GLIDA Lounge

Every Science begins as philosophy and ends as an art

Acceptance of EV by end customers are intrinsically hinged on  two actors – Original Equipment Manufacturers (OEMs), and Charge Point Operator (CPO). Having enjoyed the choices offered by OEMs on ICE platform (which has evolved over 100 years) customer would expect to have a bouquet of products on EV platform as well to choose from as each one of us has varying need when it comes to buying vehicle for personal use. Simultaneously, customers would like to be assured of charging facility as most of the present breed of EVs are having limited range of 150-300km which is otherwise quite good to meet daily need but 100 years of use of ICE vehicles have created that urge of not getting worried for undertaking long distance road trip at our wish. 

Given the limited consumption of e-vehicles in India currently, the infrastructure for the same is also at a nascent stage. Consumers would like to be confident about charging the vehicles as per their convenience, at the location of their choice, and at a price commensurate with service. Currently, the foremost concern a driver of an electric vehicle is what they would do if they are stuck in jam and battery is showing low. If adequate and appropriate charging points are available within cities as well as along highways, it would alleviate such concerns. A robust charging station network would give them a confidence and that would work as pull effect for OEMs, as well. This warrants that an ubiquitous, reliable and safe public charging network is created.

Principles of Charging

Before I delve into how and what kind of charging infrastructure should be built in our country, it is important to understand how vehicle gets charged. All vehicles driving with electric power terrain has a battery which supplies energy to traction/propulsion motor. So it is battery fitted in vehicle which gets charged using electric supply. As we know battery requires DC (Direct Current) to get charged whereas electricity supply generally is AC (Alternating Current). It means for battery to receive the appropriate type of current for its charging, AC supply has to be converted to DC supply for the battery. This is done by AC-DC converter. This converter is typically fitted in Car which is called “On-Board Charger”. This mode of charging using On-Board Charger is called AC charging. When this conversion happens outside Car/Vehicle, On-Board Charger gets bypassed and DC current is directly supplied to battery fitted in vehicle. This mode of charging is called DC Charging. So, technically there is no AC charger as charger is in-built on board not outside the vehicle. However, in common parlance we term AC charging when On-Board charger gets AC supply either from a wall socket directly or through Electric Vehicle Supply Equipment (EVSE) and On-Board Charger converts AC to DC and battery gets charged. 

Charging point is point of supply of electric current in appropriate form to battery either through On-Board Charger or directly. Charging station is facility where one or more charging point or EVSE are located and there is facility for vehicles to remain parked while getting charged. Generally charging station is used with reference to public charging or captive charging for a dedicated group of vehicles.

A charging station can be identified in terms of level of power output, mode of charging, and Type of Charging station (or EV) Connector. Here I am taking charging based on level of power output delivered by charger for the purpose of understanding the need of charging network. 

Charging Type

Level of charging refer to power level of charging outlet. Based on this, it has been classified as Level-1, Level-2, and Level-3 charging.

Level 1 charging – Plug-in Vehicles gets charged by drawing AC supply using household wall socket. Delivered power is product of voltage and current supply which is generally restricted to less than 3.3 KW. This charging is done in single phase. In India this could at 230V 15 amps supply. This will take quite longer time to fully charge a car requiring frequently overnight plugged status of the vehicle. Time in full charging will depend on battery size of vehicle and also the On-Board charger capacity. A typical Mahindra e2o would take about 9-10 hours whereas Hyundai Kona and MG ZS would take 12-15 hours. 

Level 2 charging – Power capacity of EVSE in Level-2 could vary from 7 KW to 43 KW.  Charging at 22 KW and above in this mode is also termed as AC fast charging. This charging is done using 240V with amperage ranging from 30amp  to 80amp in single to three phase delivering higher rate of charging compared to Level-1 charging. Battery fitted with small battery pack like Nissan Leaf takes 30 amp whereas Tesla charger delivers 80amps. Please note that it is still AC charging as it is the capacity of On-Board Charger which will determine how much power it will accept from EVSE. Level-2 charging is generally located in shopping malls, golf field, cinema halls, parking places and similar locations where we are expected to spend reasonably longer time while vehicle gets charged. Depending upon battery capacity and EVSE power capacity, cars like Hyundai KONA and MG ZS can get charged in 6-7 hours.

Level 3 charging – This is also known as DC fast charging or DC quick charging. This is high amperage, high voltage – typically 400 volts plus. Power delivered is generally 50 KW and above. The purpose of this charger is to charge upto 80% of battery pack in less than an hour. Hyundai KONA and MG ZS are the vehicles which can get charged with such chargers. In DC fast charging it is standard practice to refer time needed for charging battery pack only upto 80% capacity as beyond that it takes longer time. Batteries in vehicles like Mahindra e-Verito and Tata Tigor is designed to take not more than 72 Volt with current as high as 200amp. Since it is low voltage charging, time taken in full charging of these electric car is about 90-120 minutes depending upon battery pack size. 

Charging Station can also be classified as per the location where chargers are installed.

Home Charging

Charging point located in home where electric car is plugged in to charge while it is parked, typically overnight. Compared to destination charging, it is generally cheaper – or better for the wallet; as well as slower – or better for the battery. Home charging is the obvious alternative for private homes, garages, and housing societies with dedicated parking spaces.

Destination Charging

Destination charging is the term used to describe charging stations away from home. These are typically located at shops, malls, hotels, park-and-ride parking lots, service stations, and restaurants at destinations. Destination chargers tend to be quick chargers or semi-fast ones, depending on the location. Quick chargers (50kW) can fill a battery from zero to 80% in approximately 30-40 minutes, and are necessary when travelling greater distances, particularly, along highways; or for businesses such as taxis and postal delivery services. Semi-fast or flexible chargers (up to 22kW) take approximately three to four hours to charge a battery to 80%, and are frequently found around shopping centres, office parking lots, and street-side.

Requirement for Charging Network

Developing large scale charge point network in Indian urban environment will be more challenging. Unlike petrol station where serviceability of station is quite high – due to faster rate of fuel filling- Charging station would cater to lesser number of vehicles in a given time. It means we need large number of charging points to cater to equivalent number of vehicles. This warrants huge parking space. Further, it requires adequate electricity infrastructure to supply power to vehicle at desired rate. As the adoption of EV is likely to be in Urban centers during initial years of adoption, both availability and cost of space and electricity infrastructure are high.

Further, EV charging would be a different proposition. Unlike oil and CNG, this has interdependency on battery and electricity. An appropriate communication is needed between battery and charger and charger and grid to ensure safety & reliability to vehicle and grid. This necessitates that charging infra must be smart. What is needed is greater and urgent push for upgradation and strengthening of electricity infrastructure along with charging infra. India would require adding lakhs of charging points year on year if all vehicles are sold on Electric in future.

Present Situation of Charging Infrastructure in India

Unlike developed countries where EV refers primarily to electric Cars, in India EV has to cater to various segment of automobiles -2W, 3W and 4W. Hitherto battery chemistry for 2W, 3W segment and 4W segment has been Lead Acid and Li-ion respectively. Lead Acid and Li-ion batteries have different characteristics in terms of charging. Lead Acid batteries are generally charged at slow rate most often overnight which does not make a good use case for public charging network, though it can be good from grid point of view. Li-ion batteries have the capability of getting charged at high/very high rate. However, 2W and 3W vehicles do not prefer to have fast charging Li-ion batteries as it makes the product costlier at the present state of battery development. This leaves 4W (passenger car vehicles, bus, and other commercial vehicles) as candidate case requiring public charging network. 

Keeping this in view, most of the public charging and captive charging networks have come up to serve 4W cars and buses. DHI notified the standards for chargers for low voltage battery system and these are called Bharat Charger AC001 and DC001. Charger conforming to AC001 delivers 3.3KW per connector whereas that conforming to DC001 or equivalent gives a power output of 10/15 KW per connector. 

With the interdiction of high voltage battery cars like Hyundai KONA and MG ZS in market, need for 50KW DC chargers have emerged. Fortum has setup 10 such chargers in five cities at 10 locations on public charging mode to cater to such cars.

Outlook for Charging Infrastructure

Globally, charging technology has matured and CPOs have started offering charging at 150-350 KW level which can charge a compatible car in less than 10 minutes to give 125-150km range. This kind of charging would need robust electricity infrastructure which is neither needed at this stage for India nor it is commercially feasible presently in India. However, once EV becomes mainstream, consumer would like to prefer these kind of chargers as this would not only alleviate range anxiety but also reduce the space requirement as one charger can serve 5-6 times more vehicles than the 50 KW chargers. 

Another development which is taking shape at global level is wireless charging. This would be very helpful for fleet particularly at locations where drivers are waiting in queue for their turn like at the Airport. Wireless charging will offer continuous charging to the vehicles while it is waiting and moving in queue. This would remove the need of plugging the cars to charger inlet. 

How we can create a Robust Charging Infrastructure

Private charging and workspace charging are obvious to be pursued. In this direction, Ministry of Housing and Urban Affairs, Government of India’s proposed guidelines to permit establishment of private charging stations at residences is welcome step. However, the future lies in public charging. Space is a prized commodity in India particularly in urban centre. The average per capita space in India is 100 sq. feet. 70% of cars in major cities such as Delhi and Mumbai are parked on roads. So to derive better economic value, public charging makes more sense than home charging which would cater to a single car opposite to public charging where one unit of space can cater to more number of cars. For a resource stretched country, public charging, thus, should be the priority. The solutions though, should be bespoke and charging infrastructure providers will have to take cognizance of that. For example, in workplaces, cars can be charged on AC fast charging mode and at places like shopping malls, where a consumer spends 2-3 hours, a slow charger of 7-22KW can be installed. A one size fits all approach cannot work here, and a mix of fast chargers and slow chargers will be able to serve the consumers, according to their particular needs. 

Charging stations should be capable of servicing all kinds of vehicles. On this front, India need not reinvent the wheel. On DC Fast charging front, globally two leading standards – CHAdeMO and CCS- are widely accepted and same can be adopted/adapted for 4-Wheeler segments. On AC side of charging, Type-2 charging would make the charging station completely interoperable. Fortunately, this issue has been settled after a protracted discussions amongst stakeholders. 

Very soon we will master the art of developing charging stations in India.