1. Introduction

With the acceleration of globalization, the expansion of industrialization and urbanization has inevitably brought about serious environmental issues, particularly carbon emissions and energy crises, both of which have become global challenges. According to the International Energy Agency (IEA), the transportation sector is one of the major sources of global energy-related carbon dioxide emissions, accounting for nearly one-fourth of the total emissions. In this context, effectively reducing the carbon footprint of the transportation sector is an urgent issue to be addressed[1]. New energy vehicles (NEVs), due to their lower carbon emission characteristics, are considered sustainable alternatives to traditional fuel vehicles. However, the environmental benefits of new energy vehicles largely depend on the cleanliness of electricity production[2]. Therefore, the introduction of smart grids provides a possibility to improve the environmental benefits of new energy vehicles.Smart grids, through efficient energy management and storage systems, can utilize renewable energy generation, further reducing the indirect carbon emissions of electric vehicles[3]. In addition, the vehicle-to-grid (V2G) functionality of smart grid technology can achieve bidirectional energy flow between electric vehicles and the grid. This not only helps balance grid loads and improve energy utilization efficiency but also allows the energy stored in vehicles to be fed back into the grid during peak demand, further optimizing energy allocation and reducing overall carbon emissions[4].

Based on the above background, this study aims to analyze in depth the carbon emission reduction potential of the interaction between new energy vehicles and smart grids. By comprehensively examining the promotion of new energy vehicles and the application of smart grid technology, this paper attempts to explore how the two can synergize and jointly address the challenges of global climate change, providing policymakers with scientific decision-making basis.

2. Review of the Current Applications

2.1. The Current Development and Future Prospects of New Energy Vehicles

New Energy Vehicles (NEVs) refer to vehicles that use non-traditional fuels as power sources or employ new types of vehicle propulsion systems. These vehicles include Electric Vehicles (EVs), Plug-in Hybrid Electric Vehicles (PHEVs), and Fuel Cell Electric Vehicles (FCEVs). By adopting electricity, hydrogen fuel, or other renewable energy sources, NEVs significantly reduce reliance on traditional petroleum fuels while also decreasing harmful emissions and greenhouse gases from vehicle exhaust, thereby positively impacting environmental friendliness and energy sustainability[5].

NEV technology has made significant progress over the past decade. Innovations in battery technology, particularly the increase in energy density and decrease in cost of lithium-ion batteries, have greatly improved the driving range and reduced charging time of electric vehicles. Furthermore, the efficiency of electric motors and power electronics has also significantly increased, further optimizing energy conversion and utilization efficiency. Supported by advancements in autonomous driving and vehicle connectivity technologies, NEVs are gradually becoming smarter and more networked, enhancing not only the driving experience but also enabling optimal energy management and maintenance of vehicles[6]. Despite challenges posed by the COVID-19 pandemic, global sales of NEVs reached a record high in 2020 according to data from the International Energy Agency (IEA). Government policy support, such as vehicle purchase subsidies, tax incentives, and dedicated lanes for low-emission vehicles, has greatly facilitated market acceptance. The promotion of new energy vehicles (NEVs) has made significant strides globally, with Europe, China, and the United States being key regions driving the market. In Europe, strict emission standards and high carbon taxes incentivize purchases. China, on the other hand, has rapidly developed through subsidy policies and infrastructure construction. Although federal support in the United States fluctuates, local policies such as California's stringent environmental standards have driven widespread adoption. China has emerged as one of the world's largest NEV markets. According to the China Association of Automobile Manufacturers, the proportion of NEV sales continued to rise in 2020. The government also actively promotes electric vehicles in smaller cities and rural areas to expand environmental benefits. Overall, the outlook for the development of new energy vehicles is optimistic.

Continuous technological advancements and proactive policy promotion will increasingly position new energy vehicles as key players in the future of transportation. As more countries and regions recognize the potential of new energy vehicles in addressing climate change and environmental protection, it is expected that the global market for new energy vehicles will continue to experience rapid growth.

2.2. Smart Grid Technology and Development

Smart Grid refers to an electricity network system that achieves efficient, reliable, and secure operation through the integration of advanced communication technologies and network control devices. It not only enables self-healing and optimization of energy usage but also facilitates sustainable production and consumption of energy. Key technologies of smart grids include Advanced Metering Infrastructure (AMI), Distributed Energy Resources (DER), Demand Response (DR) management, and power electronics equipment[7]. Globally, the development of smart grids has become a core component of energy strategies in many countries. As a critical supporting technology for the development of new energy vehicles, the prospects and challenges of smart grids will directly impact the effectiveness of interactions between new energy vehicles and the grid, as well as the potential for carbon emission reduction[8]. With advancements in technology and policy improvements, smart grids are poised to be further promoted globally, laying the foundation for building low-carbon, efficient, and sustainable energy systems.

2.3. The Interaction Mechanism between New Energy Vehicles and Smart Grids

The Vehicle-to-Everything (V2X) technology refers to the communication technology that allows vehicles to communicate with other vehicles, infrastructure, pedestrians, and the network itself. An important application of this technology is Vehicle-to-Grid (V2G), which enables electric vehicles to not only charge from the grid but also feed energy back into it[9]. The key to V2G technology is to make electric vehicles dynamic storage units for the grid, releasing power during peak demand and storing it during off-peak periods. V2G operates based on intelligent charging systems that control the charging time and rate of electric vehicles. Through this system, electric vehicles can charge when electricity prices are low and demand is low, and discharge power back to the grid when prices are high or when additional power is needed. This bidirectional interaction not only increases the flexibility of energy supply for the grid but also helps balance supply and demand, thereby improving the overall efficiency and stability of the grid.

Distributed Energy Systems (DES) refer to small-scale power generation facilities that generate electricity at or near the point of consumption. These systems typically include renewable energy resources such as solar photovoltaic panels, wind turbines, and small hydroelectric stations[10]. The integration of distributed energy systems is an important aspect of achieving efficient energy management in smart grids, allowing the grid to utilize locally generated power, reduce transmission losses, and increase energy supply reliability. Smart grids achieve seamless integration with distributed energy systems through the use of advanced communication and automation technologies. Additionally, smart grids can automatically adjust power flow to respond to changes in energy prices and consumption demands, making the entire system more economical and efficient.

The integration of smart grids and distributed energy systems provides new opportunities for new energy vehicles to utilize renewable energy sources, further reducing carbon emissions during operation. Additionally, through V2G technology, electric vehicles can become part of distributed energy systems, supporting the grid when necessary, thereby enhancing system stability and reliability.

3. Analysis of Carbon Emission Reduction Potential

3.1. The Enhancement of Energy Efficiency through the Interaction between New Energy Vehicles and Smart Grids

The interaction between new energy vehicles and smart grids is primarily achieved through Vehicle-to-Grid (V2G) technology, which allows electric vehicles to not only draw energy from the grid but also feed energy back into it, enabling bidirectional energy flow. This interaction can store energy during periods of low grid load and release it during peak hours, thereby helping to balance grid load and improve the overall system efficiency. Additionally, this technology can optimize the utilization of renewable energy sources by reducing reliance on fossil fuels. Surplus wind and solar energy can be stored for later use during peak demand periods. Through intelligent scheduling systems, the charging and discharging processes of new energy vehicles can be automatically adjusted based on grid demand and price signals, reducing users' electricity expenses and minimizing grid operation costs and carbon emissions. Furthermore, smart grids can optimize grid operation and maintenance plans through real-time data monitoring and predictive tools, further enhancing energy efficiency and system reliability.

3.2. Case Study Overview of Success Stories

California is one of the pioneers in the application of new energy vehicle (NEV) and smart grid interaction technology. The state government has implemented a series of policies to support the development of electric vehicles (EVs) and smart grids, including providing purchase subsidies, constructing public charging stations, and implementing V2G pilot projects. In San Diego, a V2G pilot project demonstrates how electric vehicles can help manage the variability of renewable energy generation in the grid. Through this project, when surplus electricity is generated from solar and wind energy, electric vehicles store energy, and during peak electricity demand, these vehicles discharge power back to the grid. Preliminary results indicate that this interaction mode not only stabilizes the grid but also significantly reduces operating costs and carbon emissions.

Denmark is one of the countries with the highest utilization rates of renewable energy globally and is also promoting the integration of smart grid and new energy vehicle technologies. In Copenhagen, smart grid technology has been widely used to optimize the city's energy management. Electric vehicles are widely used and, through V2G technology, become part of the city's energy system. This not only helps Denmark reduce its reliance on fossil fuels but also effectively lowers the city's overall carbon footprint.

Through these case studies, we can see that the interaction between new energy vehicles and smart grids has significant potential for enhancing energy efficiency and reducing carbon emissions. The promotion and application of this technology, especially in regions with high energy demand and strong environmental policy support, can provide effective technical support and practical pathways to achieve global carbon reduction goals. With the maturity of technology and further optimization of policies, it is expected that this interaction mode will be more widely applied globally.

4. Challenges Facing the Interaction between New Energy Vehicles and Smart Grids

4.1. Technical Challenges

Firstly, interoperability and standardization are crucial for the effective interaction between smart grids and new energy vehicles (NEVs). Currently, the lack of unified technical standards among manufacturers and service providers has led to compatibility issues between devices and systems. This limitation hinders the widespread adoption of the technology and the achievement of economies of scale. Secondly, there are concerns regarding data security and privacy protection. While the high level of connectivity between smart grids and NEVs offers efficiency advantages, it also increases the risk of data security breaches and privacy violations. Sensitive information such as users' driving habits, locations, and charging behaviors must be rigorously protected to prevent misuse of data. Lastly, the implementation of Vehicle-to-Grid (V2G) technology heavily relies on advanced energy management systems and energy storage technologies. Currently, battery technology faces challenges such as high costs, limited lifespan, and efficiency losses, all of which need effective solutions in the future.

4.2. Economic Challenges

The construction of infrastructure for smart grids and new energy vehicles (NEVs) requires significant initial investment. Additionally, the implementation of Vehicle-to-Grid (V2G) technology also necessitates the installation of additional hardware and software within existing grids, which poses a substantial financial burden for many economies. Furthermore, uncertainty regarding economic returns must be considered. Although the interaction between NEVs and smart grids theoretically enhances energy efficiency and reduces costs, in practice, economic returns are often influenced by factors such as fluctuations in electricity prices, policy changes, and market acceptance.

4.3. Social Challenges

Firstly, consumer acceptance is a significant challenge. The complexity of new energy vehicles (NEVs) and smart grid technologies may exceed the understanding and acceptance of ordinary consumers. Concerns about privacy protection may also affect their willingness to adopt these new technologies. Additionally, the effective operation of smart grid and NEV technologies requires skilled technical personnel. Currently, there is a shortage of technical talent in related fields, and widespread education and training systems have not yet been fully established.

4.4. Policy Challenges

Inconsistency and inadequate support in policies: The development of new energy vehicles (NEVs) and smart grid technologies heavily relies on government policy support. However, policies may vary among different regions and countries, and even within the same country, policies can change due to political fluctuations, leading to uncertainty for the long-term development of the technology.

5. Strategy Recommendations

5.1. Strategic Recommendations at the Technical Level

Firstly, promote technological innovation and standardization. Foster collaboration across enterprises and industries to establish and promote unified technical standards, enhancing system interoperability and compatibility. Support research and development activities by scientific institutions and businesses, focusing on improving battery efficiency, reducing costs, and optimizing energy management systems. Secondly, strengthen data protection. Implement robust data security measures to ensure the privacy and security of user information, employing advanced encryption technologies to safeguard data transmission and storage. Enhance public trust in smart grid data handling and protection measures, increasing user acceptance through transparent operations.

5.2. Economic Strategies

Provide policy and financial support to reduce the investment costs of new energy vehicles (NEVs) and smart grid technologies through government subsidies, tax incentives, and financial incentives. Encourage Public-Private Partnerships (PPPs) to attract private investment in smart grid and NEV projects. Explore cooperation with financial institutions to develop relevant financial products and services.

5.3. Strategic Recommendations for Social and Policy Aspects

Enhance public awareness and education by increasing the promotion of new energy vehicles (NEVs) and smart grid technologies. Raise public awareness and acceptance through educational initiatives and public engagement activities. Strengthen relevant technical and application courses in the education system to cultivate future technology development and management talents. Establish clear long-term energy policies to provide market participants with a stable investment and operating environment. Additionally, enhance international cooperation and exchanges to promote policy dialogues and international coordination of technical standards.

6. Conclusion

The interaction between new energy vehicles (NEVs) and smart grids represents an innovative and promising development direction in modern energy systems, with significant potential for carbon emissions reduction. This interaction not only improves energy efficiency but also enhances the reliability and stability of the grid while promoting the wider application of renewable energy. Firstly, the application of Vehicle-to-Grid (V2G) technology provides a new means of energy storage and regulation for the grid, enabling electric vehicles to store energy during off-peak periods and release it during peak demand, thereby helping to balance supply and demand and reduce reliance on traditional power plants. Secondly, the development of smart grid technology improves the grid's acceptance of distributed energy resources such as solar and wind power, which is crucial for increasing the proportion of renewable energy in the energy mix and reducing overall carbon emissions. Additionally, smart grids can enhance the operational efficiency of the power system and its flexibility in responding to market changes. However, realizing these potentials requires overcoming various challenges, including technological, economic, policy, and social acceptance challenges. In conclusion, the effective interaction between new energy vehicles and smart grids will be a key strategy for achieving global carbon reduction goals. Only through interdisciplinary cooperation and comprehensive strategy implementation can we fully harness the potential of this technology and contribute to building a cleaner and more sustainable energy future.