The following is a brief introduction to the topic:
V2G is the term used to describe the process by which electric vehicles (EVs), in addition to charging electricity from the grid, can also discharge. Vehicle batteries can stabilize the grid in the event of excess or inadequate power generation or when power lines are too overloaded to transport electricity to consumers. The technology will address the key challenge in the energy transition that relies on renewable (non-dispatchable energy) sources. They cannot adjust their power production according to electricity demand but must rely on flexible consumers and energy storage units to match electricity supply and demand. The EV can provide this flexibility by charging during times of abundant electricity and discharging during times of scarcity. The concept is well-known in the literature, but its real-world application has been limited to small demonstrations and trial projects.
The term “vehicle-to-grid” was first coined in 2001. 5 These developments have been closely tracked by academia and industry from different perspectives. The most common is to look at the economics behind a particular system. Steward was elected as Steward in 2017. 6  found that the expected profitability of studies was very different, with net revenues for light-duty cars ranging between USD 4/a to USD 3320/a. The wide range in values can be explained by the different assumptions and markets vehicles are involved in. Heilmann and Friedl 7  revealed that these assumptions and market segments can be classified into four categories: technical conditions, cost, and controls. The studies confirm the wide range of revenue and business cases. Some cases have losses up to EUR 700/a, while others report revenues of EUR 5,200. Ravi and Aziz suggest that another way to classify the applications of vehicles to the grid is to consider the type of service they provide to the grid. 8 [ have been carried out. They emphasize that vehicle-to-grid is just one aspect of a broader category called vehicle-grid integrated, which includes smart charging. The authors confirm that, in practice, the term “vehicle-to-grid” has almost become synonymous with vehicle grid integration. Researchers have also begun to focus on more specific topics in addition to the more general ones. Some works focus on certain countries, such as Indonesia. 9 China 10, 11 Germany 12 The Netherlands 13 The economic analysis also has a marketing aspect: the promotion of V2G among potential users. Baumgartner et al. [ 14 ] used a survey approach to ask people who had low, medium, and high levels of experience with EVs for their participation. They found that people are motivated by a minimum range remaining in the vehicle, as well as climate-neutral charging. Bohdanowicz et al. [ 15 They argue that intrinsic and altruistic motivations are highly important. They claim that altruistic and inherent reasons are of great importance.
Lehtola et al. Lehtola et al. 16  showed what many subsequent studies have confirmed: smart and bidirectional chargers can reduce battery aging compared to charging the vehicle immediately after it reaches a full charge. Calearo & Marinelli demonstrate that the additional aging caused by extensive V2G operations over five years results in a net profit of approximately EUR 3500 per vehicle. EUR 3500 for each car during the period. 17, 18 Market reports [With all the announcements and developments, it is difficult to get a good overview of the state of the industry. Market reports 19, 20, 21, 22 Research papers 23 [ ] focus primarily on the electric car market as a total, but V2G is often only an aside topic. Research that focuses on V2G faces a challenge in keeping up with the fast-paced market. Das et al. [ 24 [ ] was considered a future technology, but it is now being developed just three years after it was first proposed. This paper aims to provide an analysis of V2G, including the latest developments in markets, regulations, and technology. We have focused on Europe to analyze the regulatory readiness as well as the bidirectional vehicles and available charging stations. Germany is the largest car market in Europe, based on the number of cars sold. We hope to help both practitioners and researchers with this report by providing clarity on the technologies and capacity available now and – extrapolated – in the future. We hope that this submission will provide a realistic view of the market dynamics for actors who are interested in raw material demand and manufacturing volumes.
- Materials and Methods
This paper is based upon two major pieces of work: extensive research to gather data about the readiness and availability of regulatory frameworks for vehicles, chargers, and charging stations, as well as data analysis to conduct a German market analysis.
2.1. Literature Review
The Mobility House conducted the Literature Review for this Paper in April 2023. Product catalogs and field test reports are the main sources of data. Due to the method of data collection, it is possible that the list of models of cars and charging stations may not be complete, and the evaluation of regulatory states by country contains partial, subjective assessment. The two do not claim to be finished, and the market is constantly changing.
2.2. Data Analysis
This paper presents an analysis of data previously collected and reported in 23. The interactive version is available in 25 ]. RWTH Aachen performed the work. The data collection method will be briefly described in this article for the sake of clarity. Readers can also refer to 23 ]. For the years observed, the car registrations were retrieved from the German Federal Office for Motor Traffic (in Flensburg, Germany, “Kraftfahrtbundesamt,” KBA) [ 26 The ADAC has merged the ADAC’s technical data catalog with that of the General German Automobile Association (ADAC). 27 ]. Using this method, it is possible to determine the DC fast-charging connectors, battery capacity, and charging power for many car models. The KBA doesn’t assign model identifiers to vehicles that are not significantly different. The number of cars to which we were able to give technical characteristics did not match the actual registered number of battery electric vehicles and plug-in hybrid electric vehicles. Scaling was done for each data point. The plots in this article are based on different primary sources of data. We report each data source separately in the caption.
Four sections are presented. The first two sections, “Overview V2G readiness of the regulatory framework” and “Overview V2G readiness by hardware provider”, are focused on what’s currently possible with regard to regulation, vehicles, and charging stations. The majority of devices are in an early stage and haven’t yet made a strong impact on the market. Many of the bidirectional vehicles we identified are only capable of supplying loads as a vehicle to load setup, or they only support V2G during field testing. These two options do not provide a V2G solution that is ready for the customer. The last two sections, “Electric Vehicle Sales in Germany” and “Properties of BEVs sold in Germany”, focus on the whole fleet of BEVs in Germany and not just on those with bidirectional charging capabilities. In order to support the topic, an analysis of the existing fleet was conducted. The focus of the study was on the effect and implications of the analyzed vehicle characteristics for a V2G.
3.1. Overview of the V2G Readiness of the Regulatory Framework
A technical solution is not enough to make V2G possible. The regulatory environment must also be set up in a way that allows vehicles to interact with grids and electricity markets. In Europe, there are three main obstacles to market adoption:
- Taxation of consumption
- Electricity consumption in many European countries is only measured by kWh. There are also significant taxes and levies on the energy consumed. For example, in Germany, electricity prices have been around EUR 30 ct/kWh over the past decade [ 28], whereas wholesale power costs were EUR 4 to 5. It was, therefore, impossible to make a business case for selling heavily taxed power back into the grid. This ratio has changed a little since the energy crisis began in 2021. However, without any changes to market rules, creating a business case was nearly impossible. This problem can be overcome by compensating taxes and levies in proportion to the amount sold back to the grid. In Germany and other European countries, this approach is being used. Arbitrage trading is then possible.