Trends and outlook for charging infrastructure in India
Given the limited consumption of EVs 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. Awadhesh Jha, VP Charge & Drive & Sustainability - Fortum India, explains all we need to know about chargers – their types, locations, and need.
'Every Science begins as philosophy and ends as an art.'
Acceptance of EV by end customers is intrinsically hinged on two factors - 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) customers would expect to have a bouquet of products on EV platform as well to choose from, as each one of us has varying needs when it comes to buying a vehicle for personal use. Simultaneously, customers would like to be assured of the charging facility as most of the present breed of EVs have a limited range of 150-300km, which is otherwise quite good for the daily run, but 100 years of use of ICE vehicles has created the need for that assurance of not getting worried about fuel when undertaking a long distance trip.
Currently, the foremost concern for EV drivers is what they would do if they get stuck in a jam and the 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 the confidence, and that would work as a pull effect for OEMs as well. This warrants that a ubiquitous, reliable and safe public charging network is created.
Principles of charging
Before delving into how and what kind of charging infrastructure should be built in our country, it is important to understand how a vehicle gets charged. All vehicles driving with electric power terrain have a battery that supplies energy to the traction/propulsion motor. So, it is the battery fitted in the 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 an AC-DC converter. This converter is typically fitted in the car and is called on-board charger.
The mode of charging using an on-board charger is called AC charging. When this conversion happens outside the car/vehicle, on-board charger gets bypassed and DC current is directly supplied to battery fitted in the vehicle, called DC charging. So, technically there is no AC charger, as the charger is on board and not outside the vehicle. However, in common parlance we term it AC charging when on-board charger gets AC supply, either from a wall socket directly or through Electric Vehicle Supply Equipment (EVSE). The on-board charger then converts AC to DC and the battery gets charged.
Charging point is the point of supply of electric current in appropriate form to the 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.
Level of charging refers 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 get charged by drawing AC supply using household wall sockets. 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 amp supply. This will take quite longer time to fully charge a car, requiring frequent 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 30 amp to 80 amp 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 80 amp. Please note that it is still AC charging, as it is the capacity of on-board charger that will determine how much power it will accept from EVSE.
Level-2 charging is generally located in shopping malls, golf fields, cinema halls, parking places and similar locations, where we are expected to spend reasonably longer time while the 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 V plus. Power delivered is generally 50 kW and above. The purpose of this charger is to charge up to 80 percent 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 to time needed for charging battery pack only up to 80 percent capacity, as beyond that it takes longer time. Batteries in vehicles like Mahindra e-Verito and Tata Tigor are designed to take not more than 72 V with current as high as 200 amp. Since it is low voltage charging, time taken in full charging of these electric cars is about 90-120 minutes depending upon battery pack size.
Charging stations can also be classified as per the location where chargers are installed.
Charging points located at homes where electric car is plugged in to charge while it is parked, typically overnight. Compared with destination charging, it is generally cheaper – or better on the wallet, as well as slower – or better for the battery. Home charging is the obvious choice for private homes, garages, and housing societies with dedicated parking spaces.
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 (50 kW) can fill a battery from zero to 80 percent 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 22 kW) take approximately three to four hours to charge a battery to 80 percent, and are frequently located around shopping centers, office parking lots, and street-sides.
Requirement for charging network
Developing a large-scale charge point network in Indian urban environment will be more challenging. Unlike petrol stations where serviceability of station is quite high – due to faster rate of fuel filling, charging stations 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 vehicles 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 would be high.
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, and 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 are electric in the future.
Present charging infrastructure
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, fast charging Li-ion batteries are not preferred for 2W and 3W vehicles, as it makes the product costlier at the present state of battery development. This leaves 4W (passenger car vehicles, buses, 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 set up 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 125-150 km range. This kind of charging would need robust electricity infrastructure which is neither needed at this stage for India nor is it currently commercially feasible in India. However, once EV becomes mainstream, consumers would like to prefer these kinds 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 inlets.
Creating a robust charging infrastructure
Private charging and workspace charging will obviously be pursued. In this direction, the proposed guidelines of the Ministry of Housing and Urban Affairs, GoI, to permit establishment of private charging stations at residences is a welcome step. However, the future lies in public charging. Space is a prized commodity in India particularly in urban centers. The average per capita space in India is 100 sq. feet. Almost 70 percent 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 as against public charging where one unit of space can cater to more 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 7-22 kW 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 the DC fast-charging front, globally two leading standards – CHAdeMO and CCS - are widely accepted and same can be adopted/adapted for 4W 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 discussion amongst stakeholders.
Very soon we will master the art of developing charging stations in India.