Electric vehicles (EVs) have emerged as an important element of India’s plans for reducing the tailpipe emission of greenhouse gases and noxious pollutants from its transportation sector. The adoption of EVs depends mainly on the cost of the car; the range of EV models; and the availability of charging infrastructure.

The issue of pricing and variety has been reasonably addressed over the years. The charging infrastructure, however, still needs work in terms of developing viable commercial models as well as technologies.

EVs are of two types — one that charge at low voltages, and thereby require more time for a full charge, and another that charge at high voltages, and therefore take less time. Some of the more developed EV markets in the world have deployed high-powered chargers for an easy charging experience that’s almost as fast and effortless as refuelling conventional vehicles with petrol or diesel. Even 10 minutes of such high-voltage fast charging can power an EV for up to 125 km.

India is a nascent EV market with very limited capabilities at present for fast-charging EVs. However, as EVs are likely to be adopted first in cities, it will necessitate the establishment of a widespread public fast-charging network.

A McKinsey report in 2018 had estimated that India would need about five million public charging points at an investment of approximately $6 billion. Public fast-charging should be complemented by AC chargers of capacity ranging from 3 KW to 22 KW at workplaces, shopping malls, movie multiplexes, and restaurants.

All these charging stations must be usable for all kinds of EVs. CHAdeMO and CCS are globally accepted DC fast-charging standards that India can adopt, or adapt, for its four-wheelers. On the AC charging front, Type-2 charging would make the charging station completely interoperable.

Charging EVs on the move

The fear that EVs might run out of power between charging points is leading the industry to explore alternative ways of sourcing power. One of the possible solutions is to use the roadways themselves to transfer energy from power grids to EVs. There is growing interest in this concept of dynamic charging of vehicles on the move.

It can be accomplished by using onboard inductive units to draw a charge from power sources on or under the road surface. The EV battery can get charged by having an electromagnetic field down the middle of the driving lane and a level-controlled armature on the EV’s underside.

South Korea operates one such dynamic charging route, using subsurface cabling. Electric buses ply on this 24-km-long service route between Gumi and Seoul. Sweden, too, has implemented a 1.6 km stretch of inductive electric road, compatible with all types of EVs, in Visby. The EVs get charged as they drive along this stretch.

A big advantage of such systems is that they allow for a significant reduction in battery size and cost. For billing purposes, each EV can be identified by means of a vehicle-mounted barcode and scanners located at the starting and the end point of the charging lane.

Charging stationary EVs

Charging solutions are being developed not only for EVs that are on the move but also for those that are stationary. One such system already exists in Oslo, Norway, where charging stations have been set up for the city's EV taxi fleet, allowing them to charge wirelessly, without needing to go off-route. These taxis can charge their batteries at the pick-up and drop-off stations, while they wait for their next fare.

Technology company Qualcomm, meanwhile, has developed a technology that allows energy to be transferred from induction coils in a plate on the ground to a receiver plate on the underside of the EV.

For charging to begin, the car simply needs to be parked over the plate. Many automotive companies and fleet owners are interested in stationary inductive charging technologies, as they have the potential to maximise revenue.

EVs and the power grid

From a grid perspective, EV charging technologies are being developed along two lines: Managed Charging, and Vehicle-To-Grid Charging. In managed charging, a charging station will have an upper limit for the power it draws from the grid (say 100 kW) and multiple charging points of lower capacity (say five charging points of 50 kW each).

Whenever there are more than two cars using this station, all the charging points will automatically dispense power at levels lower than 50kW. This will ensure that the total load does not exceed 100 kW and that the grid is not destabilised.

Meanwhile, as India enhances its solar power capacities, vehicle-to-grid technology can help in balancing the power grid by using EVs to draw power from the grid during peak generation hours, store it in their battery when not running, and transfer it back to the grid when needed.

As the power grid becomes “greener” and battery technology evolves, EVs will help India move towards a sustainable future for both mobility and power.

In an EV ecosystem, communication between the battery and the charger, and between the charger and the grid, is essential for the safety and reliability of both the vehicle and the grid. There’s as much a need for developing smart charging infrastructure as for upgrading the existing electricity infrastructure to be EV-ready.

In coming years, the uptake of e-mobility in India will depend, to a considerable extent, on the policy interventions, private sector participation, and technology development on the EV-charging front.

The writer is Vice-President – Charge & Drive and Sustainability, Fortum India Pvt Ltd