Hydrogen internal combustion engines and hydrogen fuel cells

A convoy of trucks on a highway leading through a green forest.

Regulations limiting greenhouse gas emissions (GHGs) from motor vehicles are tightening around the world. With this, both hydrogen engines and hydrogen fuel cells are receiving an increasing interest. 

Given medium and heavy-duty trucks are a major source of CO2 emissions, the transportation sector’s journey to destination zero features both technologies.

As more truck makers join the ranks of auto companies developing CO2-free or CO2-neutral alternative to gasoline and diesel vehicles, let’s look at the similarities and differences between hydrogen engines and fuel cells.

Hydrogen engines and fuel cells: Similarities and differences in how they work?

Both hydrogen internal combustion engines and hydrogen fuel cells can power vehicles using hydrogen, a zero-carbon fuel.

Hydrogen engines burn hydrogen in an internal combustion engine, in just the same way gasoline is used in an engine. Hydrogen internal combustion engines (Hydrogen ICE) are nearly identical to traditional spark-ignition engines. You can read more about how hydrogen engines work if interested.

Fuel cell hydrogen vehicles (FCEVs) generate electricity from hydrogen in a device known as a fuel cell, and use that electricity in an electric motor much like an electric vehicle. 

Hydrogen engines and fuel cells: Complementary use-cases

Hydrogen engines and hydrogen fuel cells offer complementary use cases. 

Internal combustion engines tend to be most efficient under high load—which is to say, when they work harder. FCEVs, in contrast, are most efficient at lower loads. You can read more examples of hydrogen engines in mobility and transportation. These range from heavy-duty trucking to construction.

So, for heavy trucks that tend to spend most of their time hauling the biggest load they can pull, internal combustion engines are usually the ideal and efficient choice. On the other hand, vehicles that frequently operate without any load—tow trucks or concrete mixer trucks, for example, may be more efficient with a fuel cell. Fuel cell electric vehicles can also capture energy through regenerative braking in very transient duty cycles, improving their overall efficiency.  

Hydrogen engines can also operate as standalone powertrain solutions and handle transient response demand without the need for a battery pack. Fuel cells combined with battery packs can also accomplish the same.

click to view infographic
Click to view infographic

Hydrogen engines and fuel cells: Similarities in emissions

Hydrogen engines and hydrogen fuel cells also have similar emissions profiles.

FCEVs, actually, produce no emissions at all besides water vapor. This is a very attractive feature for vehicles operating in closed spaces or spaces with limited ventilation. 

Hydrogen engines release near zero, trace amounts of CO2 (from ambient air and lubrication oil), but can produce nitrogen oxides, or NOx. As a result, they are not ideal for indoor use and require exhaust aftertreatments to reduce NOx emissions.

Hydrogen engines and fuel cells: Hydrogen fuel considerations

Yes, both hydrogen engines and fuel cells use hydrogen fuel; but there is more to this story.

Hydrogen engines often are able to operate with lower grade hydrogen. This becomes handy for specific use cases. For example, you might have a site where hydrogen can be produced on site using steam methane reforming and carbon capture and storing (CCS). This hydrogen then can be used in hydrogen engines without the need for purification. 

The hydrogen engine’s robustness to impurities is also handy for a transportation industry where the transition to high quality green hydrogen will take time.

Hydrogen engines and fuel cells: Varying maturity levels

Finally, hydrogen engines and hydrogen fuel cell technologies have different levels of maturity. 

Internal combustion engines have been universally used for decades and are supported by extensive service networks. Rugged engines that can operate in dusty environments or that can be subjected to heavy vibrations are available in all sizes and configurations.

From the perspective of vehicle manufacturers and fleet operators, the switch to hydrogen engine drivetrains involves familiar parts and technology. Risk-averse end-users will find comfort in the tried-and-tested, reliable nature of internal combustion engines.

So it is not really the case that FCEVs and hydrogen ICEs are competing with one another. On the contrary, the development of one supports that of the other, since both drive the development of a common hydrogen production, transportation, and distribution infrastructure. Both also involve the same vehicle storage tanks. They are complementary technologies that are part of reducing vehicle and transportation emissions towards destination zero, now.

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Jim Nebergall

Jim Nebergall

Jim Nebergall is General Manager of the Hydrogen Engine Business at Cummins Inc. and leads the company’s global efforts in commercializing hydrogen-fueled internal combustion engines. Hydrogen internal combustion engines are an important technology in the company’s accelerated path to decarbonization.    

Jim joined Cummins in 2002 and has held numerous leadership roles across the company. Most recently, Jim was the Director of Product Strategy and Management for the North American on-highway engine business. Jim is passionate about innovation and has dedicated his Cummins career to advancing technology that improves the environment. He pushed the boundaries of customer-focused innovation to position Cummins as the leading powertrain supplier of choice, managing a portfolio ranging from advanced diesel and natural gas to hybrid powertrains. 

Jim graduated from Purdue University with a bachelor’s degree in electrical and computer engineering. In 2007, he completed his Master of Business Administration degree from Indiana University.

Safety considerations around natural gas engines and vehicles

Natural Gas Vehicle

When switching to natural gas engines, there are many different aspects to consider. Safety is an absolute priority for engine and vehicle manufacturers, distribution and transportation companies, and end-users. 

Natural gas engines are a safe technology

Natural gas engines and diesel engines have relatively similar architectures. The decades of knowledge Cummins Inc has accumulated designing internal combustion engines helps engineer safe, reliable natural gas engines. Thus, many common safety considerations are well-known and have well-documented solutions, such as the avoidance of pre-ignition events in the cylinder.

In some respects, natural gas is safer than liquid fuels. If a leak occurs inside the engine compartment, natural gas tends to dissipate at a faster rate while liquid fuels may coat engine parts or form puddles. Leaked diesel or gasoline can lead to fires, whereas natural gas is either already gone or present in concentrations so low it’s not conductive to ignition. In addition to natural gas, there are other alternative comparable fuels that have grown in popularity.

Natural Gas Vehicles keep drivers safe

Compressed natural gas (CNG) vehicles store their fuel in sturdy gas cylinders under high pressures. High storage pressures enable storage of more fuel in the same cylinder, extending the range of the vehicle. These cylinders are critical for the safety of the vehicle and are subject to stringent design standards and safety margins. Compressed Natural Gas (CNG) cylinders are typically rated to store gas at up to 3,600 psi. They are also required to feature pressure relief valves, which release some gas to reduce pressure when abnormal conditions occur. Other critical safety components include a pressure regulator and a shut off valve. A pressure regulator monitors the pressure of the natural gas reaching the engine. The main shut off valve allows isolation of the fuel system from the engine. These components are thoroughly verified and tested to ensure the safety of the vehicles incorporating them. Cummins has formed a new joint venture called Cummins Clean Fuel Technologies to provide natural gas storage tanks.

Natural gas is lighter than air and can dissipate into the atmosphere. To avoid severe damage in the tanks, most fuel delivery systems are designed robustly in case vehicle accidents take place. CNG tanks must pass acid exposure and drop tests in horizontal, vertical and 45-degree angles. They also must pass a penetration test that requires them to be shot with a rifle without resulting tank ruptures. Finally, all CNG cylinders must be tested and certified to a continuous operating temperature range of -40⁰F to 185⁰F.

It is important for natural gas fuel systems to be leak-free. Periodic inspections and maintenance are essential to avoid leakage. The gross vehicle weight rating (GVWR) determines tanks’ maintenance intervals. If the number is greater than 10,000 lbs., inspection takes place at least every 12 months. Then, if GVWR is lesser or equal to 10,000 lbs., the inspection interval is three years (36 months) or every 36,000 miles. CNG cylinders have a limited useful life of 15 to 20 years and do not requalify for use beyond their useful life. 

These are some of the many best practices listed in safety standards such as the National Fire Protection Association 52 standard. Tank manufacturers also provide instructions to prevent cylinder damage. Some of these instructions include not dragging or walking on the cylinders and protecting the valves, fittings, and piping when transporting them.

Top 5 Safety Design Elements for CNG Maintenance Facilities

CNG is mostly methane (CH4) with slight amounts of other hydrocarbons. Its lighter than air, so in the event of a release, it will rise to the ceiling of the maintenance facility and quickly dissipate rather than pooling at or near floor level like liquid fuel vapors. If concentrations of 5% - 15% by volume of natural gas encounter an ignition source, the gas may ignite, with potentially serious results. However, according to the U.S. Department of Energy, due to natural gas’s ability to rapidly dissipate, this concentration is rarely seen in practice. That said, to prevent potential safety hazards, facilities that service natural gas vehicles require specific safety measures.

1.    Ventilation must provide sufficient air flow to reduce the concentration of any released gas and at the same time evacuate gas from the structure.
2.    Paths of migration must be controlled to prevent any released gas from entering unprotected areas of the structure.
3.    Space heating must be designed in accordance with guidelines so that open flames or hot surfaces don’t provide an ignition source.
4.    Electrical wiring and equipment must be installed in such a way that they don’t provide ignition due to sparking. The equipment itself can be designed to be “explosion         proof.”
5.    Methane detection and control systems and alarms must provide defense against dangerous concentrations of natural gas by alerting personnel in the building and             disabling potential electrical ignition sources.  

Local Clean Cities coordinators are an excellent resource for fleets and facility maintenance managers with questions about safety measures, or who need help accessing their facilities. Visit cleancities.energy.gov to find a local Clean Cities coordinator.

Ultimately, using natural gas in the transport industry can be a safe fuel. This is an addition to the many advantages of using natural gas engines. Therefore, natural gas vehicles are clean, safe and reliable thanks to the use of best practices and the incorporation of smart safety features.

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Puneet Singh Jhawar

Puneet Singh Jhawar

Puneet Singh Jhawar is the General Manager of the global natural gas business for Cummins Inc. In this role, he is responsible for the product vision, financial management and overall performance of the natural gas business. Over his 14-year career at Cummins, Jhawar has cultivated successful relationships with a number of Cummins’ largest customers. Jhawar has extensive global experience, with roles based in the Middle East, India, Europe and the US.

Inside Cummins’ Newest Natural Gas Generators - QSJ8.9G C175N6B & C200N6B – A chat with the Senior Manufacturing Engineer


As part of Cummins’ efforts to introduce its customers and Cummins Inc. employees to the two new natural gas generators, the C175N6B and C200N6B, Cummins is pleased to share this interview with Akshay Suresh, the Senior Manufacturing Engineer at the Cummins plant in Fridley, Minnesota (U.S.).
Learn more about these products here.   

1.     What has been your favorite part about working on C175N6B and C200N6B? 

I’m really excited about the new segments and the business we would be reaching with these two new generator sets. Our previous product offering leveraged a much larger engine that resulted in a larger product, and there are multiple benefits to expanding our product offerings. We are dedicated to meeting our customers' needs with our products made in Fridley including these two new gas generator sets. On top of serving our customers, we aim to serve our communities through our work as well. We are looking forward to creating more job opportunities and continuing to partner with our communities in various ways like our Community Involvement Team.

2.    When there is a new product development effort, how does that impact the manufacturing team?

Generally, it starts with the engineering team creating a prototype. Then the manufacturing team and the cross-functional project team are invited to discuss the feasibility of the new product. We need to learn if it would be possible for the manufacturing team to build the new product in our factory lines. We identify if there are any additional training, components and tools needed for the manufacturing team. Once we agree on the feasibility, we proceed towards building beta units which are test units to see how these new generator sets fit into our factory lines. This is followed by validation of build capability and extensive quality checks. Throughout the entire process of identifying and validating potential developments, our teams make sure that our products are safe and reliable for our employees and the customers. 

3.    What is one word you would use to describe the new C175N6B and C200N6B?

“Efficient.” The Cummins team has worked on creating C175N6B and C200N6B with an 8.9-liter engine which have incomparable power densities in our industry to this date. These two new generator sets are not only efficient in footprint, but also in their maintenance. With their natural gas engines, they require less fuel refills and are better for areas with a higher population. Our PowerCommand® 2.3 provides automatic remote-control for our customers as well. 

The Cummins C175N6B and C200N6B use 8.9-liter QSJ8.9G engine with natural gas as their fuel. With these two nodes, QSJ8.9G provides the highest power density among the natural gas generator set products in the industry. Cummins is dedicated to powering our customers' needs with our leading technology, expertise and commitment. Click here if you want to read more about what our product owner wanted to share about these new gas generator sets.

For inquiries about this product please reach out to your local Cummins salesperson.

No paint? No problem. 6.7 turbo diesel engine ditches clear coating for improved sustainability

Caption: Senior Industrial Engineer Clarissa Arriaga, who along with Current Product Senior Engineer Ashwini Khandelwal conducted the study that led to the elimination of engine coatings at Columbus Mid-Range Engine Plant.

For over 30 years, the Columbus Mid-Range Engine Plant (CMEP) has built the heavy-duty diesel engine for pickup trucks and coated it in a rust-preventative. In 2021, this coating was eliminated, making manufacturing cleaner for the popular engine.

Despite how sophisticated a painted Cummins Inc. diesel engine may look, painting engines hasn’t always been for the dashing looks, cool style, and flash. As the most common source of material used to build an engine in the past was grey iron, it was necessary to use a rust-preventative coating on all of our engine models to avoid corrosion. Coating contributed to the extended lifespan of an engine, its components and overall durability.

While paint offers protection and, to some, great style, it comes with a heavy environmental cost – from massive water and chemical waste and increased energy use and natural gas output to emissions of volatile organic compounds (VOCs). Sustainability leaders and manufacturing and service engineers at the plant recognized the advancements in material diversity on the 6.7-liter engine and conducted an assessment on their coating process.

Through their assessment in 2020, engineers validated that the coating elimination would not expose the engines to excess corrosion, ensuring the same quality, capabilities, and durability without the environmental impacts.

In fact, less than 10 components were at risk of oxidation. With the advancements in technology, most engines today are built using a variety of materials from aluminum to cast iron, with composite components here and there. Over time, the 6.7-liter engine had evolved and with it, its components. As the majority of parts and surfaces on the engine would not be impacted due to the evolution of the engine over time, eliminating the coating process was clear. For the components that were prone to oxidation, engineers found more sustainable ways, like powder coating prior to final assembly, to seal these parts from potential exposure. Only a few components now still receive a rust preventative coating.

Engineers developed a strategy that would eliminate VOCs from coating operations, reduce greenhouse gas emissions (GHGs), water use and waste production, and recycle all packaging plastics.

Here are the top ways removing the coating process has increased the sustainability in manufacturing of the 6.7-liter diesel engine.

Reduced water usage and hazardous waste

In one day, CMEP would use between 10,000 gallons and 14,000 gallons of water solely on the coating processing line. Water from the coating wash tank was mixed with three different chemicals that cleaned the engine thoroughly, protecting coating from peeling over time. Yearly, the plant used an average of 23,500 gallons of chemicals to ensure engines were sealed.

For OEMs, fleets, and customers looking to reduce their scope three emissions, achieve environmental goals, and adhere to strict sustainability regulations, it’s important to know products are manufactured to the same environmental standards. Paint elimination reduces CMEP’s VOCs, particulate matter, and absolute water consumption – key 2030 goals included in Cummins’ PLANET 2050 environmental sustainability strategy – allowing the plant to save roughly 5 million gallons of water per year. 

Reduced NOx emissions

You can image that running an industrial wash tank, two ovens, and automated spray robots requires a significant amount of natural gas and energy usage. With daily use of these tools natural gas use was significant. While natural gas is one of the more environmentally friendly fossil fuels, as it burns cleaner, emitting 50 percent to 60 percent less CO2 than regular oil, it still emits small amounts of NOx.

As a result of eliminating the coating process, natural gas usage was reduced by 88 percent, saving nine million gallons of natural gas used monthly – that’s equivalent to powering an average home in the United States for 20 years. Reducing the use of natural gas on the paint line eliminates NOx emissions, contributing to both a cleaner plant and cleaner product, with key cost savings to both the customer and manufacturer.

Decrease in plastic usage; increase in material and equipment recycling

Not every component on the 6.7-liter engine received the clear coating. To protect these pieces from overspray, plant workers would use single-use plastic cups, rolls of tape, stickers, and other small plastic covers. With fewer components and sections of the engine to cover, the plant can eliminate most of their plastic, which can often take years to decompose. It’s estimated the plant has eliminated nearly 16,500 pounds of waste.

The coating line alone occupied nearly 20,000 square feet of space in the plant, which has allowed for endless possibilities for how to use the machinery and material. With room for new innovations, The Columbus Mid-Range Engine Plant can continue to improve the 6.7-liter engine for pickup customers.

Coating elimination at CMEP has been widely successful. During Indiana’s 25th Annual Pollution Prevention Conference, the plant received the 2022 Indiana Governor’s Award for Environmental Excellence

Eliminating a coating or paint process is not always feasible for other manufacturing plants, but Columbus Mid-Range Engine Plant leaders hope other facilities will conduct assessments of their own to determine if elimination and increased sustainability is possible. Cummins’ Jamestown Engine Plant implemented water-based paint in 2013 to eliminate VOCs, while other Cummins plants, like the Rocky Mount Engine Plant are currently evaluating the conversion to water-based paint.

CMEP is manufacturing cleaner, meeting strict EPA and regulatory standards, and continuing to produce the same, durable, and legendary 6.7-liter engine for the pickup customers.

Just as the 6.7-liter turbo diesel engine has evolved over time, with new innovations and technological advancements, so too will manufacturing facilities continue to evolve for the needs of society and the planet’s wellbeing.

Learn more about Cummins’ PLANET 2050 strategy here. 

Inside our Newest Natural Gas Generators

generator rendering

Cummins Inc. is excited to introduce two new natural gas generators, the C175N6B and C200N6B, to our customers. These additions use the same QSJ8.9G engine platform as the C125N6 and C150N6  natural gas generators which are popular among various industrial applications. In North America, the market for natural gas generators has been increasing over the past few years. Environmental concerns regulations and convenience for fuel refill are some of the reasons customers choose natural gas generators over other fuel types. 

We invited Vijay Jayaprakash, Cummins Product Manager for <1MW Gas Generator Sets & G-Drive, to share his experience at Cummins and introduce the two new products. 

1. What was your role in developing C175N6B and C200N6B?

As a product manager, I performed extensive research on what the customer and industry needs are and how Cummins can meet and deliver those needs by building close relationships with the customers and the sales team.   Our team invested a great amount of time and effort in researching and developing the right generators to bring improved power output of our tried and tested QSJ8.9G engine that is well recognized in the market. With these two new products  , the QSJ8.9G engine generator product range will span from 125kW to 200kW.


2. Where do you see these two new products being used?

Similar to C125N6 and C150N6, C175N6B and C200N6B will be used in government buildings, water wastewater treatment plants, healthcare facilities, commercial buildings, public infrastructure and many more.  These products would also be amazing additions to wherever paralleling  is needed for one’s pre-existing power systems. To learn more about paralleling, click here.

With the QSJ8.9G engine, C175N6B and C200N6B run on natural gas fuel , making it better for more populated areas and cities. For more information on the benefits of natural gas generators, click here.

3.Working on these new products through the COVID-19 pandemic, what did you see in your team that made it possible and successful?

Teamwork and dedication to getting the product out faster was what made this project possible. Although there were hardships along the way, I really appreciate everyone putting in effort across multiple teams at the factory , engineering, marketing and so many more. The team members have been willing to come into the office/plant for beta builds, product testing  and working flexibly to deliver this product successfully for our customers. Teamwork is one of Cummins' Values and our team showed above and beyond what teamwork can achieve. Always powering on.

4. What is one word you would use to describe the new 175 and 200kw generator sets?

Power. C175N6B and C200N6B are the market leading natural gas generator products in power density with its 8.9-liter  engine. So far, no other product is able to bring this power  in a smaller footprint including sound level 2 enclosure (73.6 (175kW) and 74.4 (200kW) dbA). We believe the C175N6B and C200N6B will change the market with their footprint, providing reliable power to our customers.

Cummins C175N6B and C200N6B use 8.9-liter QSJ8.9G engine with natural gas as their fuel. With these two nodes, QSJ8.9G provides the highest power density among the natural gas generator set products in the industry. Cummins is dedicated to powering our customers' needs with our leading technology, expertise and commitment. 

Cummins Office Building

Cummins Inc.

Cummins, a global power technology leader, is a corporation of complementary business segments that design, manufacture, distribute and service a broad portfolio of power solutions. The company’s products range from internal combustion, electric and hybrid integrated power solutions and components including filtration, aftertreatment, turbochargers, fuel systems, controls systems, air handling systems, automated transmissions, electric power generation systems, microgrid controls, batteries, electrolyzers and fuel cell products.

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