Medium duty vehicle fleets, from postal vans to school buses, are switching to alternative fuels. Among low-carbon emitting fuels, propane, also known as autogas, is one of the most readily available options.

As an alternative to gasoline and diesel, propane vehicles produce less greenhouse gases and harmful air pollutants. Thirty billion gallons of propane are produced domestically in the United States, with 20 billion gallons being exported each year. Its price is not subject to shocks connected to global supply and demand. This results in more stable prices over the long run, among other operational benefits. Therefore, propane vehicle operators can secure long-term fuel contracts at fixed costs.

Centralized, regional, and return-to-home base fleets are well suited for propane autogas vehicles. Propane-powered transit vehicles can help improve the air quality in densely populated areas. That’s because, compared to diesel, they have lower NOx emissions, particulate matter and other air pollutants.  Additional benefits for more suburban and rural fleets include easy, affordable, and scalable infrastructure as propane is available in every community across the country. Propane is also one of the most accessible alternative fuel sources not only nationwide, but worldwide. Most propane fleets own their fueling infrastructure due to low installation costs, but drivers can also access over 2,600 public refueling sites across the United States. 

Urban delivery trucks can lower emissions with propane autogas engines

In 2019, the U.S. Postal Service (USPS) committed to lowering its greenhouse gas emissions 30 percent by 2025. Today, USPS operates a fleet of over 30,000 alternative fuel vehicles and has implemented incentives for contractors to do the same. The Cummins B6.7 propane is an ideal engine for postal vehicles, like USPS and its contractors, seeking to achieve key sustainability goals. 

With 325 hp and 750lb-ft peak torque at 1800 RPM, the B6.7 propane can also be used in class 6 straight-box trucks for food and beverage delivery, tow trucks, and terminal tractors. Propane autogas offers fleets in these markets the lowest total cost-of-ownership compared with other fuels. In fact, many fleets have reduced their operating costs by 50 percent after making the switch from diesel.

Utility and service vehicles have been using propane for a long time

Propane is a good fuel source for everyday utility and service vehicles. Propane is widely used for forklifts and can be used for other utility vehicles such as golf carts, street sweepers, and snowplows. Propane is also well-suited for emergency service vehicle fleets such as ambulances and police cars. In 2021, the city of Petersburg, Virginia converted its public fleet of 49 vehicles to run on renewable propane. By switching to the propane fueled fleet, the city forecasted it would save $1,000 per vehicle per year.

School buses running on propane help improve air quality

As mentioned above, propane vehicles help improve air quality. Residents and passengers in city, suburban, and rural areas are less likely to be exposed to harmful exhaust fumes, as propane burns significantly cleaner than other fossil fuels.

School buses are one of the most visible markets for propane autogas. There are currently more than 22,000 propane autogas school buses transporting kids to school each day. Propane autogas engines are also quieter than gasoline/diesel engines and help decrease noise pollution. The Cummins B6.7 propane engine can provide large buses the power to run long, high-capacity routes.

Propane delivery trucks can lower fuel and maintenance cost

Propane delivery trucks, also known as bobtails, are specially designed bulk delivery vehicles that deliver propane to businesses and homes.

Bobtails that run on propane can benefit from lower fuel and maintenance costs while reducing carbon emissions. The new Cummins B6.7 propane engine is well-suited for use in bobtails.

Overall, propane offers many benefits and is well suited for delivery trucks, school buses, utility vehicles and bobtails. It’s a clean burning, low-cost alternative fuel source, available in abundant quantities across the United States and around the world. Are you interested in learning more about propane use in motor vehicles? Check out Cummins B6.7 propane engine for various medium duty applications.

Natural gas powers more than 175,000 vehicles in the United States and 23 million vehicles worldwide. It’s an ideal alternative to gasoline and diesel for heavy and medium-duty applications. These include freight-hauling trucks, buses, and garbage trucks. Natural gas engines provide horsepower, acceleration, and cruise speed comparable to conventional fossil fuel engines. This fuel can also replace gasoline in smaller applications, such as forklifts and commercial lawn equipment. 

Natural gas engines reduce emissions and environmental risks

Many companies are setting carbon reduction targets for tailpipe emissions. Fleets can meet these requirements by replacing older vehicles or generators that run on diesel to new ones that use natural gas. 

Switching to natural gas can reduce hydrocarbons, carbon dioxide (CO2), nitrous oxide and other greenhouse gas (GHG) emissions. The size of the reduction depends on vehicle type, duty cycle, and engine calibration. Vehicles that use compressed natural gas (CNG) can reduce their GHG emissions by 13-18%. That percentage is a lot higher when using renewable natural gas (RNG) or a blend between the two gases. 

Natural gas vehicles offer additional air quality and environmental justice benefits too. They emit almost no particulate matter, volatile organic compounds or carbon monoxide which lead to poor air quality.

There are also other environmental risks that can be eliminated. For example, natural gas can’t spill because it’s lighter than air. It doesn’t puddle or cause ground contamination like a diesel or gasoline spill would.

Renewable natural gas is a carbon neutral fuel alternative

RNG is manufactured from agricultural by-products and organic waste from food manufacturing, farming and groceries. The systems needed to fuel a vehicle with RNG or with fossil natural gas are identical. Both fuels are interchangeable and can be blended. National, state and local incentives for RNG projects are also available. RNG is considered a carbon neutral fuel and it can even be carbon negative when using waste from landfills -that’s at least a 100% GHG reduction! 

RNG provides more benefits than CNG. Methane (CH4) from a landfill or a wastewater treatment facility is typically vented into the atmosphere. Its global warming potential (GWP) is more than 25 times greater than CO2. That makes capturing and refining methane into a fuel for natural gas engines a better alternative. 

Enabling fleets to more affordable engine solutions with natural gas

Natural gas engines meet stringent environmental standards with less complicated emissions controls. As a result, they offer an affordable advantage over diesel engines.

Additional cost savings can be achieved by converting conventional vehicles to run on natural gas. Kits are available to retrofit existing fleets. And automotive original equipment manufacturers (OEMs) offer natural gas versions of their medium and heavy-duty vehicles.

Natural gas refueling stations also can be less expensive to construct than those for hydrogen (H2) or electric vehicles. Their proven equipment and systems are less complex.

National gas also allows fleets to better predict operational costs. The fuel itself costs less than gasoline and diesel. In some areas, natural gas can even be half of the price of diesel. These prices have remained relatively flat for 20 years. This helps fleet operators by being able to reliably forecast monthly and yearly natural gas costs.

Expanding the natural gas supply for national energy independence

The United States has an estimated 2,926 trillion cubic feet of natural gas — enough to last about 98 years. In 2021, 64% of all on-road fuel used in natural gas engines was renewable natural gas. That percentage increases in California, where it’s 98%. The growing use of RNG further diversifies domestic energy supplies. 

Natural gas is readily available through established distribution channels. Supplies are so abundant that natural gas is also compressed and exported. It moves across the United States through a pipeline network that links production areas and storage facilities with 77 million customers.

Compressor stations utilize natural gas engines to keep fuel flowing to distribution companies. They deliver natural gas to consumers through small-diameter, lower-pressure service lines.

Natural gas is available at nearly 900 compressed natural gas (CNG) stations. Another 60 liquefied natural gas (LNG) fueling stations are located in areas that service long-haul trucks. 

Refueling is done at:

• Fast-fill stations, where natural gas vehicles can fill up in about the same time it takes to refuel gas and diesel vehicles
• Long-fill stations, where natural gas vehicles slowly fill up overnight or during extended breaks between trips

In summary, natural gas engines can help fleets lower their total transportation emission and operating costs without major disruptions to their day-to-day operations. Natural gas, as a fuel, has a key role to play in our renewable future.  

Our planet is facing a dire crisis: carbon dioxide concentrations in the atmosphere continue to soar above record highs. If gone unaddressed, the collective stress of climate change will produce an irreparable impact. Our health, energy, water, and food ecosystems are at risk. 

As it stands, there are many long-term effects of climate change. In North America, climate change is forecasted to cause decreasing snowpack in the western mountains. It will also lead to a 5–20% increase in yields of rain-fed agriculture and great intensity of heat waves. In fact, over the last five years, the United States has incurred roughly $120 billion a year in damages as a result of natural disasters caused by extreme weather and climate events.

Beyond natural catastrophes, climatic risks to the United States will have a cascading effect on the country’s interconnected ecosystems. Reduced labor and overall economic productivity, and altered crop yields, will disproportionately harm lower-income and marginalized populations. These groups lack the resources to prepare or cope with extreme weather and climate events.

The world is investing in clean energy innovation

Combating the intensifying climate crisis requires a strategic combination of research and development (R&D), innovation, technology — and bold attempts.

Around the globe, countries are investing in clean energy to contribute to a livable planet now and for generations to come. In 2022, the US passed the Inflation Reduction Act, which includes a historic $370 billion investment to address the climate crisis. The Inflation Reduction Act provides tax credits and incentives to power homes, businesses, and communities with clean energy by 2030. The Act will increase investments in the fastest-growing power generation technologies, solar and wind. It will also advance cost-saving clean energy projects and protect two million acres of national forests. These initiatives are in addition to substantial tax credits and rebates offered to families and businesses in the United States.
Consequently, a stronger clean energy economy will contribute to overall economic growth and competition. As a result, there will be millions of new well-paying jobs for Americans to make clean energy.

It is possible to start decarbonizing now

Governmental policy strategies and investments in decarbonization technologies are part of the solution to produce increasingly cheap, dependable, and clean energy.

Strong communities and vibrant economies depend on a healthier planet. As a global power technology leader, Cummins is in a unique position to power customer success by leading during this energy transition. We intent to do so by providing customers with the right technology at the right time, understanding of their needs and applications.

We think of this journey to carbon neutrality in two distinct and complementary ways. First, by innovating zero-emission solutions and introducing them in markets and applications where the infrastructure, development and deployment are ready. Secondly, by advancing internal combustion engines through efficiency improvement and by running them on cleaner alternative fuels for a well-to-wheels solution.

Through Destination Zero, we are advancing low- and no-carbon platforms. This includes diesel and natural gas engines, hybrid, and electric platforms, as well as powertrain components, controls, and related technologies.

Join Cummins in powering a better tomorrow

Cummins environmental sustainability strategy includes goals timed for 2030. Progress toward the reduction of carbon emissions from company plants and facilities — in addition to our products — is in full swing. For more than one hundred years, we have brought technological solutions to market. As a power solutions leader, we will continue to power a more prosperous world for today and tomorrow. Are you ready to consider investing in new power solutions?

There are over 23 million natural gas vehicles in the world, including over 175,000 in the United States. Of these, 64% of all on-road fuel used in these vehicles in 2021 was renewable natural gas (RNG), according to industry trade group, NGV Americas. That percentage increases in California, where it’s 98%. Unlike regular natural gas, RNG is not obtained from fossil resources and constitutes a carbon-neutral or even carbon-negative fuel. However, the amount of available organic feedstock from which RNG can be made is finite. So, how much RNG can be made exactly from existing and potential resources? Let’s take a look.

RNG availability today and tomorrow

RNG is made from biogas, which is the product of a biological process known as anaerobic fermentation. It’s obtained when the undesirable components of biogas, such as CO2 and nitrogen, are removed.

A variety of organic materials feed the biogas-producing bacteria. In many cases, RNG is made opportunistically at facilities which generate a feedstock as a by-product of their operation. Wastewater treatment plants and dairy farms can produce RNG using sewage sludge and manure. Another option is to process food waste into biogas and RNG. Although only are only a few RNG companies, more are seeking to increase production.

The Argonne National Laboratory’s database captures the total annual RNG production capacity in the United States. In 2021, production capacity was about 660 million gallons gasoline equivalents (GGE). That’s a 20% increase compared to the previous year. This is a lot of RNG, yet still just a fraction. -about 3% - of the total natural gas consumption each year in the country, beyond solely vehicles’ consumption. 

It may be possible to increase the production of RNG in the United States—and in other countries—by orders of magnitude. According to a study quoted by the American Gas Association, the US could have the potential to produce up to 36 billion GGE equivalent of RNG each year by 2040. If all of it was used in transportation applications, it would be enough to fuel about two thirds of all diesel vehicles in the country.

How is RNG transported and distributed? 

Producing RNG is only part of the challenge of making RNG more available. RNG also needs to be transported and distributed to end-users. Compared to other alternative fuels, RNG has many advantages. RNG is, chemically, nearly identical to natural gas obtained from fossil resources. Therefore, RNG can be injected into the existing natural gas transportation and distribution infrastructure, as long as it meets each pipeline’s specifications. End users can also purchase RNG from RNG producers and receive natural gas from utility companies. They can claim that they are, effectively, using RNG. In the United States, 3 million miles of distribution lines and over 300,000 miles of transportation pipelines are ready to accept in-spec RNG and deliver it to customers. That’s something which hydrogen producers and users can only dream of. 

How many RNG refueling stations are there?

Finally, RNG needs to make its way into the tank of vehicles. The systems needed to fuel a vehicle with RNG or with fossil natural gas are identical. Both fuels are interchangeable and can be blended. 

However, the network of natural gas fueling stations is less dense than the one for gasoline or diesel. There are about 1,500 public and private stations dispending compressed natural gas in the United States, compared to over 150,000 gas stations with gasoline or diesel. Most of the RNG supply is sent to states with low carbon fuel credits for natural gas. Right now, only California, Oregon and Washington state offer these credits, so suppliers prioritize shipping fuel to them. Fleets can check with their local fuel provider to find out the exact source of their natural gas.  

Businesses who wish to switch their vehicles to RNG often opt to construct a fueling facility on their own premises. These businesses may choose from several categories of fuel pumps dispensing compressed natural gas or compressed RNG. For on-site refueling, most businesses will choose time-fill stations. Time fill systems are best suited for vehicles that can complete a day’s shift on a single tank before ‘going home’ for the night to be refilled. Time-fill stations offer more flexibility and efficiency for fleet managers who can make the most of off-peak electricity rates at night.

Did you know that RNG can offset fuel costs?

RNG can also be produced and used locally. Certain businesses have the option to integrate the production and use of fuel as part of their normal operations. Some waste management companies, for example, gather biogas emanating from landfills they manage. The biogas is refined into RNG, and then used to fuel their garbage collection fleet. This can result in net negative greenhouse gas emissions. The methane emissions that would otherwise make their way into the atmosphere from the landfills are avoided. That’s a huge decarbonization effort considering that methane is greenhouse gas several times more powerful than carbon dioxide, and it’s essentially free fuel for the refuse company.

California leads the way on RNG use and production

RNG made up 98% of the total natural gas vehicle fuel consumption in 2021 in California, according to the government. That’s up from 92% in 2020.

A local waste management company, the City of Perris, operates one of the largest organic waste digesters ever built. Using residential waste such as yard waste and food scraps, it produces about 1 million GGE of RNG every year. Some of that RNG fuels the garbage collection fleet and the rest is sold via an interconnection to the local natural gas network. 

It is not by chance that RNG is so popular in the state. California’s carbon reduction and air quality policies (i.e. Low-Carbon Fuel Standard) have heavily incentivized fleets to use RNG as an alternative to traditional natural gas and petroleum fuels. As other states such as Oregon, Washington and Colorado consider similar rules, the likelihood is high that the appetite for RNG will continue to grow. If you want to learn more, read about the different factors to consider when switching to natural gas engines.

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