As new energy vehicle penetration reached 40% on a weekly basis, home charging conditions have become an important constraint for battery electric vehicle development. Could widespread 800V fast charging alleviate the shortage of fixed parking spaces in the Chinese market? Can an 800V fast-charging network deliver immediate benefits to consumers?
Part 1 — Can public stations substitute for home charging in residential communities?
1) Impact of building standards from different eras on parking
Over time, residential building standards have varied by era, resulting in tight parking resources in older communities. Many parking spaces are non-owned or not fixed, which makes it difficult to install charging stations and limits the deployment of charging infrastructure. The higher the urban level, the older many residential communities are, and the worse the conditions for private charger installation. This creates a larger share of residents unable to meet home-charging needs. As penetration rises, the proportion of people without community charging conditions in the potential market will grow, and conversion will become more difficult.
2) Key difficulties for home/community charging
- Parking spaces are scarce and installation conditions are restrictive.
- Distribution power capacity is limited and allocation is often first-come, first-served.
Can we use an 800V fast-charging network to replace home charging with centralized charging?
Part 2 — Challenges for 800V public fast-charging network deployment
Covering home-charging demand with a fast-charging network is inherently difficult. Two main issues are matching new build scale with utilization, and matching existing power capacity and voltage.
1) Matching new build scale and utilization
Building new chargers is easy at first but becomes difficult later. Based on current conditions, the pace of public fast-charging network construction may lag behind new-energy vehicle sales growth. Charger costs include multiple components and many operators are currently losing money. Industry forecasts suggest profitability may not begin until after 2025. A reasonable profit margin is set at ≥10%, but current utilization is only 7%. As the ratio of vehicles per operating charging point changes, the car-to-charger ratio will rise, making utilization issues more apparent.
2) Power matching and voltage matching
Charger power and voltage must match the installed base of vehicles, so buying an ultra-fast-capable vehicle does not automatically mean enjoying an ultra-fast charging experience. Charger-side voltage must be higher than vehicle-side voltage to charge the onboard battery, and upgrading voltage requires a certain time cycle.
Part 3 — Distribution network capacity constraints and expansion challenges
As the number of new-energy vehicles increases, distribution network load will come under pressure, limiting deployment of public fast-charging stations in central urban areas. Core difficulties for distribution expansion include conduit availability and land. Expansion cost depends on whether spare capacity exists nearby. Distribution capacity refers to the amount of power the grid can provide to fast-charging stations; in a sense it represents the additional load the power delivery network can bear under existing conditions, imposing constraints on public fast-charging deployment in central districts. In central urban areas with relatively high grid load, especially near supermarkets and office buildings where parking requires fast chargers, power capacity is clearly limited and further expansion faces obstacles. At highway rest stops this is the most obvious bottleneck area: more investment is needed, but the investment may not be justified by the returns.
At the micro level, conduit availability and land are key challenges in expansion. Trenching and cable laying are needed, and existing designs must be traced; most distribution conduits and corridor resources were not reserved initially, making expansion difficult. Regarding land, building transformers requires occupying public land again, which needs multi-party coordination.
China's power transmission network is the largest in the world. Because of electricity demand driven by economic development, the main transmission network is usually built in advance and is relatively stable, while the distribution network is built according to actual demand. The grid adjusts expansion planning annually or every five years, dynamically updating transmission and distribution network construction. Given current conditions, broadly deploying 350 kW or 500 kW chargers faces significant difficulties.
Conclusion and outlook
After penetration reaches a certain level, charging faces multiple challenges, including limited home-charging conditions, lagging public fast-charging network construction, distribution network expansion difficulties, and rising electricity costs. In 2024, a step-by-step approach is required.
