E-Mobility, however, offers an opportunity for a broad transformation while achieving more sustainable forms of transportation.
“Range anxiety” has been one of the biggest challenges for the electric vehicle (EV) market due to a combination of poor battery performance and a lack of charging infrastructure.
Today a growing number of national and international policy frameworks are aiming to support the deployment of EV supply equipment (EVSE), and of an EV charging infrastructure. For instance, Germany is pursuing the goal of building 50,000 additional fast and standard charging stations by the end of 2021, with the aim of making fast charging stations reachable within 10 minutes – a public fast-charging network with 1,000 locations is to be established by the end of 2023 with charging points providing a minimum output of 150 kW.
The German government has also introduced a number of measures to promote e-mobility such as EV discounts, car tax exemptions and the introduction of the Electric Mobility Act to accelerate the move to electric vehicles. The latest Charging Infrastructure funding program, which began in 2021, has also received additional funding of almost 500mn euros.
As a consequence Germany has seen a record number of registrations of EVs. In 2020, around 194,200 battery electric vehicles (BEVs) were newly registered, around three times as many as in the previous year.
Interoperability
As the battery capacity of newer EVs reaches 60 to 80 kWh, range anxiety will become less of a factor. But the deployment of public EVSE will need to be sufficiently advanced to encourage and support mass adoption. Users don’t want to be confronted by quick chargers that fail to work or deliver just a fraction of the power required.
If we are going to supplant the internal combustion engine (ICE), EVs will need to be capable of delivering much longer ranges so charging points will need to be operational and interoperable with different vehicles – and while that sounds simple, it is in fact very complex to achieve.
Consider the introduction of Wi-Fi in consumer laptops - nobody would expect a new mobile device to have issues in connecting to any private or public Wi-Fi network. But to achieve that, it needed the Wi-Fi Alliance to develop dedicated compatibility tests that weren’t included in the IEEE 802.11b standard itself.
Today, that situation applies to EVs and the charging infrastructure and while we may be in the middle of a wave of second generation EVs the issue of charging interoperability has yet to be solved.
A CCS charging interface is certainly complex as it includes high voltages and the transfer of a significant amount of electrical energy, and while cars have to be designed according to specific automotive standards the charging infrastructure has tended to follow more generic electro technical standards. As a result, the technical specification for EV DC charging remains fragmented.
No conformance test specification has yet been published regarding system and safety requirements of EV and EVSE beyond the communication protocols, which mean that all currently deployed CCS products have not undergone harmonised testing.
This is about to change, however, as major stakeholders in the Charging Interface Initiative e.V. (CharIN), are about to publish an interoperability test program that will initially focus on EVSE conformance tests and will allow OEMs to test their products.
Outlook for the near Future
Mass adoption and addressing ‘green’ and ‘sustainable’ goals are critical when it comes to EVs and the driver needs to have a ‘universal experience’ when it comes to charging, whether that’s ‘easy access’ or automated communication between the vehicle and charging station.
Currently, EVs need to be identified with Radio Frequency Identification (RFID) cards to start a charging session and arrange payment. This can be error-prone and inconvenient as many different identification means and payment services currently exist.
With Plug and Charge, specified within the ISO 15118 series, the process of identification and payment will be automated whereby the user will only need to plug-in the charging cable. But to support this, the charging communication and especially the payment information will need to be encrypted. In addition, and adding to the complexity, the payment information will need to be communicated securely to other stakeholders via a secure backend infrastructure.
Wireless charging will have a critical role to play going forward. Without the need of a charging cable, the EV driver could simply park their vehicle and then charging, communication and power transfer could be executed automatically.
When it comes to sustainability, the concept of ‘green’ mobility depends heavily on CO2 neutrality and energy that’s provided by renewable sources.
Smart charging will enable the scheduling of EV charging sessions controlled by intelligent load management determining the (minimum) amount of energy needed to support the driving range of the EV user, while managing the power that’s demanded from the wider grid.
The challenge of load balancing will involve handling the complexity associated with numerous connected charging spots at the same time as managing the availability of renewable energy. That unpredictability will require buffering and EV batteries will need to contribute significantly in such situations acting as energy storage systems.
This provides scenarios like ‘vehicle to grid (V2G)’ or ‘vehicle to home (V2H)’, where the EV battery itself serves as a power source for other consumers, whenever renewable energy sources can’t provide the necessary amount of energy.
Conductive charging is the next logical step in providing greater convenience and the upcoming ISO 15118-20 standard will introduce support for Automatic Connection Devices (ACD) which can be implemented in various ways (e.g. pantograph, specific under-body connection or conventional connector being plugged by a robotic system).
The distant future
When talking about the challenges of e-mobility, the focus is usually on passenger vehicles with an electrified powertrain. While there are many existing DC charging standards, none are sufficient to charge commercial vehicles within a reasonable time.
To charge a vehicle with 200-600 kWh batteries in 20-30 minutes (the charging time requested by the customer), a power of over 1 MW and a current of over 1,000 ampere will be required. For this reason, the commercial vehicle industry is trying to create a new solution for charging heavy-duty electric vehicles.
Due to the need for a connector for charging commercial vehicles, CharIN initiated the Megawatt Charging System (MCS) working group back in 2018 to develop a holistic system approach based on CCS. Currently discussed technical requirements for a global MCS are for a maximum 1,500 volt and 3,000 amperes (DC), which is based on PLC + ISO/IEC 15118, but only as a single conductive plug.
It’s fair to say that the concept of e-mobility is now entering a critical phase and mass adaption and a viable charging infrastructure will be key factors.
New governmental policies and huge investments are required and even though the total number of charging points, including very capable high-power charging stations for long distance journeys, is set to increase significantly by 2025, there’s still much that needs to be done.
Smart features are helping to turn the charging experience into a seamless and highly automated for users. However, to get there the industry needs to take up an invisible but decisive challenge.
Those challenges require the industry and standardisation bodies to come together to better integrate these new advanced smart features, while maintaining backward compatibility with existing products.
Author details: Michael Tybel is managing director of the Scienlab Solution Centre; Simon Reitemeyer is a solutions architect and Julian Tomczyk is a marketing specialist
