Fork(Lifts) in the (Off-)Road: Should We Ban Internal Combustion Engines for Electric?
Contributor: Propane Education and Research Council (PERC)
The California Air Resources Board (CARB) recently proposed a ban on Internal Combustion Engine (ICE) forklifts based on the California Governor’s Executive Order N 79 20. The proposed ban would impact ICE material handling applications up to 12,000 lbs. of lift capacity with some exceptions (e.g., rough terrain forklifts, military tactical vehicles, pallet jacks and forklifts owned and operated by facilities subject to the mobile carbon handling equipment at ports and intermodal railyards regulation).
As written, CARB’s proposal accelerates “zero”-emissions forklift (e.g., battery electric and hydrogen fuel cell electric) adoption through mandating “zero”-emission-only forklift sales by 2025, with a forced retirement of all ICE forklifts over a CARB-defined 13-year useful lifespan. Specifically, CARB is mandating ICE forklifts up to 12,000-lb. (6-ton) capacity, which predominantly includes Class 4 (cushion tire) & Class 5 (pneumatic tire) forklifts. Several fuels are used in material handling operations including diesel, propane, natural gas, and gasoline. The mandate would ban all equipment that uses these fuels, including hybrid electric solutions, and only allow battery electric and hydrogen fuel cell electric forklifts.
This white paper analyzes whether the rulemaking constitutes a favorable solution for the environment not only for California but for the entire U.S. PERC conducted an internal analysis using available certification emissions data and the Environmental Protection Agency’s (EPA) MOtor Vehicle Emission Simulator (MOVES3) tool for comparing lifecycle equivalent carbon dioxide (CO2eq) and nitrogen oxide (NOx) emissions chiefly between propane and electric forklifts. Note, the white paper does not address the capital costs, infrastructure costs and practicality of the implementation of this rulemaking, including loss of revenue (e.g., charging an electric forklift during a shift, impact of public safety power shutoffs or PSPS on a business operating forklifts) but analyzes it only from a technical standpoint. In this white paper, an energy cycle analysis compares propane and battery electric forklifts for each individual state, taking into account each state’s electricity mix. Note, hydrogen fuel cell forklifts have not been considered in this analysis, as nearly 95% of hydrogen in the U.S. is produced using a highly endothermic process of conventional natural gas steam methane reforming. For electric forklifts, both state electric grid average and marginal emissions have been accounted for. Since this “zero”-emission forklift transition is expected to occur by 2025, the marginal electric grid emission is a better metric for comparison with propane forklifts since electric forklifts do not currently constitute toward the baseload.
The figures that accompany this article show a variety of cases that were simulated in this study with available certification data for propane forklifts and emissions comparisons with electric forklifts for California. In the charts, the emissions are expressed in grams per kWh of delivered power.

Lifecycle emissions of electric vs. propane forklifts: CO2eq for ICE forklifts. Image courtesy of PERC.

Lifecycle emissions of electric vs. propane forklifts: CO2eq for hybrid electric forklifts. Image courtesy of PERC.
In California, propane forklifts do emit more lifecycle CO2eq emissions as compared to electric forklifts even when considering marginal electric grid emissions. The propane industry is investing in renewable propane and blends of propane with renewable dimethyl ether (rDME).
Performance of forklifts operating with renewable propane extracted from U.S.-based used cooking oil and Asia Pacific-based animal tallow is superior to that of electric forklifts, especially when considering marginal emissions. Blended propane/rDME fuels also lead to a lower carbon footprint compared with baseline conventional propane forklifts.

Lifecycle emissions of electric vs. propane forklifts: NOx for ICE forklifts. Image courtesy of PERC.
Since “zero”-emission forklifts may not indeed result in significant emissions reduction under all conditions and in some scenarios may indeed lead to degradation of lifecycle emissions, we make the following recommendations:
- Regulatory agencies should conduct detailed lifecycle analyses for gasoline, diesel, propane, natural gas, battery electric and hydrogen fuel cell electric forklifts before considering a ban on specific technologies.
- Criteria pollutant emission standards for non-road spark-ignited engines have not been updated since 2007; however, most current ICE technologies are capable of meeting lower criteria pollutant standards.
- Fuel innovation (e.g., renewable propane, blends of propane and rDME) and technology innovation, including hybridization, must be further developed and utilized in parallel. This co-optimization is key to the success of achieving decarbonization and reducing criteria pollutants.
- An abrupt transition to battery electric-only forklifts would not necessarily reduce CO2eq emissions and NOx emissions will only be displaced from warehouses to power plants.
- Replacing all ICE forklifts in the state of California with battery electric forklifts would warrant nearly 10 GWh/day charging capacity. This is extremely challenging to achieve for a state that depends on electricity imports from neighboring states and where PSPS are becoming more frequent.
- Propane and other low-carbon fuels qualify for California LCFS for forklift applications. An abrupt shift toward “zero”-emission forklifts will be a missed opportunity for accelerating decarbonization using low-carbon, renewable and blends of renewable and low-carbon fuels.
As good stewards of environmental justice, we need to ensure that we are not displacing the problem in space and/or time but are indeed solving a problem for the greater good of humanity and all life on Earth. WMHS
Read more about this study at propane.com.