Revving Up: Growing focus on EV charging infrastructure

The global electric vehicle (EV) charging market is poised for significant growth and is expected to reach $30.4 billion by 2023 and $35 billion by 2026. The future of EV charging infrastructure holds immense potential, with the emergence of innovative next-generation vehicles and complementary components expected in the coming years. Several new technologies are being developed in the EV charging space, with the potential to transform the sector, enhance efficiency and drive adoption.

EV charging encompasses a range of methods, depending on factors such as location and specific use cases. The sp­ecifications and standards for EV chargers, also known as electric vehicle supply equipment (EVSE), vary from one country to another. These distinctions are influenced by the wide range of EV models available in the market and the unique characteristics of local electricity grids.

The core component of EV charging infrastructure is the EVSE. This unit connects to a nearby electricity source, utilising a control mechanism and physical connection to effectively and securely charge EVs. The control system integrated into the EVSE facilitates multiple operations such as user validation, permission for charging, data logging and network administration. It also ensures data privacy and security.

EVSE varies in power ratings, determining the required input power for charging infrastructure. Standard alternating current (AC) charging is suitable for electric two-wheelers and three-wheelers and electric cars. Unique to India, normal power DC charging serves low emission vehicles (LEVs) and low-voltage e-cars. Single-phase AC (up to 7 kW) is sufficient for LEVs and single-phase e-car chargers, while larger e-cars require three-phase AC (up to 22 kW). Normal power supply from the grid suffices for these cases. High voltage e-cars (30-80 kWh) utilise 50 kW high-power DC charging, currently available up to 60 kW, with higher power options ex­pec­ted. While high-power DC offers faster speeds, it demands more electricity and infrastructure. Normal power charging is sui­table for most needs, including over­night e-car charging.

Battery charging methods

Automobile manufacturers are exploring innovative methods of charging EVs with the objective of establishing an effective and elaborate EV charging infrastructure. Batteries can be charged in various ways. Conductive charging, commonly known as plug-in or wired charging, is the prevailing technology for recharging EVs. The specifications for EVSE in conductive ch­arging depend on variables such as vehicle category, battery size, charging techniques and power levels.

EVs equipped with in-motion (dynamic) wireless charging have emerged as a potential solution to enable longer service hours, smaller battery packs and autono­mous capabilities. Wireless charging systems can either be stationary, which mea­ns that they can only be utilised when the car is parked or is in stationary mode, such as in car parks, garages, or at traffic signals; or they can be dynamic.

Bidirectional charging is another emerging charging technology. It involves channelling energy from vehicles to various so­u­rces such as loads, other vehicles, hom­es or the grid (V2G), standardised in ISO 15118-20. Infrequent drivers only utilise a fraction of their EV battery capacity, leaving potential for storing unused PV power or rapidly charging needy EVs. Shifting electricity use based on variable tariffs can help reduce costs and support grid stability, while a network of connected EVs could potentially transfer power back to the grid.

EV charging companies and third-party players are providing software solutions to enhance the end-user experience. Su­ch network management software de­te­cts the location of different EV chargers, generates billing for the charging, and pro­vi­des detailed reports and analytics of char­ging trends, costs, and even greenhouse gas reductions. Some chargers provide V2G support as well.

Charging standards

Standards ensure that all EVSEs are compatible and can work seamlessly with any EV model. In India, the Bureau of Indian Standards (BIS), the national standards organisation, formulates the country’s EV charging standards. BIS is aligned with the International Electrotechnical Com­m­is­sion (IEC), a global entity that develops reference standards to enhance EV interoperability and ease trade barriers.

IS 17017 is India’s primary EV charging standard, divided into three parts and six sections. IS 17017 Part 1 outlined the fundamental features of all EV charging systems. The standard focuses on general requirements, characteristics, operations and communication connections between EVs and EVSE to create a favourable EV charging system. It is applicable to EV systems with supply voltages of up to 1,000 V AC or 1,500 V DC, and output voltages of up to 1,000 V AC and 1,500 V DC.

IS 17017 Part 2, Section 1, covers the general requirements of plugs, sockets, vehicle connectors and inlets for conductive charging. The standard applies to a system rating of up to 690 V AC at a rated current of 250 A, as well as 1,500 V DC at a rated current of 200 A8. It covers details such as wiring, terminals, ratings and the connection between the power supply and the EV.

IS 17017 Part 21 standardises the electromagnetic compatibility of EV chargers and onboard EVSE. Both AC and DC EVSE are required to meet the technical standards outlined in IS 17017 Parts 21 and 22. Additional Indian standards are in place for affordable AC EVSE suitable for light EVs and e-cars, designed for parking areas.

In April 2023, BIS introduced standards and tests for EV charging infrastructure, as well as criteria for battery swapping systems, including safety standards for such systems. The series consists of 10 parts that define charging modes, communication protocols, and electrical safety and performance test requirements for EV charging systems.

Interoperability is another critical aspect that requires attention from all charging point operators and original equipment ma­nufacturers. Cooperation between them is essential for managing asset utilisation and capex related to land, power connection and upgradation of transformers at the distribution level. Recently, the Bh­arat Charge Alliance and the CHAdeMO Association collaborated to develop interoperable charging infrastructure. The specifications for constructing this infrastructure will align with IS/IEC standards. The alliance aims to implement standards published by BIS, including IS 17017:25 (based on IEC 61851-25) EVSE standard and IS 17017-2-6 (IEC 62196-6) for vehicle inlets and connectors.

EV charging technologies

A key technology focus area in the EV charging market is fast charging. Fast ch­ar­gers are starting to appear in cities and are a necessity for public and on-street ch­ar­ging to minimise waiting tim­es. Currently, commercially available feasible EV batteries require approximately 10 hours for a complete home recharge, while the fastest superchargers available today can achieve a full recharge in 20-40 minutes. Emerging advancements, such as 800 V charging and quantum ch­arging, which expedite battery charging, are ex­pe­c­ted to reshape the EV charging landscape.

The majority of EVs currently operate on 400 V batteries. However, experts predict that new EV models introduced after 2025 will adopt an 800 V framework. This transition is driven by advanced higher voltage technologies, which enable rapid-charging of batteries by directing more current to cells due to increased voltage with the same resistance. With fast-charging batteries, 800 V charging systems can provide a 10-80 per cent charge within 10 minutes.

In the near future, public EV charging must also achieve ultra-high-speed levels to address key adoption hurdles, such as concerns about range and charging times. Globally, manufacturers are developing stable lithium-ion and solid-state batteries for faster charging, potentially within 20 minutes or less. Despite technological progress, the feasibility of commercialising ultra-fast charging remains uncertain due to grid demands and existing challenges.

Net, net, rapid advancements in battery technologies and charging methods are essential for achieving the required pace of transition towards cleaner mobility.