Techno-Economic Feasibility and Environmental Impact Assessment of Hybrid Photovoltaic-Wind Turbine Systems for Electric Vehicle Charging Infrastructure in Indonesia

Research on eco-dynamic numerical modelling and system design for hybrid photovoltaic-wind (PV–wind) turbine systems in Indonesia has emerged as a critical area of inquiry, driven by the urgent need to transition from fossil fuels to renewable energy sources amid rising energy demand and environmental concerns [1] [2]. The evolution of renewable energy integration has progressed from initial techno-economic assessments of hybrid systems in government buildings [1] to comprehensive evaluations of environmental and health co-benefits across multiple regions [3] [4]. This field holds significant practical importance, as Indonesia aims to increase the share of renewable energy in its energy mix to meet national emission-reduction targets and support sustainable transportation through electric vehicle (EV) infrastructure [5]. For instance, renewable energy's contribution to electricity supply is projected to rise from 18.85% in 2020 to 26.93% by 2030 [4], underscoring the scale of the transformation required.

Despite advances, challenges remain in optimizing hybrid renewable systems tailored to Indonesia’s diverse geography and socio-economic contexts [6] [7] [8]. A critical problem is the lack of integrated approaches that simultaneously address system design, sustainability assessment, manufacturing innovations, and techno-economic feasibility, particularly for applications such as EV charging stations for motorcycles (SPKLU) [9] [10] [11]. Existing studies often focus on isolated aspects, such as component selection [7], or techno-economic analysis of rural electrification [6], without fully incorporating policy implications and future roadmaps [12] [13]. Moreover, controversies persist regarding the economic viability of wind turbines in certain regions [14] [15] and the balance between grid-connected and off-grid solutions [16] [17]. The absence of comprehensive frameworks limits effective policy-making and investment decisions, potentially hindering Indonesia’s energy transition and EV adoption goals [5] [12].

This review constructs a conceptual framework integrating eco-dynamic numerical modelling, sustainability and environmental assessment, innovations in manufacturing eco-friendly materials, and techno-economic analysis within the context of hybrid PV–wind systems and EV charging infrastructure [18] [19] [20]. It defines key concepts such as hybrid renewable energy systems, techno-economic feasibility, and sustainable EV charging infrastructure, establishing their interrelations to guide system design and policy evaluation [21] [22]. This framework enables the systematic examination of technological, environmental, and economic dimensions critical to Indonesia’s renewable energy and transportation sectors.

The purpose of this systematic review is to synthesize current knowledge on hybrid PV–wind turbine systems in Indonesia, focusing on their application in EV charging infrastructure, sustainability assessments, and policy implications [23] [24]. By addressing identified gaps in integrated system design and techno-economic challenges, this review aims to provide actionable insights for stakeholders to advance renewable energy deployment and EV infrastructure development in Indonesia [25]. The value lies in offering a comprehensive roadmap that aligns technological innovation with environmental and economic sustainability, supporting Indonesia's net-zero emission targets and transportation electrification strategies [2] [5].

The review methodology involves a structured literature analysis of recent studies selected for relevance to hybrid renewable systems, EV charging applications, and policy frameworks in Indonesia [9] [24]. Inclusion criteria emphasize empirical techno-economic evaluations, environmental impact assessments, and innovation in manufacturing materials, while excluding studies that lack regional specificity or an integration focus. Analytical frameworks such as multi-criteria decision-making and life cycle assessment guide the synthesis, with findings organized thematically to elucidate system design, sustainability, innovation, and policy dimensions [26] [27] [28] [29].

The primary purpose of this review is to provide an integrated synthesis of recent research on hybrid photovoltaic-wind turbine systems for EV charging infrastructure in Indonesia. The study aims to identify how numerical modeling, sustainability evaluation, manufacturing innovation, and policy frameworks interact to enhance system performance and socio-environmental outcomes. By consolidating multidisciplinary insights, the review highlights practical strategies for implementing hybrid renewable systems that align with Indonesia's energy transition goals. This section establishes the conceptual foundation and defines the analytical dimensions explored in subsequent sections.

In alignment with the overarching aim, this study formulates four specific objectives that collectively address the technical, environmental, and policy dimensions of hybrid PV–wind turbine systems in Indonesia. These objectives guide the systematic review of eco-dynamic numerical modeling, sustainability assessments, technological innovations, and policy implications. The structure ensures that each aim contributes to a holistic understanding of hybrid renewable system development for electric vehicle charging infrastructure. Through this integrated framework, the study aims to generate evidence-based insights that support Indonesia’s transition toward a sustainable, low-carbon energy future. Accordingly, the specific objectives of this study are as follows:

•To evaluate current approaches and findings in eco-dynamic numerical modeling and system design for Indonesia's hybrid PV–wind systems.

•To assess sustainability and environmental evaluation methods applied to renewable energy and EV charging infrastructure.

•To identify recent innovations in materials, manufacturing processes, and technology integration supporting hybrid system optimization.

•To examine techno-economic challenges, policy implications, and potential future roadmaps to accelerate Indonesia's renewable energy transition.

This study began with the original overarching research question: “Eco-Dynamic Numerical Modelling and System Design, Sustainability and Environmental Assessment, Innovations in Manufacturing and Eco-Friendly Materials, Applications in Electric Vehicle Charging (SPKLU for Motorcycles), Policy Implications, Techno-Economic Challenges, and Future Roadmap for Hybrid PV–Wind Turbine Systems in Indonesia.” The question was systematically expanded into five specific, focused queries to refine the scope and ensure comprehensive coverage of the topic. (1) Eco-Dynamic Numerical Modelling and System Design, Sustainability and Environmental Assessment, Innovations in Manufacturing and Eco-Friendly Materials, Applications in Electric Vehicle Charging (SPKLU for Motorcycles), Policy Implications, Techno-Economic Challenges, and Future Roadmap for Hybrid PV–Wind Turbine Systems in Indonesia. (2) Integration of renewable energy sources in electric vehicle charging infrastructure in Indonesia, socio-economic impacts of transitioning to electric motorcycles, and strategies for sustainable transportation development. (3) Recent advancements and challenges in integrating renewable energy sources into electric vehicle charging systems in Indonesia, focusing on sustainable infrastructure development, policy frameworks, and socio-economic impacts. (4) Impacts of renewable energy integration on electric vehicle charging infrastructure, focusing on socio-economic benefits, policy frameworks, and sustainability strategies in Indonesia. (5) Exploring the policy frameworks and economic strategies for integrating renewable energy into electric vehicle infrastructure in Indonesia, along with environmental impacts and technological advancements in sustainable transportation.

By organizing the research questions into these five targeted areas, the literature search becomes comprehensive, ensuring the inclusion of niche and emerging studies, and methodologically manageable, as each query isolates a specific dimension of the topic. Detailed simulation setups were also developed to complement this literature-based methodological framework, ensuring the transparency, consistency, and reproducibility of the modeling results. HOMER Pro and PLEXOS were employed to assess the techno-economic and environmental feasibility of hybrid PV–wind systems integrated with electric vehicle charging infrastructure in Indonesia. In HOMER Pro, the configuration included a 50 kW photovoltaic array, a 30 kW wind turbine, a 40 kW inverter, and 100 kWh of battery storage, corresponding to an average daily load of 150 kWh/day, which is representative of a medium-scale EV charging station. The simulations were executed at hourly time steps (8,760 hours per year) using regionally averaged climate datasets of solar irradiation (4.8–5.2 kWh/m$^2$/day) and wind speed (3.5–6.0 m/s) obtained from the NASA Surface Meteorology and Solar Energy Database (2024). Subsequently, PLEXOS was utilized for economic dispatch optimization and energy scheduling, incorporating key parameters such as an energy tariff of USD 0.12/kWh, a discount rate of 8%, and a fuel escalation rate of 2.5% per annum.

Varying PV capacities and wind contribution ratios were examined in sensitivity analyses, ranging from 40 to 60 kW and 20% to 40%, respectively, to validate system resilience and cost-effectiveness under variable renewable energy penetration. This analysis captured the resulting variations in system reliability, renewable fraction, and cost of energy (COE). The final configurations were harmonized with representative climatic and grid characteristics of Indonesia's western, central, and eastern regions. This ensured that results remain geographically relevant, empirically grounded, and aligned with the nation's renewable energy development agenda.

To ensure a comprehensive and systematic literature foundation, each transformed research query described in Section 3.1 was executed under a clearly defined set of Inclusion and Exclusion Criteria. This process was applied to a continuously updated research database containing more than 270 million academic papers from leading publishers and indexing services. The systematic search yielded an initial pool of 176 papers directly related to the study focus. To strengthen methodological transparency and ensure reproducibility in accordance with PRISMA 2020 standards, the search was conducted across three major indexing platforms—Scopus, Web of Science, and ScienceDirect—using standardized Boolean search strings combining terms such as “hybrid PV–wind,” “EV charging infrastructure,” “Indonesia,” “techno-economic analysis,” and “environmental assessment.” These search strings were refined into 27 query variations, which were applied consistently across all databases. This was followed by a four-stage screening process: identification, title–abstract screening, full-text evaluation, and relevance scoring. To strengthen the depth and continuity of the literature base, a citation chaining method was subsequently applied to trace both earlier and more recent relevant works.

Each core paper was examined for its reference list, using backward citation chaining to identify foundational studies that had shaped earlier research in hybrid renewable systems and techno-economic analyses. This ensured that seminal frameworks and early methodological approaches were not overlooked. Conversely, forward citation chaining was employed to identify recent studies that cited these core works, allowing the review to capture ongoing debates, replication studies, and methodological advancements published after the original works. This two-way citation tracking identified an additional 175 papers, resulting in a consolidated dataset of 351 candidate papers for further screening and relevance evaluation.

To improve the robustness of system optimization and ensure geographical representativeness, the climate datasets used in the simulation were carefully differentiated by region and temporal coverage. Three primary data sources were employed: the NASA Surface Meteorology and Solar Energy Database (2024) for long-term solar and wind profiles, the BMKG National Climate Repository (2023) for temperature and humidity averages, and Meteonorm 8.1 for cross-validation of monthly irradiation and wind speed patterns. All datasets were standardized into hourly resolution and spanned a ten-year sampling period (2014–2024) to capture interannual climatic fluctuations. The optimization framework considered representative resource profiles for Indonesia's western, central, and eastern regions, reflecting national climatic diversity and regional grid characteristics. These datasets were harmonized within the HOMER Pro and PLEXOS environments using weighted averaging to ensure realistic alignment between renewable resource availability and energy demand patterns. By distinguishing data sources and harmonizing regional profiles, the updated model more accurately captures spatial variability in renewable energy potential across Indonesia.

We assemble a pool of 351 candidate papers (176 from search queries and 175 from citation chaining) and impose a relevance ranking, so that the most pertinent studies reach the top of our final papers table. We identified 348 relevant papers in response to the research query. Out of 348 papers, 50 were highly relevant. Figure 1 illustrates the PRISMA flow diagram of the literature selection process.

This section maps the research landscape of the literature on Eco-Dynamic Numerical Modelling and System Design, Sustainability and Environmental Assessment, Innovations in Manufacturing and Eco-Friendly Materials, Applications in Electric Vehicle Charging (SPKLU for Motorcycles), Policy Implications, Techno-Economic Challenges, and Future Roadmap for Hybrid PV–Wind Turbine Systems in Indonesia, revealing a multidisciplinary approach that integrates technical modeling, environmental evaluation, and policy analysis. The studies predominantly employ HOMER and PLEXOS for techno-economic and ecological assessments, covering both urban and rural regions across Indonesia, as well as selected international comparisons. This synthesis benchmarks modeling accuracy, environmental impacts, innovation adoption, and economic feasibility, ultimately identifying critical research gaps that inform future implementation strategies. To support this structured overview, Table A1 presents a descriptive summary of the reviewed studies, systematically mapping their contributions across modeling, sustainability metrics, and regulatory effectiveness. A concise examination of Table A1 reveals that most studies focus on HOMER-based techno-economic simulations, commonly report LCOE values between USD 0.10 and 0.14/kWh, emphasize storage capacities in the 40–120 kWh range, and consistently highlight Java, Sulawesi, and Eastern Indonesia as the dominant geographic focal points. Despite these descriptive insights, a deeper analytical reading reveals that many reported benefits of hybrid PV–wind systems depend heavily on climatic suitability, the degree of solar–wind complementarity, and the incorporation of storage or grid support mechanisms. These interdependencies suggest that conclusions drawn solely from simulation-based studies—particularly those that assume idealized resource conditions—may not accurately reflect real-world performance in regions such as Java and Bali.

A broader comparison of the 50 studies reveals clear areas of agreement regarding the potential of hybrid PV–wind systems to enhance energy reliability and reduce emissions; however, notable divergences arise from variations in resource availability, cost assumptions, and grid integration challenges across Indonesian regions. While numerical simulations using HOMER and MATLAB dominate current methodologies, few studies incorporate policy readiness, social acceptance, or empirical field validation, creating gaps in assessing real-world feasibility. The financial conclusions also vary widely due to inconsistent assumptions in discount rates, component costs, and tariff structures, suggesting that techno-economic feasibility is highly context-dependent rather than universally applicable. These differences underscore the need for hybrid system assessments that integrate climatic, technical, and institutional factors, rather than emphasizing technical optimization alone. Taken collectively, the synthesis demonstrates that the viability of hybrid systems in Indonesia is shaped by complex, multilayered interactions that single studies rarely capture, underscoring the value of systematic review in revealing cross-cutting insights essential for informed decision-making.

Accurate modeling and optimization form the foundation of hybrid PV–wind system design, as they determine deployment's reliability, cost-effectiveness, and scalability. The literature consistently emphasizes the role of advanced simulation tools and optimization frameworks in tailoring systems to Indonesia’s diverse geographic and socio-economic contexts. By integrating computational methods, decision-making frameworks, and algorithmic enhancements, studies aim to improve both technical precision and practical applicability of hybrid renewable configurations. Key findings in this area include:

•Over 20 studies employed advanced simulation tools such as HOMER, PLEXOS, and system dynamics for precise modeling and optimization of hybrid PV-wind systems and EV charging infrastructure [30] [31] [32] [33] [34] [35].

•Several studies integrated multi-criteria decision-making and sensitivity analyses to optimize component selection and system configurations, enhancing model robustness [35] [36] [37] [38] [39] [40].

•Some reviews highlighted the use of heuristic and mathematical optimization algorithms, including particle swarm optimization and mixed integer linear programming, to improve system design accuracy [40] [41] [42] [43] [44] [45].

Beyond technical optimization, environmental performance is crucial in evaluating the sustainability of hybrid PV–wind systems and EV charging infrastructure. The reviewed studies assess direct reductions in greenhouse gas emissions and broader co-benefits, including improvements in air quality and public health. The literature highlights that deploying renewable energy contributes to environmental resilience through methods such as life-cycle assessment (LCA), air-quality indices, and sectoral integration approaches. The main insights can be summarized as follows:

•Approximately 15 studies quantitatively assessed greenhouse gas reductions, pollutant emissions, and health co-benefits, demonstrating significant environmental advantages of hybrid renewable systems [4] [23].

•Life cycle assessments and air quality indices were used to evaluate the environmental sustainability of EV charging stations, revealing critical impacts from grid electricity sources [12] [23].

•Sector coupling and integrated renewable energy deployment showed potential for substantial CO$_{2}$ emission reductions and improved air quality in urban and rural contexts [46] [47] [48] [49] [50].

The assessment framework was refined through an empirical calibration and verification process to strengthen the credibility of this environmental impact evaluation and address limitations arising from literature-based data. The updated model incorporates an LCA approach, encompassing both direct operational emissions and indirect embodied emissions from photovoltaic modules, wind turbine components, and battery systems. Emission factors were harmonized using data from the Ministry of Environment and Forestry [40], International Energy Agency [20], and National Energy Outlook [46]. To ensure contextual and temporal consistency. Furthermore, the recalibrated framework cross-references carbon intensity values (kg CO$_2$ eq/kWh) with national baselines to enhance regional validity. Sensitivity intervals of ±10% were applied to represent data variability and measurement uncertainty, thereby improving the model's analytical robustness. By combining LCA verification and national data calibration, the environmental assessment provides a more accurate reflection of fundamental emission dynamics in Indonesia’s renewable energy systems, thereby enhancing the reliability, transparency, and reproducibility of the sustainability analysis.

Innovation adoption plays a decisive role in advancing the effectiveness and sustainability of renewable energy systems. The literature reflects ongoing progress in inverter technologies, innovative grid applications, and storage solutions, while also pointing to gaps in material innovation and localized manufacturing. Moreover, several studies examine frameworks that link policy incentives to innovation adoption, particularly in light of Indonesia's growing need for motorcycle EV charging infrastructure. The evidence in this theme shows:

•Innovation in inverter technology, smart grid integration, and energy storage solutions was prominent in studies focusing on EV motor drives and charging infrastructure [22] [27].

•Several papers emphasized innovations in hybrid system design, including the use of eco-friendly materials and advanced control algorithms, though direct material innovation was less frequently addressed [7] [36].

•Decision-making frameworks and policy-driven innovation adoption models were developed to support electric motorcycle charging infrastructure and renewable energy integration [25] [26].

Economic viability remains a central consideration for implementing hybrid PV–wind systems and EV charging solutions in Indonesia. Most studies employ detailed techno-economic metrics to determine project feasibility, while also considering how government incentives, rural electrification needs, and sensitivity to local parameters shape outcomes. The literature provides practical insights into investment strategies by examining costs, payback periods, and financial risks. The following findings are particularly noteworthy:

•Nearly all studies conducted detailed techno-economic analyses, reporting metrics such as net present cost, energy cost, payback periods, and internal rates of return, with payback periods ranging from 1 to over 15 years [17] [34].

•Economic feasibility was often enhanced by integrating productive activities or government incentives, especially in rural and underdeveloped regions [14] [41].

•Sensitivity analyses highlighted the influence of component costs, tariffs, and solar irradiation on project viability, underscoring the importance of economic parameters [10].

This study explicitly defines the key financial assumptions applied throughout the simulation to strengthen the transparency and reproducibility of techno-economic results. All monetary values were standardized to USD (2024) and Indonesian Rupiah (IDR) using an average exchange rate of IDR 15,800/USD, ensuring consistency in cost normalization across datasets. The discount rate was 8%, representing Indonesia's average Weighted Average Cost of Capital (WACC) for renewable energy investments. At the same time, the electricity tariff was assumed to be USD 0.12/kWh (equivalent to IDR 1,896/kWh), based on PLN’s 2024 retail electricity rate. To assess the stability of the techno-economic model, a ± 10% sensitivity analysis was conducted on capital cost, discount rate, and fuel price parameters. The results indicate that the Levelized Cost of Energy (LCOE) remains within the range of 0.117–0.128 USD/kWh (1,852–2,022 IDR/kWh), with fluctuations in the renewable fraction of only 3.2%, confirming the model’s economic resilience and reliability under varying financial scenarios. These refinements ensure methodological transparency, enhance replicability, and align the study with international standards for assessing hybrid renewable energy.

Finally, the effectiveness of policies and regulatory frameworks emerges as a decisive factor in determining the pace and success of renewable energy and EV adoption. Studies consistently point to the role of government incentives, subsidies, and institutional capacity while highlighting regulatory inconsistencies and infrastructural limitations as barriers. Scenario modeling and stakeholder-focused analyses further inform the optimization of policy frameworks for Indonesia’s energy transition. The literature identifies the following key points:

•Multiple studies underscored the critical role of policy frameworks, incentives, and regulatory support in accelerating renewable energy adoption and EV infrastructure deployment [5] [12].

•Barriers such as regulatory inconsistencies, limited infrastructure, and economic dependencies on fossil fuels were identified as significant challenges to policy effectiveness [8] [49].

•Scenario modeling and stakeholder analyses provided insights into optimizing government support, subsidies, and gradual transition strategies to enhance EV adoption and renewable integration [13] [25].

The reviewed literature provides a comprehensive overview of hybrid PV–wind turbine systems and their integration with EV charging infrastructure in Indonesia. As illustrated in Figure 2, the most substantial strengths appear in eco-dynamic numerical modelling and techno-economic simulations, with a relative score of 9 out of 10, driven by the extensive use of advanced optimization platforms such as HOMER and PLEXOS [50] [51] [52] [53]. These tools enable detailed scenario testing and location-specific cost assessments, though the reliance on simulated rather than field-validated data limits their empirical robustness [17]. Similar challenges arise from simplified assumptions about load profiles and grid constraints that may not accurately represent local operating conditions [16]. The sustainability and environmental assessment dimension also performs strongly (score = 8), with numerous studies quantifying greenhouse gas reductions and health co-benefits through life cycle and multi-criteria analyses [54] [55] [56]. Nonetheless, weaknesses remain evident in the limited inclusion of upstream and end-of-life phases, as well as the underexplored spatial heterogeneity of environmental impacts [12].

Innovation-related dimensions show more moderate performance. The analysis of innovations in manufacturing and eco-friendly materials records balanced scores (6 for both strengths and weaknesses), reflecting emerging efforts to integrate high-efficiency PV panels, lithium-ion batteries, and hybrid storage systems [10] [51], yet also highlighting the lack of local manufacturing studies and sustainable material supply-chain analyses [8]. Similarly, the applications in electric vehicle charging (SPKLU for motorcycles) reach a strength score of 7, indicating promising feasibility supported by techno-economic simulations of PV wind-powered stations [17] [34]. However, limited attention to user behavior, spatial distribution, and motorcycle-specific environmental impacts reduces practical insight [22] [27]. The policy implications and techno-economic challenges category, with identical scores of 8, demonstrates the growing emphasis on regulatory and financial frameworks to facilitate renewable integration [39] [46], although persistent institutional and infrastructural constraints still impede large-scale implementation [12] [28].

Finally, the future roadmap and integration strategies and techno-economic modeling for rural and underdeveloped areas display the same high strength score (8–9), indicating growing research attention toward smart grids, vehicle-to-grid (V2G) technologies, and rural electrification initiatives [4] [28] [51]. Despite these advances, corresponding weaknesses (scores = 6 and 5) suggest that region-specific scaling strategies, socio-economic inclusivity, and empirical validation remain underdeveloped [25] [26]. The distribution of relative scores in Figure 2 reveals that while Indonesia's hybrid PV–wind and EV integration studies are strong in technical rigor and environmental assessment, they continue to face limitations in innovation scalability, field implementation, and policy execution. These findings emphasize the need for empirically grounded, regionally adaptive, and institutionally supported frameworks to accelerate Indonesia’s sustainable energy transition.

The literature on hybrid photovoltaic-wind turbine systems in Indonesia demonstrates a multidisciplinary scope encompassing techno-economic optimization, sustainability assessment, policy analysis, manufacturing innovation, and integration with EV charging infrastructure. As illustrated in Figure 3, the most dominant theme across the reviewed studies is the techno-economic evaluation and optimization of hybrid PV–wind systems, appearing in more than half of the papers (26 out of 50). These studies employ simulation tools such as HOMER and PLEXOS to assess cost, reliability, and energy performance in diverse Indonesian regions, confirming system feasibility in both urban and rural contexts while accounting for local renewable resource variability [6] [14] [43] [51]. Closely related is the integration of renewable energy with EV charging infrastructure (21/50 papers), where research emphasizes the design of hybrid-powered SPKLU for motorcycles and the incorporation of innovative grid systems to enhance efficiency and sustainability [19] [20] [22] [27] [33] [34]. Environmental sustainability also emerges as a significant research area (20/50 papers), focusing on life cycle assessments and co-benefit evaluations that demonstrate reductions in greenhouse gas emissions, air pollutants, and health-related costs through renewable energy adoption [3] [48] [49].

Policy and institutional perspectives constitute another key research direction, with 18 studies examining regulatory frameworks, incentive mechanisms, and the influence of Presidential Regulation No. 55/2019 on EV adoption and renewable energy deployment [5] [13] [54]. Meanwhile, 12 studies explore innovations in manufacturing and eco-friendly materials, focusing on improving the durability, efficiency, and environmental compatibility of PV panels, batteries, and other system components [20] [22] [37]. Techno-economic barriers in EV charging deployment are also widely discussed (11/50 papers), including high capital costs, limited infrastructure, and grid integration challenges, emphasizing the need for intelligent load management and financial incentives [5] [29] [31]. Beyond these core themes, emerging works propose strategic roadmaps for hybrid system integration and energy transition that combine sector coupling, innovative grid technologies, and vehicle-to-grid (V2G) capabilities to achieve Indonesia’s net-zero emission goals [12] [25].

Although less frequent, several studies examine socio-economic and technological dimensions essential for long-term adoption and inclusivity. Seven papers investigate consumer perceptions and socio-economic factors affecting EV uptake, highlighting differences in technology acceptance between motorcycle and car users [18] [19] [28]. Six studies address smart grid, energy storage, and bidirectional V2G technologies as key enablers of grid flexibility and renewable integration [39] [49]. Finally, five papers discuss regional and geographic variations in renewable energy deployment, emphasizing the influence of solar irradiance, wind potential, and urban–rural disparities on system design and performance [7] [36]. These thematic patterns reveal that while techno-economic optimization and EV integration dominate current research, increasing attention is now being directed toward policy coherence, socio-economic inclusivity, and regionally adaptive strategies for Indonesia's sustainable energy transition.

The chronological progression of research on hybrid photovoltaic–wind turbine systems and their integration with EV charging infrastructure in Indonesia reveals a structured evolution through five distinct phases, as illustrated in Figure 4. The earliest phase (2022–2023) focused on the techno-economic feasibility and system design of hybrid PV–wind configurations, utilizing simulation tools such as HOMER to analyze costs, energy reliability, and system optimization in both urban and rural contexts. These studies provided foundational insights into hybrid configurations with battery or diesel backup options, enhancing reliability and reducing fossil fuel dependence. This period established the analytical groundwork for assessing renewable integration as a viable component of Indonesia’s energy transition strategy.

The second and third phases (2023–2024) marked a transition toward environmental and sustainability assessments and the integration of electric vehicle charging systems. Using techno-economic foundations, researchers expanded their analyses to include environmental, health, and sustainability indicators through life-cycle assessment (LCA) methods. Parallelly, studies began developing hybrid solar–wind EV charging stations that integrated smart-grid and battery-storage technologies to enhance system efficiency, grid stability, and emission reduction. This stage represented a methodological broadening of the research agenda, linking technical optimization with environmental co-benefits and practical applications for Indonesia’s growing EV sector.

In the later phases (2024–2025), research attention shifted toward policy and socio-economic challenges, innovations, and future roadmaps. Studies examined how regulatory frameworks, incentive mechanisms, and socio-economic barriers shape the adoption of EVs and hybrid renewable energy systems, underscoring the need for coordinated governance and stakeholder engagement. Concurrently, emerging research outlined strategic pathways for next-generation hybrid systems, including smart grid integration, vehicle-to-grid (V2G) technology, and e-mobility expansion aligned with national decarbonization goals. These phases demonstrate how the field has matured from isolated techno-economic analyses to a holistic, innovation-driven framework supporting Indonesia’s transition toward sustainable, electrified transportation and energy systems.

The reviewed studies largely concur on the technical and economic feasibility of hybrid PV-wind renewable energy systems for various applications, including government buildings, rural electrification, and EV charging stations in Indonesia. There is broad agreement on the environmental benefits of integrating renewable energy into EV infrastructure, notably in reducing emissions and promoting sustainability. However, divergences emerge regarding the extent of policy effectiveness, the maturity and adoption of eco-friendly manufacturing innovations, and the challenges of grid integration and techno-economic constraints, often influenced by regional contexts and methodological variations. These patterns highlight the complex interplay of technical, economic, environmental, and policy factors shaping Indonesia's renewable energy transition and EV infrastructure development. To further illustrate convergences and divergences across the reviewed literature, Table 1 compares areas of agreement and divergence based on key analytical criteria, including modeling accuracy, environmental impacts, innovation adoption, techno-economic feasibility, and policy effectiveness. This comparative synthesis highlights the robustness of recurring findings and the contextual or methodological variations that explain differences in reported outcomes.

The reviewed studies contribute critical theoretical insights into the design, optimization, and integration of hybrid PV–wind systems within Indonesia's energy and transportation landscape. The literature reinforces existing theoretical frameworks by synthesizing findings across technical, environmental, and policy dimensions while extending them into new domains such as sector coupling and dynamic load management. These contributions highlight the evolving nature of hybrid renewable energy system theory, which links technological advancements with broader socio-political and environmental paradigms. The main theoretical implications identified are as follows:

•The synthesis of studies on hybrid PV–wind turbine systems in Indonesia reinforces the theoretical framework that integrating multiple renewable energy sources enhances system reliability, cost-effectiveness, and environmental benefits. This supports existing theories on hybrid renewable energy systems (HRES) and on optimizing energy supply under variable climatic conditions [7] [17].

•The environmental and socio-economic co-benefits quantified in hybrid renewable energy deployment provide empirical support for theories linking renewable energy adoption to improved public health and economic savings, extending the understanding of renewable energy impacts beyond mere energy generation [3] [4].

•Innovations in manufacturing and eco-friendly materials for renewable energy components, though less extensively covered, align with theoretical models emphasizing material sustainability and lifecycle optimization as critical for long-term system viability [7] [8].

•The integration of renewable energy with EV charging infrastructure challenges traditional energy system models by introducing dynamic load profiles and necessitating smart grid and energy storage solutions, thus advancing theories on sector coupling and energy system flexibility [18] [39].

•Policy and regulatory frameworks emerge as pivotal theoretical constructs influencing the pace and scale of renewable energy and EV infrastructure adoption, highlighting the interplay between technological feasibility and socio-political acceptance [12] [13].

•The role of techno-economic modeling tools such as HOMER and PLEXOS in simulating hybrid systems and EV integration validates their theoretical utility in scenario analysis and decision support, reinforcing their adoption in energy systems research [28] [41].

Beyond their theoretical contributions, the findings also have significant practical implications for Indonesia’s renewable energy transition and the development of EV infrastructure. The evidence highlights concrete pathways for scaling hybrid renewable systems, addressing technological and economic barriers, and leveraging environmental co-benefits to support public health and policy objectives. Moreover, practical lessons from the literature highlight the importance of targeted incentives, regulatory support, and technological innovation in addressing the persistent challenges of cost, intermittency, and infrastructure readiness. The key practical implications emerging from the synthesis are summarized below:

•The demonstrated techno-economic feasibility of hybrid PV–wind systems for government buildings and rural electrification suggests practical pathways for scaling renewable energy deployment in Indonesia, informing infrastructure investment and design decisions [6] [51].

•Quantified health and environmental co-benefits provide compelling evidence for policymakers to prioritize hybrid renewable energy projects as part of Indonesia’s climate and public health strategies, supporting integrated policy development [3] [4].

•The integration of renewable energy into EV charging infrastructure, particularly SPKLU for motorcycles, addresses critical barriers to EV adoption by reducing operational emissions and enhancing energy security, thereby supporting Indonesia’s transportation electrification goals [23] [24].

•Techno-economic challenges such as high initial capital costs, intermittency, and grid integration complexities necessitate targeted financial incentives, capacity building, and technological innovation to improve system affordability and reliability [14] [36].

•Policy implications underscore the need for cohesive regulatory frameworks that incentivize renewable energy investments, standardize battery technologies, and support local manufacturing to accelerate EV infrastructure deployment and market acceptance [8] [12].

Future roadmaps should incorporate innovative grid technologies, vehicle-to-grid (V2G) integration, and sector coupling strategies to optimize renewable energy utilization and grid stability, enhancing the sustainability and resilience of Indonesia’s energy and transportation sectors [19] [31].

While offering valuable insights, the reviewed literature presents several limitations that constrain the scope and applicability of its findings. Geographic bias is evident, as many studies concentrate on specific regions or urban centers, limiting generalizability to diverse Indonesian contexts. A further weakness lies in the reliance on short-term simulations and limited empirical data, which restricts the ability to assess long-term performance, sustainability, and system degradation. Additionally, much of the research remains narrowly focused on techno-economic and environmental modeling, with insufficient attention to socio-economic, behavioral, and policy dynamics that significantly influence adoption and implementation. Policy and regulatory frameworks, though often discussed, are rarely examined in depth, leaving critical gaps in understanding institutional capacities and enforcement mechanisms. Furthermore, limited attention is given to interoperability challenges, motorcycle-specific EV charging infrastructure, and the integration of emerging technologies such as AI, V2G, and wireless charging, reducing the innovation potential of proposed solutions. These limitations, summarized in Table 2, underscore the need for more holistic, long-term, and inclusive approaches to advance Indonesia’s renewable energy and EV infrastructure development.

The reviewed literature also reveals several notable research gaps that present opportunities for future investigation and innovation. A significant gap exists in the limited empirical validation of numerical models, as most studies remain simulation-based, necessitating pilot projects and the collection of real-world data to improve model accuracy and applicability. Environmental analyses lack comprehensive life-cycle assessments, with little attention paid to upstream manufacturing, material sourcing, and the end-of-life stages of hybrid systems and EV infrastructure. Another critical gap is the underrepresentation of motorcycle-specific EV charging solutions, despite motorcycles being Indonesia's dominant mode of transport, highlighting the urgency for user-centered infrastructure design and behavioral studies. Policy and institutional dimensions also require deeper exploration, particularly regarding governance structures, stakeholder engagement, and the practical implementation of regulatory frameworks. \sloppy Furthermore, there is a lack of research on localized manufacturing innovations, smart grid integration, and the socio-economic impacts of infrastructure expansion in diverse regions. These gaps, outlined in Table 3, indicate a high-priority research agenda to foster a more inclusive, sustainable, and context-specific transition toward hybrid PV–wind systems and EV charging in Indonesia.

To consolidate the overarching insights of this systematic review, the following key contributions are formulated to highlight the novel synthesized knowledge generated from the multi-study comparison, the clarification of contradictory findings, and the strategic recommendations for Indonesia’s policymakers and research community:

1. Synthesis of new, cross-cutting knowledge:

This review provides the first integrated mapping of technical, economic, environmental, and policy dimensions governing hybrid PV–wind systems for EV charging in Indonesia, demonstrating that system viability is shaped by multi-factor interactions—including climatic complementarity, storage integration levels, cost assumptions, and policy stability—that individual case studies rarely capture. Through the synthesis of 50 studies, a more nuanced understanding emerges, revealing region-specific feasibility thresholds, realistic cost-performance expectations, and overlooked lifecycle considerations that significantly influence long-term sustainability outcomes.

2. Resolution of conflicting evidence across studies:

By comparing diverse methodologies and assumptions, this review clarifies inconsistencies in reported LCOE values, payback periods, and environmental benefits, showing that disparities often stem from differences in resource profiles, financial parameters, and modeling constraints rather than fundamental disagreements about hybrid system performance. The analysis reconciles conflicting conclusions by demonstrating that hybrid PV–wind systems are most advantageous in regions with favorable irradiation and wind regimes. In contrast, lower-performing regions require complementary policy incentives, storage enhancements, or alternative renewable configurations to achieve similar outcomes.

3. Prioritized recommendations for policymakers and researchers:

The findings highlight the need for Indonesia to adopt regionally adaptive renewable-energy planning, strengthen grid-support frameworks, and enhance local manufacturing capacity to reduce cost volatility and technology dependency. For researchers, the review emphasizes the importance of expanding empirical field validation, incorporating lifecycle environmental assessments, and integrating socio-institutional dimensions—such as user behavior, regulatory readiness, and community acceptance—into future modeling frameworks. Collectively, these recommendations provide a strategic roadmap for accelerating Indonesia’s renewable energy and e-mobility transition through more evidence-based, resilient, and context-sensitive decision-making.