High-powered charging experience from Chinese city has lessons for Berlin’s future charging rollout

Cities have a high potential for integrating renewable energy on a large scale, particularly for electric vehicle charging, which often offers some flexibility in terms of time and speed of charging. However, understanding this potential requires fully understanding the challenges cities and EV users face. In cities, EV charging must compete with other uses for locations, and must obtain grid access, which can be difficult. Users also have to complete necessary trips without undue inconvenience due to charging. Under the BMWK-supported Sino-German Energy Transition project, Chinese and German experts examined the approaches to high-power charging (HPC) in Shenzhen, China, and Berlin, Germany.

In our first article, we discussed the results of our research on Berlin, which showed the importance of including multiple stakeholders in planning, as well as the high potential for HPC to absorb midday surplus solar energy production. However, Berlin is at the early stages of rolling out HPC.

In contrast, Shenzhen already has hundreds of thousands of EVs on the roads, along with thousands of high-power chargers. The city has mandated EVs for buses, taxis, and many logistics vehicles, whereas Berlin is at the early stage of deploying EVs for these functions. Indeed, our interviews show that many German experts doubt that such vehicles will come available in the coming years, while in Shenzhen thousands of EV trucks and buses are already on the roads. Charging infrastructure in Shenzhen is adequate to meet the city’s charging needs.

Yet Shenzhen’s progress doesn’t imply it is a perfect case of HPC planning for Berlin to emulate. To the contrary, the interviews for this study suggest Shenzhen and China plan charging infrastructure with limited input from important stakeholders. The grid company plays an outsized role in designating sites, which may or may not meet the needs of fleet owners or other users. While China Southern Grid has an app that could theoretically enable users to see what energy is used for vehicle charging, the app is not yet functioning, and there is no timeline for developing smart charging from clean energy on a citywide or provincial basis.

Shenzhen: EV city

Shenzhen, located in China’s southern province Guangdong, is one of the world’s EV capitals. The city has fully electrified its bus and taxi fleets, while making rapid progress on EV adoption in logistics trucks and private passenger vehicles. By 2020, Shenzhen has 19,000 EV buses, 24,000 taxis, and approximately 63,000 private ride-hailing vehicles registered in the city. Of a total fleet of 300,000 logistics vehicles, roughly 80,000 are EVs. Shenzhen is also at an early stage of electrifying its sanitation and utility vehicle fleets, with amount around 4,300 on the roads. Shenzhen had over 250,000 private passenger EVs at the end of 2020, and anticipates having 750,000 on the roads by 2025.

Figure: EV share by types in Shenzhen (2020)

On charging infrastructure, Shenzhen has built more than 5,000 charging stations with a total of 83,000 charging points, which including 30,000 HPC and 53,000 slow-charging, while 7,900 and 16,500 HPC are for buses and taxies respectively. Charging for the bus fleet consists of 388 charging stations located at bus depots, 304 of which are restricted for use by buses, while the others are also used by others at times. These stations comprise a total of 11,768 charging points, of which 9,249 are dedicated to buses only. Most are 120-150 kW chargers installed and operated by bus fleet operators, sometimes jointly owned with private charging companies. Most charging is at night, from 23:00 to 3:00 am, to take advantage of low time-of-use power prices, with a minor amount of charging midday for buses on longer routes. Shenzhen’s present bus charging infrastructure suffices to meet current bus charging demand for existing routes and operations, though the sharing of some charge points does create bottlenecks.

Figure: The number of charging point by using types in Shenzhen (2020)

Taxis and private ride-hailing vehicles charge at stations owned by private charging players, and this separation has led to some difficulties in charging convenience. The HPC dedicated to taxis only consist of 609 charging stations with a total of 18,288 charging points. Taxis experience operational peaks during rush hours (from 8:00-9:00 in the morning and around 18:00 in the evening), and the taxis with only one driver are more inclined to rest at night, in contrast, more private ride-hailing vehicles operate from late evening to morning, which fills the gap in taxi services.

Taxis mainly charge during their low- or non-operational periods, such as between 11:00-17:00 and during night. Taxis mainly use HPC during the daytime to minimize idle time, despite high daytime electricity prices. Statistics indicate taxis on average charge 28.6 times per month, or roughly once per day. The preferred charging methods is clearly HPC, on average 80% of charges or 22.7 times per month. The private ride-hailing vehicles rely on charging between rides as well as at night, and use HPC occasionally to avoid downtime, the average number of HPC is 18 times per month while relying on slow charging for 70% of charging events.

For private passenger EVs, charging infrastructure has faced major obstacles. Shenzhen is a megacity where most residents live in huge apartment blocks—some old and some new. Most residential buildings or complexes provide only a limited number of specifically assigned parking spots, lack sufficient grid connections for charging, and have fire-prevention policies that prevent installation of EV chargers. Local authorities have thus focused on public charging, and Shenzhen has 60,000 shared charging points for passenger cars, mainly offering slower charging speeds.

Shenzhen’s charging strategy enabled a quick rollout

During the ramp-up phase of e-mobility in Shenzhen after 2015, the local authorities laid their focus on the fast expansion of charging services throughout the city. Expansion focused on charging in public areas, with less emphasis on charging for private users and individuals. Indeed, where possible Shenzhen installed large-scale charging infrastructure at major transportation hubs. Most of these facilities are open to all types of users whether private or commercial, with some charging points dedicated to specific user groups. Central facilities have dedicated amenities and are located at places with high existing grid capacity. In contrast, decentralized facilities are smaller, have few amenities and typically offer slower charging.

Charging times are relatively short, less than one hour on average, but charging times vary by vehicle category. 63.6% of taxis and private ride-hailing vehicles charge for less than 60 minutes, whereas 45.9% of buses and 41% of logistics vehicles charge for less than 60 minutes. These users prefer HPC infrastructure, seeking to avoid idle time during operating hours. Private passenger cars are an exception, since only 29.3% of charges last under 60 minutes, reflecting the relative higher flexibility and lower need for all-day vehicle operation for private vehicles. Private vehicles can therefore charge at either centralized or decentralized facilities. Centralized charging facilities on the other hand are predominantly equipped with 120-150 kW HPC equipment, which makes them highly attractive for commercial operators.

Table: Charging time by EV types in Shenzhen (2020)

Shenzhen’s charging infrastructure can basically meet the EV charging demand of the city’s vehicle fleet today. However, the location and size of charging facilities is largely based on space availability and grid capacity rather than driving patterns or the preferences of different EV users. These result a variety of challenges that could be addressed by greater collaboration between local transportation and grid authorities with infrastructure operators and user groups.

Shenzhen’s experience shows drawbacks of centralized planning by grid company

The main drawback of Shenzhen’s charging rollout to date has come from the separation of charging infrastructure planning by the grid companies from the actual needs of users and charging station owners and operators. Emphasizing grid connection over other characteristics has accelerated the construction of charging infrastructure, but results in suboptimal placement from the perspective of maximizing utilization or convenience.

Not only does this discourage investment and financing, but low utilization also doesn’t benefit the grid, since suboptimal placement results in greater need for additional charging investment as well as larger spikes in charging load at dedicated chargers that only serve certain groups. Currently, utilization rates for HPC stations are around 24%, and low-speed public chargers are utilized at around 10%.

Low utilization also affects the incentives for operators to properly maintain charging equipment, repair broken equipment, and share information on charger function with various charging apps. This has been exacerbated by the rushed investment in charging infrastructure starting in 2015, in which a large number of new entrants competed for a limited number of charging locations, not necessarily with regard towards economic efficiency or utilization. Many of these providers adopted their own charging apps, leading to interoperability problems and limited sharing information on charger availability and maintenance.

Currently, Shenzhen is seeking to address these problems while also preparing for a steady increase in EV numbers, especially private passenger EVs and commercial trucks. More centralized supervision of EV infrastructure planning, consolidation of EV charging provider companies, and improvement of residential charging conveniences are among the government’s priorities.

Lessons for other cities:  stakeholder engagement, data transparency, and uptake of RE

Shenzhen relied on grid company planning to enable a rapid expansion of public charging infrastructure at places with existing grid capacity. Arguably, wider stakeholder engagement from the outside might have delayed Shenzhen’s charging rollout, since upgrading grid infrastructure would have taken years, and charging behavior of different groups was largely unknown prior to widespread EV adoption in the city. Nevertheless, EV adoption in other cities will likely take place at a slower pace, allowing more widespread engagement with different stakeholders, resulting in more efficient overall charging investments.

The land rush of new charging providers has also contributed to problems with low utilization and a poor user experience, reducing the incentives to maintain or repair charging equipment and share information with users on charger availability. In the case of Berlin, where RLI’s study found that reservation systems and scheduling functions could enable greater utilization and reduced overall infrastructure costs, Shenzhen would likely benefit from EV charging apps with such functions, but this would require greater data sharing among private operators, few of which are likely to share real-time usage or operational information unless required. Consolidation of charging providers will help improve the quality of apps, but will fall short of a fully interoperable app that enables users to see information on scheduling and functioning.

Finally, Shenzhen’s EV charging infrastructure currently lacks a clear connection to uptake of renewable energy. While China’s national government is encouraging the creation of aggregation companies to purchase renewable energy, we were unable to find evidence of such activity in Shenzhen. China also has a national market for green energy, but green energy purchases mainly take the form of monthly or annual contracts for a certain volume of MWh of wind or solar output. Therefore, green energy purchases are not linked to real-time consumption. China Southern Grid has added the green power query function to the Shenzhen page of its website (the Green Power Calendar 绿电历) that theoretically could enable users to see the electricity generation sources at the time of charging, but currently it is not yet fully functional or open to individual users. Time-of-use prices are the only smart charging element currently in place in Shenzhen, and these TOU prices are static on a seasonal basis, rather than reflecting real-time pricing information or renewable output.

Shenzhen represents a unique case of EV adoption. In some respects, Shenzhen is an amazing success, having scaled up EVs to cover a huge number of vehicles in the span of only a few years, with a charging network sufficient to cover its needs. By focusing on buses, taxis, and trucks—vehicles responsible for a large share of emissions and driving mileage—Shenzhen has substantially reduced emissions from transportation sector, with immense benefits for public health.

However, other cities can also learn from the drawbacks of Shenzhen’s rapid charging rollout. Greater stakeholder involvement in infrastructure planning would likely improve both economic efficiency and the user experience. Better interoperability of charging apps would help optimize charging times and reduce the need for new infrastructure investment, while also helping charging providers and the grid. More effort on smart charging could enable greater uptake of renewable energy, reducing the strain on the grid by shifting load to periods when renewable energy is abundant.

To implement the analysis on high power charging, the GIZ-implemented Sino-German Energy Transition project cooperated with two research partners: The China Society of Automotive Engineers (SAE) supported with stakeholder interviews and modeling usage scenarios to investigate the integration of RE and development pathways of HPC infrastructure in Shenzhen. The Reiner Lemoine Institute (RLI) examined HPC development and future charging scenarios in Berlin. The research is carried out under the framework of the Sino-German Energy Transition Project commissioned by the German Federal Ministry for Economic Affairs and Climate Action (BMWK), implemented by GIZ.