A Review of Renewable Energy Investment in Belt and Road Initiative Countries: A Bibliometric Analysis Perspective

Abstract

Since the proposal of the “Belt and Road” initiative (BRI) in 2013, China’s renewable energy investments in the countries along the route have shown rapid growth and diversification. These investments have shifted from initial product exports and engineering contracts to deeper equity investments and financing cooperation. They not only promote a global energy structure transformation towards green and low-carbon development but also bring significant economic growth and social progress to the participating countries. This study aims to systematically review the research status and trends of renewable energy investments in “Belt and Road” countries through comprehensive bibliometric analysis. Utilizing the Web of Science database and VOS viewer 1.6.17 software for visualization, this research reveals the publication trends, high-impact articles, institutional collaborations, and author networks in this field. Additionally, through keyword co-occurrence network analysis, three core research themes are identified: investment motivations, synergy effects, renewable energy consumption, and international cooperation. This systematic bibliometric analysis not only outlines the current research landscape but also provides important insights for identifying emerging research directions, thereby supporting more in-depth investigations into renewable energy investments within the “Belt and Road” initiative.

1. Introduction

The Belt and Road Initiative (BRI), led by China, is a vital platform for promoting global economic cooperation and development. It aims to enhance global economic growth and regional collaboration through improved infrastructure, trade, and investment, ultimately supporting the United Nations Sustainable Development Goals. Over the past decade since the BRI was launched, China’s energy investment has significantly increased, with total assets exceeding USD 1 trillion in countries along the BRI route. This includes USD 634 billion in construction contracts and USD 419 billion in non-financial investments. Energy investments have undergone a notable transformation from traditional to green energy, shifting focus from fossil fuel projects, such as coal and natural gas, to clean energy sectors like solar and wind, ensuring energy supply security.

Renewable energy investments refer to financial contributions to renewable energy technologies, projects, and infrastructure that utilize natural renewable resources, such as wind, solar, hydro, biomass, and geothermal energy, to reduce carbon emissions in the energy structure [1,2,3]. The “China Belt and Road Initiative Investment Report 2023” highlights that green energy investments reached a record high of USD 7.9 billion in 2023, with solar and wind investments accounting for 28% of energy investments, and an additional 6% directed towards hydropower projects. In 2023, the investment participation rate in the BRI reached 52%, with significant growth in technology sectors (particularly investments related to electric vehicle batteries) and metal mining, increasing by 1046% and 158%, respectively. Chinese enterprises have made substantial investments in critical mineral resources, such as lithium and battery manufacturing, leaning towards equity investments and assuming higher risks (Data source: Ministry of Commerce of the People’s Republic of China China’s Outward Investment and Economic Cooperation Report 2023 http://fec.mofcom.gov.cn/article/tzhzcj/tzhz/202407/20240703522165.shtml) (accessed on 1 August 2024). Renewable energy investments are becoming central to future energy investments, with predictions indicating that by early 2025, renewable energy will account for over one-third of global electricity production, surpassing coal. The share of renewable energy in electricity generation is expected to rise from 30% in 2023 to 37% by 2026, driven mainly by the expanding and increasingly cost-effective solar photovoltaic sector (Data source: International Energy Agency IEA Electricity 2024 https://iea.blob.core.windows.net/assets/18f3ed24-4b26-4c83-a3d2-8a1be51c8cc8/Electricity2024-Analysisandforecastto2026.pdf) (accessed on 28 July 2024). This trend underscores the crucial role of renewable energy in the future energy landscape.

Existing studies have primarily focused on single countries or specific types of investments (Li et al., 2022; Cheng et al., 2023) [4,5], mainly using gravity models or spatial econometric models to analyze investment effects. However, there is a lack of systematic literature reviews addressing renewable energy investment issues across all countries along the Belt and Road Initiative. This paper utilizes VOS viewer 1.6.17 software, which not only processes the large-scale literature samples but also visually illustrates the evolution of research hotspots and the relationships between keywords. This approach transcends the limitations of traditional reviews that rely heavily on qualitative analysis, providing a more objective and comprehensive knowledge map of renewable energy investment research in the Belt and Road context. Specifically, through keyword co-occurrence network analysis, this study identifies three main research themes (investment motivations, synergy effects, and cooperative governance). It reveals the dynamic shifts in research focus over time. This quantitative and visual analysis method captures the overall pattern of existing studies and predicts future research trends, offering valuable references for researchers and decision-makers. Moreover, the interdisciplinary perspective and comprehensive consideration of multidimensional factors make the analysis results more holistic and forward-looking than reviews focused on specific aspects.

2. Materials and Methods

The literature data for this study was sourced from the Web of Science database, a key platform for accessing global academic information. The literature search strategy was as follows: subject matter = ((“Belt and Road Initiative” or “BRI” or “One Belt One Road” or “Silk Road Economic Belt”) and (“renewable energy” or “green energy” or “clean energy” or “sustainable energy” or “solar energy” or “wind energy” or “hydropower” or “geothermal energy” or “biomass energy” or “tidal energy”)); the search period was limited to 2017 to 2024, and the search date was 20 July 2024; the document type was limited to “journal articles”. Initially, we gathered a wide range of the literature related to this study, followed by a manual screening process to retain articles closely linked to renewable energy investment. After the initial search, we obtained 278 articles. After removing duplicates and carefully reviewing the remaining articles to exclude those irrelevant to the research topic, 268 core articles were included for effective analysis.

This study utilized VOS viewer 1.6.17.0 visualization software to create collaboration maps of core authors, cluster maps of main keywords, and overlay views of the average occurrence time of key terms. The specific procedure involved downloading the filtered data in txt format, then importing it into VOS viewer, selecting the data type as “based on bibliographic data”, the data source as “reference manager file”, and the citation format as “RIS” For analysis type, “Co-authorship” was chosen. VOS viewer analyzes the imported bibliographic data by calculating the co-occurrence frequency of keywords, authors, or institutions, thereby identifying their relationships. A higher co-occurrence indicates a closer frequency of appearance in the literature, establishing stronger connections and forming a corresponding network model that allows users to intuitively understand the structure and dynamics of the data. Through a force-directed algorithm, nodes automatically adjust their positions based on the strength of their relationships, creating a clear network structure. This approach is efficient for handling large-scale bibliometric data and is particularly suited for visualizing keyword co-occurrences, author collaboration networks, and institutional relationships. Compared to Cite Space’s focus on mutation point analysis and Gephi’s complex operations, the VOS viewer is more focused on bibliometric analysis, with expressive color coding and node size design that enhance clarity, especially in revealing trends in renewable energy investments in Belt and Road countries. It provides reliable data support and visual evidence for subsequent research.

3. Results

From the time distribution of the published literature, Figure 1 shows the annual number of publications related to renewable energy investment in Belt and Road Initiative (BRI) countries from 2017 to 2024. The number of publications from 2017 to 2019 is relatively low, primarily because the BRI was proposed in 2013, and the keyword limitation to BRI affects the count. However, from 2019 to 2022, the number of publications significantly increased, reaching a peak in 2022 before starting to decline. It is important to note that only publications up to July 2024 were included, so this does not indicate a decrease in interest.

From 2017 to 2021, the publication trend of research related to renewable energy investment increased significantly, primarily driven by policy initiatives, technological advancements, and financial support. Since the launch of the Belt and Road Initiative in 2013, China and the countries along the route have increased their investments in renewable energy. Particularly after the signing of the Paris Agreement in 2015 and the United Nations Climate Change Conference (COP26), global attention to climate change intensified, making green development a key component of China’s foreign investments. Following the introduction of the “Green Silk Road” concept in 2015, multiple policy documents further clarified the direction of green investment. For example, the 2022 document titled “Opinions on Promoting Green Development in the Belt and Road Initiative”, issued by the National Development and Reform Commission, provided strong policy support for green investments. Additionally, China’s green finance policies, such as the green investment principles and the global green finance leadership program, have ensured sufficient funding for renewable energy projects. Technological advancements, especially significant cost reductions in solar panels and wind turbines, have also made clean energy projects more economically attractive. With policy support, the deepening of green development and green finance has stimulated a surge in renewable energy investments, fostering academic research growth and accelerating the development of the global green economy.

However, since 2022, the number of published studies on renewable energy has declined, potentially due to geopolitical risks, supply chain bottlenecks, and global economic uncertainty. The impacts of the COVID-19 pandemic, slowing economic growth, rising inflation pressures, and tightening monetary policies in developed countries have all contributed to a slowdown in the pace of investment. The energy market fluctuations triggered by the Russia–Ukraine conflict have weakened international investor confidence, as many renewable energy projects depend on a stable international environment to ensure the supply of raw materials and technology transfer; geopolitical tensions have directly affected project advancement. According to the United Nations’ “World Investment Report 2024”(Data source: the United Nations “World Investment Report 2024” https://unctad.org/system/files/official-document/wir2024_overview_ch.pdf)(accessed on 2 August 2024), foreign direct investment (FDI) in the renewable energy sector significantly declined after 2022, with a 2% drop in global FDI in 2023 and over a 10% decrease in investment in new projects in developing countries. Furthermore, supply bottlenecks for critical materials such as lithium and cobalt have driven up costs for renewable energy projects, causing delays in implementation and hindering the initiation of new projects. While China continues to advance green energy policies, uncertainties regarding environmental regulations and financing standards in some Belt and Road countries complicate and slow project implementation. This policy and regulatory uncertainty affect the flow of capital and the pace of execution. Although the number of publications has decreased in the short term, renewable energy investment remains a hotspot in both academic and policy discussions, and short-term fluctuations will not alter its core role in the global energy transition. Despite reduced financing for large infrastructure projects, the rise in small-scale greenfield projects indicates a growing interest in renewable energy investment among Belt and Road Initiative countries, reflecting a steady increase in attention to this sector in recent years.

According to the funding agencies (as shown in Figure 2), from 2017 to 2024, Shenzhen University published a total of 37 articles, ranking first. This was followed by the Chinese Academy of Sciences, which published 24 articles. The top five research institutions primarily consist of universities and research organizations, all from China. In terms of the countries/regions with the highest publication outputs (as shown in Figure 3), China ranked first with 208 articles, followed by Pakistan with 45 articles, and the United States in third place with 26 articles. Other contributing countries included the United Kingdom, Malaysia, Saudi Arabia, Japan, Ghana, India, and Poland.

Based on the data from Figure 2 and Figure 3, we can observe that China holds a dominant position in the field of renewable energy investment research along the Belt and Road Initiative. At the institutional level, all of the top five contributing institutions are from China, with Shenzhen University leading significantly with 37 publications. At the national level, China’s total of 208 articles far exceeds that of other countries, accounting for nearly 60% of the total. Notably, Pakistan, viewed as the core country of the China–Pakistan Economic Corridor (CPEC), ranks second, reflecting its importance in this field. The United States, as a non-BRI country, ranks third, indicating its high level of interest in this topic. Furthermore, the distribution of research institutions and high-output countries reflects the geographical diversity of research in this area, covering regions including Asia, Europe, the Middle East, and Africa. This highlights the global influence of renewable energy investment research within the Belt and Road Initiative and suggests a certain degree of international collaboration and exchange in these fields. This distribution not only reflects China’s leadership in promoting research on related topics but also demonstrates the widespread interest of the international academic community in this issue.

In the analysis of the scientific collaboration network of high-output authors (as shown in Figure 4), the nodes in the figure represent the authors, with the size of each node proportional to the number of publications. The more publications an author has, the larger their node, making them more likely to be included in the network. The thickness of the lines between nodes reflects the strength of collaboration among authors: thicker lines indicate more frequent collaborations, suggesting closer relationships. In this study, the VOS viewer 1.6.17 software set a threshold of a minimum collaboration count of three, meaning only authors exceeding this threshold were included in the graph. The degree of collaboration among authors is represented not only by the thickness of the lines but also by color coding; authors with close collaborations are shown in the same color. Among the 801 core authors in this study, only 36 exhibited collaborative relationships, forming 14 independent collaboration teams. While collaboration within each team is relatively tight, there is limited cooperation and exchange between different teams.

From

Table 1. The top 10 documents on renewable energy investment in BRI countries.

Title	Authors	Source Title	Year	Citations
Public spending and green economic growth in BRI region: Mediating role of green finance [6]	Zhang, DY; Mohsin, M; Rasheed, AK; Chang, Y; Taghizadeh-Hesary, F	Energy Policy	2021	462
Natural resources, tourism development, and energy-growth-CO2 emission nexus: A simultaneity modeling analysis of BRI countries [13]	Khan, A; Yang, CG; Hussain, J; Bano, S; Nawaz, A	Resources Policy	2020	199
Impact of technological innovation, financial development, and foreign direct investment on renewable energy, non-renewable energy, and the environment in Belt and Road Initiative countries [10]	Khan, A; Yang, CG; Hussain, J; Kui, Z	Renewable Energy	2021	187
Testing EKC hypothesis with energy and sustainable development challenges: fresh evidence from Belt and Road Initiative economies [8]	Rauf, A; Liu, XX; Amin, W; Ozturk, I; Rehman, OU; Hafeez, M	Environmental Science And Pollution Research	2018	186
The dynamic links between CO2 emissions, energy consumption, and economic development in the countries along the Belt and Road [7]	Liu, YY; Hao, Y	Science Of The Total Environment	2018	184
The role of technology innovation and people’s connectivity in testing environmental Kuznets curve and pollution heaven hypotheses across the Belt and Road host countries: new evidence from Method of Moments Quantile Regression [12]	An, H; Razzaq, A; Haseeb, M; Mihardjo, LWW	Environmental Science And Pollution Research	2021	140
Nexus between green logistic operations and triple bottom line: evidence from infrastructure-led Chinese outward foreign direct investment in Belt and Road host countries [14]	An, H; Razzaq, A; Nawaz, A; Noman, SM; Khan, SAR	Environmental Science And Pollution Research	2021	136
Rule of law and CO2 emissions: A comparative analysis across 65 belt and road initiative(BRI) countries [11]	Muhammad, S; Long, XL	Journal Of Cleaner Production	2021	126
The role of fixed capital formation, renewable and non-renewable energy in economic growth and carbon emission: a case study of Belt and Road Initiative project [9]	Abbas, Q; Nurunnabi, M; Alfakhri, Y; Khan, W; Hussain, A; Iqbal, W	Environmental Science And Pollution Research	2020	114
Estimating the role of green financing on energy security, economic and environmental integration of bri member countries [15]	Tu, CA; Chien, FS; Hussein, MA; Mm, YR; Psi, MSS; Iqbal, S; Bilal, AR	Singapore Economic Review	2021	113

Data source: compiled by the author from Web of Science.

, “The top 10 documents on renewable energy investment in the BRI countries”, it can be seen that the most cited article is by Zhang et al., published in Energy Policy, titled “Public spending and green economic growth in the BRI region: Mediating role of green finance” [6], with a total of 462 citations, averaging 154 citations per year. Among the top ten most cited articles, four are from Environmental Science and Pollution Research, and six were published in 2021. Liu and Hao (2018) first revealed the bidirectional causal relationship between energy consumption and economic growth, laying the foundation for subsequent research [7]. Studies by Rauf et al. (2018) and Abbas et al. (2020) further supported the environmental Kuznets curve (EKC) hypothesis, emphasizing the importance of renewable energy [8,9]. Khan et al. (2021) and Zhang et al. (2021) focused on the impact of technological innovation and financial development on energy efficiency, supplementing previous research [6,10]. Muhammad and Long (2021) and An et al. (2021) expanded the research perspective to environmental policy and governance, exploring the impact of political stability and the rule of law on reducing carbon emissions [11,12]. Scholars have focused on the relationship between energy, economic growth, and the environment, highlighting the crucial roles of green energy, technological innovation, and financial support in achieving sustainable development. Their work provides insights for policy-making under the BRI.

From the distribution and clustering analysis of the main keywords, keywords succinctly summarize the primary content of the literature. Through keyword co-occurrence network analysis, the research focus within a disciplinary field can be effectively revealed. VOS viewer constructs a network of associations between keywords by calculating their co-occurrence frequency in the literature, thus uncovering the core themes and hot topics of the research field. The selection of keywords is primarily based on their frequency and relevance in the literature, with a co-occurrence threshold set at 6 to ensure the representativeness of the analysis. Among the 268 articles, a total of 1158 keywords were identified, of which 89 appeared six times or more and were included in the analysis.

Figure 5 displays the clustering results of these high-frequency keywords, where nodes represent keywords, and the size of each node indicates the frequency of occurrence. The lines between nodes represent the co-occurrence relationships between keywords, with the thickness of the lines reflecting the number of co-occurrences; thicker lines indicate a stronger association. The keywords are categorized, with circles of the same color representing clusters of the same research theme. By observing the clusters of different colors and reviewing the relevant literature in detail, the researchers identified three main research themes related to renewable energy investment and governance in Belt and Road Initiative countries (as shown in

Table 2. Literature clustering theme classification.

Clustering Themes	Keywords	High-Frequency Words
1. Research on the driving factors of renewable energy investment	Belt and Road Initiative, BRI, policy, China, power, countries, consumption, growth, China belt, BRI countries, investment, challenges, energy transition, sustainability, oil, environment, infrastructure, determinants, electricity, model, geopolitics, industry	BRI, China, investment, energy transition, policy, determinants
2. Research on the synergistic benefits of renewable energy investment	belt and road, CO2 emissions, carbon emissions, financial development, carbon dioxide emissions, climate change, environmental Kuznets curve, Kuznets curve, co-integration, urbanization, trade openness, electricity consumption, renewable electricity consumption, empirical evidence, panel data, unit root tests	belt and road, BRI countries, CO2 emissions, Financial development, carbon emissions, climate change
3. Research on renewable energy consumption and cooperative governance	impact, economic growth, renewable electricity consumption, renewable energy-consumption, institutional quality, income inequality, carbon dioxide emission, trade openness, pollution, degradation, technological innovation, BRI countries, FDI, nexus, governance, energy efficiency, gmm	impact, economic growth, renewable energy-consumption, renewable electricity consumption

Data source: compiled by the author based on results calculated using VOS viewer 1.6.17 software.

). This sorting process comprehensively considers the frequency of keywords, clustering structures, and the actual content of the literature, systematically summarizing the core concerns of renewable energy investment and governance research in Belt and Road countries. This method not only visualizes the research hotspots but also reveals the intrinsic connections between different themes, providing important insights for a deeper understanding of the research dynamics in this field.

Theme 1: Driving Factors of Renewable Energy Investment in BRI Countries. The keywords for Theme 1 include Belt and Road Initiative, BRI, policy, China, power, countries, consumption, growth, China belt, BRI countries, investment, challenges, energy transition, sustainability, oil, environment, infrastructure, determinants, electricity, model, geopolitics, and industry. The high-frequency keywords are BRI, China, investment, energy transition, policy, and determinants. The larger size of these keyword nodes indicates high weight and attention. Scholars mainly focus on China’s role, policies, energy transition, sustainable development, investment determinants and challenges, geopolitical impacts, and energy consumption and growth. These factors essentially point to the drivers of renewable energy investment.

Renewable energy investment in BRI countries is driven by various factors. Externally, global climate change and frequent extreme weather events are pushing global energy transitions, with reducing carbon emissions becoming a common goal for all countries [16,17]. International climate agreements, such as the Paris Agreement, further reinforce countries’ commitments to renewable energy investments and are strategic considerations for energy security and mutual benefit [4,18]. China’s Belt and Road Initiative provides significant opportunities for renewable energy development in participating countries through foreign direct investment (FDI) and policy orientation [4,19,20,21,22]. By providing financial and technical support, China is helping these countries accelerate their energy transitions [4,19,23]. Chinese policy banks play a crucial role in financing overseas renewable energy projects, breaking the carbon lock-in effect in high-risk, low-income regions neglected by traditional donors, and enhancing renewable energy financing through energy partnerships [5,24]. Initially, there were concerns about the BRI exporting pollution models, but studies have found that its investment in low-carbon infrastructure contributes to green development. Green BRI activities exhibit both genuine green development and selectively executed greenwashing. Clearly defining and properly implementing a green BRI is essential for achieving equitable and sustainable development [25]. The development of green finance provides new funding sources for renewable energy projects and reduces financing costs. Studies show that public spending, FDI, and green finance significantly impact renewable energy deployment, significantly increasing the renewable energy installed capacity in these countries [26,27]. The preference for green investment in international capital markets and trade openness significantly broadens financing channels for renewable energy projects, as confirmed by multiple studies (Ming et al., 2014; He et al., 2019; Cheng et al., 2023; Narain et al., 2022; Wu and Song, 2023; Xu, L. 2023) [5,27,28,29,30,31]. Ucler et al. (2023) point out that trade openness is a key factor in promoting renewable energy investment in BRI countries, with varying effects depending on income levels: beneficial for high- and upper-middle-income countries, detrimental for lower-middle-income countries, and negligible for low-income countries [32]. Additionally, international energy price fluctuations enhance the demand for energy independence, while rapid advancements and cost reductions in global renewable energy technologies provide valuable insights for these countries [33,34,35]. However, the scale of renewable energy development, especially solar and wind, requires high capital thresholds. The host country’s development needs and absorption capacity also determine the extent of technological improvements [36].

Multiple studies have focused on the risk assessment of renewable energy investments in BRI countries, employing quantitative analysis methods such as TODIM and fuzzy analytic network process (F-ANP) [3,37], QFD (quality function deployment) and G1-entropy method [38], TOPSIS (technique for order preference by similarity to ideal solution) [39], AHP (analytic hierarchy process) and CRITIC (criteria importance through intercriteria correlation) [40], the Delphi–entropy weight method [41], and SWOT analysis [42]. These studies consider decision-making and risk quantification under uncertainty from perspectives such as collaborative consensus, national capacity, political, economic, technical, socio-cultural, and institutional environments. They also examine China’s investment scale, investment location choices, OFDI (outward foreign direct investment) greening trends, and their links to the host country’s energy structure, energy efficiency, and emission reduction benefits in BRI countries [1,24,26,43,44], identifying regions with varying investment efficiencies [45], and highlighting the significance of comprehending and mitigating investment risks.

Additionally, scholars have discussed how to optimize investment strategies. Harlan, T. (2021) utilized a political ecology approach to differentiate between green BRI activities focused on low-carbon infrastructure investments and those aimed at mitigating environmental risks. The findings revealed that low-carbon investments are predominantly situated in high-income countries and regions, whereas risk mitigation efforts are primarily concentrated in low-income countries and regions [25]. Chiyemura et al. (2023) [46] highlighted that China’s domestic institutional fragmentation and gaps result in a lack of clear strategies for participating in the African renewable energy market. They emphasized the need for new institutional arrangements to better adapt to the diverse market conditions and regulatory changes. Lin et al. (2023) [47] proposed an inexact fuzzy multi-stage programming (IFMSP) method to address the planning challenges for South Africa’s power system transition to clean energy from 2021 to 2050, considering multiple scenarios to optimize investment decisions.

From internal factors, the geographical and natural resource endowments, trade openness, energy consumption structure, governance capacity, and environmental policies of BRI countries significantly impact renewable energy investments. BRI countries possess abundant natural resources and favorable climatic conditions conducive to developing and utilizing renewable energy projects. Firstly, hydropower remains the largest source of renewable electricity globally, and the BRI region, especially around the Qinghai-Tibet Plateau, has enormous hydropower potential. However, its development is constrained by factors such as technological advancement, relative economic benefits, and environmental protection [48,49]. Secondly, Central Asia and North Africa have suitable topography and climatic conditions for developing onshore wind power, such as the mountainous regions of Kazakhstan, Tajikistan, and Kyrgyzstan [50,51], while South Asia’s Pakistan and Bangladesh, with their long coastlines, are suitable for offshore wind farms [52]. Southeast Asia is considered rich in solar photovoltaic potential, particularly in parts of Myanmar and Thailand [42]. Africa also boasts abundant solar resources, with high annual radiation and significant potential for distributed photovoltaic power systems [53]. Egypt, Iran, and Saudi Arabia, located at low latitudes with suitable land, have immense photovoltaic potential [54]. However, BRI countries generally exhibit low green energy efficiency with regional disparities [55,56,57,58], heavily relying on fossil fuels, and facing pressure for energy transition [59]. Short-term industrial upgrading and technological progress are challenging, so solutions to improve energy efficiency focus on gradually enhancing energy efficiency and developing clean energy [60]. Introducing carbon taxes and adopting new technologies such as carbon capture and storage can achieve energy diversification and security [47,61,62,63,64]. Meanwhile, developing energy infrastructure and finance, along with increasing trade openness, are effective ways to promote renewable energy investment. The diversity of green financial tools, the availability of financing channels, and the cost of financing directly affect the feasibility and attractiveness of investments [10,65,66,67,68]. Good governance (e.g., political stability, rule of law, regulatory quality, and corruption control) can create a favorable environment for renewable energy investments [1,11,17,19,68,69]. Trade openness can amplify or mitigate the impact of governance quality on investment, and the level of globalization significantly affects renewable energy development in high-income, upper-middle-income, and low-income countries, influenced by the single threshold effect of the digital economy [70].

The driving factors of renewable energy investment in countries along the “Belt and Road” Initiative interact with each other, forming a multidimensional and multilevel dynamic system. From a multidimensional perspective, factors such as economic, political, technological, environmental, and socio-cultural aspects interact with each other, promoting or limiting the development of renewable energy. The multilevel nature is reflected in how macro-level national policies and diplomatic strategies influence the overall investment landscape, while meso-level industry and regional development plans determine the layout of specific projects, and micro-level corporate financial conditions and technological innovation capabilities affect the success or failure of individual projects. There are interaction mechanisms between various driving factors. For example, economic factors may promote technological progress through investment in research and development, while technological progress, in turn, reduces energy costs, thereby stimulating economic demand [71]. Factors at different levels also interact. For instance, macro policies may guide meso-level industrial layout, and conversely, they can influence national energy strategy adjustments [72]. Additionally, relevant domestic and international factors can produce synergistic effects. International cooperation under the “Belt and Road” Initiative may promote technological exchanges and capital flows among countries along the route, thereby influencing their respective renewable energy investment decisions [73]. All of these reflect the complex decision-making environment faced when making renewable energy investments.

Theme 2: Synergistic Benefits of Renewable Energy Investment in BRI Countries. The keywords for Theme 2 include Belt and Road, CO₂ emissions, carbon emissions, financial development, carbon dioxide emissions, climate change, environmental Kuznets curve, Kuznets curve, co-integration, urbanization, trade openness, electricity consumption, renewable electricity consumption, empirical evidence, panel data, and unit root tests. The high-frequency keywords are Belt and Road, BRI countries, CO₂ emissions, financial development, carbon emissions, and climate change. It can be observed that scholars mainly focus on carbon emissions, financial development, technological innovation, the applicability of the environmental Kuznets curve in BRI countries, and the relationship between economic activities and renewable energy consumption. These themes ultimately summarize the environmental, economic, and social benefits of renewable energy investment under the BRI. By promoting financial development and technological innovation, participating countries are pushed towards clean energy transitions, reducing carbon emissions, addressing climate change, and achieving economic growth and sustainable development.

In terms of environmental benefits, the BRI enhances the environmental governance capacity of host countries through technology transfer and knowledge sharing, significantly improving environmental quality, particularly in countries that have achieved carbon peaks, are non-tropical, highly industrialized, and have high citizen participation [74]. However, the environmental benefits vary significantly across regions [16,28,75,76], indicating that the environmental impacts of the BRI are complex and location-dependent, with renewable energy investment playing a crucial role. Wu et al. (2023) found that renewable energy investment directly improves carbon emission efficiency (CEE), benefiting not only the investing country but also the environment of neighboring countries through spatial spillover effects [16]. This finding aligns with Anwar et al. (2021), who revealed the synergistic effect between renewable energy consumption and increased forest area [77]. Multiple studies further support this view, emphasizing that improving institutional quality and increasing renewable energy consumption positively impact reducing CO₂ emissions [73,78,79,80], especially in low-income economies [81]. To achieve the global 2 °C target, it is essential to increase investments in clean energy and associated new infrastructure in BRI countries. These investments are expected to surge to over USD 100 trillion by the end of this century [82]. Technological advancements are viewed as crucial for enhancing CEE and energy efficiency, with investments in renewable energy fostering technological innovation. Research indicates that the implementation of information and communication technology (ICT), greater consumption of renewable energy, the development of human capital, and urbanization all play significant roles in reducing CO₂ emissions in BRI countries [56,83]. In the long term, technological innovation, through increasing the number of patents and trademarks, improves environmental quality in countries along the BRI, especially in Europe, the Middle East, North Africa, and Central Asia. However, Nanli et al. (2022) discovered a bidirectional causal link between patents, trademarks, and CO₂ emissions in the short term [84], highlighting the intricate dynamic relationship between technological innovation and environmental impact.

Nonetheless, the relationship between economic growth and environmental preservation is not purely linear. Studies have validated the income-induced environmental Kuznets curve (EKC) and the pollution haven hypothesis (PHH) based on Chinese outward foreign direct investment (FDI), with these effects varying across countries with different emission levels [56,83]. These findings reveal the nonlinear relationship between economic growth and environmental impact, as well as the potential environmental risks of cross-border investments. Although energy consumption, economic growth, and FDI typically increase carbon emissions [85,86], studies have found that countries with higher carbon efficiency in BRI trade may help reduce emissions in other countries through trade [87]. International cooperation and technology transfer can support global carbon reduction efforts while ensuring fair responsibility allocation to prevent carbon leakage [87,88].

In terms of economic benefits, renewable energy investment under the BRI framework demonstrates multifaceted economic benefits. Firstly, numerous studies have identified a two-way causal relationship between renewable energy consumption and economic growth [89]. In BRI countries, renewable energy significantly contributes to economic growth, not only directly promoting economic development but also indirectly affecting capital formation and trade. Technological innovation plays a crucial role in this process. Renewable energy investments promote technological progress, indirectly fostering economic growth [89,90,91,92], while economic growth, in turn, stimulates renewable energy consumption [93], creating a virtuous cycle. In terms of job creation, China’s renewable energy investments in BRI countries have shown significant results. For example, in Pakistan, Chinese-invested renewable energy projects have created numerous jobs and spurred related industries’ development [4]. However, the advantages of investment differ across countries with varying income levels. In high- and upper-middle-income BRI nations, trade openness boosts renewable energy consumption. Conversely, in lower-middle-income countries, there is a negative correlation, while in low-income countries, the effect is negligible [32]. Therefore, differentiated policies are needed to promote green growth [94].

In terms of social benefits, renewable energy investment improves public health and environmental quality by reducing air pollution and greenhouse gas emissions. For example, China’s renewable energy investments in Pakistan have not only promoted local economic growth but also created numerous jobs, addressing some unemployment issues while enhancing local technical and managerial capabilities [36,60,95]. In the wind and solar energy sectors, Chinese equipment suppliers have significantly improved the renewable energy industry levels in BRI countries through technology transfer and skill training, driving the construction of related industrial chains, including new materials, manufacturing, power, and automation [96]. Despite facing financial and policy challenges, these collaborations provide clean, affordable energy to related countries, contributing to broader economic and social welfare.

Theme 3: Renewable Energy Consumption and Cooperative Governance in BRI Countries. The keywords for Theme 3 include impact, economic growth, renewable electricity consumption, renewable energy consumption, institutional quality, income inequality, carbon dioxide emission, trade openness, technological innovation, degradation, pollution, BRI countries, FDI, nexus, governance, energy efficiency, and GMM. The top keywords appearing frequently are impact, economic growth, renewable energy consumption, and renewable electricity consumption. The relatively smaller nodes of these keywords indicate that the research primarily focuses on trade openness, economic growth, renewable electricity consumption and renewable energy consumption, technological innovation and institutional quality, income inequality, and governance. These can be viewed as the comprehensive impact and governance of renewable energy consumption under the BRI.

Renewable energy consumption plays a crucial role in the green development of the BRI, and its relationship with economic, environmental, and social factors is complex. Studies have shown that renewable energy consumption generally has a positive contribution to economic growth [91,92], mutually promoting each other [97], and providing strong support for regional cooperation. However, this relationship is not simply linear; there may be negative effects in the short term, and cross-country economic growth inequality mainly stems from regional inequality in capital investment [58]. Therefore, policymakers need to find a balance between short-term costs and long-term benefits.

In terms of environmental impact, renewable energy consumption significantly helps reduce carbon emissions and ecological footprints [78,95,98,99], highlighting its importance in achieving green development under the BRI. However, the interplay between energy consumption, economic growth, and carbon emissions is more intricate. Research has shown that income inequality and renewable energy consumption typically have a negative correlation with carbon emissions. Conversely, economic growth, foreign direct investment, and financial development generally lead to higher emissions [100]. Moreover, the industrial structure also plays a vital role; increased agricultural and energy consumption raises carbon emissions, while manufacturing and service sectors help reduce them [101]. In terms of institutional factors, although governance generally has a positive role in reducing CO₂ emissions, its effect becomes more complex when interacting with technological innovation and income inequality [102]. Political and legal systems positively impact carbon emissions, while income inequality and foreign direct investment negatively affect emissions [103]. These findings emphasize the importance of balancing income distribution, improving institutional quality, and promoting sustainable energy use while driving economic development.

Regarding global collaboration on renewable energy, Zhao et al. (2022) revealed multiple factors influencing cooperation in renewable energy. Trade costs, differences in additional benefits, technological spillover gains, and income distribution coefficients all play critical roles in promoting cooperative strategies [104]. Additionally, the Xinjiang power grid has become an important channel for the interconnection of power grids between China and neighboring countries, optimizing cross-border energy allocation [105], and providing new possibilities for energy cooperation among BRI countries.

Overall, the green total factor energy efficiency (GTFEE) of developed economies is generally higher than that of developing economies, with significant regional differences. Although the overall energy efficiency of BRI countries has declined, their renewable energy development levels have shown a steady upward trend. Significant differences exist in development speed and technological maturity among regions; the Americas and Oceania have advantages in renewable energy technology, while Europe and Oceania have significant advantages in institutional management and economy. Asia, Oceania, and Europe perform well in the energy environment [39]. To achieve sustainable development, it is crucial to enhance international cooperation, advance technological innovation, increase the use of renewable energy [106], promote the construction of low-carbon industrial parks and green energy projects, and establish green development funds [107].

The keyword time series diagram is an effective tool for analyzing research trends in renewable energy investments related to the “Belt and Road Initiative”. By observing the frequency changes of keywords over time, researchers can gain insights into the dynamics of this field and its future directions. In this study, we set the overlay analysis threshold for the average occurrence time of key keywords at 8. This setting aims to focus on significant keywords and reveal research hotspots. By filtering out low-frequency terms, we ensure that only representative and influential keywords are included in the analysis. The keywords displayed in the diagram typically reflect recent research focuses. This analytical approach enables researchers to identify keywords with high academic impact, observe their frequency over different periods, and track the evolution of research themes. Through this precise filtering and analysis process, we can not only grasp current research priorities but also anticipate potential future research directions, providing valuable insights for a deeper understanding of the academic development in the field of renewable energy investments related to the “Belt and Road Initiative”.

From Figure 6, which shows the chronological keyword map of the renewable energy investment literature under the Belt and Road Initiative (BRI), we can see that the larger nodes include “renewable energy”, “CO₂ emissions”, “Belt and Road initiative”, “financial development”, and “China”, indicating these themes are central focuses in related research. The color changes represent research trends over different periods, with newer research hotspots appearing in brighter colors. Keywords such as “economic growth”, “environmental Kuznets curve”, and “foreign direct investment” also frequently appear, reflecting the ongoing interest of researchers in the relationship between economic development, environmental impact, and international investment.

In Figure 6, the color transition from dark to light yellow indicates the timeline from earlier to more recent publications. The brighter areas marked with dashed keywords such as “renewable energy consumption”, “BRI countries”, “quality”, “pollution”, “determinants”, “impacts”, “electricity”, and “investment” show that over time, the research hotspots in renewable energy investment in BRI countries have shifted. Earlier research focused on verifying the environmental Kuznets curve (EKC) hypothesis for BRI participating countries [108,109], the economic benefits of FDI investments, and the environmental benefits such as carbon emissions [97,110,111]. More recent studies have explored the influencing factors of renewable energy consumption in BRI countries, the impact of renewable energy consumption on economic growth, the interactive effects of institutional differences on energy efficiency [112], and the environmental benefits of renewable energy investments such as hydropower [89,113,114]. Additionally, the role of the digital economy in moderating the relationship between globalization and renewable energy development in BRI countries should be noted [70], along with the comprehensive approach of environmental, economic, and governance (ESG) synergistic development.

4. Discussion

In recent years, research on renewable energy investments in countries along the “Belt and Road Initiative” has become increasingly rich and diverse in perspective. From the content of the studies, scholars generally focus on the impact of China’s foreign direct investment in renewable energy and related fields, involving multiple aspects such as political risks, energy trade, financial support, and technological innovation. New variables and indicator systems have been introduced to explore how different distances—cultural, geographical, and institutional—affect energy investments, as well as to assess the effects of the “Belt and Road Initiative” from various angles [3,7,115,116]. For example, Li et al. (2022) [4] investigated the impact of international trade, China’s foreign direct investment, and green innovation on consumption-based CO₂ emissions, focusing specifically on China’s foreign direct investment rather than overall FDI. They found that China’s foreign direct investment and imports have a positive impact on consumption-based carbon emissions, while green innovation and exports have a negative impact, thereby providing a better understanding of infrastructure-driven emission issues [117]. Alqurran et al. (2024) [118] examined the role of green finance in supporting sustainable energy investments from the perspective of Jordan’s energy sector, discovering that green finance in renewable energy, green buildings, and sustainable transportation significantly supports sustainable energy investments. They innovatively segmented green finance into multiple areas, providing a more detailed perspective for the research. In terms of research methods, scholars have employed various econometric models, such as the gravity model, spatial Durbin model (SDM), difference-in-differences model (DID), and CS-ARDL model, focusing on empirical analyses in different areas, including risk assessment, carbon emission performance, and energy poverty [28,117,119,120]. Cheng et al. (2023) used spatial difference methods to analyze the impact of the “Belt and Road Initiative” on China’s overseas renewable energy development financing [5]; Geng (2021) combined case analysis with the Rising Power Framework to explore the impact of the “Belt and Road Initiative” on host countries’ renewable energy development [36]; and Alqurran et al. (2024) conducted research through surveys and quantitative analysis [118]. The diversity of these methods helps to validate the robustness of the research findings from different angles. This study uses the VOS viewer 1.6.17 software to analyze the literature on renewable energy investments in countries along the “Belt and Road Initiative” explaining themes such as driving factors, synergies, and cooperation. This approach presents research hotspots and the relationships between keywords visually, demonstrating unique advantages in revealing the knowledge structure and evolution of the research field. Moreover, it incorporates multiple factors such as institutional quality and technological innovation, providing a more macro and systematic perspective compared to specific econometric models, which aids in a better understanding of the multidimensional impacts of renewable energy investments under the “Belt and Road Initiative”.

In renewable energy projects in the BRI countries, the investment cooperation model significantly impacts project outcomes. According to Wu Shifang (2022) [121], these models can be categorized into government-led, market-led, and new investment cooperation models. The government-led investment cooperation model includes “aid + investment” models, policy-based financial models, and multilateral investment platforms, which are suitable for projects with strong policy support and government leadership. The market-led investment cooperation model encompasses EPC, equity investment, bank loans, and PPP models, which are appropriate for mature markets and commercially operated projects. New investment cooperation models, such as green financing models, SPC investment, and cluster-based financing models, are suitable for more complex and innovative project financing arrangements.

Table 3. Investment cooperation models and experiences with renewable energy in BRI Countries.

Project Name	Project Type	Investment Model	Project Size	Investment Results	Project Experience
Pakistan Dawood Wind Project	Market-led Investment Cooperation	Equity Investment + Bank Loan	49.5 MW	Successfully operational	EPC ensured project completion on schedule, while policy-based financial support reduced financing costs, easing the financial pressure on the company.
Kazakhstan Zhanatas Wind Power Plant	New Financial Cooperation Model	Non-recourse Syndicated Loan	100 MW	Project under construction,15-year fixed price, 3500 h/year	The new financial model introduced multiple financing sources or agencies, offering flexibility in funding structures, such as bonds and equity funds, which effectively mitigated risks and alleviated financial pressure.
Vietnam HoaHoiSolar Power	Government-led Investment Cooperation	EPC + Policy-based Financial Support	257 MW	Project completed on schedule, advanced technology	EPC model ensured on-time project completion, and policy-based financial support lowered financing costs, easing company financial pressure.
Pakistan Karot Hydropower Project	Government-led Investment Cooperation	BOT (Build-Operate-Transfer) + Policy-based Financial Support	720 MW	Critical energy project under the China–Pakistan Economic Corridor, stable power generation	The BOT model secured funding and transferred risks to the project operator, while policy-based financial support ensured stable long-term financing, enabling project sustainability.
UAE Noor Solar Power Project	Market-led Investment Cooperation	PPP (Public–Private Partnership)	1177 MW	Project operational, increased clean energy proportion	PPP model diversified project financing and combined government resources with private sector expertise, ensuring the project’s long-term operation and success.
Argentina Jujuy Hydroelectric Power Station	Market-led Investment Cooperation	EPC + Foreign Capital Cooperation	1740 MW	Significant power output supports local grid	EPC with foreign capital secured timely project completion, while foreign investment reduced financial pressure, improving overall project viability.

Data source: compiled by the author based on publicly available information.

presents specific case studies of renewable energy investment cooperation models in Belt and Road countries to better understand the actual impact of renewable energy investments in these nations, as detailed below:

Table 3 illustrates that different project types are closely related to investment outcomes, with project scale and national policy support being interconnected. Particularly when host countries implement policies encouraging green investment, the attractiveness of social capital significantly increases [122]. Diverse financing channels and mechanisms can alleviate funding pressures and ensure smooth project operations. Large projects tend to adopt structured and diversified models to manage higher risks, while small- and medium-sized projects thrive through simpler equity or EPC methods. For instance, EPC and BOT models provide strong guarantees in project construction, especially when it comes to large infrastructure projects such as hydropower stations or wind farms. Policy-based financial support can significantly reduce financing costs and ensure stable funding. Furthermore, the maturity of technology and cost control also influence the scale and returns of projects, making policy incentive measures crucial during the early stages of project development. Many projects face delays due to financing, technical, or policy issues. Timely commissioning can help reduce cost overruns and ensure that investment returns are realized as scheduled. Even if a project is completed on time, its ability to generate stable power, maintain efficiency, and achieve the expected economic and environmental benefits depends significantly on long-term operation and maintenance, which are critical factors in assessing its sustainability.

Despite Chinese scholars leading in funded institutions and high publication countries, only 36 out of 801 core authors have collaborative relationships, and although there are 14 tightly-knit collaboration teams, communication and cooperation between these teams are insufficient. This issue is particularly prominent in BRI research, which involves numerous countries and regions, highlighting significant heterogeneity between different areas. Future efforts need to strengthen cooperation between different teams, especially between Chinese and foreign scholars, to address this complex research environment.

The main research questions and controversies facing the drivers of renewable energy investment in the “Belt and Road Initiative” include: Legal and policy risks are prominent, encompassing challenges related to imperfect legal systems and policy instability in the countries along the route. Economic and financial risks are also significant, characterized by the single economic structures of some countries, large exchange rate fluctuations, difficulties in financing, and uncertainties regarding project profitability. Market competition is intensifying, with both domestic and foreign companies vying for investment opportunities, leading to diminishing marginal returns on projects. Additionally, the influence of geopolitical factors and international relations is becoming increasingly significant as containment policies from the West and global crises such as the Russia–Ukraine conflict introduce uncertainties. The technology and industrial chains face new challenges as varying technological pathways impact costs and efficiency. These factors reflect the multilayered internal and external challenges faced by renewable energy investments under the “Belt and Road Initiative”, necessitating a comprehensive assessment of investment risks. Governments and enterprises must adopt cautious and innovative strategies to determine optimal investment directions, sequences, and portfolios, thereby promoting sustainable clean energy cooperation.

Renewable energy investments in BRI countries present multiple synergistic benefits, including energy transition and environmental, economic, and social benefits. The main research issues and controversies include: First, the relationship among carbon emissions, financial development, and technological innovation, particularly regarding the applicability of the environmental Kuznets curve (EKC) theory. Different countries exhibit nonlinear relationships between economic growth and environmental impacts at various stages of development. Given the large number of BRI countries, the impact of renewable energy investments on economic growth may vary significantly, with differences even observed within the same country across different development periods. Some middle-income countries may experience the “pollution haven” effect [123]. For instance, renewable energy development heavily relies on geographic resource endowments, but economically underdeveloped regions often lack funding, skilled personnel, technical support, and infrastructure when developing renewable energy industries. These shortcomings can limit the implementation and benefits of their renewable energy projects [124]. In the short term, environmental benefits may conflict with economic and social gains [125]. Large-scale renewable energy investments initially require substantial financial and resource inputs, which may increase short-term economic burdens and affect social resource allocation. However, in the long term, these investments can improve environmental quality, reduce pollution and carbon emissions, and enhance public health, ultimately lowering environmental governance costs and promoting sustainable economic and social development. Secondly, countries face issues related to the distribution of benefits from technology transfer and independent innovation during their participation in global supply and value chains. The "bottleneck" problem of technology makes it difficult for many host countries to fully grasp core technologies, leaving them in a passive state in key areas. For example, the globalized supply chain and reliance on key components make nuclear technology more challenging to master, whereas solar photovoltaic technology benefits from greater supply chain flexibility [126] This dependency limits the host countries’ ability to innovate independently, making it challenging to expand the depth and breadth of their industrial chains. This is not only related to national energy security but also involves issues of wealth distribution and fairness within society. Therefore, how to achieve a transition from technology transfer to independent innovation becomes crucial. Finally, there are discrepancies regarding the fairness of carbon reduction benefits and spatial spillover effects. Renewable energy investments have significant carbon reduction benefits that not only affect the investing country itself but also produce environmental spillover effects in neighboring countries. However, the spatial distribution of these benefits is not uniform; some low-income countries may be unable to enjoy equivalent environmental benefits due to a lack of technology and funding, especially when considering complex factors like carbon leakage. Ensuring fair responsibility distribution among all participating countries becomes a key issue, thereby prompting discussions on the equity of investment benefits under the Belt and Road Initiative [127].

The main issues and controversies regarding renewable energy consumption and governance cooperation among the BRI countries include the heterogeneous effects of enhancing renewable energy efficiency and its influencing factors. Research indicates that China’s technology exports and investments have positively impacted the renewable energy utilization efficiency in these countries, though this effect varies significantly across different regions and sectors [56,128]. In developing countries, increased economic levels drive energy consumption growth; conversely, in more developed countries, reduced energy intensity decreases energy consumption through enhanced efficiency, with population size having a certain promoting effect on renewable energy consumption, although this impact is relatively minor and exhibits a diminishing trend [127]. Moreover, the competitive and cooperative relationships in renewable energy face numerous challenges, including trade costs, unequal benefit distribution due to technological spillovers, and uncertainties in the choice of cooperation and competition strategies [73,76]. These issues pose challenges to the promotion of renewable energy, particularly in middle- and low-income countries. However, opportunities arise from cross-border grid interconnections, green technology transfers, and knowledge dissemination [111]. The research by Xu et al. (2024) [76] reveals the complex relationships of cooperation and competition in renewable energy trade among “Belt and Road” countries, highlighting that geographical location influences the clustering of competitive relationships. China exhibits a high inflow and low outflow model, and over time, trade relationships display a dynamic pattern of concurrent competitive cooperation and cooperative competition. To address these challenges, countries along the “Belt and Road” can promote renewable energy investment cooperation by strengthening international collaboration, advancing green technology research and transfer, establishing green financial mechanisms and low-carbon industrial parks, combating corruption, and fostering open trade.

5. Conclusions

This study employs bibliometric analysis of the Web of Science Core Collection and VOS viewer for quantitative visualization to systematically review the literature on renewable energy investment related to the BRI countries. The number of publications from these countries in the field of renewable energy investment showed an upward trend from 2017 to 2022, primarily benefiting from policy promotion, technological advancements, and financial support, reflecting the global focus on climate change and green development. After 2022, the number of research publications declined, likely due to factors such as geopolitical risks, supply chain bottlenecks, and global economic uncertainties, which have led to slowed investments and complicated project implementations. Nevertheless, renewable energy investment remains a hot topic in both academic and policy discussions, with an increasing number of small-scale greenfield projects indicating a growing interest among “Belt and Road” countries in renewable energy investments. While Chinese scholars lead in this field, the research collaboration network is loose, suggesting a need for enhanced cooperation between Chinese and foreign scholars in the future. Among the articles on renewable energy investment in “Belt and Road” countries indexed in the Web of Science Core Collection, the most cited paper by Zhang et al. [6] published in Energy Policy has been cited 462 times, primarily investigating the role of public spending and green finance in promoting green economic growth in the “Belt and Road” region. In the top ten most cited documents, scholars emphasize the critical roles of green energy, technological innovation, and financial support in achieving sustainable development.

Through the keyword distribution and clustering analysis of 268 articles on Belt and Road countries, the study identifies three main themes: the drivers of renewable energy investment, the synergistic benefits of investment, and consumption and cooperative governance. Theme one reveals that external factors such as global climate change, Chinese policy support, green finance development, and international energy price fluctuations, as well as internal factors like geographical resource endowments and governance capacity, drive renewable energy investment. Theme two indicates that renewable energy investment has significant synergistic benefits in reducing carbon emissions, promoting economic growth, and improving social welfare; although it may have negative impacts in the short term, it contributes to sustainable development in the long term. Theme three highlights the critical roles of trade openness and technological innovation in improving energy efficiency and reducing carbon emissions, noting that China’s investment model has evolved from being dominated by single countries to multilateral cooperation, with the involvement of multilateral financial institutions and private capital significantly enhancing financing diversity, underscoring the importance of international cooperation and policy support.

Based on the temporal analysis of keywords in the literature on renewable energy investment under the “Belt and Road” initiative, future research trends will primarily explore the macro-level factors and consequences affecting renewable energy consumption. This includes investigating the spatial and spillover effects of renewable energy consumption within interconnected power systems and the impact of digital transformation on the renewable energy consumption patterns of participating countries. Big data and artificial intelligence can be utilized for detailed modeling and forecasting, assessing the effectiveness of establishing digital technology cooperation centers and digital demonstration projects for renewable energy investments in these countries, thereby optimizing governance structures and policy design to achieve carbon neutrality goals. On a micro level, field research and case studies combined with corporate carbon accounting data will evaluate the policy effects of renewable energy investment and residents’ attitudes and behaviors, aiming to propose targeted promotion strategies. Additionally, the study will explore the impact of renewable energy development on social equity and employment, seeking methods to achieve inclusive growth during the energy transition.

The limitations of this study arise from the dataset’s sufficiency, which depends on the selection of search terms and the quality of data sources. Variations in search terms can significantly affect both the quantity and quality of retrieved articles, thereby influencing research outcomes. To ensure a comprehensive literature review, extensive testing of search terms was conducted, categorizing them into three parts: “Belt and Road countries”, renewable energy, and investment and governance. Synonyms were connected using “or”, while the three categories were linked with “and”. For instance, synonyms for “Belt and Road countries” include “Silk Road Economic Belt nations” and “Maritime Silk Road countries”; synonyms for “renewable energy” encompass “sustainable energy”, “solar energy”, “wind energy”, “hydropower”, “geothermal energy”, “biomass energy”, and “tidal energy”; synonyms for “investment and governance” include “investment”, “policy”, “funding”, “financing”, and “subsidies”. After numerous trials, it was determined that retaining only the synonyms for the first two categories was adequate to retrieve a sufficient number of core documents. These documents were subsequently filtered and reviewed manually to include as many relevant articles as possible. The Web of Science was selected as the primary data source due to its extensive coverage and high-quality literature; however, only journal articles were included, which may exclude conference papers, books, and reports, potentially omitting relevant findings. The research primarily relies on bibliometric analysis combined with the authors’ qualitative review and classification. Although it highlights several renewable energy investment cases in Belt and Road countries, due to the large number of countries involved and the significant differences in their development stages and natural resource endowments, future research could expand to explore more specific cases in greater depth. In addition, incorporating more databases, books, and conference reports, along with fostering increased collaboration between Chinese and international scholars, could provide a more comprehensive analysis from interdisciplinary and diverse perspectives.