Although buses constitute just 1% of the vehicle population in India, they contribute approximately 15% of total carbon dioxide (CO₂) emissions from transportation. To help address this, the Ministry of Housing and Urban Affairs (MoHUA) initiated the PM-eBus Sewa scheme, which aims to deploy 10,000 electric buses (e-buses) across 100 cities with populations exceeding 300,000. In December 2023, Convergence Energy Services Ltd. (CESL) issued the first tender under the scheme, and it aggregated demand for 3,825 buses across 49 cities. As these e-buses are expected to be deployed soon, let’s approximate the greenhouse gas (GHG) and tailpipe pollutant emissions avoided by their deployment compared with conventional diesel buses.

The ICCT supported the MoHUA in the PM-eBus scheme and back-of-the-envelope calculations such as these help us understand the environmental benefits of e-buses. Following this list of our assumptions is a table with the specifications of the e-buses modeled:

• If not for the PM-eBus Sewa scheme, the 49 cities would have deployed diesel buses.
• The fleet constitution is the same as the current CESL tender, in other words, 12 m air-conditioned (A/C) e-buses would be deployed on routes that would have been otherwise served by 12 m diesel buses, 9 m A/C e-buses would be deployed on routes served by 9 m diesel buses, and so on.
• GHG emissions are estimated for the use phase of the vehicle, for a lifetime of 12 years from 2023 to 2035. For diesel buses, these are tailpipe exhaust emissions. For e-buses, the tailpipe emissions are zero and we estimate the emissions from generating the electricity to charge the buses.
• The grid emissions are calculated under three scenarios: The future grid mix based on India’s stated policies from the International Energy Agency’s (IEA) Stated Policies Scenario (STEPS); a more ambitious shift to renewable energy under IEA’s Sustainable Development Scenario (SDS); and a 100% renewable electricity scenario.
• This analysis of use-phase emissions is the same as the use-phase emissions assessed in a full life-cycle emissions comparison performed in a previous ICCT study in India.

Table. Assumed specifications of e-buses deployed under the CESL tender

*Because no bids were received in the first tender, the 7 m buses were re-tendered with the second tender issued by CESL. These buses are thus expected to be deployed under the second phase of bus deployment.

Energy efficiency and emissions reduction 

Under our assumptions, e-buses are about 70% more energy efficient than diesel ones. Hence, even with the future development of India’s electrical grid under the STEPS scenario, which includes heavy reliance on coal, e-buses show a 19% reduction in use-phase GHG emissions over a vehicle lifetime from 2023 to 2035 compared with diesel buses (Figure 1). Additionally, although a diesel bus’s emissions are mostly locked in for its operational lifetime, the emissions from an e-bus will decline as the grid becomes greener. E-buses would reduce GHG emissions by 34% if the power grid transitions toward renewable sources like solar and wind under the SDS. In the scenario with 100% renewable energy powering the grid, we estimate e-buses have the potential to achieve a 96% reduction in emissions compared with diesel buses (the remaining 4% emissions are due to upstream emissions from renewable energy infrastructure estimated at 35g CO₂e/kWh).  

Figure 1. Estimated use-phase emissions from 3,825 buses over 12 years of life

The transition to e-buses not only curbs GHG emissions but also eliminates tailpipe pollutant emissions of nitrogen oxides (NO_x), sulphur dioxide (SO₂), carbon monoxide (CO), hydrocarbons (HC), and particulate matter (PM). Nitric oxide, nitrous oxide, nitrogen dioxide, and CO all contribute to the formation of secondary pollutants like ozone, nitric acid, and others. When combined with organic compounds, these pollutants can also create photochemical smog. NO_x and SO₂ contribute to acid rain. 

For the first 3,825 e-buses under the PM-eBus Sewa scheme, we project over 1,200 tonnes of NO_x emissions and 700 tonnes of CO avoided (Figure 2). To give a sense of the impact of this, research in Brazil suggests that decreasing NO_x concentrations in medium-sized cities by 3 micrograms per cubic meter can lower the risk of respiratory disease-related deaths by 10%–18%. Hence, e-buses are not just a win for the environment but also for public health. With its initiative, the MoHUA is not just encouraging public transport-centric urban development but also investing in creating healthier cities. 

Figure 2. Estimated tailpipe pollutant emissions avoided by 3,825 e-buses during 12 years of operation

Economic and social benefits 

Beyond environmental and health benefits, e-buses can offer economic advantages such as lower operational and maintenance costs. Such financial flexibility could allow transport authorities to invest in further planning and innovation. Moreover, the Government of India projects that the PM-eBus Sewa scheme will generate as many as 55,000 jobs. It will also contribute to energy security by reducing dependency on imported fossil fuels. 

It’s also notable how the MoHUA developed and executed this scheme. Although electrification of transport has traditionally been under the purview of the Ministry of Heavy Industries (MHI), this scheme saw inter-ministerial collaboration that aided in its execution. Such collaboration is also reflected in two separate instances: The recently announced “PM-eBus Sewa-Payment Security Mechanism (PSM) scheme” by MHI, which has an outlay of ₹3,435.33 crore to aid procurement of 38,000 e-buses, and under PM-eBus Sewa scheme implementation, where the Ministry of Power’s support for evaluating behind-the-meter infrastructure requirements was crucial in estimating the depot electrification costs for the e-bus depots being developed under PM-eBus Sewa. The ICCT looks forward to continuing a productive partnership with the MoHUA to pave the way for cleaner, more efficient, and sustainable urban mobility solutions in India. 

The growth of online shopping was accelerated by the COVID-19 pandemic, and e-commerce revenue approximately doubled in the United States in the past 5 years. In the neighborhoods where new warehouses have been built to meet this increase in demand, the trend has brought noticeable changes, including emissions from large tractor-trailers that bring containers from nearby ports and vans that collect packages for home delivery. These vehicles emit harmful pollutants including fine particulate matter and a group of gases called nitrogen oxides (NO_x).

While the warehouses don’t emit pollution like a power plant, their operations mean that truck traffic and tailpipe emissions concentrate around them. Researchers have detected increases in air pollution in communities where new warehouses have opened.

We at the ICCT partnered with researchers from The George Washington University on a new nationwide study in Nature Communications that helps quantify how much warehouses worsen local air pollution in the United States. The study focuses on nitrogen dioxide (NO₂), which is associated with new asthma cases in children, respiratory symptoms such as coughing and difficulty breathing, and other adverse health impacts. NO₂ emissions also lead to the formation of fine particulate matter and ozone in the air, which increase the risk of dying prematurely from heart and lung diseases, cancers, and other conditions.

Our study analyzed NO₂ satellite data along with a database of nearly 150,000 warehouses in the contiguous United States. The figure below illustrates the pattern in annual average NO₂ pollution around a warehouse, averaged across all locations. It shows that there is a spike in annual NO₂ of nearly 20% associated with warehouses. The highest NO₂ concentration is around 4 km away from the warehouse in the direction of the wind. Additionally, larger numbers of loading docks or parking spaces were associated with more truck traffic and higher levels of NO₂.

Figure. Annual average NO₂ concentration in 2021 from TROPOMI satellite data averaged over all warehouses in the contiguous United States. Source: Kerr et al. (2024).

Like others, our study also found that census tracts with greater numbers of warehouses tended to have higher shares of residents of color. This aligns with results from previous studies which showed that racial and ethnic inequities in NO₂ exposure are largely attributable to diesel truck traffic. Clearly, warehouse-related truck emissions are important to understand when taking action to address air pollution exposure disparities.

Addressing the issue requires action at multiple levels. At the federal level, the U.S. Environmental Protection Agency (EPA) recently finalized standards that will reduce emissions from new trucks starting in model year 2027. Under these, new engines sold by manufacturers must meet NO_x emission limits more than 80% below current levels. Additionally, the Phase 3 greenhouse gas rule, finalized in 2024, will encourage the deployment of more efficient technologies like hybrids and zero-emission vehicles, further reducing NO_x emissions from trucks.

At the state level, California’s Advanced Clean Trucks and Advanced Clean Fleets rules require manufacturers to transition to 100% zero-emission sales for medium- and heavy-duty vehicles by 2036. The Advanced Clean Fleets rule also includes a zero-emission drayage registration requirement that will accelerate the adoption of cleaner vehicles at ports and warehouses. Both EPA’s greenhouse gas rule and the California Advanced Clean Fleets rule face legal challenges, but these rules need to stay in place to support the transition to cleaner vehicles and reduce air pollution near warehouses.

Regulations can also directly target warehouse-related pollution. The South Coast Air Quality Management District in California implemented an indirect source rule that requires large warehouses to reduce pollution, and credit is awarded for actions like transitioning to zero-emission and near-zero-emission trucks and installing charging infrastructure. New York City recently announced plans to implement a similar policy.

Lastly, addressing this issue requires action from both the private sector and regulated electric utilities. Amazon, the largest player in the e-commerce space, has committed to deploying 100,000 electric delivery vans by 2030. While a significant step, commitments to end diesel drayage contracting by 2030 and work toward implementing zero-emission service contracts with logistics operators and warehouse owners, and installing charging infrastructure at warehouses, would further demonstrate industry leadership. Prologis, the largest owner of warehouses in the United States, pledged to install 900 MW of charging capacity at its facilities. Simultaneously, electric utilities proactively planning grid upgrades and streamlining permitting for necessary charging infrastructure can help ensure the success of these initiatives.

Emissions from trucks have declined substantially in recent years thanks to regulations requiring more advanced emission control technology. With a nearly 50% increase in freight tonnage moved by trucks projected over the next 30 years, the new rules from EPA and California are key to continuing to make progress. The private sector, electric utilities, and other local rules also have important roles. The status quo is simply not enough. A commitment to delivering clean air requires action to address warehouse-related truck emissions.

This blog was originally published in ETAuto.

The Government of India is emphasizing the need to decarbonize road transport, and low-emission zones (LEZs), geographically defined areas where the operation of highly polluting motorized vehicles is restricted, can accelerate this transition toward cleaner mobility. LEZs also have the potential to improve quality of life for urban residents because of the health benefits they bring.

LEZs are becoming an increasingly adopted intervention to curb urban air pollution and traffic congestion, especially among European cities where more than 320 such zones exist. In addition to regulating the movement of polluting vehicles, LEZs also help spur mode shift from private vehicles to public transit and more active mobility alternatives like walking and cycling. As cities in India consider such interventions to address the issues of pollution and traffic congestion, and to meet decarbonization goals, how would upgrading transport infrastructure bring a range of benefits, including support for LEZs?

Enabling regulation of highly polluting vehicles

To identify vehicles that are contributing to most emissions, city authorities need vehicle-specific information like the fuels they run on, their years of manufacture, and the emission standards to which they are certified, for every vehicle plying in the city. While vehicle-specific information is available through the VAHAN database, the challenge lies in ascertaining polluting vehicles that are plying in the city and their travel patterns.

Vehicle registration data available with the Regional Transport Offices (RTO) that cover a given city is seldom considered a proxy to determine the motor vehicles plying in that city. However, the vehicles plying within a city could have been registered anywhere in the country, and the registration data from RTOs is not likely to be a complete representation of vehicles operating in that city. In 2016, for example, it was estimated that over 5 lakh personal passenger vehicles enter Delhi every day, which was more than the total number of vehicles getting registered in the capital in a year. An equal number could be traveling out of the city as well, deeming the registration data inept for determining polluting vehicles.

Installing closed-circuit television (CCTV) cameras, preferably those with the ability to read license plates, at strategic locations across the city is an ideal way to access real-time insights into vehicular movement. Using the vehicle registration numbers detected by this network of CCTVs, local authorities can determine the age, engine type, Bharat Stage emission standard, and other characteristics of each vehicle plying in the city to develop a vehicle emission inventory and identify vehicles that should be regulated by the LEZs.

While CCTVs are already extensively used in security surveillance and traffic and parking management, they are now being integrated with artificial intelligence and machine learning capabilities for many things, including crowd management, threat detection, and improving road safety. Bigger cities like Delhi and Bengaluru already have over 2 lakh CCTVs installed for improving law and order. Such a robust network of cameras in a city augments the eyes-on-the-street concept and can be used to enforce future LEZs, all while remaining compliant with the rules governing this equipment in India.

Encouraging alternative modes of travel

Alternatives to private vehicles include public transport modes like metro, light rail, and bus, para transit modes like feeder buses and auto-rickshaws, and non -motorized modes like cycle-rickshaws, cycling, and walking.

Public transport is especially crucial in metropolitan areas, where about half of all motorized trips are made via buses or metros. It’s also effective in moving more people and consumes less fuel per passenger kilometers travelled than private vehicles. Cycling and walking are the cleanest modes of travel, and the cheapest and healthiest. Across 27 cities in India, research found that the number of people cycling and walking ranges from 48% to 55%, depending on population size (large cities of more than 10 million people are on the lower end of the range).

It’s estimated that India operates only one-fifth of the buses it currently needs. With a few exceptions (Chennai, Mumbai, and Hyderabad), most cities with any form of rapid transit system (metro, bus-rapid transit, or light rail) operate at less than 20% of their estimated ridership. Most Indian cities lack adequate and safe infrastructure for non-motorised transport.

Efforts are being made at both national and subnational levels to improve the availability of and access to non-personal modes of travel. The PM e-Bus Sewa program aims to add 10,000 new electric buses in 169 cities. The operational network of metros in cities is expected to double in the next few years. While there is a clear need to increase availability, the barriers to using public transport, which include safety, accessibility, reliability, and comfort must also be addressed. This can not only encourage a mode shift from personal to public transportation, but also increase the acceptability of LEZs.

LEZs are not an isolated solution to a city’s deteriorating air quality but contribute towards the overall enrichment of the urban ecosystem. Studies show LEZs have helped reduce nitrogen dioxide emissions from road traffic by up to 46%. By integrating technological solutions and upgrading transport infrastructure, cities not only improve the efficiency of transport system but also add infrastructure that is a utility for other urban services. With the environmental and health benefits they bring, LEZs could be a valuable part of India’s vision for cleaner, healthier, and more liveable cities.