Renewable Power Systems: A Comprehensive Meta-Analysis

Abstract

The ongoing amplification of climate change necessitates the exploration and implementation of effective strategies to mitigate ecological issues while simultaneously preserving economic and social well-being. Renewable power systems offer a way to reduce adverse anthropogenic effects without hindering economic growth. This study aims to conduct a comprehensive bibliometric analysis of renewable power systems to explore their historical context, identify influential studies, and uncover research gaps, hypothesizing that global contributions and policy support significantly influence the field’s dynamics. Following Preferred Reporting Items For Systematic Reviews And Meta-Analyses guidelines, this study utilized Scopus tools analysis and VOSviewer 1.6.20 software to examine the metadata sourced from scientific databases in Scopus. The outcomes of this investigation facilitate the identification of the most prolific countries and authors, as well as collaborative efforts that enrich the theoretical landscape of renewable power systems. The study also traces the evolution of research on renewable power systems. Furthermore, the results reveal key scientific clusters in the analysis: the first cluster concentrates on renewable energy and sustainable development, the second on the relationship between government policies and renewable power systems, and the third on the role of incentives that catalyse the advancement of renewable power systems. The findings of this meta-analysis not only contribute valuable insights to existing research but also enable the identification of emerging research areas related to renewable power system development.

1. Introduction

The global energy landscape is undergoing a transformative shift, moving away from traditional fossil fuels toward renewable power systems (RPSs). Renewable power systems generate electricity from naturally replenished sources like solar, wind, hydropower, biomass, geothermal, and ocean energy, providing a sustainable, environmentally friendly, and increasingly cost-effective alternative to fossil fuels. In 2022, the total renewable energy capacity increased to 3,371,793 megawatts (MW), the largest expansion in renewable power capacity in history [1]. This increase represented nearly 40.2% of all new electricity capacity added globally, underscoring the dominant role of renewables in energy production. Furthermore, global investments in renewables have shown resilience and growth, with approximately USD 1.77 trillion invested in renewable energy in 2023 alone, a testament to the sector’s robustness and appeal to investors [2]. Solar and wind energy are the basic sources of the renewable surge, with solar photovoltaic (PV) systems and wind power accounting for 90% of the new renewable capacity in 2022. The total installed capacity of solar PV systems globally reached approximately 1,046,614 MW by the end of 2020, while the installed capacity of wind energy reached approximately 898,824 MW [1]. These figures highlight the rapid scale-up and declining cost curves of solar and wind technologies, making them increasingly competitive with conventional power sources. Furthermore, the cost of renewable energy technologies has plummeted over the past decade. Between 2010 and 2022, the cost of solar PV electricity declined by 82.9% (5124 U.S. dollars per kilowatt in 2010 and 876 U.S. dollars per kilowatt in 2022), while the cost of onshore wind power decreased by 41.2% (2170 U.S. dollars per kilowatt in 2010 and 1274 U.S. dollars per kilowatt in 2022), and offshore wind power costs decreased by 41.3% (5900 U.S. dollars per kilowatt in 2010 and 3461 U.S. dollars per kilowatt in 2022) [3]. These cost reductions have made renewables the most cost-effective energy source in many parts of the world, fundamentally altering the economics of energy production.

The evolution of renewable power systems is not merely a response to the diminishing reserves of conventional energy sources but also a proactive strategy to address the growing concerns over climate change and environmental degradation and their impact on health [4,5]. For instance, the European Union has set a goal to achieve at least a 32% share of renewable energy by 2030 [6], highlighting the collective momentum toward a future powered by renewable energy. Similarly, India aims for a renewable energy capacity of 450 GW by 2030 [7], underscoring the global urgency and commitment to adopting renewable power systems.

As the global community faces the imperative to transition toward sustainable energy systems, recent research underscores the accelerated adoption of renewable energy resources. A study by Afrianda et al. [8] examined the sustainability of business strategies within the electricity sector, emphasizing the integration of wind-based hybrid energy complexes. This research highlights the evolving landscape of renewable energy technologies and their pivotal role in sustainably meeting future energy demands. Nie et al. [9] illustrated how green public finance mechanisms and dual control strategies for carbon emissions are vital for steering the world’s largest energy consumer, China, toward a sustainable trajectory. Their findings contribute to the understanding of how financial policies can support the global transition to renewable energy, thereby limiting global warming and fostering economic growth. Ssembatya and Claridge [10] investigated quantitative fault detection and diagnosis methods for vapor compression chillers and explored their potential for field implementation. Their work signals the importance of technological innovation in enhancing the performance and reliability of renewable energy systems.

The purpose of this study is to conduct a comprehensive bibliometric analysis to trace the development trajectory and thematic evolution within the field of RPS. By analyzing highly cited articles from the Scopus database, this study aims to provide a foundational guide for researchers engaged in RPS, offering insights into historical context, evolutionary processes, contemporary advancements, and future directions in the field. The objectives of this study are to explore the historical development and key moments in renewable power systems research, analyze influential studies that have shaped the field, and identify research gaps and future directions to advance the field. This research involves shedding light on pivotal moments, key discoveries, and shifts in the research focus that have shaped the current state of RPS research to analyze the most influential studies within the RPS sphere. This includes identifying works that have significantly impacted the field’s trajectory, thereby highlighting seminal contributions and the intellectual framework they provide for ongoing and future research and identifying research gaps and future directions within the landscape of RPS research, aiming to uncover areas that warrant further investigation and could contribute to the field’s advancement. The hypothesis of this study is that the field of renewable power systems is characterized by significant global contributions and that the dynamics of research in this field are heavily influenced by policy support and technological advancements. Furthermore, this study hypothesizes that a bibliometric analysis will reveal key trends, influential studies, and critical research gaps that can guide future research efforts and policymaking in renewable energy.

The structure of this paper is outlined as follows. Section 2 provides an overview of the bibliometric methodology. This section details the criteria used to determine which publications from the Scopus database should be considered. Section 3 elucidates the outcomes of the bibliometric study, highlighting trends in scientific research and geographical contributions, an analysis of citation networks over the past decade, a categorization of research types and domains, and an overview of dissemination through publishers, academic journals, thematic categories, and prevalent keywords. Section 4 is devoted to analytical discussions, while Section 5 synthesize the study’s findings, address key issues and challenges, and propose recommendations for the RPS domain.

2. Materials and Methods

The bibliometric analysis methodology was based on PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The PRISMA guidelines significantly advance the scientific community’s efforts toward enhanced transparency, reproducibility, and quality in research reporting. According to Liberati et al. [11], the PRISMA checklist and flow diagram serve as essential tools for researchers, guiding them in comprehensively presenting their systematic reviews and meta-analyses. This detailed reporting framework not only facilitates the understanding and replication of research [12] but also plays a crucial role in ensuring the reliability and validity of the research findings [13]. By fostering a structured reporting environment, PRISMA aids in the critical appraisal and synthesis of research, which is pivotal for evidence-based practice and policymaking [14].

The data for analysis were compiled from the Scopus database for 2000–2023 within the following thresholds:

• Time—2000–2023;
• Language—English;
• Keywords—renewable power systems;
• Boolean operators—AND.

After applying the abovementioned filters, 670 documents were selected. After checking and screening, 659 documents were selected for analysis (Figure 1).

Based on prior studies [15,16,17], this investigation applied Scopus Tools Analysis to achieve the following:

• Examine trends in publications related to renewable power systems;
• Identify key authors who have substantially contributed to the field of renewable power systems;
• Analyze the focus on renewable power systems across different countries;
• Identify leading countries investing in research on renewable power systems;
• Review the most cited works in the area of renewable power systems.

Furthermore, VOSviewer software was used for co-occurrence and co-authorship analyses, including historical horizon analysis. VOSviewer is a powerful visualization tool specifically designed for bibliometric analyses, such as co-occurrence, co-authorship, and historical horizon analyses. This software provides substantial benefits by mapping knowledge domains through co-occurrence analysis, which helps in identifying core themes and detecting emerging trends by visualizing how often certain terms appear together in the literature [18,19]. In co-authorship analysis, VOSviewer illustrates the collaborative links between researchers, revealing key influencers and the dynamics of scientific collaboration, thereby aiding institutions in identifying potential research partnerships [20,21]. The inclusion of a historical dimension allows researchers to track the evolution of topics over time, offering insights into the developmental trajectories of research fields and aiding strategic decision-making for policymakers and research administrators [22]. VOSviewer’s capabilities not only enhance the comprehension of complex scientific data but also promote a strategic, data-driven approach to research and policy planning.

3. Results

The steady increase in publication volume (Figure 2) mirrors the escalating role of renewable energy within the international energy landscape, driven both by technological progress and an enhanced global consciousness of environmental challenges. There has been a marked surge in research activity since 2012, which correlates with the enactment of critical international climate frameworks, such as the Paris Agreement [23], and substantial innovations in renewable energy technologies [1]. Furthermore, the decreasing expenses associated with renewable energy implementations have made them more attractive and widely adopted [24]. This trend is reinforced by increasing public and political interest in environmental sustainability [25,26,27,28,29]. Additionally, the Energy Policy Institute’s report [30] highlighted that the increasing partnerships between academic institutions and the energy industry have played a crucial role in stimulating research efforts.

Figure 3 presents the distribution of renewable power system publications by country. China leads in publications within the field of renewable power systems, with its authors contributing 148 documents. This substantial output highlights China’s strategic initiatives and investments in clean energy technology. The Chinese government’s 13th Five-Year Plan, which includes ambitious targets for renewable energy, has resulted in significant state funding and policy support for research and development [31]. Moreover, China’s desire to mitigate severe environmental issues has led to the prioritization of renewable energy solutions [32].

Following China, the United States, with 77 documents, has made considerable contributions to the field of renewable power systems (

Table 1. The top 10 countries in terms of the number of publications.

Countries	Documents	Countries	Documents	Countries	Documents
China	148	Germany	44	Egypt	27
United States	77	United Kingdom	38	Canada	23
India	64	Australia	29	Saudi Arabia	20
				United Arab Emirates	19

). The investigations in this country are bolstered by its robust innovation ecosystem comprising academia, industry, and government entities. Federal agencies such as the Department of Energy (DOE) have long supported renewable energy research through initiatives such as the SunShot program and the Advanced Research Projects Agency-Energy (ARPA-E) [33]. The contributions of 64 documents from India are reflective of its National Action Plan on Climate Change, which promotes the strategic development of renewable energy technologies to diversify its energy portfolio and reduce greenhouse gas emissions [34]. Furthermore, the country’s investment in solar energy [35], exemplified by the International Solar Alliance, underscores its commitment to advancing renewable energy research [36].

Germany, with 44 publications, and the United Kingdom, with 38, demonstrate strong research activities in Europe (Table 1). Germany’s approach has been characterized by substantial public and private investment in research and development, as well as incentives for renewable energy deployment [37]. This has fostered a vibrant research community and innovation in technologies such as wind and solar power. The UK’s Climate Change Act, which was the first of its kind in the world, set legally binding targets to reduce carbon emissions and increase the use of renewable energy. The UK is also home to several leading research institutions and collaborative initiatives focused on renewables, such as the Offshore Renewable Energy Catapult and the Carbon Trust, which contribute to the country’s high volume of research output in this area [38]. This geographical diversity in renewable power systems research indicates a global commitment to advancing knowledge in this area. Thus, knowledge must be enhanced [39,40], and best practices for energy savings and green energy must be shared [41,42].

The findings of the co-authorship analysis of publications that focused on the investigation of renewable power systems allow us to conclude that most Chinese authors collaborate within the common investigation (Figure 4). Thus, the results allow the allocation of seven scientific alliances, among which Liu Feng, Song Yonghua, and Lin Jiin are the most prolific from the point of view of collaboration.

Liu et al. [43] provided a comprehensive multicriteria techno-economic analysis of hybrid power systems combining solar and wind energy, with storage solutions for remote islands in the South China Sea. This research exemplifies the detailed, system-level approach that is characteristic of the collaborative efforts within this alliance, focusing on practical solutions for energy independence in remote areas. He et al. [44] outlined the design of power supply systems for data centers, emphasizing the utilization of renewable energy. This research represents a forward-looking perspective on the integration of renewable energy sources in industrial applications, a topic of significant interest within the research community. This kind of innovative work underscores the strategic importance of collaborative efforts in tackling practical and futuristic renewable energy applications. The study by Li et al. [45] focused on the reliability assessment of renewable power systems, a critical aspect of ensuring the stability and efficiency of power grids that are increasingly reliant on variable renewable energy sources.

In the landscape of renewable power systems research, a Scopus-based analysis has highlighted the prolific contributions of certain scholars, delineating a cohort of influential researchers chiefly from China, Egypt, the United Arab Emirates, Japan, Finland, and Ireland (

Table 2. The top 10 researchers in the analysis of renewable power systems in terms of the number of publications and their scientific metrics according to Scopus.

Researchers	Country	Number of Publications in Scopus		IC	AC	H
		Total	RPS
Wu H.	China	239	16	6.3%	3.7%	39
Xing Y.	China	325	15	4.1%	3.1%	45
Ghenai C.	United Arab Emirates	212	14	63.0%	–	34
Magdy G.	Egypt	65	11	89.3%	–	21
Sun K.	China	351	7	32.8%	3.3%	41
Elbaset A.A.	Egypt	107	6	54.8%	1.2%	21
Mitani Y.	Japan	318	6	67.4%	2.9%	34
Shabib G.	Egypt	60	6	75.0%	–	15
Zhang J.	China	25	6	–	–	11
Bakeer A.	Egypt	67	4	60.9%	–	14
Breyer C.	Finland	217	4	36.5%	10%	64
Flynn D.	Ireland	218	4	41.7%	23.3%	39

Note: H—h-index in Scopus; IC—international collaboration; RPS—number of papers on renewable power systems; AC—academic–corporate collaboration.

).

The tenacity of these academics is quantified not only by their publication count but also by their h-index, a metric of impact predicated on citation frequency, as well as their propensity for international (IC) and academic–corporate (AC) collaboration. Wu H. from China has authored 239 publications with a substantial h-index of 39, indicating robust influence within the field, complemented by an IC rate of 6.3% and an AC rate of 3.7%. Xing Y., also from China, boasts an even higher publication count of 325 and an h-index of 45, reflecting a significant scholarly footprint, underscored by IC and AC rates of 4.1% and 3.1%, respectively. Ghenai C., representing the United Arab Emirates, with 212 publications and an h-index of 34, demonstrated a remarkable IC rate of 63.0%, showing extensive global research collaboration. Egypt’s Magdy G. shows an impressive IC rate of 89.3%, the highest among the cohort, across 65 publications, which solidifies an h-index of 21, indicative of rising prominence. With the largest corpus of 351 publications and an h-index of 41, Sun K. maintains an IC rate of 32.8% and an AC rate of 3.3%, reflecting a strong network of collaborations. Elbaset A.A., another Egyptian scholar, demonstrated a high IC rate of 54.8% across 107 publications, alongside an h-index of 21, denoting a significant contribution to the renewable power systems discourse. In Japan, Mitani Y. presented an influential suite of 318 publications and a notable h-index of 34, along with an IC rate of 67.4%, indicating extensive international engagement. Egyptian Shabib G. contributed 60 publications with an h-index of 15, accompanied by an exceptional 75% IC rate, suggesting intensive collaborative efforts. Zhang J. from China, despite having a lower total of 25 publications, still has an h-index of 11, reflecting a nascent but notable academic influence. Bakeer A., the third Egyptian on this list, presented 67 publications, an IC rate of 60.9%, and an h-index of 14, reinforcing the substantial collaborative and impact-oriented nature of his research. Breyer C. from Finland, though listed with four publications in the field, stands out with an h-index of 64, the highest on the list, and a significant AC rate of 10%, demonstrating a profound impact on the scientific community. Flynn D. from Ireland rounds out this distinguished group with an AC rate of 23.3% across 218 publications, an indication of extensive industrial collaboration and an h-index of 39, underscoring his scholarly influence. This compilation from Scopus encapsulates the vibrancy of academic inquiry in renewable power systems, showcasing a collaborative network that spans continents and industrial divides, united in advancing sustainable energy solutions.

Table 3. The most cited documents in Scopus that are focused on the investigation of renewable power systems and corresponding SDGs.

Title	Authors	Citations	Organizations—Sponsor	SDGs
Is a 100% renewable European power system feasible by 2050?	Zappa W., Junginger M., and van den Broek, M. [46]	397	n/a	SDG7; SDG13
A review of clear sky radiative cooling developments and applications in renewable power systems and passive building cooling	Zeyghami M., Goswami D. Y., and Stefanakos E. [47]	261	n/a	SDG9
Topology derivation of nonisolated three-port DC-DC converters from DIC and DOC	Wu H., Sun K., Ding S., and Xing Y. [48]	254	n/a	n/a
Rejecting renewables: The sociotechnical impediments to renewable electricity in the United States	Sovacool B. K. [49]	250	Ministry of Education—Singapore	SDG7
Analysis of battery lifetime extension in a small-scale wind-energy system using supercapacitors	Gee A. M., Robinson F. V. P., and Dunn R. W. [50]	238	n/a	SDG7
Role of Long-Duration Energy Storage in Variable Renewable Electricity Systems	Dowling J. A., Rinaldi K. Z., Ruggles T. H., Davis S. J., Yuan M., Tong F., Lewis N. S., and Caldeira K. [51]	229	Low Carbon Energy Science and Policy; Gordon and Betty Moore Foundation; Gates Ventures	SDG7
Technico-economic analysis of off grid solar PV/Fuel cell energy system for residential community in desert region	Ghenai C., Salameh T., and Merabet A. [52]	202	n/a	SDG7; SDG13
Hybrid off-grid renewable power system for sustainable rural electrification in Benin	Odou O. D. T., Bhandari R., and Adamou R. [53]	199	Bundesministerium für Bildung und Forschung	SDG7; SDG13; SDG17
Short-term wind speed forecasting via stacked extreme learning machine with generalized correntropy	Luo X., Sun J., Wang L., Wang W., Zhao W., Wu J., Wang J.-H., and Zhang Z. [54]	199	National Natural Science Foundation of China; National Taipei University of Technology; National Basic Research Program of China; Fundamental Research Funds for the Central Universities	n/a
Job creation during the global energy transition toward 100% renewable power system by 2050	Ram M., Aghahosseini A., and Breyer C. [55]	198	Deutsche Bundesstiftung Umwelt	SDG7; ASG8; SDG13

contains a summary of the most cited documents in Scopus that are focused on the investigation of renewable power systems and corresponding SDGs. The foremost cited work by Zappa et al. [46], cited 397 times, examines the feasibility of a fully renewable energy infrastructure in Europe by 2050, aligning with SDG7 (Affordable and Clean Energy) and SDG13 (Climate Action). This paper stands out for its timely and significant exploration of renewable transitions essential for climate mitigation.

Following this, a study by Zeyghami et al. [47], which has garnered 261 citations, outlines radiative cooling technologies that significantly enhance energy efficiency in buildings, contributing to SDG9 (Industry, Innovation, and Infrastructure). This research is crucial for sustainable urban development by improving passive cooling techniques. Wu et al. [48], receiving 254 citations, although not directly tied to any SDGs, provided fundamental insights into power electronics that support the functionality of renewable systems. The analysis by Sovacool B. K. [49], supported by the Ministry of Education—Singapore and cited 250 times, identifies the sociotechnical barriers hindering renewable energy adoption in the U.S., pertinent to SDG7. This paper provides a comprehensive overview of the impediments to sustainable energy access. The study of Gee et al. [50], cited 238 times, focuses on extending battery life in wind energy systems using supercapacitors, aligning with SDG7. It addresses key technological advancements that promote reliability and sustainability in energy systems. Dowling J. A. et al. [51] focused on the integration of long-duration energy storage to stabilize renewable energy outputs, which has been cited 229 times. This research highlights the essential role of storage technologies in supporting sustainable energy infrastructures under SDG7. Further impactful studies [52,53,54,55] include research on off-grid solar PV/fuel cell systems for desert regions and hybrid renewable power systems for rural electrification in Benin, each aligning with multiple SDGs such as SDG7, SDG13, and SDG17, and have been cited 202 and 199 times, respectively. These papers are instrumental in addressing energy poverty and promoting climate resilience, offering solutions that are both innovative and necessary for sustainable development.

The visualization of the text-mining of the studies that focused on the investigation of renewable power systems is shown in Figure 5.

The network visualization of the co-occurrence analysis of the studies that focused on the investigation of renewable power systems (Figure 6) allows five patterns of scientific investigations to be outlined.

The largest cluster (red) merges investigations on electronic batteries, solar energy, energy conservation, etc. Furthermore, the red cluster likely signifies a focus on the technical aspects of renewable power, with terms such as “hybrid power system” and “system stability”, highlighting research into the engineering challenges of integrating renewable sources into existing grids. The thickness of the connecting lines represents the frequency with which two terms co-occur in the literature, illustrating strong relationships between certain concepts such as “electric power system control” and “energy management”. The green cluster indicates a concentration of fundamental renewable energy technologies and systems. In contrast, the blue cluster seems to emphasize the intersection of renewable energy with policy and infrastructure planning, including the incorporation of technologies such as “hydroelectric power” into energy supply chains. Moreover, the yellow cluster appears to be associated with the financial and economic dimensions of renewable energy implementation, considering factors such as “cost-benefit analysis” and “cost-effectiveness”. This visualization captures the multidimensional nature of renewable power system research, intersecting diverse areas from technical engineering challenges to economic viability and policy frameworks. It not only aids in identifying the central themes within the research landscape but also fosters an understanding of the interconnectedness of these themes, which is crucial for the development of comprehensive renewable energy strategies.

The overlay visualization of co-occurrence analysis serves as a dynamic map of scholarly exploration within renewable power systems, delineating how focal areas of research have shifted and expanded over the years. The visualization (Figure 7) offers a multiyear perspective on the themes that have dominated the field.

Since 2017, perennial topics such as ‘energy policy’, ‘solar energy’, and ‘energy conservation’ have been robust areas of study. These topics are central to the discourse on renewable energy, addressing policy frameworks, technological advancements in solar power, and strategies to conserve energy—all foundational to the field. Between 2017 and 2019, there was a marked focus on the analysis of ‘renewable energies’, assessing the ‘cost-effectiveness’ of these technologies, and the integration of ‘hybrid systems’. These studies likely encompassed both technical and economic evaluations of renewable energy systems, highlighting the importance of cost in transitioning to sustainable power sources.

The years 2019 to 2021 saw a shift toward ‘digital storage’, ‘power systems control’, and ‘investments’. During this period, the importance of managing energy storage and ensuring the reliability of power systems through control mechanisms became more pronounced, reflecting technological advances [56,57,58] and increased investment in renewable energy infrastructure [59,60,61,62].

After 2021, the emphasis has largely been on ‘decarbonization’, ‘carbon dioxide’, ‘greenhouse gases’, and ‘operating costs’. This shift signals a heightened focus on the environmental impact of energy systems, the economics of reducing carbon emissions [63,64,65,66], and the costs associated with operating renewable power systems in a more eco-conscious manner.

4. Discussion

This research aimed to comprehensively understand the dynamics and progress within the field of renewable power systems, particularly through bibliometric analysis. Key findings highlighted significant growth in renewable energy capacity globally, with an unprecedented increase in solar and wind energy installations. These results affirm the global shift toward renewable energy, underscored by both technological advancements and policy support. This study’s main takeaway aligns with the research question regarding the factors propelling the rapid adoption and development of renewable power systems.

The extensive co-authorship networks identified in this study, especially from contributors in China, Egypt, and the United Arab Emirates, underscore the global nature of renewable energy research and its reliance on cross-border cooperation to innovate and refine technologies. The results do not support the theory that renewable energy advancements are predominantly driven by Western countries. Instead, the significant contributions from Asian and Middle Eastern countries highlight diverse geographical engagement, suggesting a shift toward a more globally inclusive effort in renewable energy research. The results provide new insights into the effectiveness of policy and government support in fostering innovation within the renewable energy sector. This study shows how countries with robust government support, such as China and the United Arab Emirates, lead in publication output and technological advancements, emphasizing the role of policy in steering research and development. These results should be taken into account when considering how to approach future investments in renewable energy. Understanding which countries are leading in research can guide international collaborations and funding allocations, ensuring that investments are directed toward regions and projects with the highest potential for impact and innovation. The data contribute to a clearer understanding of the dynamics within the renewable power system research community. By mapping the most influential researchers and their network of collaborations, this study provides insights into the core areas of expertise and potential gaps in the global research landscape. While previous research [67,68,69,70] has focused on the technological aspects of renewable power systems, these results demonstrate that understanding social dynamics, such as co-authorship networks and the distribution of research output, is crucial. This sociological perspective allows the identification of key players and potential collaborative networks that might not be visible through purely technical research reviews. Moreover, the data contribute to a clearer understanding of the economic viability of renewable power systems. The marked reduction in costs over the past decade positions renewables as a financially competitive alternative to traditional fossil fuels. This aspect is crucial for countries and companies considering large-scale transitions to renewable energy.

An additional key finding of this research is the identification of emerging trends and hot topics within the renewable energy field. Through detailed keyword analysis and citation tracking, this study reveals a growing emphasis on energy storage solutions, smart grid technologies, and the integration of artificial intelligence in optimizing renewable energy systems. These trends not only reflect the current technological advancements but also highlight the future directions of research and development. Understanding these emerging trends is essential for stakeholders aiming to stay at the forefront of innovation and for policymakers to support the most promising areas of research that could lead to significant breakthroughs in renewable energy technologies.

5. Conclusions

This study aims to evaluate global research efforts in the field of renewable power systems. Employing the knowledge mapping tool VOSviewer, this research presents findings from a bibliometric analysis and a review of literature based on 699 documents related to renewable power systems, as indexed in the Scopus database.

The analysis of research trends in the field of renewable power systems highlights a significant shift, distinguishing research activities into two periods: before and after 2012. Initially, studies in this domain were less prevalent, but since 2012, there has been a dramatic increase in interest and scholarly publications, driven by increasing concerns over climate change and the environmental impacts associated with traditional energy consumption. This surge in research aligns with broader global trends in which renewable energy is gaining prominence due to technological advancements and a heightened global awareness of environmental issues. The key factors contributing to this increase include major international agreements such as the Paris Agreement [23] and significant technological breakthroughs in renewable energy. Additionally, the decreasing costs of deploying renewable technologies [24] have made them more attractive and widely adopted, further fueled by increasing public and political interest in environmental sustainability [71,72]. Moreover, the analysis of the most cited documents reveals a keen focus on aligning renewable energy innovations with Sustainable Development Goals (SDGs), particularly SDG7 (Affordable and Clean Energy) and SDG13 (Climate Action) [73,74,75,76,77]. This alignment is crucial for addressing global challenges such as climate change and energy poverty. The network and overlay visualizations of co-occurrence analysis underscore the multifaceted nature of renewable power system research, intertwining technical, economic, and policy dimensions. This comprehensive approach is vital for developing effective, sustainable energy strategies that can adapt to changing technological landscapes and environmental priorities. The co-authorship and citation analyses illustrate a dynamic and collaborative research landscape focused on advancing renewable power systems. This collaborative effort is crucial for addressing the technical challenges and policy implications of transitioning to sustainable energy sources, with a clear alignment toward achieving global sustainability goals.

Along with the scientific contributions in terms of the basic features and significant processes, this investigation has the following limitations: the analysis primarily focuses on publications from the Scopus database, potentially overlooking influential works and collaborations from other sources or countries not covered in the dataset. This limitation could affect the comprehensiveness and generalizability of the findings. Additionally, the emphasis on quantitative metrics such as publication counts, h-index, and citation analysis might not fully capture the qualitative aspects of the research collaborations, such as the depth of partnership, the interdisciplinary nature, or the innovation level of the research outputs. Furthermore, the study primarily analyzed publications in English, leading to an incomplete picture of international research in this sphere.

The field of renewable power systems offers extensive opportunities for expanding research based on current findings. The increasing number of articles and interest in this sector underscore the dynamic nature of bibliometrics within the field, necessitating ongoing research to track developments and shifts. Conducting longitudinal studies to monitor these trends is crucial, as it helps refine strategies and adapt to technological advancements over time. The multilevel analysis conducted in previous studies, which examined the technological, individual, firm, and environmental factors influencing renewable power systems, provides valuable insights. However, these studies often treat these factors in isolation. Future research should integrate these dimensions, examining how interactions among various factors influence the development and implementation of renewable power systems. This integrated approach could lead to more comprehensive theoretical models and practical strategies to enhance the effectiveness and efficiency of renewable power systems. Moreover, this study focuses on the Scopus database; however, extending the range of databases to include others such as Web of Science, PubMed, and Google Scholar will allow for more comprehensive and in-depth future analyses. This broader approach will enable researchers to capture a wider array of publications, enhance the robustness of the findings, and provide a more holistic understanding of the research landscape. Additionally, incorporating multiple databases can help identify trends and patterns that might be missed when relying on a single source, thereby enriching the overall quality and reliability of the study. Moreover, as the global emphasis on reducing environmental impact intensifies, there is a pressing need to explore the entire lifecycle of renewable power projects, including their planning, operation, and maintenance phases. Questions about the specifics of implementation processes in different regions, the effectiveness of policy enforcement, and the assessment methods for technology adoption are critical. Addressing these aspects will not only fill existing knowledge gaps but also provide valuable directions for future research, potentially leading to the wider adoption and optimization of renewable power systems worldwide.