5 questions about electric buses answered

5 questions about electric buses answered

Zero-emission transportation? Now that’s electrifying! Battery electric buses are gaining speed as a new norm for transportation that is environmentally friendly. But how exactly do they work? We’re answering the top five frequently asked questions surrounding electric buses.

1. What is an electric bus?

A battery electric bus is an electric vehicle that replaces the traditional combustion engine and transmission with an electric motor and a battery. In an electric bus, there is no longer an engine, nor fuel tank. Instead, the electric motor on the bus serves as the engine and transmission, while the battery is essentially the “fuel tank.”  

Electric buses work by sending a signal to the powertrain system controller upon start. That signal powers up the high-voltage battery, where chemical energy is stored, and converts it into electrical energy. This electrical energy is then distributed throughout all the different components that make the bus run, such as the electric motor and thermal management system.

Bluebird battery electric school bus equipped with a Cummins battery system
Bluebird battery electric school bus equipped with a Cummins battery system
Gillig battery electric transit bus equipped with a Cummins battery system
Gillig battery electric transit bus equipped with a Cummins battery system

2. What is the range of an electric bus?

The range of an electric bus is the distance a bus can cover before running out of charge. How long this range is depends on a variety of factors, including battery size and duty cycles.

Battery size correlates to how big of a "fuel tank" an electric vehicle has. Bigger batteries can store more energy, which in turn can fuel longer distances. For example, transit buses typically require bigger batteries than school buses because they need to run for longer periods of time and need more fuel to do so.

The second factor that significantly affects the range of an electric bus is the duty cycle. Duty cycles describe how the vehicle is used and helps determine performance and battery life.

A battery electric bus route mapped out
A battery electric bus route mapped out

Consider the following analogy to understand duty cycles:

  • You live on the third floor of an apartment building and like to take the stairs. The energy required to ascend these flights of stairs isn't too strenuous, and you'd be operating at a “light-duty” cycle. 
  • Suppose you have to carry a 50 lb. weight with you up the three flights of stairs. In that case, you are working harder and would be operating at a “medium-duty” cycle. 
  • Now, you have decided to carry a piano up the three flights of stairs. You are using maximum energy and would be operating a “heavy-duty” cycle. 

For buses, factors that affect how demanding a duty cycle is include road conditions, driving conditions, vehicle speed, number of stops/starts, elevation changes, how quickly you accelerate, weight transported, weather and more. A lighter duty cycle will use less energy than a heavier duty cycle. Therefore, with light-duty cycles, electric buses can achieve a greater range.

3. How do electric buses charge?

There are a few ways that electric vehicle fleets can charge. Which is best for a particular fleet depends on the duty cycle and battery size of its buses. 

Today, the two main types of chargers for an electric bus are:

  1. Plug-in chargers
  2. Pantograph chargers

Plug-in chargers for buses work very similarly to those used for electric cars. Electric buses have ports that a driver can plug into. With this method, charging can take anywhere from two to eight hours, based on the charger's current (which we’ll explain momentarily).

A plug-in charger for an electric school bus
A plug-in charger for an electric school bus

A new, more autonomous charger is the pantograph charger. With this charger, buses drive underneath a charging station, and robotic arms attach themselves to the electrical conductors on top of the vehicle to charge it. This charger is designed to carry more current and allows for faster charging.
 
In addition to being either plug-in or pantograph, a charger is also characterized by how it converts electric currents, classified as either a direct current (DC) charger or an alternating current (AC) charger. All batteries need DC power to function, and both types of chargers convert AC power to DC power. DC chargers are faster but come at a higher cost. AC chargers are slower but are very affordable.
While plug-in chargers can be AC or DC chargers, pantograph chargers are only DC. DC plug-in chargers can charge a battery up to 150 KW, while pantograph chargers can charge up to 350 KW. 
 
No matter what your charging choice, Cummins has worked hard to make our battery systems compatible with all of the leading chargers available in today's market.

A bus driver operating a Blue Bird electric school bus
A bus driver operating a Blue Bird electric school bus

4. Why are battery electric buses becoming more popular?

Sustainability is a main driver in electric buses becoming more common. As governments implement more intense emissions regulations and corporations advance their sustainability goals, electric buses are seen as the suitable zero-emissions solution that can help cities and communities meet their environmental objectives, without compromising their transportation infrastructure.

Electric buses also have instant torque that improves drivability/performance. Drivers are able to accelerate more responsively, making buses with electrified systems more desirable.

Electric buses also offer improved driver comfort. This is because electric motors are much quieter and allow smooth handling. This improved driving experience reduces driver fatigue.

5. Are electric buses cheaper?

While the initial cost of purchasing an electric bus isn’t cheaper than internal combustion engine (ICE) buses, they are becoming more affordable. There are a number of incentive programs in place that buyers can take advantage of that make electric buses the same cost to the city or district as a conventional bus. 

Cost savings occurs in the operation of electric bus fleets over time. They have lower maintenance costs and fuel costs, as they don’t require diesel fuel. Electric buses also run more efficiently with regenerative braking, which simultaneously lowers the wear on the braking system and captures the kinetic energy to feed back into the battery to extend the range of the bus. With traditional braking, the kinetic energy was once “wasted” through the service brakes and transferred into heat, meaning regenerative braking is more efficient.

A technician working on the undercarriage of a Blue Bird electric school bus
A technician working on the undercarriage of a Blue Bird electric school bus

Across the U.S., communities are looking to make their fleets more sustainable and have already begun adding both electrified school and transit buses to their fleets. Cummins alone has already assisted in delivering over 400 buses across the country, each equipped with the Cummins Battery Electric System. This system is built to be zero-emission when in use, reduce service and create savings, all while maintaining vehicle performance.

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Cummins Office Building

Cummins Inc.

Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.

All Aboard: A roundup of Cummins-powered zero-emission transit buses

Cummins-powered zero-emission transit buses

Despite an unprecedented year for riders and the transit bus industry, cities across the globe are continuing to invest in their communities for brighter days ahead. With quiet, zero-emission solutions hitting the road, it won’t be long until you’re taking a ride on a Cummins-powered zero-emission transit bus. 

The GILLIG zero-emission battery electric bus powered by Cummins was first unveiled in 2017 and since then both organizations have worked diligently to engineer, test and validate our offering in all climates and conditions. Riders in the city of Santa Monica were the first to experience the battery electric bus but now with an impressive 20,000 miles on the clock, the electric transit solution has accelerated production and is available for all cities to meet their carbon neutral goals. 

With the transit electric powertrain reaching the production phase and these solutions hitting the market, it’s important to acknowledge a few of our milestones. Join us as we highlight some of our successes and take you on a bus ride like no other.

Hawaii

First stop, Hawaii. The City and County of Honolulu Department of Transportation Services (DTS) was the first to pursue our new electric offering and added their first electric bus to their fleet, TheBus. According to Mayor Kirk Caldwell, this is the first step to reaching their goal of transforming their public bus fleet with 100% renewable fuel by 2035. Funded by the FY2020 Low-No Emissions Bus Program grant award from the Federal Transit Administration, the 40-foot bus can service the majority of the current bus routes in Honolulu. 

Utah

Next on board is Utah. With high hopes of being predominately electric by 2028, The Utah Transit Authority (UTA) is now shifting their attention to electrified power solutions. UTA recently awarded the Cummins-Gillig electric bus team with our largest electric transit bus order to date. Given the large area UTA serves, length of service on a single charge is important. Depending on duty cycle, the Cummins Battery Electric System (BES) can achieve approximately 200 miles of high-quality service before needing to recharge. When the bus does need charging, UTA plans to use existing charging depots in the Salt Lake City area and aims to consider in-route charging options down the road. 

Cummins and GILLIG are also collaborating closely to ensure readiness and product familiarization to demonstrate our full support and gain customer confidence with this product right off the bat.

California

Last stop on our recap journey is California. Last fall, Cummins outlined an ambitious strategy for hydrogen to meet decarbonization goals. Now, North America’s first transit bus powered by Cummins fuel cells is hitting the roads in sunny Palm Springs, California. Working with New Flyer and SunLine Transit Agency, residents will soon be stepping on board a 40-foot fuel cell demonstration bus that was delivered in January 2021. The fuel cell bus is one of several pre-commercial hydrogen fuel cell powered vehicles that will be delivered this year and will provide rich insights that will help shape the next generation fuel cells. 

We salute the cities, governments and organizations that are on route to zero-emission transportation, but this tour is just the beginning. Recently, we have seen how China has become dedicated to transporting future Olympic tourists in fuel cell transit buses, and Australian company Bustech announce their next generation Bustech XDi low floor transit bus will be using Cummins zero-emission battery electric and hydrogen fuel cell technologies

Momentum is continuing to build, and Cummins is ready to support communities on their path to zero emissions with our range of alternative power solutions. As you go about your travels, keep an eye out for Cummins-powered zero-emission transit buses. If you happen to take a trip on one, be sure to snap a photo and tag us on social media! 

Stay Updated with New Power News

From long-range possibilities to innovations happening now, our New Power Nine newsletter brings you the top nine things you need to know about low-carbon energy each month. Subscribe today to get your first issue in your inbox.

Cummins Office Building

Cummins Inc.

Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.

Driving forward: electric school buses inspire art

Cummins Bluebird Electric School Bus

School buses producing zero emissions were once a dream, but Cummins and Blue Bird are now powering zero-emission student transportation for districts nationwide.

With more than 100 battery electric school buses that have been delivered throughout the country, school districts continue to invest in their communities, despite the unprecedented challenges they face during a global pandemic.

But with challenges, come new opportunities. Opportunities to dream big and dream of an even better tomorrow. And who better to dream big than kids?

When the school year started to look different this past fall, Cummins encouraged parents to share their kids’ dreams for the future via social media. From aspiring to be an astronaut, teacher and video game maker, to seeing the oceans and discovering new fish, to “making music that brings people together,” to working for world peace, there was no shortage of big dreams.

And with caretakers, explorers, creators, lifelong learners and simple kindness – the road ahead appears very bright.

Cummins then commissioned artwork to help bring these dreams to life. The mural was donated to a school district in California. The art will be used to help inspire students when they return for in-person learning.

"Education provides the platform for success”, said Brian Wilson, general manager of electrified components at Cummins. “Our company was founded on innovation. We have the best and brightest minds creating solutions that power a more prosperous world. We’re proud to support our communities and hope that this art will inspire students to dream big, innovate, and work hard towards their dreams."

The future looks bright when we unleash the power to dream big and embrace the opportunity that each tomorrow brings.

So, what do your dreams look like?

Cummins Bluebird Electric School Bus

For more information on Cummins-powered Blue Bird electric school buses or to download a printable coloring book of the mural, please visit ElectricDreamBus.com.

Stay Updated with New Power News

From long-range possibilities to innovations happening now, our New Power Nine newsletter brings you the top nine things you need to know about low-carbon energy each month. Subscribe today to get your first issue in your inbox.

Cummins Office Building

Cummins Inc.

Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.

Powered by Cummins: XCMG Electric Excavator Makes its Beautiful Debut

Cummins electric excavator

When looking to describe our electrified power applications, many adjectives come to mind, including durable, reliable, safe, and ...beautiful? It's a new (and unusual!) one to add to the list, but this spring, the newly debuted XCMG electric excavator powered by Cummins added “most beautiful” to its list of attributes. Read on to learn more.  electric excavator

Cummins collaborated with XCMG, the 4th largest construction machinery company in the world, to design and build the 3.5 ton electric excavator, which will serve as a technology demonstrator. Often operating on work sites in densely populated towns and cities around the globe, construction equipment must meet stringent emissions requirements and keep noise and disruption to a minimum while getting the job done. The new electric excavator is suitable for working conditions that require more stringent environmental standards and noise reductions.

Powered by Cummins BM5.7E battery modules, the excavator has 45 kWh of battery power. Each battery module is designed for very high shock and vibration capability to endure the harsh conditions of the construction environment. Precise matching between motor and hydraulic system creates an efficient, reliable and quiet drive system, making it ideal for use in urban and suburban construction.

On a single charge of less than six hours, the excavator meets operational needs for a full 8-hour shift. Short charge time means that equipment can be charged overnight, eliminating downtime and taking advantage of off-peak energy savings. 

Construction & Collaboration

Last October Cummins and XCMG cemented their long-standing relationship by signing a strategic cooperation agreement. The agreement ensures close collaboration on developing and integrating comprehensive product lines, value chain and global operations, creating new applications, exploring new markets and sharing resources on research and development for continuous improvement. 

XCMG agreement
In October 2019, Cummins and XCMG cemented their long-standing relationship.

Mirror, mirror on the wall…

XCMG excavatorThe XCMG electric excavator powered by Cummins made its debut at this year's ConExpo, North America’s largest construction show held in Las Vegas, Nevada. The excavator earned its descriptor as "beautiful" because it won the award for the most beautiful machine at ConExpo! Beating some tough contenders to the top spot, the excavator was voted the fairest of them all, and we couldn’t agree more. 

After its win in Vegas, the excavator is now back in China where it will be used in a series of performance and customer tests conducted by Cummins and XCMG, to prove capability of the demonstrator and refine a robust solution for the market.  

Cummins Office Building

Cummins Inc.

Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.

Trusted because it's tested: Cummins-powered GILLIG Battery Electric Bus

Cummins-powered GILLIG Battery Electric Bus

Trusted because it’s tested.  

What do sand bags, mountains, a drone and a film crew all have in common? Well, not much, except that they were all an important part of GILLIG and Cummins’ effort to illustrate the extent of the testing and validation process for the Cummins-powered GILLIG battery electric bus.  

Since 2017 when Cummins and GILLIG announced the partnership to work together on developing an industry-leading all-electric powertrain, both organizations have worked diligently to engineer, test and validate our offering. This is no easy feat, but one that helps distinguish us from the competition. As we bring forward new technologies, we do so with the same commitment to quality customers have come to expect. But how?  

I have not failed. I’ve just found 10,000 ways that won’t work.”  - Thomas Edison

Testing and validation 

A critical piece in bringing forth best-in-class solutions is Cummins commitment to test and validate our offerings against the needs of the customer. For our battery electric system (BES), this means validating products on a component level (e.g. Cummins proprietary BP74E batteries), a powertrain level, and even more broadly working with GILLIG to test performance of the overall bus.  

Ultimately, like most students taking a test, we want to pass. But, just as Thomas Edison noted, the ability to innovate would not be complete without small failures along the way. Testing, and not succeeding is also critical to the process. The failed tests provide insight on the current limits of a product so that designs can be adjusted, and performance optimized to meet the many different scenarios our customers will see in their daily work. We’d be failing our customers, without a few failures along the way.  

Real world conditions

GILLIG and Cummins also take pride in validating our products under real world scenarios, not just ideal conditions. To this end, which was illustrated recently in the gradeability test for the GILLIG bus, various tests were run on the bus as it was loaded with sandbags to simulate the weight of passengers. A powertrain that can operate efficiently, but can only do so empty, is of no value to a community looking to transport people all day, every day.  

Similarly, we work closely with field test customers to refine solutions and deliver a trusted and reliable product. Big Blue Bus in Santa Monica, who received the first field test bus in July 2019, has been a critical partner in providing feedback using real routes and day-to-day operating scenarios. Working with valued customers and end users to identify opportunities that can be enhanced is crucial. The collaboration and partnership that field test customers provide allows us to deliver a product that will meet and exceed customer expectations. Thankfully, the field test has gone well, and as testament to that Big Blue Bus announced that they will be purchasing 18 additional electric buses.  

Trust: a commitment we take seriously 

So, the next time you’re driving up a mountain or simply travelling in your city, and see a Cummins-powered GILLIG battery electric bus, rest assured that it has been through an extensive testing process to ensure safety and reliability. Our customers and communities trust us – and that is something we don’t take lightly.  

Cummins Office Building

Cummins Inc.

Cummins is a global power leader that designs, manufactures, sells and services diesel and alternative fuel engines from 2.8 to 95 liters, diesel and alternative-fueled electrical generator sets from 2.5 to 3,500 kW, as well as related components and technology. Cummins serves its customers through its network of 600 company-owned and independent distributor facilities and more than 7,200 dealer locations in over 190 countries and territories.

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