1. "Co-construction and sharing" creates a light-asset operating model to ease the pressure of early capital investment
Considering that the construction of charging piles is an asset-heavy, long-term investment, in order to alleviate the pressure of early capital investment, some operators have innovatively launched a "partner" model. Operators recruit groups or individuals with the resources (sites, equipment, funds, etc.) required for the construction of charging stations to jointly build and operate charging stations to achieve reasonable distribution of social resources and sharing of benefits. Compared with independent pile construction and operation, the partnership model can reduce the proportion of self-owned funds invested in charging stations, changing from asset-heavy to asset-light operations. Operators focus more on the operation and maintenance of charging stations.
2. Software and hardware upgrades combined with time-of-use charging strategy gradually increase charging utilization rate
The soft charging pile solves the problem of power solidification in a single pile, flexibly allocates charging power, and improves equipment utilization. In recent years, flexible charging piles have been regarded as an important technological upgrade for charging piles. According to the technical standard definition of the "Technical Requirements for Electric Vehicle Flexible Charging Stacks" issued by the Shenzhen Municipal Administration for Market Regulation in 2017, flexible charging piles are "converting electric vehicles into All or part of the charging modules of the car charging station are gathered together. The power distribution unit dynamically allocates the charging modules according to the actual charging power required by the electric vehicle. The station-level monitoring system can be integrated to centralize the charging equipment, power distribution equipment and auxiliary equipment. Control, a system that can charge multiple electric vehicles simultaneously." The core advantages of flexible charging piles are:
- Solve the power curing problem of single charging pile . The power of a single charging pile is fixed and cannot meet the charging needs of higher-power models. With the upgrade of fast-charging batteries and vehicle models, it cannot be "upward compatible." The flexible charging pile is a power cluster that can allocate charging power on demand to meet higher power charging needs. In addition, even if electric vehicle fast charging technology iterates in the future, the charging stack can be upgraded to meet higher power charging needs and solve the "upward compatibility" problem.
- Flexibly allocate charging power to improve equipment utilization . The flexible charging pile can allocate charging power on demand according to the charging requirements issued by the vehicle BMS, which helps the charging equipment work in the optimal load rate range and improves the equipment utilization efficiency of the charging pile.
- Significantly reduce investment costs and eliminate the need to repeatedly increase subsequent investments . For investors, flexible charging piles solve the problem of "upward compatibility". There is no need to worry that the charging piles invested in the early construction do not match the charging needs of subsequent higher-power models. There is no need to repeatedly increase subsequent investments, significantly reducing investment costs and increasing the willingness to build charging piles. .
Figure 1: Flexible charging piles are regarded as an important technological upgrade for charging piles
Head operators’ technologies related to flexible power allocation and flexible charging are relatively mature. Take Telaidian, a leading operator in the industry, as an example. Its group charging product concentrates all power modules in the charging box transformer, forming a maximum power pool of 1600kW. It adopts an original PDU power distribution scheme to achieve single-module granular power deployment. In the current situation where public stations meet the same needs of multiple vehicles and multiple powers, group charging equipment improves module utilization through power sharing. Xingxing Charging's "Beidou" second-generation 360KW split DC charging system uniformly controls the power of the entire pile. The maximum output power of a single gun reaches 360Kw. Through the principles of on-demand distribution, overall optimization, and flexible customization, the overall charging efficiency is increased by 10%. Achieve improvements in operational efficiency.
The time-sharing charging electricity price charging strategy is expected to adjust user demand and improve the time utilization rate of charging piles. An important reason for the low time utilization rate of public charging piles is that when the supply is limited, the user's charging demand is unevenly distributed in the time dimension. Usually, the two time periods of 10-15 o'clock and 18-21 o'clock in the daytime are the peak charging periods, and the charging trough period at night is 23 o'clock to 7 o'clock in the morning. The charging demand is relatively mild in other time periods. Therefore, there are often queues during the peak charging period and no one is interested in the charging trough period, so that the charging piles cannot be fully utilized.
In response to this problem, current mainstream charging operators have launched a time-of-use charging electricity pricing strategy. They charge higher electricity fees during peak charging hours and cheaper electricity during off-peak periods. They use low-price strategies to encourage users to charge during off-peak periods and monitor charging demand. Adjust across time to make full use of charging piles. Still taking Telaidian and Xingxing Charging as an example, the peak-valley charging price difference can reach 0.5794 and 0.5502 yuan/kWh respectively. Therefore, compared with "peak" time, a pure electric vehicle with 50kWh of electricity can save about 28.97/27.51 yuan.
Charging operators have different time utilization rates, and it is expected that some leading companies have crossed the break-even point. Based on the charging pile ownership, total power and charging capacity data of each operator disclosed by the China Charging Alliance in February 2023, we calculated the charging time benefit efficiency of some charging operators. According to the calculation results, Xiaoju Charging’s average charging time utilization rate in February exceeded 10%, reaching 11.6%, which is the highest level. The time utilization rates of leading operators Telaidian and Xingxing Charging are 8.4% and 9.3% respectively. The charging time utilization rates of cloud fast charging and China Southern Power Grid are low, at 5.7% and 3.2% respectively. Based on our previous calculations of charging pile profit models, we predict that leading charging operators such as TeLaishian, Xingxing Charging, and Xiaoju Charging have crossed the break-even point in some months when charging demand is relatively strong this year.
Figure 2: Distribution of average pile number utilization and average time utilization of public piles in major cities in China in 2021
my country's average public charging pile time utilization efficiency increased from 6.7% in 2020 to 12.4% in 2021. According to the data comparison of the past two years in the "Charging Infrastructure Monitoring Report in Major Cities in China" released by the China Urban Planning and Design Institute, the utilization efficiency of public charging piles in my country is gradually improving, mainly reflected in:
- Average pile utilization rate: the ratio of the number of piles providing charging services to the total number of public piles in charging stations, from an average of 34.9% in 2020 to an average of 54.6% in 2021, an increase of 19.7pcts;
- Average time utilization: The ratio of the charging working time of all public piles in the charging station to the total service time available in a day has increased from an average of 6.7% in 2020 to an average of 12.4% in 2021, an increase of 5.7pcts.
3. The integrated optical and storage system has significant advantages, and peak and valley arbitrage improves the profitability of charging operators.
The integrated system of "optical storage and charging" has significant advantages. The "photovoltaic storage and charging" integrated system is a green charging model that integrates photovoltaic power generation, energy storage, and charging and coordinates and supports each other. Its working principle is to use photovoltaic power generation, and the remaining power is stored by energy storage equipment to jointly undertake the power supply and charging tasks. The core advantages of the "optical storage and charging" integrated system are:
- Peak and valley arbitrage, reducing business operating costs: Use energy storage devices to store electrical energy during valley periods when electricity prices are low, and use stored electrical energy during peak periods to avoid direct large-scale use of high-priced grid energy, which can reduce business operating costs. Realize peak and valley electricity price arbitrage.
- Reduce the impact on the power grid: With the increase in the number of new energy vehicles and the popularization of super-fast charging, high-power charging requires increasingly higher power supply capacity of charging facilities, which has a huge impact on the existing charging network system. The "charging" system can use photovoltaic power generation for self-use, becoming a useful supplement to the power grid.
Figure 3: Principle of the “Optical Storage and Charging” integrated charging solution
- Cost-benefit calculation: Without considering photovoltaics and only considering distribution and storage, we take a "storage and charging" system composed of 10 60kW DC piles + 1.5MWh lithium iron phosphate batteries as an example to calculate the cost-benefit. According to our calculations, the initial investment cost is about 2.69 million yuan, the static investment payback period is about 5.3 years, the total income from energy storage and charging is 5.59 million yuan, and the full-cycle net income is about 2.9 million yuan.
The economics of the "optical storage and charging" system are gradually emerging, and the application is expected to be accelerated in the future. The factors that limit the large-scale promotion and application of "optical storage and charging" systems are mainly economic issues. In the early stage, due to factors such as high battery costs, poor cycle performance, and small peak-to-valley price differences, the "optical storage and charging" system had a large initial investment and The profit model is poor and therefore not very economical. In recent years, with the advancement of battery technology, the number of cycles has gradually increased and battery costs have continued to decline. The promotion of time-of-use electricity price policies has increased the peak-to-trough price difference of electricity prices in various industrial, commercial and large industries. The economics of the "optical storage and charging" system will be further improved. Improvement is expected to be accelerated in the future.
4. Vehicle-network interaction, orderly charging, and V2G help charging operators transform into resource aggregators
Vehicle-grid interaction refers to the interaction of energy and information between electric vehicles and the power grid through charging piles. According to the energy flow direction, it can be divided into orderly charging and two-way charging and discharging (V2G) .
Orderly charging can ease the pressure on the power grid and achieve peak shaving and valley filling. Disorderly charging means charging anytime, anywhere and randomly. When a large number of electric vehicles are charged at peak load periods of the power grid, it will bring huge pressure to the power grid system. According to the forecast of the State Grid Energy Research Institute, disorderly charging of electric vehicles will lead to a 12% to 13.1% increase in the peak load of the power grid in 2030 and 2035. According to the definition in the "Ubiquitous Power Internet of Things White Paper 2019" released by the State Grid in October 2019, orderly charging refers to the full information interaction and hierarchical control between the distribution network, users, charging piles and electric vehicles, comprehensively perceive the trend of distribution transformer load changes, dynamically adjust the charging time and power, optimize the distribution transformer load operation curve, and achieve peak shaving and valley filling. This not only meets the charging needs of users, but also improves the utilization rate of distribution network equipment and power generation equipment, and reduces the investment in power grids and power generation equipment.
Figure 4: Grid load curve under disordered and ordered charging situations
V2G technology enables electric vehicles to have load management functions. V2G (Vehicle to Grid), which refers to "vehicle to grid", is also called bidirectional inverter charging technology. It is equivalent to using the electric vehicle power battery as a distributed energy storage system, which can meet driving needs through two-way charging and discharging piles. Transmitting power to the grid. When the grid load is too low, the electric vehicle is charged and the grid power is stored. When the grid load is too high, charging operators integrate electric vehicle power battery resources through digital systems to form a virtual power plant, which discharges electricity to the grid through V2G charging piles, effectively improving the operating efficiency and regulation capabilities of the power system and reducing grid load. .
Figure 5: Schematic diagram of V2G system
Charging operators are high-quality resource aggregators. Compared with load-side resources such as industrial parks and commercial buildings, the adjustment of charging behavior can be achieved through orderly charging and V2G technology. Therefore, electric vehicles are a relatively high-quality load resource, so charging operators who serve electric vehicle charging Become a natural load resource aggregator. In the future, charging operators are expected to increase their sources of profit by integrating scattered electric vehicle load resources and flexibly participating in power spot market transactions and ancillary services according to power market needs.
Flexibly schedule for different charging scenarios and participate in power market transactions to increase profit margins. By screening suitable types of electric vehicles and charging stations, charging operators aggregate dispatchable resources to participate in power spot market, demand response market, and spinning reserve market transactions to increase their own profit margins. Generally speaking, electric vehicle types with regular vehicle usage behavior and large charging needs are relatively high-quality controllable resources. Operators can obtain greater profit flexibility by optimizing charging time and charging volume.
Application side: The penetration rate of supporting car-network interactive charging equipment will be about 10% in 2022, and the market size will develop rapidly. According to data from the "White Paper on Scaled Application and Development of Vehicle-Network Interaction" released by China Southern Power Grid and the China Electricity Council, according to incomplete statistics, there will be approximately 535,000 charging equipment supporting vehicle-network interaction nationwide in 2022, accounting for 10% of the total charging equipment. 10.3% of the total, among which Te Laidian supports the largest number of vehicle-network interactive charging equipment, reaching 370,000 units, followed by State Grid, China Southern Power Grid, Weilai and other enterprises; as of 2022, the national vehicle-network interactive equipment has provided a cumulative peak load of approximately 1.8 The scale of the car-network interaction market is growing rapidly.
Figure 6: Nationally supported vehicle-network interactive charging equipment in 2022 (10,000 units)
