V2G, short for Vehicle-to-grid (Vehicle-to-Grid), is an emerging energy management technology. In reality, when the grid demand exceeds the capacity of the base load power plant, because the grid itself does not have enough energy storage, the peak power plant will be put into operation, and sometimes rotary backup will be involved. When grid demand is low, electricity consumption is lower than the output of baseload power plants, so that unused energy is wasted. Renewable energy systems (such as solar, wind, etc.) are being integrated into the power system in large numbers. Since the natural discontinuities of renewable energy can cause fluctuations in generation, there is an urgent need for compensation from other energy sources, such as battery energy storage systems, to smooth the natural variability of renewable energy, ensure the stability of grid frequency and suppress voltage rises caused by reverse power flows. In response to this energy waste, V-2G technology came into being, and its core idea is to connect electric vehicles (EVs) with the power grid to achieve two-way energy exchange. Traditionally, electric vehicles only obtain energy from the grid, and V2G technology allows electric vehicles to feed excess electricity back to the grid for grid use, thus achieving a two-way flow of energy.
At present, V2G technology needs to realize the two-way flow of electric energy between the power grid and the vehicle power battery, so it can be seen that its technical core mainly involves two aspects of the vehicle network: charging stations on the grid side and grid technology and car-power battery related technologies on the user side.
1. Power monitoring system
The power monitoring system is a platform for monitoring and controlling the process of power production and supply based on computer, communication equipment and measurement and control unit. This technology has been relatively mature in the traditional power grid construction.
2. Electric vehicle big data acquisition, invocation and response
The technology focus is on the manufacture of intelligent sensors, the introduction of AI technology, cloud computing, blockchain technology, etc., to collect and analyze big data of electric vehicles.
3. Orderly charging control system
The research focus of this technology is two aspects: one is to optimize the algorithm model of the control system with the updating of power monitoring technology and data acquisition and invocation technology, so that the calculation result is close to the actual optimal value of productivity efficiency; The second is to minimize the loss caused by the collective access of electric vehicles to the grid and ensure the quality of the transmitted power.
4. Two-way charging technology
Two-way charging technology is divided into two forms: vehicular AC charging and off-board DC charging. Vehicular AC charging not only requires a dedicated AC charging device to achieve two-way power transmission, but also needs to improve two-way power transmission in the electrical system on the vehicle side. At present, the mainstream two-way charging form is the use of off-board DC charging equipment.
At the end of August 2016, Nissan, Italian power company Enel and converged system solutions provider Nuvve officially opened the world's first commercial V2G center in Copenhagen, Denmark. Electric vehicle owners in Denmark earn up to $1,530 a year by sending excess power from their cars back to the grid at charging stations, and car operators earn €1,300 (about $1,530) a year through two-way charging stations, which effectively balances electricity supply and demand during peak periods.
The University of California San Diego is working on a V2G project to enable two-way energy interaction between electric vehicles and campus microgrids by integrating electric vehicles and charging piles on campus to support energy management on campus, reduce energy costs, and improve grid stability.
Nissan Motor Co. 's Leaf all-electric model has been approved by German regulators to use V2G technology to support the German power grid, initially targeting enterprise users with a fleet of more than 60 electric vehicles, and offering V2G technology-based services in Germany from 2019.
While the V2G market is promising, it also faces some challenges, such as the high cost of upgrading existing charging infrastructure and the lack of standardized charging solutions. Despite these obstacles, major industry players are forging partnerships and investing in research to improve the efficiency, scalability, and performance of V2G systems. In addition, the biggest obstacle facing V2G at the moment is the ideological problem that consumers still subconsciously think of vehicles only as means of transportation. Consumers do not have the awareness of peak and valley arbitrage, nor do they have the awareness to face the fluctuations of new energy generation and ensure the stability of grid supply. Moreover, electricity market transactions are still too far away for Chinese consumers, and the business model will not be mature in the short term.
The impact of V2G technology extends beyond electric vehicles and affects the stability of the power grid. The transition to renewable energy means further reliance on the grid, so the introduction of technologies designed to ease this strain is generally welcomed. Similar technologies, such as Vehicle-to-Home (V2H) and Vehicle-to-building (V2B), are useful umbrella terms for vehicle-to-everything (V2X) and are gaining ground. The future of V2G technology includes not only traditional electric vehicles, but also integration with other forms of energy storage and power generation, such as stationary batteries and renewables. This broadens the scope of V2G applications and creates more versatile integrated solutions for grid management and support. The shift to renewables underscores the importance of energy storage capacity. Electric vehicles (EVs) are no longer just means of transport, but also as a potential energy storage solution to support the grid, making vehicle-to-grid (V2G) technology more important than ever