Electric vehicles exacerbate the "evening peak" of the power grid, what should be broken?

Core reading

The industry suggests that an access policy for the interaction between electric vehicles and the power grid should be introduced, allowing low-voltage charging stations to participate in the demand response and auxiliary service markets, reasonably setting threshold conditions such as load volume and adjustment amount, and striving for a more relaxed assessment standard for the charging and discharging deviation of electric vehicles.

(Wen 丨 This newspaper reporter Sunan)

According to the latest data released by the China Association of Automobile Manufacturers, from January to November this year, the production and sales of new energy vehicles continued to reach a new high, with a cumulative output of more than 3 million vehicles and sales of nearly 3 million vehicles, and in November alone, the market penetration rate of new energy vehicles reached 17.8%.

Industry insiders said that the explosive growth of electric vehicles has increased the load on the grid, and the characteristics of electric vehicles charging at the same time have aggravated the peak-to-valley difference of the regional power grid, bringing new variables to the regulation of the power grid. How to deal with this large variable has become a difficult problem facing the industry.

The "evening peak" power balance pressure is high

The research of the State Grid Energy Research Institute shows that the development potential of electric vehicles is huge, and the future will show an S-shaped curve growth trend. China's electric vehicle ownership is expected to exceed 66 million in 2030, and the number of electric vehicles in 2060 is expected to reach about 350 million.

Forecast data shows that the demand for electric vehicle charging continues to grow, and it is expected to reach 420 billion kWh and 180 billion kWh in 2030 and 2060 respectively, accounting for about 3.5% and 11.5% of the total electricity consumption of the whole society. According to this forecast, the annual charging capacity of electric vehicles in China will increase by more than 10 times compared with 2020 in 2030.

"The charging load of electric vehicles is increasing year by year, and if it is not guided, the peak load in 2030 will reach more than 6% of the maximum electricity load in the whole society, and the distribution of time and space will be uneven, which will cause huge pressure on the 'evening peak' power balance of the power system." An industry insider told reporters bluntly that although the habits of electric vehicle users are different from the travel rules, and the charging load of electric vehicles has a large randomness, it is relatively concentrated in the "evening peak" period of the power system, showing the peak-to-valley difference momentum of increasing the load of the power grid. "Considering that in the future, new energy sources such as photovoltaics will gradually become the main body of power, photovoltaic power generation will have no output at night, and the charging load of superimposed electric vehicles will surge, and the power balance and safe and stable operation of the system in the evening peak will face great tests."

Tap potential to participate in power grid dispatch at all levels

Industry insiders generally believe that orderly charging and V2G (Vehicle-to-grid) technology can make electric vehicles an important flexibility resource for new power systems, and it is initially estimated that the theoretical potential of contributing peak shaving capacity in 2030 is about 600 million kilowatts.

The above-mentioned industry insiders said that most of the small and micro buses are in a state of suspension for more than 90% of the time, and can be combined with market mechanisms such as peak-valley time-of-use electricity prices, demand response, spot markets, and auxiliary services, to reasonably set incentive prices, make full use of the flexible and adjustable resource potential of electric vehicles, encourage electric vehicle owners to participate in orderly charging, and reduce the demand for grid and power supply expansion generated by electric vehicle access. "In the near and medium term, it is mainly guided to the trough period of electricity consumption in the early morning, and in the long term, it will turn to the guidance of the noon photovoltaic dafa period to promote the consumption of new energy."

According to the research of the State Grid Energy Research Institute, through the subsidy policy, half of the small and micro buses, trucks, large and medium-sized buses charged from 19:00 to 23:00 will be guided to charge from 1:00 to 7:00 a.m., which can promote the proportion of the maximum charging load in the evening peak to the maximum electricity load in the whole society from 6.8% to 3.4%.

Dai Xianzhong, director of the Smart Grid Research Office of the State Grid Energy Research Institute, said in an interview with reporters that it is necessary to innovate the operation mode of charging facility construction and take the initiative to reduce the peak-to-valley difference. First of all, in terms of construction mode, combined with distributed photovoltaic, distributed energy storage and other user-side equipment, promote the integrated construction of optical storage and charging, rely on light storage and direct flexible buildings to build charging piles, and achieve local balance of "source network load storage"; secondly, in terms of charging operation, actively explore and promote orderly charging, V2G, power exchange and other operating modes, under the premise of ensuring the travel needs of car owners, take the initiative to take measures for staggered peak charging, and dissolve the peak-to-valley difference at the local power grid level; finally, in terms of market mechanism, through time-sharing electricity prices and economic compensation Agents participate in auxiliary services and other ways to motivate users to charge more during the trough period and less charge or discharge during the peak period.

"In addition, accurately predicting the charging load curve can actively cope with the peak-to-valley difference." Dai Xianzhong said that relying on the travel data platform, under the premise of not infringing on the privacy of the owner's personal trip, big data analysis is carried out, the travel characteristics of the electric vehicle group are profiled, the charging load curve of the electric vehicle is accurately predicted, the power system is flexibly adjusted, and the demand balance during the load peak and valley period is guaranteed through the active adjustment of traditional units, the active response of other loads, and the mutual benefit of power grid partitions.

Industry insiders also believe that accelerating the construction of the Internet of Vehicles platform is a key measure to tap the value of adjustable resources of electric vehicles, through the large-scale aggregation of electric vehicles to the Internet of Vehicles platform, participate in the scheduling system at all levels, and realize the collaborative interaction of the vehicle network.

It is recommended to introduce a car network interaction policy

Industry experts believe that electric vehicles have huge potential as adjustable resources, and many technical, policy and market obstacles need to be solved. In terms of technology, one is that frequent charging and discharging will affect the life of the power battery, thereby shortening the mileage of electric vehicles; second, the large-scale access of electric vehicles will have an impact on the reliability of the distribution network; third, the lack of "vehicle-pile-network" communication protocol standards, electric vehicles can not be connected to the grid on a large scale; fourth, electric vehicle access to the grid involves user privacy, which may reduce the enthusiasm of electric vehicle users to participate.

"In terms of policies, the state has not yet issued a special policy specifically for the interaction between electric vehicles and the power grid, at the same time, the current market entities interacting with the power grid have a high threshold of quasi-people, which is not conducive to the interaction of the car network." Informed sources admit that in terms of the market, the incentive mechanism for vehicle network interaction is not perfect, and it is impossible to enhance the willingness of users to participate; the business model is not perfect, such as charging piles participating in car network interaction, with large investment and less output.

Experts from the State Grid Energy Research Institute suggest that an access policy for the interaction between electric vehicles and the power grid should be introduced, allowing low-voltage charging stations to participate in the demand response and auxiliary service markets, reasonably setting threshold conditions such as load volume and adjustment amount, and striving for more relaxed assessment standards for the charging and discharging deviation of electric vehicles.

For the problem of vehicle network interaction, Dai Xianzhong suggested that by strengthening the interconnection of platforms and establishing a data platform sharing mechanism, we should open up the interaction relationship between different enterprise car networking platforms in society, as well as with the dispatching platform and the power trading platform, aggregate the flexibility potential of electric vehicles, and play an active regulatory role. "In addition, the green certificate obtained by the electric vehicle charging and replacing green electricity exchange can be used as a certificate for carbon emission accounting and incorporated into the carbon market transaction, so that the low-carbon value of electric vehicles can be reflected as economic benefits, and electric vehicles can be encouraged to consume green electricity at different peaks."

End

Welcome to share it with your friends!

Produced by | China Energy News (ID:cnenergy)

Trainee Editor | Li Zemin

Responsible editor 丨 Yan Zhiqiang