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Propane Tank On Forklift

Powering Fleets with Propane to Achieve Sustainability Goals

Oct. 3, 2022
Propane is an approved clean alternative energy source under the Clean Air Act.

Analysis & Commentary

Sustainability is critical to business planning and supply chain management across the nation. While going all electric is touted as the best solution, the reality is that a more sustainable energy option exists with propane. In fact, propane is an approved clean alternative energy source under the Clean Air Act.

Recently, the California Air Resources Board (CARB) proposed a ban on all internal combustion engines (ICE) by 2035. This will mandate forced retirement of ICE forklifts with up to 12,000 lbs. of lift capacity in favor of battery electric and hydrogen fuel cell electric forklifts.

Battery electric power is considered the greenest and most reliable power option, but it’s important to consider what’s happening beyond the operation of the forklift itself and review the full lifecycle of emissions generated by each energy source. The United States relies primarily on coal and natural gas to operate power plants, which has significant impact on the environment and air quality in the surrounding areas. It’s also important to consider emissions output while transporting energy sources to the facility. 

Propane Forklifts Effectively Reduce Emissions

In response to CARB’s proposed ban, PERC recently analyzed emissions of electric forklifts in comparison to emissions of the most commonly used ICE engines for propane forklifts using publicly available data in the study, Fork(lifts) in the (Off) Road: Should We Ban Internal Combustion Engines for Electric. The analysis compares the lifecycle emissions profiles of propane and electric-powered forklifts, including carbon dioxide (CO2) and nitrogen oxide (NOx) emissions. The study aims to answer the question, “Should we ban internal combustion engines for electric?” If the goal is to be greener, we believe propane is a more favorable fuel choice for California and for the entire U.S.

The findings show for most states, engines powered with conventional propane are superior to electric forklifts, especially when considering marginal emissions. This is due to the amount of emissions released from each state’s unique energy mix for electricity generation using coal, petroleum, or other energy sources. In the case of marginal emissions, states with relatively clean electric grids often buy from neighboring states with carbon intensities worse than their own.

The study presented the following scientific findings:

• A zero-emissions forklift does not exist.

• In most states, NOx emissions from propane-powered forklift engines can be less than half that of battery-electric forklifts powered by the electric grid.

• 314,000 ICE forklifts are operating in California alone. Replacing all ICE forklifts in the state with battery-electric forklifts would require nearly 10 GWh/day of additional charging capacity.

• Electrification as a means of decarbonization sounds attractive; however, without consideration to lifecycle emissions, inefficiencies in power production, transmission and distribution, and grid instability, it is misguided to think that it is the best and greenest choice.

The findings emphasize that regulatory agencies should conduct detailed lifecycle emissions analyses for gasoline, diesel, propane, natural gas, battery electric and hydrogen fuel cell electric forklifts to better view the full clean energy picture before considering a ban on specific technologies.

Full electrification of forklifts is frequently cited as the only way for warehouses and distribution centers to cut emissions. This way of thinking fails to account for the carbon emissions that are produced in the generation and distribution of electricity.

Renewable Propane

In the future, all energies will be renewable clean energy sources. What is important is to look beyond battery power to other renewable resources. Renewable propane is a low-carbon energy source produced today from a variety of renewable feedstocks. Production of renewable propane itself is environmentally-friendly, as it is a byproduct of renewable diesel and sustainable aviation fuel (SAF). The feedstocks and pathways for producing renewable propane include soybean oil, camelina plant oil, vegetable oil, animal fats, or used cooking oil.

Conventional propane is cleaner than many other energy sources with a carbon intensity of 79 g/MJ (grams CO2 equivalent per megajoule), whereas the average national electric grid carbon intensity is 139 g/MJ. Measuring a fuel’s carbon intensity helps to capture emissions across the full lifecycle of an energy carrier. While the carbon intensity of renewable propane depends on the feedstock and pathway, renewable propane made from U.S.-sourced non-rendered used cooking oil has a low carbon intensity of just 20.5.

Because renewable propane’s molecular structure and physical properties are the same as traditional propane, renewable propane is a “drop in” fuel for any existing propane engine. The abundance of propane and growth of renewable propane means it is clean today and cleaner tomorrow.

Sustainable Propane-Hybrid Forklifts

An abrupt shift from traditional forklifts toward “zero” emissions forklifts is unrealistic and a missed opportunity to accelerate decarbonization using low-carbon fuels, renewable fuels and blends of the two.

Propane is already a clean solution, available today to accelerate decarbonization and reduce harmful NOx emissions and will continue to improve as time goes on. When it comes to powering forklifts, it can also be cleaner than an all-electric option if you consider fuel blends, like propane and dimethyl ether (DME).

As PERC’s study points out, when blended, renewable DME and propane have a lower carbon footprint when compared with baseline conventional propane forklifts. The performance of hybrid electric forklifts, with both conventional and renewable fuels, is superior to the performance of electric forklifts, particularly when comparing marginal CO2eq, NOx and marginal emissions.

Overall, hybrid forklifts, renewable fuels and fuel blends are effective ways to make a significant dent on the carbon footprint of the material handling industry.

Technology is only continuing to advance and with it, so does propane technology to drive us even further down the path to zero.

It is important for material handling decision makers in the value stream of distribution to look at immediate and long-term solutions to reduce emissions. Although the electric grid will get cleaner over time, propane meets those requirements today and will continue to well into the future.

Joe Calhoun is director of off-road business development for the Propane Education & Research Council (PERC).

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