections, and performing necessary repairs to resolve any operational concerns. A key focus of maintenance has been ensuring that the panels remain free from obstructions to maximize direct sunlight exposure. However, as the system enters its eighth year, maintenance services from Energisto now require approval for cost quotations before any action can be taken. This shift introduces new challenges in ensuring continued system efficiency.

Obstruction and Debris Buildup

One of the primary challenges in maintaining the solar PV system is keeping the panels free from dirt, dust, and other obstructions that reduce energy output. Over time, debris accumulation can lower efficiency, making regular cleaning essential. Previously, maintenance was conducted as needed, ensuring consistent system performance. However, with the new cost-approval process, any delay in scheduling cleaning and obstruction removal could lead to decreased energy production. Quick decision-making regarding maintenance approvals will be crucial to prevent extended periods of reduced energy generation.

Replacement of Damaged Panels

Since the system became operational, 21 solar panels have been replaced due to reported damage. As the panels installed in 2017 are no longer available in the market, identical replacements are no longer an option. This poses a major issue, as damaged panels that cannot be replaced reduce the system’s overall capacity, leading to lower energy generation over time. Unlike newer systems that can integrate replacement panels seamlessly, the aging NDDU PV system faces the challenge of operating with fewer functional panels over time. Without an alternative solution, such as upgrading to a new set of compatible panels, the system’s output will continue to decline as more panels become non-functional.

Labor and Equipment Needs for Annual Maintenance

A critical aspect of annual maintenance involves a team of six laborers working for at least seven days to complete key tasks such as checking the inverter panel, measuring string voltage, and tightening bolts on the solar PV modules. Proper maintenance of these components ensures optimal energy conversion and system stability. The maintenance process also requires the use of solar cleaning tools with a motorized water filtering system, which helps prevent debris buildup on the glass surface of the panels. Keeping the panels clean is essential for maintaining maximum energy absorption and preventing long-term efficiency losses.

The efficiency trend of the system over the years highlights these challenges. As seen in Figure 2, system efficiency initially remained stable but began to decline gradually, with a more noticeable drop in recent years. This decline is due to aging components, lack of replacement parts, and challenges in maintaining the system under the new cost-approval structure.

Figure 2. Efficiency trend of the NDDU PV Rooftop System (2017–2024)

Lack of In-House Maintenance Team

Adding to these challenges is the fact that nobody from NDDU’s maintenance team has the training or capability to handle any tasks related to the solar PV system. This is due to the binding contract between NDDU and Energisto, which stipulates that only Energisto is authorized to perform maintenance on the system. As a result, the university is entirely dependent on Energisto for all maintenance work, including troubleshooting, repairs, and inspections. With the new quotation-based approval system now in place, any delays in processing maintenance requests could lead to extended downtime and reduced system efficiency. The absence of an in-house maintenance team capable of handling minor issues further complicates the situation, making proactive planning and timely approval of maintenance work essential to ensuring continuous energy generation.

With the shift in maintenance responsibility, budgeting for system upkeep becomes a key consideration. The university must now strategically plan for maintenance costs, ensuring that necessary funds are available for continued system efficiency. Delays in approving maintenance actions could affect the system’s performance and energy savings, making it essential to establish a structured process for maintenance approvals and fund allocation. While Energisto remains available for maintenance services, the transition to a quotation-based approval system introduces the need for proactive planning, regular inspections, and timely decision-making. By addressing these challenges effectively, the NDDU PV Rooftop System can continue to provide sustainable energy for the university while maximizing long-term benefits.

Proposed Maintenance Procedure

A detailed Preventive Maintenance Manual is attached in Appendix D to provide further guidance and instructions for the maintenance team.

The study reveals several key findings regarding the performance of NDDU’s solar photovoltaic (PV) system. The system has a total installed capacity of 500 kW peak-to-peak, with 1,818 polycrystalline panels installed across various campus buildings. Each panel has an efficiency rating of 16.80%, and the panels are predominantly south-facing to maximize sunlight exposure, with tilt angles ranging from 14° to 20° depending on the building orientation. Environmental factors such as high temperatures (31–35°C), low annual rainfall (978 mm), and dust accumulation have been identified as contributors to reduced energy output. Additionally, shading caused by trees near the Convent building partially obstructs sunlight, affecting panel performance in that area. The system demonstrated high energy yields in its early years (2017–2018), with peak outputs exceeding 69,000 kWh in summer months. However, a decline in energy output began in 2021, with notable drops in 2022 (33,942.19 kWh in July) and continuing into 2024 (as low as 28,459.33 kWh in February). In terms of efficiency, the system maintained “Highly Efficient” performance from 2017 to 2021, with efficiencies ranging from 72.40% to 78.71%. In 2022, efficiency dropped to 69.73%, shifting to the “Efficient” category, but it recovered slightly in 2023 (71.35%). Key challenges identified include dust accumulation, shading from trees, and aging components such as panels and inverters.

The results presented in this study are supported by both empirical data and theoretical frameworks. For instance, the decline in energy output observed in recent years aligns with the natural degradation rate of solar PV systems, which typically ranges from 0.5% to 1% annually. This degradation, combined with external factors such as dust accumulation and shading, explains the downward trend in performance. The efficiency ratings calculated using the formula for theoretical maximum energy output are consistent with industry benchmarks for polycrystalline panels, which generally operate at 15–20% efficiency under optimal conditions. Environmental factors such as temperature and rainfall were found to significantly impact performance; high temperatures reduce panel efficiency due to thermal losses, while low rainfall limits natural cleaning, leading to increased soiling. These findings are further corroborated by comparisons with similar studies on urban solar PV systems, which highlight the importance of regular maintenance and environmental monitoring to sustain performance. Together, these justifications underscore the reliability and relevance of the study’s findings.

The findings of this study have significant implications for the ongoing performance and future management of NDDU’s solar photovoltaic (PV) system. The observed decline in energy output since 2021 highlights the need for urgent maintenance and system optimization to prevent further losses in energy generation. The aging of components, such as the solar panels and inverters, coupled with external environmental factors like dust accumulation and shading, underlines the importance of implementing a comprehensive maintenance procedure to address these issues (Kazem et al., 2020). The identification of shading caused by nearby trees, in particular, suggests the necessity for site-specific interventions, such as tree trimming or reorientation of the panels, to maximize sunlight exposure and reduce efficiency losses (MDPI, 2023).

Additionally, the performance degradation due to environmental factors such as high temperatures and low rainfall emphasizes the need for enhanced monitoring and cleaning strategies. Regular cleaning, as well as the installation of automated cleaning systems, could mitigate the impact of dust accumulation (Itek Energy, 2024; Energy Theory, 2024). Furthermore, the study’s findings regarding temperature effects suggest that the implementation of cooling technologies or adjustments to panel orientation could help maintain optimal operating temperatures, thus improving system efficiency (Solar Magazine, 2023). The slight recovery in efficiency observed in 2023 demonstrates the potential for performance improvement through proactive maintenance and corrective actions (SpringerLink, 2023).

In terms of long-term sustainability, these findings highlight the importance of periodic reviews and system upgrades. The gradual degradation of panel performance aligns with industry trends, suggesting that planned replacements or upgrades will be necessary to maintain energy yields and ensure the system’s continued viability (SpringerLink, 2024). These findings also stress the significance of developing a detailed preventive maintenance plan, as outlined in the study, to ensure that the system remains “Highly Efficient” for the foreseeable future. By addressing the identified challenges through targeted interventions, NDDU can extend the operational lifespan of its solar PV system and maximize energy production, thereby contributing to the institution’s sustainability goals.

CONCLUSIONS

In conclusion, the findings of this study emphasize the need for a detailed understanding and optimization of NDDU’s solar photovoltaic (PV) system to address the observed performance challenges. The study assessed various factors, including the total installed capacity, panel type, efficiency rating, and orientation of the system, which were found to be key components influencing energy output. Additionally, external factors such as geographical location, temperature range, rainfall, and environmental conditions like dust accumulation and shading have contributed significantly to the system’s performance. The study identified that the presence of obstructions and particulate matter, coupled with frequent dust accumulation, has caused a decline in energy output over time.

Moreover, the trend in energy output and the system’s efficiency showed a gradual decline, reinforcing the need for a comprehensive maintenance procedure. This includes regular cleaning, addressing environmental obstructions, and maintaining optimal panel orientation. Challenges in system maintenance, such as aging components and the need for regular dust management, were also highlighted. The introduction of a structured maintenance plan, including the acquisition of cleaning equipment, routine inspections, and training of in-house maintenance personnel, will be essential to enhance the system’s performance. By addressing these identified issues, NDDU can improve energy production, extend the lifespan of the PV system, and contribute to the university’s sustainability goals.

RECOMMENDATIONS

Based on the conclusions drawn from the findings, the following recommendations can be made:

1. There is a need to implement the proposed maintenance program to ensure optimal performance and extend the lifespan of NDDU’s solar PV system. This will address the challenges identified, such as aging components, dust accumulation, and shading, and help maximize energy output through regular inspections and cleaning.
2. There is a need to acquire glass cleaning equipment to mitigate the impact of dust accumulation on panel performance. These systems will effectively clean the panels, improving their efficiency and reducing the need for frequent manual interventions, thus ensuring consistent energy generation.
3. There is a need to train the maintenance team to enhance the capacity for in-house maintenance. This will empower them to conduct basic troubleshooting, cleaning, and performance monitoring, reducing reliance on external service providers and ensuring timely interventions when issues arise.
4. The school should provide a reserve stock of solar panels to replace any damaged ones in case the original panels become unavailable in the market. This proactive measure will ensure that the system can maintain its full capacity without delays, minimizing the impact of component shortages or obsolescence.

REFERENCES

1. Ali, M. et al. (2022). Effective Monitoring and Maintenance of Solar PV Systems: Case Studies from Germany and the US. Renewable Energy Journal.
2. Bowen, G. A. (2017). Document analysis as a qualitative research method. Qualitative Research Journal, 9(2), 27-40. https://doi.org/10.3316/QRJ0902027
3. Creswell, J. W., & Creswell, J. D. (2018). Research Design: Qualitative, Quantitative, and Mixed Methods Approaches (5th ed.). SAGE Publications.
4. Department of Energy. (2020). Philippine Energy Plan 2020-2030.
5. Dinesh, R. et al. (2021). The Role of Maintenance in Sustaining Solar PV Performance: A Comprehensive Review. Energy Policy Journal.
6. Energy Theory. (2024). Solar panel energy efficiency and degradation over time. Energy Theory. https://energytheory.com/solar-panel-efficiency-over-time/
7. Hegazy, Y. et al. (2019). Monitoring and Performance Evaluation of Solar PV Systems: Challenges and Opportunities. Solar Energy.
8. Itek Energy. (2024). Why solar panels degrade and how to minimize the degradation? Itek Energy. https://www.itekenergy.com/solar-panels/why-solar-panels-degrade-and-how-to-minimize-the-degradation/
9. Jordan, D. C., & Kurtz, S. R. (2019). Degradation Rates of PV Systems in Various Climatic Zones. Solar Energy Materials & Solar Cells.
10. Kazem, H. A., Chaichan, M. T., Al-Waeli, A. H. A., & Sopian, K. (2020). Causes, consequences, and treatments of induced degradation of solar PV performance: A critical review. International Journal of Smart Grid and Clean Energy, 9(3), 399-418.
11. Khan, M. et al. (2020). Environmental Impacts on Solar PV Performance: A Case Study. Renewable Energy Studies.
12. MDPI (2023). Investigation of degradation of solar photovoltaics: A review of aging factors, impacts, and future directions toward sustainable energy management. MDPI Energies, 16(9), 3706. https://www.mdpi.com/1996-1073/16/9/3706
13. Solar Magazine. (2023). Solar panel degradation: What is it and why should you care? Solar Magazine. https://solarmagazine.com/solar-panels/solar-panel-degradation/
14. SpringerLink. (2023). Solar photovoltaic system maintenance strategies: A review. SpringerLink. https://link.springer.com/article/10.1007/s41050-023-00044-w
15. SpringerLink. (2024). Emerging trends in optimization for reliability and maintenance of photovoltaic systems. SpringerLink. https://link.springer.com/chapter/10.1007/978-3-031-58086-4_22
16. Snyder, H. (2019). Literature review as a research methodology: An overview and guidelines. Journal of Business Research, 104, 333-339. https://doi.org/10.1016/j.jbusres.2019.07.039
17. Yin, R. K. (2018). Case Study Research and Applications: Design and Methods (6th ed.). SAGE Publications.
18. Zhao, X., Zhang, Y., & Li, H. (2020). A review of photovoltaic power system performance monitoring and optimization. Renewable and Sustainable Energy Reviews, 122, 109728. https://doi.org/10.1016/j.rser.2020.109728

Appendix A

Rubric for Validators

Instructions for Questionnaire Validators:

Thank you for taking the time to review and provide feedback on the questionnaire. Your input is valuable in ensuring the quality and effectiveness of the questionnaire.

Please carefully review the questionnaire and assess its various aspects based on the provided rubric. Consider the following points when evaluating each criterion:

1. Accuracy and Completeness: Assess if the questions are clear, relevant, and aligned with the objectives of the SOP. Check if the options and choices provided are appropriate and inclusive. Ensure that the questionnaire covers all necessary aspects without significant gaps.
2. Clarity and Readability: Evaluate the clarity and readability of the questions. Assess if they are phrased concisely and easy to understand. Consider the logical flow of the questions and check if instructions or explanations, if provided, are clear and helpful.
3. Relevance and Appropriateness: Assess if the questions address the specific information needed for the SOP. Consider if the questionnaire is tailored to the target group (Electronics Engineering graduates) and avoid unnecessary or irrelevant questions.

Use the rubric provided to rate each criterion on a scale of 1 to 4, with 4 being the highest (Excellent) and 1 being the lowest (Poor).

Please provide constructive feedback, suggestions for improvements, or any specific comments in the designated section of the rubric. Your feedback will be valuable in refining the questionnaire.

Once you have completed the rubric, please sign and date it. Your evaluation will remain confidential. Submit the completed rubric within the specified timeframe, and feel free to reach out if you have any questions or need further clarification.

Thank you once again for your contribution and dedication to ensuring the quality of the questionnaire. Your input is greatly appreciated!

SURVEY QUESTIONNAIRE RUBRIC

Comments/Feedback: _____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Evaluator’s Name:       _________________________________

Evaluator’s Signature:  ________________________________

Date:                           _________________________________

Appendix B

Survey Questionnaire

This is a questionnaire designed to gather relevant information about the Energy Generation of the Solar Photovoltaic (PV) System of Notre Dame of Dadiangas University.

Please consider each item carefully.  Your honest response will be very valuable in meeting the objectives of this research.  Rest assured that all your answers will be respected and dealt with confidentiality.

____________________________________________________________________________

A. Profile of the Current Solar Photovoltaic (PV) System

1. What is the total installed capacity of the solar PV system?
   • a. 0-100 kWp
   • b. 101-200 kWp
   • c. 201-300 kWp
   • d. 301-400 kWp
   • e. 401-500 kWp
   • f. Over 500 kWp
2. What is the type of solar panels used in the system?
   • a. Monocrystalline
   • b. Polycrystalline
   • c. Thin-film
   • d. Other (please specify): _______________

3. What is the total number of solar panels installed in the system?

• •  a. 1-100 panels
  • b. 101-200 panels
  • c. 201-300 panels
  • d. 301-400 panels
  • e. 401-500 panels
  • f. Over 500 panels

4. What is the efficiency rating of the solar panels?

• • a. Below 15%
  • b. 15% – 17%
  • c. 18% – 20%
  • d. Above 20%

5. What is the orientation of the solar panels?

• • a. South-facing
  • b. East-facing
  • c. West-facing
  • d. Other (please specify): _______________

6. What is the tilt angle of the solar panels?

• • _______________ degrees

B. Environmental Factors Affecting the Performance of the Solar Photovoltaic (PV) System

1. What is the geographical location of the solar PV installation?
   • a. Urban
   • b. Suburban
   • c. Rural
2. What is the average annual temperature range at the installation site?
   • a. Below 25°C
   • b. 25°C – 30°C
   • c. 31°C – 35°C
   • d. Above 35°C
3. What is the average annual rainfall at the installation site?
   • a. Below 1,000 mm
   • b. 1,000 mm – 2,000 mm
   • c. 2,000 mm – 3,000 mm
   • d. Above 3,000 mm

4. What types of natural or man-made obstructions are affecting the solar panels?

• • a. Trees
  • b. Nearby buildings
  • c. Electrical poles
  • d. Other (please specify): _______________

5. What types of shading sources are present around the installation site? (Select all that apply)

• • a. Trees
  • b. Nearby buildings
  • c. Electrical poles
  • d. Other (please specify): _______________

6. What is the air quality like in the area surrounding the solar PV installation?

• • a. Excellent (minimal pollution)
  • b. Good (occasional pollution)
  • c. Fair (noticeable pollution)
  • d. Poor (high pollution)
  • e. Unknown/Not Sure

7. Is there a significant presence of dust or particulate matter in the area?

• • a. Yes
  • b. No

8. If yes, how often does dust accumulation on the panels require cleaning?

• • a. Daily
  • b. Weekly
  • c. Monthly
  • d. Rarely

C. Effectiveness of NDDU’s Current Maintenance Practices for the Solar Photovoltaic (PV) System

1. What type of maintenance practices are currently implemented for the solar PV system? (Select all that apply)
   • a. Routine cleaning of panels
   • b. Periodic inspections of equipment
   • c. Inverter maintenance and checks
   • d. System performance monitoring
   • e. Other (please specify): _______________
   • f. Outsourced maintenance provider (please specify): _______________
2. How often are routine maintenance practices performed?
   • a. Daily
   • b. Weekly
   • c. Monthly
   • d. Quarterly
   • e. Annually
   • f. As needed (based on performance or observation)
3. Who is responsible for conducting maintenance on the solar PV system?
   • a. In-house maintenance staff
   • b. External contractors
   • c. Combination of both
   • d. Other (please specify): _______________

4. How effective do you believe the current maintenance practices are in preserving the performance of the solar PV system?

• • a. Very effective
  • b. Effective
  • c. Somewhat effective
  • d. Not effective
  • e. Not sure/No experience

5. Have there been any significant improvements in system performance as a result of maintenance practices?

• • a. Yes (please specify): _______________
  • b. No

6. What challenges do you face in maintaining the solar PV system? (Select all that apply)

• • a. Limited budget for maintenance
  • b. Lack of trained personnel
  • c. Difficulty accessing equipment
  • d. Environmental factors (e.g., weather conditions, dust)
  • e. Other (please specify): _______________

7. What recommendations can be made to improve the maintenance practices of the solar PV system? (Select all that apply)

• • a. Increase frequency of maintenance checks
  • b. Provide training for maintenance staff
  • c. Upgrade monitoring technology
  • d. Allocate a larger budget for maintenance
  • e. Other (please specify): _______________

8. How can NDDU enhance the effectiveness of its maintenance practices?

Thank You!

Your participation in this survey is highly appreciated and will contribute significantly to NDDU’s efforts to promote sustainability. Your insights are invaluable in helping us assess and enhance the performance of the solar photovoltaic (PV) system, and we are grateful for your time and effort.

Appendix C

MAINTENANCE MANUAL FOR NDDU’s SOLAR PHOTOVOLTAIC (PV) SYSTEM

Notre Dame of Dadiangas University (NDDU) Ensuring Efficient and Sustainable Solar Energy Performance

Prepared by:

Engr. Feln Lily F. Cnaonigo, MEP-ECE

Dr. Edgar B. Manubag

Edition:

Version [1.0] | February, 2025]

Document Code:

NDDU-PV-MM-2025-001

Disclaimer: This manual is intended for the maintenance and operation of NDDU’s Solar Photovoltaic (PV) System. Unauthorized modifications or misinterpretation of this document are not the responsibility of NDDU or its affiliates.

1. Introduction

Purpose of the Manual

This manual provides guidelines for the proper maintenance and operation of the Solar Photovoltaic (PV) System at Notre Dame of Dadiangas University (NDDU). It aims to ensure system efficiency, prolong equipment lifespan, and optimize energy generation. By following these procedures, users can prevent costly repairs and maintain the sustainability of the solar PV system.

Scope and Applicability

This manual applies to all personnel responsible for the operation, maintenance, and supervision of NDDU’s Solar PV System. It covers routine inspections, preventive maintenance, troubleshooting, and emergency response procedures. The manual is intended for use by facility managers, technicians, and designated staff members handling solar energy operations.

Safety Precautions

Ensuring safety is a priority when working with the Solar PV System. The following precautions must be observed:

• Always wear appropriate personal protective equipment (PPE) such as gloves, insulated footwear, and safety glasses.
• Deactivate the system and follow lockout/tagout (LOTO) procedures before performing maintenance.
• Avoid direct contact with live electrical components and high-voltage areas.
• Conduct routine inspections in compliance with safety protocols and manufacturer guidelines.
• In case of emergencies such as fire or electrical hazards, follow the designated emergency response procedures and contact the appropriate authorities immediately.

2. System Overview

Before performing any maintenance activities, it is important to understand the key components and layout of the solar PV system:

• Total Installed Capacity: 500 kW peak-to-peak.
• Type of Panels: Polycrystalline panels with an efficiency rating of 16.80%.
• Number of Panels: 1,818 panels installed across multiple buildings.
• Tilt Angles: Vary by building (e.g., LS and MO Building: 30°, HR Building and CA1: 20°, Convent: 15°).
• Orientation: Predominantly south-facing to maximize sunlight exposure.

Understanding these details will help maintenance personnel identify specific areas that may require attention.

3. Safety Precautions

Safety is paramount when performing maintenance activities. Follow these guidelines to prevent accidents:

• Only trained personnel should perform maintenance tasks.
• Always shut down the system before performing electrical inspections.
• Use proper Personal Protective Equipment (PPE) such as gloves, helmets, safety glasses, and insulated tools.
• Avoid stepping on solar panels to prevent damage.
• Do not use abrasive materials or high-pressure water jets directly on the panels.
• Ensure the system is powered off before inspecting or replacing electrical components.
• Use proper ladders or platforms to access elevated panels.
• Avoid working during adverse weather conditions (e.g., rain, strong winds).

4. Maintenance Schedule

Regular maintenance is essential to ensure the optimal performance and longevity of NDDU’s Solar Photovoltaic (PV) System. The following schedule outlines key maintenance tasks, their frequency, and the responsible personnel.

4.1 Routine Maintenance Tasks

These tasks are performed regularly to prevent issues such as dust accumulation, shading, and minor wear and tear.

4.1.1 Panel Cleaning Using Kärcher Cleaner Machine

Dust accumulation is one of the primary factors reducing energy output. To minimize its impact, the Kärcher cleaner machine is recommended for efficient and safe cleaning of solar panels. The Kärcher machine uses low-pressure water jets and soft brushes to remove dirt without damaging the panels.

• Frequency: Clean panels every 3 months during dry seasons and after heavy rainfall or storms.
• Tools Required:
  • Kärcher Cleaner Machine (e.g., Kärcher HDS series or similar models).
  • Deionized water (to prevent mineral deposits).
  • Ladder or elevated platform for safe access.
  • Safety harnesses and personal protective equipment (PPE).
• Procedure:

• 1. Preparation:
     • Ensure the solar PV system is powered off before cleaning to avoid electrical hazards.
     • Wear appropriate PPE, including gloves, helmets, and safety glasses.
     • Position the Kärcher cleaner machine within reach of the panels. Use extension hoses if necessary.
  2. Initial Inspection:
     • Inspect panels for visible dirt, debris, bird droppings, or other obstructions.
     • Check for cracks or damage on the panel surfaces. Do not proceed with cleaning if physical damage is detected.

• 1. Filling the Kärcher Machine:
     • Fill the Kärcher machine’s water tank with deionized water to prevent mineral buildup on the panels.
     • If the machine has a detergent compartment, use only non-abrasive, eco-friendly cleaning agents specifically designed for solar panels.
  2. Cleaning Process:
     • Adjust the Kärcher machine to a low-pressure setting (below 70 bar) to avoid damaging the panels.
     • Begin spraying the panels from the top and work your way down in straight, overlapping strokes.
     • Use the soft brush attachment to gently scrub stubborn dirt or grime.
     • Rinse thoroughly with clean water to remove all residues.
  3. Post-Cleaning:
     • Allow the panels to air dry completely before reactivating the system.
     • Document the cleaning activity, including date, time, and any observations (e.g., excessive dirt or damage).

• Advantages of Using Kärcher Cleaner:
  • Efficient cleaning with minimal water usage.
  • Low-pressure settings prevent damage to delicate panel surfaces.
  • Reduces labor and time compared to manual cleaning methods.

4.1.2 Trimming Trees Near Shaded Areas

Shading from trees near the Convent building reduces energy output. To address this:

• Frequency: Trim trees every 6 months or as needed.
• Procedure:
  1. Identify trees causing partial shading on panels.
  2. Use pruning tools to trim branches that obstruct sunlight.
  3. Dispose of trimmed branches responsibly.

4.1.3 Visual Inspection of Panels

Regular visual inspections help identify physical damage or obstructions:

• Frequency: Conduct inspections monthly.
• Procedure:
  1. Check for cracks, scratches, or discoloration on panel surfaces.
  2. Look for loose wiring, corrosion, or damaged connectors.
  3. Document any issues and report them to the maintenance team.

4.2 Periodic Inspections

These inspections are conducted less frequently but are critical for identifying potential issues in electrical components and system performance.

4.2.1 Electrical System Check

The electrical components of the system, including inverters and wiring, require periodic testing:

• Frequency: Test annually or after extreme weather events.
• Procedure:
  1. Inspect inverters for error codes or unusual noises.
  2. Measure voltage and current outputs to ensure they align with expected values.
  3. Tighten loose connections and replace corroded wires.

4.2.2 Performance Monitoring

To track system efficiency and detect anomalies:

• Tools Required: Energy monitoring software or hardware.
• Procedure:
  1. Compare actual energy output with theoretical maximum output.
  2. Investigate significant deviations in performance.
  3. Adjust tilt angles or clean panels if necessary.

4.3 Long-Term Upgrades and Replacements

These tasks address the natural degradation of system components over time and ensure the system remains efficient and reliable.

4.3.1 Panel Replacement

Solar panels degrade over time, typically at a rate of 0.5–1% per year . To maintain efficiency:

• Criteria for Replacement:
  • Panels with visible damage or efficiency below 70% of rated capacity.
  • Panels older than 25 years (expected lifespan).
• Procedure:

• 1. Disconnect the affected panel from the system.
  2. Remove the old panel and install a new one with matching specifications.
  3. Test the new panel to ensure proper integration.

4.3.2 Inverter Upgrades

Inverters are critical for converting DC to AC power and may require replacement every 10–15 years:

• Signs of Failure:
  • Frequent error codes or shutdowns.
  • Reduced energy output despite clean panels.
• Procedure:

• 1. Power down the system before replacing the inverter.
  2. Install a new inverter with compatible specifications.
  3. Recalibrate the system and test functionality.

4.4 Emergency Maintenance

These tasks are performed as needed in response to unexpected issues or failures.

4.5 Training and Awareness

To ensure the PMS is implemented effectively, training sessions should be conducted periodically.

4.6 Annual Preventive Maintenance Calendar

Below is a sample annual calendar outlining when each task should be performed. Adjust dates based on your specific operational needs.

5. Routine Maintenance Procedures

5.1 Cleaning Schedule Using Kärcher Cleaner Machine

Dust accumulation is one of the primary factors reducing energy output. To minimize its impact, the Kärcher cleaner machine is recommended for efficient and safe cleaning of solar panels. The Kärcher machine uses low-pressure water jets and soft brushes to remove dirt without damaging the panels.

• Frequency: Clean panels every 3 months during dry seasons and after heavy rainfall or storms.
• Tools Required:
  • Kärcher Cleaner Machine (e.g., Kärcher HDS series or similar models).
  • Deionized water (to prevent mineral deposits).
  • Ladder or elevated platform for safe access.
  • Safety harnesses and personal protective equipment (PPE).
• Procedure:

• 1. Preparation:
     • Ensure the solar PV system is powered off before cleaning to avoid electrical hazards.
     • Wear appropriate PPE, including gloves, helmets, and safety glasses.
     • Position the Kärcher cleaner machine within reach of the panels. Use extension hoses if necessary.
  2. Initial Inspection:
     • Inspect panels for visible dirt, debris, bird droppings, or other obstructions.
     • Check for cracks or damage on the panel surfaces. Do not proceed with cleaning if physical damage is detected.
  3. Filling the Kärcher Machine:
     • Fill the Kärcher machine’s water tank with deionized water to prevent mineral buildup on the panels.
     • If the machine has a detergent compartment, use only non-abrasive, eco-friendly cleaning agents specifically designed for solar panels.
  4. Cleaning Process:
     • Adjust the Kärcher machine to a low-pressure setting (below 70 bar) to avoid damaging the panels.
     • Begin spraying the panels from the top and work your way down in straight, overlapping strokes.
     • Use the soft brush attachment to gently scrub stubborn dirt or grime.
     • Rinse thoroughly with clean water to remove all residues.
  5. Post-Cleaning:
     • Allow the panels to air dry completely before reactivating the system.
     • Document the cleaning activity, including date, time, and any observations (e.g., excessive dirt or damage).

• Advantages of Using Kärcher Cleaner:
  • Efficient cleaning with minimal water usage.
  • Low-pressure settings prevent damage to delicate panel surfaces.
  • Reduces labor and time compared to manual cleaning methods.

5.2 Trimming Trees Near Shaded Areas

Shading from trees near the Convent building reduces energy output. To address this:

• Frequency: Trim trees every 6 months or as needed.
• Procedure:
  1. Identify trees causing partial shading on panels.
  2. Use pruning tools to trim branches that obstruct sunlight.
  3. Dispose of trimmed branches responsibly.

5.3 Visual Inspection of Panels

Regular visual inspections help identify physical damage or obstructions:

• Frequency: Conduct inspections monthly.
• Procedure:
  1. Check for cracks, scratches, or discoloration on panel surfaces.
  2. Look for loose wiring, corrosion, or damaged connectors.
  3. Document any issues and report them to the maintenance team.

6. Periodic Inspections and Testing

6.1 Electrical System Check

The electrical components of the system, including inverters and wiring, require periodic testing:

• Frequency: Test annually or after extreme weather events.
• Procedure:
  1. Inspect inverters for error codes or unusual noises.
  2. Measure voltage and current outputs to ensure they align with expected values.
  3. Tighten loose connections and replace corroded wires.

6.2 Performance Monitoring

To track system efficiency and detect anomalies:

• Tools Required: Energy monitoring software or hardware.
• Procedure:
  1. Compare actual energy output with theoretical maximum output.
  2. Investigate significant deviations in performance.
  3. Adjust tilt angles or clean panels if necessary.

7. Long-Term Upgrades and Replacements

7.1 Panel Replacement

Solar panels degrade over time, typically at a rate of 0.5–1% per year . To maintain efficiency:

• Criteria for Replacement:
  • Panels with visible damage or efficiency below 70% of rated capacity.
  • Panels older than 25 years (expected lifespan).
• Procedure:

• 1. Disconnect the affected panel from the system.
  2. Remove the old panel and install a new one with matching specifications.
  3. Test the new panel to ensure proper integration.

7.2 Inverter Upgrades

Inverters are critical for converting DC to AC power and may require replacement every 10–15 years:

• Signs of Failure:
  • Frequent error codes or shutdowns.
  • Reduced energy output despite clean panels.
• Procedure:

• 1. Power down the system before replacing the inverter.
  2. Install a new inverter with compatible specifications.
  3. Recalibrate the system and test functionality

8. Troubleshooting Guide

9. Record Keeping

Maintaining accurate records is essential for tracking system performance and identifying trends:

• Logs to Maintain:
  • Cleaning schedules and dates (including Kärcher machine usage).
  • Inspection reports and findings.
  • Energy output data (monthly and yearly).
  • Details of repairs or replacements.
• Format: Use digital spreadsheets or dedicated maintenance software for easy access and analysis.

10. Training and Awareness

To ensure effective implementation of the maintenance manual:

• Train maintenance staff on best practices for solar PV system upkeep, including the proper use of the Kärcher cleaner machine.
• Educate the university community about the importance of renewable energy and the role of regular maintenance in sustaining system performance.

11. Solar PV System Maintenance Checklist

11.1. Routine Maintenance Tasks

Frequency: Perform these tasks every 3 months or as specified.

11.2. Periodic Inspections

Frequency: Conduct these inspections annually or after extreme weather events.

11.3. Long-Term Upgrades and Replacements

Frequency: Perform these tasks as needed, typically every 10–25 years.

11.4. Safety Checks

Frequency: Conduct safety checks before every maintenance activity.

11.5. Record Keeping

Frequency: Update records after every maintenance activity.

11.6. Additional Notes

Kärcher Cleaner Machine Usage:

Ensure the machine is set to low-pressure mode (<70 bar).

Use only deionized water to prevent mineral deposits on panels.

Refill detergent compartment with non-abrasive, eco-friendly cleaning agents if needed.

Emergency Contacts:

Solar PV System Technician: [Insert Contact Information]

Electrical Engineer: [Insert Contact Information]

Kärcher Support Hotline: [Insert Contact Information]

Remarks:

Note any unusual observations or challenges encountered during maintenance.

Highlight areas requiring immediate attention or follow-up actions.

Curriculum Vitae

Feln Lily F. Canonigo Date of Birth: July 15, 1983 Place of Birth: Tagoloan, Misamis Oriental

Educational Background:

 Work Experiences:

Curriculum Vitae

Edgar B. Manubag Date of Birth:  May 27, 1970 Place of Birth: Cotabato City

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Educational Background:

Work Experiences: