## 3 The Results
### Results of the Literature Review
Subsequently, based on the other parameters discussed in Section 3.4, papers with the highest \"centrality\" index have been examined, as these papers often serve as key references for the study in question and are connected to other works that could further deepen the research. The \"burst\" index was also crucial, as it guided the analysis to periods when the topic gained student relevance, leading the research to identify the challenges, techniques, impacts, and perspectives of V2G. Subsequently, it was understood that the demand for parking in V2G technology is characterized by a series of key attributes and variables, which are essential to understand and model the charging and usage behaviors of EVs in a V2G context. Among the main ones, the following thematic clusters have been identified:  
* parking and charging time;
* parking location;
* vehicle usage model;
* charging energy and power;
* user behaviors and preferences;
* sociodemographic factors;
* environmental conditions. _Parking and charging time_  
The concept of \"parking and charging time\" refers to the duration and dynamics of the EV charging process in the V2G mode. This approach not only optimizes the use of EV batteries but also contributes to the stability of the electrical grid. Recent studies have examined the necessary parking time for effective charging and the implications of the V2G system for the integration of renewable energy sources. Numerous studies have been developed to analyze the charging and parking time in V2G contexts, focusing primarily on optimizing charging strategies and their impact on the electrical grid and the end-user. Most of these studies have taken place in pioneering countries in electric mobility, such as Japan, Germany, and the United States. For example, research by the University of Delaware examined the effect of V2G charging on grid performance and environmental sustainability [29]. These studies found that the average parking time for electric vehicles varied significantly depending on vehicle usage and available infrastructure, with times ranging from a few hours to whole nights. Furthermore, it was observed that the benefits of V2G increased significantly with favorable policies and a well-developed charging infrastructure. Future research should focus on more advanced predictive models to manage charging and on developing optimization algorithms that account for grid variables and user behaviors. Furthermore, it is crucial to develop a smart and interconnected charging infrastructure that facilitates the seamless integration between electric vehicles and the electrical grid. _Parking location_  
This concerns the optimization of electric vehicle parking locations to maximize the benefits of V2G systems. This includes selecting strategic parking areas for both charging and energy return to the electrical grid. The location of parking spaces can significantly influence the efficiency of the V2G system, as areas with high availability of electric vehicles and easy access to charging infrastructure are crucial to the effective management of energy resources. Studies in this field analyze how different parking locations affect charging distribution, grid reliability, and the costs associated with the implementation of V2G systems. Specific studies on this topic are still limited but growing, with research focused on cities and urban areas. Countries such as Germany, with an advanced electric mobility infrastructure and a strong commitment to sustainable energy, are at the forefront of this field. Recent studies have examined the optimization of V2G parking in German urban areas, exploring how the choice of locations can improve grid efficiency and reduce management costs. Research has highlighted that the optimal location for V2G parking tends to be in densely populated urban areas or near critical nodes of the electrical grid, such as shopping centers, office buildings, and residences with an advanced charging infrastructure [30].