• Increasing electric vehicles (EVs) and the 3Ds: With the rise of decarbonization, decentralization, and digitalization, the number of electric vehicles is projected to increase significantly, necessitating the implementation of modern technologies to avoid unnecessary energy wastage.

These highlights provide an overview of the key points covered in the review article on blockchain-enabled energy trading between electric vehicles and smart grids in IoT environments.

The transition toward sustainable energy systems is characterized by three fundamental shifts, namely, decarbonization, decentralization, and digitalization, often referred to as the 3Ds. These shifts are increasingly relevant in the context of electric vehicles (EVs), which are projected to constitute 50% of the new vehicle market in the near future (Sexauer et al., 2011). This surge in EV adoption necessitates the integration of advanced technologies to ensure efficient energy utilization and support the overarching objectives of sustainable urban development. The advent of blockchain technology, alongside the Internet of Things (IoT) and related digital innovations, has emerged as a pivotal element in the evolution of smart city infrastructures. However, the current electricity management paradigms, plagued by inefficiencies and environmental concerns, demand a transformative approach to integrate renewable energy sources seamlessly with the existing grid systems (Tuballa and Abundo, 2016; Pavon et al., 2021; Si et al., 2021).

Blockchain, a decentralized ledger technology, was introduced in 2008 by Satoshi Nakamoto, revolutionizing data management with its immutable and transparent characteristics (Zamfirescu et al., 2019; Nakamoto, 2023). This technology, characterized by a sequential chain of data blocks linked through cryptographic hashes, guarantees the integrity and immutability of stored information (Yap et al., 2023). Each block encapsulates data elements like timestamps, transactions, and nonces, ensuring a robust audit trail, as depicted in Figure 1.

The diversity of blockchain networks, categorized into public, permissioned, and private domains, reflects the varying levels of access and participation. Public blockchains like Ethereum offer open access, whereas permissioned and private networks impose access restrictions, influencing network scale and operational dynamics (ethereum.org, 2023). The heart of these networks lies in their consensus protocols, which are mechanisms ensuring ledger consistency across all nodes. These protocols, including proof-of-work (PoW) and proof-of-stake (PoS), vary in attributes such as transaction speed, scalability, and security (Xie et al., 2018; Krishnamoorthi et al., 2023). The evolution from PoW to more efficient protocols like PoS reflects ongoing advancements to mitigate computational and energy inefficiencies (King and Nadal, 2012). Figure 2 illustrates the operational mechanism of the PoS protocol.

Smart contracts and automated executable codes further extend the utility of blockchains , enabling self-executing agreements based on predefined conditions (Szabo, 1996; Zheng et al., 2020). These contracts, once deployed on blockchain platforms like Ethereum and Hyperledger Fabric, facilitate transparent and secure transactions without intermediaries, ensuring trust and integrity in digital interactions (Wang et al., 2018; Amazon, 2023).

The concept of an electric grid encompasses the generation, transmission, distribution, and control of electricity. In this context, smart grids represent an advanced infrastructure paradigm, leveraging IoT and sophisticated algorithms to enhance energy efficiency and management (Fang et al., 2012; Siano, 2014). The integration of EVs and renewable energy sources (RESs) into smart grids introduces variability in power generation, necessitating innovative management strategies to maintain power quality and system stability (Dharmakeerthi et al., 2011; Ahmadi et al., 2019; Galus et al., 2019). Effective scheduling of EV charging, supported by auction-based mechanisms, can optimize energy consumption and pricing dynamics, thereby mitigating energy loss and enhancing grid efficiency (Sarenche et al., 2021). Given the environmental concerns, fossil fuel depletion, and the ascent of multi-energy system structures, there is a growing emphasis on the integration of blockchain technology in smart grids (Zhang N. et al., 2022). Energy storage (ES) plays a pivotal role in enhancing power quality and reliability within these grids, particularly in managing the variability of renewable energy sources and ensuring their dispatchability (Zhong et al., 2020). The rise of smart grids, underscored by their reliability, efficiency, and sustainability, necessitates sophisticated control and management of diverse energy devices to balance supply and demand economically (Ding et al., 2018).

This review paper delves into the incorporation of blockchain technology within EV charging systems powered by renewable energy, spanning research from 2017 to 2023 and carefully examining 48 academic publications (Li and Hu, 2021; Yahaya et al., 2020; Li and Hu, 2020; Samuel et al., 2020; Samuel et al., 2022; Zhang Q. et al., 2022; Liang et al., 2022; Liu et al., 2022; Kumar et al., 2023; Wang et al., 2023; Chen et al., 2021; Hassan et al., 2022; Wen et al., 2022; Lasla et al., 2020; Khalid et al., 2020; Dorokhova et al., 2021; Cavalcante et al., 2023; Bouachir et al., 2022; Barnawi et al., 2021; Mhaisen et al., 2019; Javed et al., 2021; Florea, 2020; Javed et al., 2020; Akhter et al., 2022; Zhang S. et al., 2022; Zhao et al., 2022; Salmani et al., 2022; Li et al., 2020; Munsing et al., 2017; Zhang et al., 2018; Meena and Yang, 2019; Elliott et al., 2020; Wang and Zhang, 2022; Li et al., 2021; Baza et al., 2021; Zhou et al., 2019; Debe et al., 2021; Javed and Javaid, 2019; Luo et al., 2022; Khalid et al., 2021; Abishu et al., 2022; Liu et al., 2019; Seven et al., 2020). The exclusion of non-academic sources was deliberate, prioritizing scientific rigor. The analysis adhered to Kitchenham’s systematic literature review methodology (Kitchenham and Charters, 2007). Subsequent sections will explore the related literature, methodology, main findings, forward-looking recommendations, and conclusions, thereby addressing the gaps identified in prior studies and outlining the direction for future research.

The field of integrating blockchain technology with electric vehicle (EV) charging systems is expanding rapidly, making it necessary to comprehensively review the existing literature to identify current research trends, methodologies, and gaps. To this end, we utilized “Publish or Perish” software (Harzing, 2023) to amass a preliminary collection of 35 surveys related to blockchain, EVs, renewable energy generation, electricity charging, and energy storage. After a meticulous screening process, 29 surveys were deemed relevant for further analysis. Figure 3 illustrates the distribution of these surveys across the specified topics. The chart reveals that most studies focused on blockchain, EVs, and energy storage, while fewer surveys address electricity charging directly. Notably, a mere 17.24% of these surveys encompass all the topics, although concisely, signifying a research void in comprehensively addressing these interconnected fields.

After identifying the topics, the surveys were assessed qualitatively to evaluate their thoroughness in covering the subject matter, rated as low (L), medium (M), or high (H). Table 1 shows the level of detail each survey provides on five central themes, aiding in spotting research trends and gaps. This evaluation particularly underscored the lack of detailed research in the areas of electricity charging and energy storage. It was found that there is extensive research on blockchain and renewable energy generation, likely due to the increasing interest in integrating these fields with energy management systems. However, there is a discernible deficiency in detailed studies on energy storage systems, which are often assumed to integrate smoothly with the grid without requiring separate scrutiny.

In dissecting individual contributions, Adil et al. (2021) proposed integrating EV energy trading using the Stackelberg game theory, emphasizing the strategic interaction of rational actors in the market. However, their analysis underrepresented the potential of blockchains in enhancing grid systems. Bao et al. (2020) concentrated on the role of blockchains in monitoring and scheduling EV charging, recognizing the technology’s security and privacy benefits. Yapa et al. (2021) envisioned Smart Grid 2.0, integrating diverse energy sources and real-time control through Internet connectivity, proposing a future grid model that leverages blockchain and artificial intelligence (AI) for energy trading. Baashar et al. (2021) highlighted AI’s potential in predicting and optimizing EV charging schedules within blockchain-based systems, while Aggarwal et al. (2021) explored advanced concepts like vehicle-to-vehicle (V2V) charging and market mechanisms within blockchain-enabled smart grids.

This literature review also acknowledges other noteworthy surveys like those by Guo et al. (2022), who emphasized the use of blockchains in grid systems, and Zafar and Ben Slama (2022), who focused on integrating blockchains with Smart Grid 2.0. These works, despite their valuable insights, did not fully address the electric charging mechanisms, indicating a research opportunity. Our analysis extends beyond identifying topical coverage to evaluating the statistical and methodological rigor of the surveyed literature. Many studies lack detailed explanations of their statistical approaches and the reproducibility of their findings, an aspect critical for advancing research in this domain.

Institutional research trends indeed show that universities and research centers with strong engineering and technology programs, such as MIT and Stanford, are leading in blockchain and renewable energy research (MIT Energy Initiative, 2024; Stanford Center for Blockchain Research, 2024). The MIT Energy Initiative, for instance, is developing sustainable, low-carbon solutions to meet the world’s energy demands (MIT Energy Initiative, 2024). Similarly, the Stanford Center for Blockchain Research is focusing on cryptocurrencies and blockchain technologies (Stanford Center for Blockchain Research, 2024). The innovative use of blockchain to enhance grid management and EV integration is a strength of these approaches (Wang et al., 2020). For example, the Mobility Open Blockchain Initiative (MOBI) standard for grid integration of electric vehicles incorporates blockchain technology into a decentralized charging system.

In conclusion, our literature review fills the existing research gap by providing an examination of blockchain applications in smart energy and electricity management (Silva et al., 2019), highlighting system performance, identifying limitations, and providing recommendations for future research. Our contributions aim to enhance the understanding of electric management systems, evaluate blockchain networks for energy applications, and propose a comprehensive, methodologically sound research framework.

The study described in this paper is based on the systematic literature review (SLR) methodology developed by Kitchenham and Charters (2007). The methodology consists of three phases: planning, conducting, and reporting. The planning phase is further divided into six stages. Initially, research questions were formulated based on the objectives of the review. A strategy was then devised to locate relevant research papers, which involved identifying appropriate search terms and criteria for paper selection. Guidelines were established to determine which studies should be included or excluded. Additionally, quality assessment rules were designed to filter the research papers. A method was outlined for extracting data from the selected studies that met the predetermined criteria. Finally, the extracted data from the chosen studies were synthesized to address the research questions. The subsequent sections of the paper will present an overview of the review protocol used in this study.

This section presents the outcomes of the systematic literature review conducted. Initially, an overview of the selected studies is provided. Subsequently, the findings for each research question are discussed individually in distinct subsections. The discussion encompasses interpretations of the review results concerning the research questions, alongside considering related dimensions intimately connected with the research questions. To substantiate the credibility of our analysis, we incorporate corroborative evidence from pertinent works in the field. Supplementary Appendix SA includes a detailed compilation of all the papers reviewed, complete with their identification numbers.

This study examines the utilization of blockchain technology in electric vehicle (EV) charging systems, focusing on its integration with renewable energy sources. After reviewing 48 academic papers, research directions or recommendations for future research have been identified to better understand and enhance this integration, with the goal of advancing effective and sustainable energy solutions. Key recommendations include the following: a) Future studies should include more extensive explanations of the blockchain architecture and its interaction with EV charging stations. This includes going over the technical requirements, operational procedures, and the role of blockchain in improving energy transaction security and efficiency. Diagrammatic representations and step-by-step explanations will help comprehend the complexity of these systems. b) More comprehensive statistical analysis is needed to validate the findings and ensure reproducibility. Future research should include detailed statistical methods, including data sampling, hypothesis testing, and confidence interval calculations, to substantiate the claims made. Additionally, examining the repetition of key parameters across studies will highlight the commonalities and variances in research focus, thus guiding more standardized and systematic investigations. c) Studies should focus more on how blockchain technology can enhance the integration of renewable energy sources within EV charging systems. This includes analyzing the impact of renewable energy on the efficiency and reliability of these systems, exploring innovative ways to manage the variability of renewable energy sources, and assessing long-term sustainability impacts. d) Explore how blockchain technology may be integrated with the latest technologies like artificial intelligence (AI) and machine learning (ML) in smart grids and EV charging systems. Investigating ways to use these technologies to improve real-time decision-making, forecast charging demands, and optimize energy distribution is required. e) A deep economic and market study of blockchain-enabled EV charging stations has to be a part of future research. This would involve market trends, cost-benefit analyses, and the economic feasibility of these systems under different market conditions and regulatory frameworks. Finally, f) evaluating the long-term impacts of integrating blockchain in EV charging systems is crucial, particularly concerning environmental sustainability, economic stability, and social equity. Research should focus on developing metrics and models to assess the long-term feasibility, sustainability impacts, and potential for scalable deployment of these systems.

In summary, our literature review on the utilization of blockchain technology in electric vehicles and energy trading highlights the increasing advancements and interest within this domain. Our analysis of the 48 publications revealed that only a limited number of them presented tangible implementations, while the majority focused on simulations. However, it is noteworthy that the implemented solutions identified were published recently, indicating a growing trend and a promising future for the integration of blockchain technology in this field. The reviewed studies underscore the significance of considering privacy and security factors in blockchain-based energy systems and emphasize the potential benefits of incorporating blockchain technology in the energy sector. Future work could involve expanding the review’s scope to encompass other related areas, conducting more comprehensive analyses of the implemented solutions, and exploring additional applications of blockchain technology in electric vehicles and the energy trading sector.