Comparing Carbon Reduction Solutions
Biofuels versus natural gas, battery-electric and hydrogen class-8 trucks
With the transportation sector being the largest source of greenhouse gas (GHG) emissions in the U.S.1, an increasing number of both public- and private-sector entities with lower carbon goals have set their sights on reducing tailpipe emissions as an important step toward achieving those targets.
While each solution has its merits, it’s important to look at all the factors to determine which one may be the most viable solution for your fleet today. Here, we’ll compare the availability, equipment and infrastructure requirements, cost, carbon reduction effectiveness and engine performance considerations for each of the solutions presented below.
|Equipment & Infrastructure
|Biodiesel and Renewable Diesel
B20 and above biodiesel blends are widely available at more than 800 public fuel stations throughout the country, whereas R20 and above renewable diesel blends are available at roughly 574 stations, primarily located in California2. Lower blends levels of biodiesel and renewable diesel are even more widely available.
Biodiesel and renewable diesel can both be used with existing diesel fuel tanks and engines, requiring no additional infrastructure or equipment investments.
B20 biodiesel blends and renewable diesel have both been relatively consistent with the price of petroleum diesel over the last five years. 3 Their use generally requires no additional equipment investment.
||Compared to petroleum diesel, biodiesel and renewable diesel may reduce carbon emissions by up to 100% for fossil carbon. 4 Biodiesel also reduces total hydrocarbon by 70% and renewable diesel does so up to 40%. 5 The carbon intensity (CI) score of both biodiesel and renewable diesel have also been consistently lower than LNG and hydrogen.6 Compared to electric, biodiesel may be about 56% more effective at reducing carbon when taking the power grid into consideration.7
|| Biodiesel offers improved lubricity and combustion, and reduced DPF clogging and regenerations versus petroleum diesel. Contrary to some misconceptions, with proper blending, handling, storage and use of additives, biodiesel may be used effectively in extreme cold. Renewable diesel is considered a direct replacement to petroleum diesel, meaning its engine performance and cold weather use could be the same as petroleum diesel.
|Natural Gas (CNG, LNG and RNG)
As of December 2022, more than 800 public CNG stations were available throughout the U.S. and Canada, but only 51 public LNG fueling stations existed in the U.S.,8 making long-haul trucking a challenge with LNG in most parts of the country. LNG engine technology is also limited to select manufacturers.
CNG and RNG would require investment in new storage infrastructure, as well as new engine technology.
||Both CNG and LNG cost has been consistently lower than petroleum diesel in diesel gallon equivalent, however, the cost of an LNG engine and LNG fuel tanks are approximately double that of diesel engines and tanks.9
||Compared to petroleum diesel, natural gas reduces CO2 emissions by an estimated 27%.10 The CI score for renewable LNG has been consistently near double that of biodiesel for years, however, the CI score for CNG has been the lowest of all fuels and power sources for the last several years.6
||Cold weather may also cause a loss of power to the battery, and O-ring freezing can prevent correct coupling, however natural gas does not gel in cold weather and does not require DEF, eliminating issues.10
||While OEMs including Tesla, Volvo and Daimler have all recently debuted battery-electric trucks, experts forecast that only 19% of heavy-duty trucks will be electric by 2040,11 indicating that widespread availability and adoption are not imminent.
|Available charging infrastructure has come a long way in recent years, however, a less than 300-mile range12 makes class 8 long-haul operations far less feasible than smaller classes, regional hauls and last-mile operations.
The cost of a class 8 electric truck can be $300,000+ more than a diesel equivalent.13 Incentives in some states can help offset some of this cost. Fuel savings is also a factor, providing an estimated $0.13/mile savings for class 6 trucks.13.
|| While EV proponents cite zero emissions, the true calculation of carbon impact takes full lifecycle emissions into account, including emissions from power generation to create the electricity. The carbon intensity score for electric (as measured based on California’s grid) has been consistently higher than biodiesel over the last five years.6
|| Specs can vary by OEM, but generally, range, charge time and top speed can be performance limitations. For instance, Kenworth’s class 8 T680E has a 150-mile range, takes three hours to charge (with DC fast charger) and has a top speed of 65 mph.14 However, lack of engine fluids reduces the need for service intervals and maintenance.
|Hydrogen Fuel Cell
||Several OEMs (Nikola, GM, Toyota, Daimler, Volvo) have been testing prototypes for the last several years,15 but they’re not yet commercially available. Hyzon touts their class 8 truck as “available now.”16 Regarding fuel availability, as of Q1 2023, there were only 60 public fueling stations offering hydrogen in the U.S. and Canada – which were limited to California, British Columbia and Québec.17
||Switching to hydrogen would require investment in new equipment, as well as new storage infrastructure. As mentioned previously, public fueling infrastructure in the U.S. and Canada is currently very limited.
|The cost of hydrogen is $16.80/kg18 — which is roughly three times the cost of diesel when considering that 1 kg of hydrogen contains approximately the same energy as 1 gallon of diesel.19 Pricing studies have provided varying estimates, but in general, the lifecycle cost of a hydrogen truck is generally thought to be double that of diesel, but less than battery electric in most cases.20
| Hydrogen offers zero tailpipe emissions, however, its CI score, just like battery electric, has consistently been higher than biodiesel – ranging anywhere from about 8% to 396% higher since Q1 2019.6
||Versus battery electric, refueling time is much faster and range is advertised as greater. For instance, Hyzon’s class 8 truck offers 500-mile range and only 15-minute refueling time.16 Just like battery electric, lack of engine fluids reduces the need for service and maintenance.
Each solution has its merits, but also may come with tradeoffs. Some enable a lower cost of operation but may require upfront investments. Others will become more viable in the future but may currently lack the fueling infrastructure or OEM availability required for widespread adoption today.
Biodiesel and renewable diesel from Chevron Renewable Energy Group offer a solution today and generally without major infrastructure or equipment investments. The carbon intensity reduction for biofuels is in most cases as great — if not greater — than some other solutions, particularly when looking at the full lifecycle, well-to-wheel carbon intensity. Chevron also offers CNG, a fuel that has comparable fueling infrastructure to biodiesel in the U.S., is lower cost in diesel gallon equivalent and has a lower CI score, but also requires investment in new engine technology and storage infrastructure.
Simply put, biodiesel and renewable diesel offer one of the simplest solutions to lower carbon emissions today.
FOOTNOTES & SOURCES
4 Product is produced from renewable oils and fats. Methanol used to make biodiesel and hydrogen used to make renewable diesel and SAF are typically made from conventional natural gas but can be produced from renewable resources.
5 CARB Assessment of the Emissions from the Use of Biodiesel as a Motor Vehicle Fuel in California "Biodiesel Characterization and NOx Mitigation Study." Durbin (2011)
7 Carbon intensity for EVs based on eGRID 2020 figures and EV EER of 3.8 for transit buses per National Renewable Energy Laboratory