Introduction

Public transport is the backbone of mobility, enabling millions of people to commute to and from work every day. Diesel Bus vs Electric Bus are also essential for linking neighborhoods and providing affordable transport for people of all social classes.

• Pollution: Diesel buses emit CO₂, NOx, and particulates, contributing to air quality and public health problems in urban areas.

• Fuel Costs: Variations in diesel prices can increase transport authorities’ costs, thereby influencing ticket prices.

• Sustainability: Under the threat of climate change, urban centers are seeking cleaner sources to help reduce carbon emissions.

Purpose of Comparison:

• Compare and analyze diesel and electric buses based on cost, performance, environmental friendliness, and necessary infrastructure.

• Realize what kind of bus would work best for the future of public transport in urban India and across the globe.

• Share key insights with policymakers, transportation organizations, and commutters on the way forward for sustainable transport.

History and Current Scenario

Diesel buses have long remained the driving force behind public transport systems and have been functioning as a dependable means of long-distance transport. The ease of refuelling and the infrastructure associated with these vehicles have already helped them dominate the transport sector worldwide. However, amid growing concerns about the environment and technological advancements, electric buses are gradually transforming public transport services worldwide.

History of Diesel Buses:

• Introduced during the mid-20th century, replacing the older petrol and steam buses.

• Became the primary choice due to high fuel efficiency and operational distance.

• An extensive refuelling and maintenance support infrastructure ensures reliability in day-to-day use.

• Remains dominant in developing nations owing to its low initial cost compared to EVs.

The Rise of Electric Buses and Worldwide Adoption Trends:

• Early 2000s: Pilot projects in Europe and North America introduced miniature electric buses.

• After 2010, mass adoption occurred in cities such as Shenzhen (China), Oslo (Norway), and Los Angeles (USA).

• The adoption of lithium-ion batteries and fast-charging technology helped enhance the range and usability.

• The governments around the globe have made the usage of EVs more compelling due to subsidies and the implementation of “low-emission” policies.

Statistics: Diesel vs Electric Buses (India & Worldwide):

• India: Approx. 1.5 lakh diesel buses, while electric buses are less than 5,000 in number.

Cost Analysis

Cost is a very important consideration for the use of buses in public transport. Diesel buses have been preferred for a long time because they were cheaper to acquire, and fueling infrastructure had been developed. Electric buses, although more expensive at initial acquisition due to their battery systems, are cheaper to run and therefore a good investment for a city aiming to adopt a sustainable transport system.

Initial Cost:

• The price of a diesel bus can range from 40 to 60 lakhs.

• Replacing batteries every 6-8 years increases the cost of electric buses over their entire life cycle.

• Although the purchase costs of electric buses are higher, their benefits make them economical in the long run.

Operating Cost:

• Diesel buses: Fuel costs are estimated at ₹7-10 per km. Additionally, maintenance costs will be high due to engine and oil changes.

• Electric Buses: The cost of electricity is approximately ₹2–4 per kilometer, with lower maintenance requirements.

• Battery degradation and replacement are the only long-term maintenance issues for electric buses.

GST Benefits:

• Encouraging cities to adopt zero-emission vehicle fleets and providing incentives, such as lower registration rates and favourable loans.

Real World Example (Cost per km Comparison):

• Diesel bus: 250 km/day route ≈ . Fuel cost: Rs 2,000, Maintenance cost: Rs 500.

• Electric bus: Same route → electricity cost of approx. Rs. 600/800 per day.

• In the past 10 years, an electric bus has returned savings of ₹50-60 lakh.

Environmental Impact

The ecological footprint left by buses is one of the most influential factors shaping the future of city transportation. Diesel buses, although reliable, have a huge impact on air emissions and climate change. Electric buses can significantly reduce air emissions because they do not produce tailpipe emissions. Nonetheless, the extent to which the use of electric buses is ecologically justifiable depends on the production costs of the electricity they use. Urban centers that have adopted electric buses have already seen reductions in air emissions and noise.

Diesel Buses:

• Release CO₂, which causes global warming.

• Emit NOx and particulate matter, contributing to respiratory and cardiovascular diseases.

• It causes significant urban smog and haze, especially in large cities.

• Noise pollution has increased due to engine operation and the exhaust system.

Electric Buses:

• There are zero tailpipe emissions, so there are no air pollutants in the locality.

• Overall, the environmental impact varies with the sources of electricity:

• Increased indirect emissions due to coal-generated power.

• Renewable sources of energy, like Wind Energy or Water Energy, are truly sustainable and have

• Requires careful disposal and recycling to protect the environment.

Cities Adopting EVs:

• Shenzhen, China: Their all-electric bus fleets cut particulate matter emissions in the city by over 30%.

• Delhi & Bengaluru, India: Successful testing of pilot EV buses indicates reduced noise levels & clean air in major routes.

• Reducing noise pollution enhances living standards in densely populated regions.

• A favourable public perception leads to an increase in the use of EVs

Performance and Efficiency

Performance and operational efficiency are major factors in selecting buses for public transport. While diesel buses have always been in demand, owing to their extensive range and hassle-free refuelling, electric buses are fast catching up, as they are coming good on range thanks to improving battery technology and charging infrastructure. Beyond range, factors such as noise, riding comfort, adaptability to different climates and terrains, and other considerations contribute significantly to their usability and passenger experience.

Range and Battery Life:

• Diesel buses: Generally cruise 500-700 km per tank for long urban and inter-city routes.

• Electric buses: With modern batteries, it is possible to cover 200–300 km per charge, while high-capacity batteries allow up to 400 km.

• Battery life: about 6–8 years, average; there is a gradual decline in performance over time.

Refuelling/Recharging Time:

• Diesel buses: Full refuelling takes 5–10 minutes, enabling quick turnaround.

• Electric buses: Standard charging time runs from 4 to 8 hours; fast chargers have cut that to 1-2 hours.

• The range can, however, be extended during operation through opportunity charging, for example, short top-ups at bus stops.

Noise Levels and Ride Comfort:

• Diesel buses are noisier because of engine vibration and the exhaust system.

• In contrast, electric buses are quieter in nature and have smoother acceleration and deceleration.

• With reduced vibrations, passenger comfort improves, and driver fatigue is reduced.

Reliability across different climates/terrains:

• Diesel buses: demonstrated performance in extreme heat, cold, and hilly terrain.

• Electric buses: Battery efficiency can be reduced at very low or very high temperatures, but modern thermal management systems enhance reliability.

• Ongoing testing in various urban and rural routes is building EV robustness.

Infrastructure and Challenges

A shift from diesel to electric buses involves changes beyond technology alone, as infrastructure, power distribution, and planning need to be updated to operate effectively and efficiently. Although there are refuelling stations for diesel buses, there is no charging infrastructure, power handling, or planning for route operations to ensure smooth functionality, especially when compared to electric buses, which pose challenges in managing a fleet, downtime, and maintenance.

Electric Bus Infrastructure:

• Charging Stations: Rapid charging infrastructure and opportunity charging stations are to be provided in cities.

• Grid Capacity: Electricity supply, or the capacity of the power grid, must be reliable because the use of renewable energy sources.
• Route Planning: The buses’ routes must be assigned based on their operational ranges; the scheduled time must include charging time.

• Investment: High initial investment for charging infrastructure and power upgrades.

Diesel Bus Infrastructure

• There are extensive fuel stations that make refilling easy.

• Does not require upgrading to the grid and/or specific route planning.

• Environmental disadvantage: It adds to air and noise pollution, affecting urban health.

Fleet Management, Downtime, and Maintenance

• Diesel buses: Increased maintenance for wear and tear, oil changes, and exhaust system repairs, which may have an impact on the level of services provided.

• Electric buses: Although batteries will eventually wear out, fewer mechanical components require replacement or repair.

• Both of these fleets need staff to service and continuously monitor.

Case Studies

Studying case studies will provide insight into the practical performance of diesel and electric buses. Cities that have adopted electric buses not only showcase the environmental benefits but also demonstrate their practical viability, thereby underscoring the importance of policy intervention in this regard.

Global Example – Shenzhen, China:

• Converted completely to an entirely electric fleet of buses exceeding 16,000 units.

• Lowered emissions of air pollutants in urban areas and GHGs.

• Installed charging infrastructure, such as depot and opportunity chargers.

• Realized cost savings in operational efficiency resulting from reduced costs for energy and maintenance.

• India – Pilot Projects and EV Adoption Trends: India has ambitious plans to adopt electric

• Delhi: More than 400 electric buses are plying; the number is expected to increase to 5,000 with support from the FAME-II scheme.

• Bengaluru: Electric bus operations with 100+ electric buses on trial routes. Feeder services for metro and high-density routes.

• Pune: The fleet comprises electric buses that are charged using renewable energy-driven charging stations.

The challenges presented by cities include charging, routing, and awareness.

• Policy Support: Subsidies, a mandate for low-emission vehicles, and government incentives are essential for promoting adoption.

• “Infrastructural Readiness”: This involves appropriate charging points, power distribution, and routing. Each actuator only

• Public Acceptance: This is facilitated by ensuring that the comfort levels of the commuters are met, as well as public sensitivities

• Operational Planning: It provides management tools for fleets and driver training programs that improve operations and minimize downtime.

Future Outlook

Urban transport in an evolving space, driven by government initiatives, technological developments, and efforts to protect the environment. Although diesel buses dominated urban transport in the past, this trend will decline steadily in the coming years, as governments increasingly prioritize emissions and climate change. Electric buses will become the new norm in eco-friendly urban transport.

Diesel Buses:

• Expected phase-down in large cities as a result of increasingly stringent emissions standards.

• Increased operating costs due to fuel prices and environmental regulations.

• Lack of public and government support for expansion, in favour of cleaner alternatives.

Electric Buses:

• Expected to lead city car ranges in the next decade with enhanced battery technology.

• Integration with solar and wind energy sources decreases the overall carbon footprint.

• Governments will most likely increase subsidies and incentives to promote the widespread adoption of the technology.

Emerging Technologies:

• Solid-State Batteries: Improved energy density, faster charging, and longer cycle life compared with existing lithium-ion batteries. Solid-state batteries replace the

• Hydrogen Fuel Cells: Enable long driving ranges and rapid refuelling, especially between cities.

• Smart Fleet Management: AI-driven scheduling, predictive analytics for maintenance, and real-time fleet tracking.

Conclusion

While cities are working to make their public transport systems cleaner and more efficient, the decision on whether to opt for diesel or electric buses is becoming increasingly important. Although diesel buses are a well-known and proven option with lower acquisition costs, their environmental impacts cannot be ignored. Electric buses, although more expensive, are a cleaner, quieter, and more economical option in the long term.

Diesel Buses:

• Lower acquisition costs and existing structures.

• Proven performance over long distances and varied terrain.

• An important contributor to air pollution and greenhouse gases.

Electric Buses:

• Zero tailpipe emissions, cutting air pollution in cities.

• Reduced noise and improved dynamics improve in-flight comfort.

• Reduced operation and maintenance expenses over the life of the bus.

Key Takeaway:

• The future of public transport will be “clean, efficient, and electric.”

• Support from policy, infrastructure readiness, and technological development can further help this process.

• Electric Buses are more than just vehicles—they symbolize the implementation of sustainable cities in the modern world.

FAQs

Q1: Are electric buses more costly than diesel buses?

Yes, electric buses have a higher initial investment cost than conventional buses due to the battery. However, the operational and maintenance costs are much lower.

Q2: How long can an electric bus run on a recharge?

The modern electric bus has an average range of 200-300 km on a single charge, with the longest-range models reaching up to 400 km. Advances in technology are ensuring that the batteries last longer.

Q3: Do electric buses require any maintenance?

An electric bus has more parts than a diesel bus, which means monitoring the batteries is necessary.

Q4: Can electric buses replace the diesel buses completely?

If a charging infrastructure is provided, the government can plan to replace diesel buses with electric buses over time.

Q5: Is the electric bus green technology?

Electric buses are zero-emission, but they can continue to contribute to greenhouse gas emissions if the power they consume comes from coal, since coal also emits during power production, albeit at lower levels than gasoline- or diesel-powered engines.

Q6: How long does it take to charge an electric bus?

Standard Charging – 8 Hours Fast Charge 1-2 hours Opportunity charging along the routes may provide range extension during usage.

Q7: For longer journeys or travelling between cities?

As of today, diesel buses are more suitable for long-distance routes because of their ease of refuelling, but with improvements in battery technology and charging times, electric buses will also be capable of long-distance routes.