Vehicle-network synergy: a combination of transportation and power emission reduction
The National Development and Reform Commission, the National Energy Administration, the Ministry of Industry and Information Technology and the State Administration for Market Regulation jointly issued the "Implementation Opinions on Strengthening the Integration and Interaction of New Energy Vehicles and Power Grids" (hereinafter referred to as the "Opinions"), proposing that by 2030, new energy vehicles will provide tens of millions of kilowatts of two-way flexible adjustment capacity for the new power system.
Industry experts pointed out that this shows China's determination to vigorously develop vehicle-network synergy, and also illustrates the development potential of new energy vehicles in China: new energy vehicles dominated by electric vehicles can not only promote the low-carbon transformation of the transportation field, but also promote the coordinated low-carbon development of the transportation and power industries as mobile energy storage units, thereby ensuring the stability of the power grid, improving the flexibility of the power grid, saving investment in grid upgrading, and promoting the consumption of renewable energy to support the construction of new power systems.
Vehicle-network synergy helps reduce carbon emissions in electric transportation
"It took about ten years from the germination of the concept in 2014 to the implementation of the documents today. Liu Mingming, deputy director of the Clean Power Program at the Natural Resources Defense Council (NRDC), is very excited about the release of the Opinions.
Vehicle-network synergy is of great significance to China's realization of the "dual carbon" goal, energy transition, and the development of new energy vehicles.
"Carbon emissions from the two sectors of electricity and transportation account for more than 60% of China's total carbon emissions. Liu Mingming said that the coordinated low-carbon transformation of the two is one of the key grasps to achieve the "double carbon" goal.
The low-carbon transformation of the power sector is mainly based on increasing the proportion of clean new energy. In the case of the continuous and rapid development of new energy power generation, it is expected that the installed capacity of wind and solar power generation will account for 40% of the total installed capacity in 2025. Large-scale, high-proportion, unpredictable wind and solar grid-connected power generation requires the power system to have sufficient flexibility and adjustment capabilities.
Huang Qili, an academician of the Chinese Academy of Engineering, believes that the flexible peak regulation power supply in the power system should reach at least 10%-15% of the total installed capacity. At present, China's flexible power supply accounts for less than 6%, and it is urgent to greatly improve the power system regulation capacity.
On the other hand, nearly 70% of China's power generation in 2022 will come from thermal power generation, especially the proportion of thermal power in the eastern load center is as high as 80%, which seriously hinders the realization of the near-zero emission goal of electric vehicles. At the same time, electric vehicles also pose challenges to the stable operation of the power grid: the random charging and disorderly charging modes of electric vehicles will exacerbate the peak load of the power grid, which may cause a huge impact on the power grid. To cope with this shock, power systems often require significant investment in upgrading and expanding the distribution network to meet increased peak load demand.
On the one hand, new energy power generation is "inexhaustible", and on the other hand, electric vehicles "can't eat" new energy electricity. Where is the breakthrough point in the coordinated low-carbon development of electricity and transportation?
"The biggest challenge in building a future zero-carbon energy system with wind and solar resources as the main body is the lack of energy storage capacity. Jiang Yi, academician of the Chinese Academy of Engineering and director of the Building Energy Efficiency Research Center of Tsinghua University, gave reporters an account: "Private cars are parked more than 85% of the time, and there is great potential for dispatching." If the number of electric private cars reaches 300 million in the future, the energy storage potential of private cars will be able to meet the demand for fluctuating power generation such as wind and solar. ”
Breaking through the "checkpoint" of green and low-carbon development of electric power transportation
Although, the combination of green and low-carbon power and transportation will play a 1+1>2 effect. But the "combination" still faces a series of "levels".
The first level is that it is difficult to access high-power fast charging stations.
After the promotion of high-power supercharging piles, it will become the norm for a fast charging station to reach the megawatt level in the future, and the increase in power level means that the difficulty of nearby access will also be significantly increased, not only the cost of grid connection will increase significantly, but in some cases, there will be problems such as insufficient resources in urban distribution channels and corridors, which will lead to the inability to land construction.
The second hurdle is the investment pressure on the transformation of personal charging piles for community residents at the "trillion-level" level.
With the rapid growth of the scale of electric private cars, the demand for power access of personal charging piles for community residents in China will grow rapidly. It is estimated that by 2035, the reported installation capacity of residential personal piles will reach 1 billion kilowatts, which will be 7 times the reported installation capacity in 2025, which will bring huge investment pressure on power grid upgrading.
According to the statistics of relevant departments and China's new residential parking space allocation standards, it is estimated that by 2035, the total number of fixed parking spaces in China's residential communities is expected to exceed 250 million. The total investment required to electrify 250 million parking spaces will be in the trillion yuan.
According to the estimation of the distribution investment cost level per unit of grid-connected capacity, the investment pressure of China's fast charging station in the future distribution network transformation will also reach the trillion level.
The third is the cost bottleneck of electric vehicles.
Li Lili, deputy director of Tsinghua Sichuan Energy Internet Research Institute, told reporters: "At present, it is difficult to achieve full electrification of low-intensity vehicles, especially private car owners who rely on public transportation on weekdays and only use cars on weekends. ”
According to the calculations of industry institutions, the annual mileage of more than 10,000 kilometers is a prerequisite for the full-cycle cost of pure electric passenger vehicles to be on par with that of fuel vehicles. However, according to the statistics of the Beijing Transportation Development Annual Report, in 2019, about 40% of private cars with an annual mileage of less than 10,000 kilometers in Beijing accounted for about 40%, which means that about 40% of private car market users choose electric vehicles compared to fuel vehicles.
The vehicle-network collaboration can just crack these three "levels" and achieve corner overtaking.
Li Lili said: "The low-cost grid-connected solution of the future megawatt-level fast charging station needs the support of vehicle-network interaction technology, which is also known as flexible grid-connection or active load management mode. ”
The vehicle-network interactive mode is expected to effectively reduce the access cost through flexible grid-connected and other modes. "Compared with the traditional grid-connected mode, it is expected to increase the allowable installed capacity by more than 50%, and the preliminary estimate is expected to reduce the investment in the transformation of the supporting power of the fast charging station by about 20%. Li Lili said.
In response to the economics of electric vehicles, Li Lili pointed out: "In order for these 40% of low-driving intensity users to buy electric vehicles, it is necessary to realize the value of their mobile energy storage. ”
At present, the unit investment cost of China's fixed energy storage power station is about 2,000 yuan/kWh, for a mainstream electric private car, calculated according to the 70 kWh battery, if it is equivalent to 1:1 for the energy storage power station, the corresponding energy storage value can reach up to 140,000 yuan.
According to the relevant statistics of the "Beijing Transportation Development Annual Report", at present, about 20%-25% of Beijing's private cars are parked in the basement all day without travel, and more than 50% of the vehicles will return to their homes before 7 p.m. to fix their parking spaces. "This means that in the future, after large-scale electric vehicles are aggregated, the average 'equivalent energy storage' potential of each vehicle is expected to exceed about 20% of the stationary power station, and the realized value of 'equivalent energy storage' is about 30,000 yuan. Li Lili said that the realization value of 30,000 yuan of "equivalent energy storage" means that about 150,000 yuan of mainstream electric vehicles can reduce the cost by 20%.
Two paths to achieve vehicle-network coordination
The introduction of the new policy undoubtedly injects a shot of strength into the comprehensive and in-depth development of vehicle-network collaboration, and also puts forward higher requirements for vehicle-network collaboration.
Liu Mingming introduced that there are various modes of coordinated development of the vehicle network, which mainly include two modes: orderly charging (V1G) and two-way interaction between the vehicle and the network (V2G).
The lowest-cost and most practiced V1G model is the V1G model, which means that users charge less during peak demand and more when electricity consumption is low or when the supply of wind and solar power is sufficient.
When the charging operation capability and grid dispatching capability are further improved, and the relevant market environment, standards and communication protocols are further improved, electric vehicles can realize two-way interaction between vehicles and the network by backfeeding power to the grid, that is, V2G. This allows electric vehicles to play an energy storage role. "For example, an electric car charging dozens of mobile phones during a rainstorm in Zhengzhou, and an electric car supplying power to homes during a power outage in California, USA, are both useful attempts at two-way interaction between the car and the network. Liu Mingming said.
A joint study by the Energy Research Institute of the National Development and Reform Commission, the Natural Resources Defense Council (NRDC) and the Electric Vehicle 100 Committee found that China's vehicle-network collaboration has great potential for flexibility and technical and economic feasibility. By the end of the 14th Five-Year Plan, the flexible adjustment resources brought by vehicle-network synergy are expected to be more than 500 million kilowatts, far exceeding the predicted installed capacity of pumped storage. The study also shows that for general passenger vehicles, the cost of vehicle-network collaboration is significantly lower than the cost of energy storage. The economics of V1G are particularly prominent, and the regulation cost of absorbing photovoltaic and wind power is 1/10 to 1/20 of that of energy storage.
In addition, the Measures for the Administration of Electric Power Ancillary Services and the Administrative Provisions on Grid-Connected Operation of Electric Power issued by the National Energy Administration in December 2021 clarified the main position of electric vehicles participating in electric power auxiliary services. Vehicle-network synergy has become a new channel for car owners and pile enterprises to benefit from the power market. Taking Guangdong as an example, pile enterprises participating in demand response can be exempted from power rationing on the one hand, and can obtain high subsidies on the other hand, up to 4.5 yuan/kWh.
"In terms of flexibility resources, according to the vehicle-network interaction potential evaluation model constructed by the team, it is estimated that by 2035, the flexible load potential of one-way peak shaving (direct control V1G) of electric vehicles in China can reach 460 million kW/2 hours, and the 'equivalent energy storage' potential (V2G) of bidirectional peak shaving can reach 250 million kW/5 hours. Li Lili pointed out that only "equivalent energy storage" is expected to save more than one trillion yuan in investment in stationary energy storage power stations by 2035.
Overall, if vehicle-network interaction, especially V2G commercialization, can be realized, vehicle-network interaction can save trillions of yuan in the medium and long-term investment in "supply assurance" and flexibility for the new power system, which is the root of the value of future vehicle-network interaction, and ultimately passed on to every aggregator and every car owner through a market-oriented mechanism.
"At present, the vehicle-network coordination policy is basically in place, and many pilots have blossomed, but there are still many challenges to achieve the predetermined goals by 2025. Zhou Xiaohang, director of clean power projects at the Natural Resources Defense Council (NRDC), believes that the next focus will be on the following two aspects:
Research standards and market-oriented mechanisms in different scenarios: Vehicle-network collaboration needs to be piloted in different application fields, and the standard system and market-oriented mechanism in different scenarios can be improved through the implementation of pilot demonstrations.
Research on the business model of vehicle-network collaboration: After the standard and mechanism are improved, the market operation needs to be guided and promoted in a healthy way, so it will be necessary to analyze the innovative business model of vehicle-network collaboration in combination with the future development trend of new energy vehicles.
