With the commitment to net zero emissions by 2070, India is on a war footing to reduce its carbon footprint in all sectors of the economy.
As the transportation sector is a large emitter of GHG emissions due to our overdependence on fossil vehicles, efforts are being made to research alternative fuel sources for the transportation sector. All the major urban transport companies are now in a hurry to upgrade their fleet of GHG-emitting buses to something clean.
NITI Aayog has given great impetus to battery-powered electric vehicles both as a means of personal and public transport. As a result, most urban transport companies are now opting for battery-powered buses to replace diesel buses as the mainstay of the urban transport system. CNG buses, common in many large cities, are no longer encouraged. Battery buses seem to be the vehicle of the future. Of course, subways are now being built in many other cities, including Tier 2 cities, to move commuters in a faster and cleaner way.
However, it must be recognized that the urban transport system based on battery operated electric buses (EV) has several inherent drawbacks.
First, battery-powered EVs cost a lot more than fossil-fueled buses. Also, since the batteries do not last long enough for a full day’s work, the buses must be switched and taken out of service. To operate at the same frequency as that of CNG / Diesel buses, an urban transport company must maintain nearly double the number of CNG / Diesel buses.
As the battery life is limited, the life of this vehicle is shorter than that of CNG / Diesel buses. In addition, disposal of used batteries is a problem as it is a hazardous material. Little attention has been paid to this aspect during the vigorous push for electric vehicles.
In hindsight, several companies have interests in battery-powered electric buses. Without a doubt, they lobbied the government intensively for this transition. However, once we turn our gaze to the rest of the world, there isn’t much evidence to show that the battery-operated electric bus is the preferred choice for the city transportation system.
The light rail or tram system is part of the urban transport system in most major cities around the world. Of course, in India, trams are currently operated in Kolkata, albeit on a limited scale. The trolleybus system is operated in 280 cities around the world and is increasingly trendy. In India, it was previously operated in Mumbai, but was discontinued in the early 1970s.
Compared to trams, the installation of trolleybuses is cheaper and they do not require the laying of lines or a dedicated corridor. Since a trolleybus operates on rubber tires (unlike a tram) which cannot close the circuit, its electrical energy supply must be ensured by two trolley poles which are in permanent contact with two contact conductors (+ and -) under direct voltage.
The trolleys are articulated on the roof of the trolleybus and are usually around 6 meters long, which gives the trolleybus freedom of lateral movement of up to 4.5 meters. So, unlike the tram, it doesn’t add to traffic congestion and works more like a regular bus.
Modern electric trolley buses are clean, reliable and relatively inexpensive to maintain. India should adopt it for multiple reasons.
It is proven technology and has a longer service life than any battery-powered electric bus.
Thus, a trolleybus system is significantly cheaper to operate, even taking into account the maintenance of overhead cables. Electric trolleybuses currently have advantages in capacity, proven life cycle performance, daily performance for high volume and high frequency journeys.
Since electric trolleybuses do not have to carry large, heavy batteries on board, they provide additional seating capacity, which makes a big difference on high demand routes.
Finally, battery-powered buses need more time to recharge (fast-charging technology remains at a sub-optimal stage) and tend to travel far fewer actual kilometers than advertised, meaning that buses cannot make so many trips in a day.
As a result, transit agencies found that they had to purchase additional battery-powered electric buses to perform the same service they would need with electric trolleybuses.
Thus, purchasing battery-powered electric buses is not an operationally sound idea. In addition, an electric bus running on battery costs more than a trolleybus. Moreover, as India relies on imported batteries for vehicles, the trolleybus system is a better bet for Atmanirbhar Bharat. In addition, the disposal of used batteries is an issue to be taken into account when making a political decision.
Recently, there has been a significant innovation that combines the flexibility of trolley wireless operation and the reliability of the trolleybus called load-in-motion. Current trolleybuses have small batteries designed to allow the bus to move away from the wire for a fraction of a mile to bypass obstacles.
Charging on the move extends this concept by equipping the bus with enough battery for approximately eight kilometers of wireless travel. This technology is increasingly popular in small towns in Central Europe as it allows all the benefits of trolley cable while avoiding the most difficult (and expensive) installation and maintenance points (ie. i.e. intersections, rotary and underpasses).
Considering these multiple advantages, India has to opt for a trolleybus system for the urban transport system.
The writer is with NCAER, Delhi. Opinions expressed are personal