EV adoption: How to spark off a charging infrastructure boom

To get the best life from batteries, it is desirable to charge them slowly (in three to six hours), and this can be done at places where vehicles are parked for a long time. Overnight charging at home and in office parking slots during daytime would, therefore, not only be the most convenient but also the best.

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This is done using alternate current (AC) chargers with a power rating of 3 kilowatts ( kW), 7kW, 11kW or 22k. While two- and three-wheelers may require only 3kW chargers, cars and larger vehicles would require higher-rate chargers. Most Indian cars use 7kW or 11kW chargers today and this may go up to 22kW in the near future.

On the other hand, for long-distance travel or when one is in a hurry, one needs fast chargers of even higher power-rating to charge cars and larger vehicles, which can juice-up a vehicle in 30 to 60 minutes. Using these only occasionally does not hurt the life of batteries.

A reasonable number of direct current (DC) fast chargers, charging at a rate between 30kW and 120kW, are already deployed on 85% of Indian highways. These fast chargers have also been deployed in various cities at locations like malls and parking buildings. What one requires is a single mobile app that can tell EV drivers where these chargers are placed, regardless of which operator they may belong to, and allow drivers to reserve them. Such apps are becoming available.

The question is whether the deployment of public chargers is financially viable today. While it is getting better, a viability gap still exists. This gap will disappear as the number of EVs on the roads increases.

Current incentive schemes to deploy fast chargers in public places are likely to see this through. The issue, however, is a bit more complicated for AC slow chargers. Here are different ways of incentivizing their deployment.

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First, as noted earlier, the best place to use an EV charger is at home. If a customer wishes to deploy it at his or her dedicated parking space, s/he could purchase and install low-cost 3kW charging equipment, as a vehicle would likely be parked long enough to charge.

Second, for residential housing complexes, the builder or welfare association of the complex should mandatorily install some chargers for residents.

A mix of 3/7/11kW AC chargers could be installed, and EV users can be asked to pay at a rate determined by the electricity used as well as the time span of charging. The system of payments should be such that it enables the builder or association to recover the capital expenditure incurred on installing the charging facility within 12 to 15 months. 

At the same time, this should incentivize the user to detach the vehicle from the charger as soon as its battery is fully charged, so that others can use it. Office and commercial complexes should also mandatorily install such public chargers. Users can be charged similar tariffs.

Three, it is important to use an appropriate source of electricity. If one uses the common area power line for the purpose of EV charging, the electricity rates (including demand charges) would be high. 

This is where electricity distribution companies (discoms) come in, as they also have a role to play in promoting the adoption of EVs. It would be best if a discom provides a separate and special EV power line (EVPL) with special tariffs for residential and commercial complexes. 

These lines are to be used exclusively for low-power EV chargers (3/7/11kW installations), complete with electricity meters and the capacity to communicate directly with the discom over wireless 4G/5G telecom networks. When the total electricity drawn on the EVPL at any time exceeds what the meters on connected EV chargers show, the line can be simply cut off.

Four, it may be desirable for EVPL chargers to have a simple electricity tariff structure—say of ₹4 and ₹6 per unit (kWh) during off-peak and peak hours, respectively, and zero demand charges. Such a system could have a provision that enables the discom to send a message to all connected chargers to reduce the maximum charging rate whenever it faces a shortage of electricity (and is purchasing power at high rates). This variability would help the discom balance its supply and demand of electricity in peak hours.

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While many states have a policy of providing special power lines for charging EVs, their approach falls short of what is needed. It is advisable to take a new approach to providing dedicated EV charging lines through a single-window system at residential and commercial complexes.

This could help accelerate the installation of EV chargers at such complexes and thereby the adoption of EVs in the country. It would not overburden electricity discoms, but will surely help customers.

Policy action in this direction is highly desirable.

The author is institute professor, IIT Madras and chairman, ITEL.