American Towman Magazine - September 2022

Page 62

Supplier Scoop more affordable, and most importantly more available than others.” He went to note that the transitions to new energy sources still have considerable uncertainties and longer timeframes—a decade or more—to meaningful implementation. Some solutions will be available sooner than others and at larger scale than others. He feels that advanced diesel technology, as well as renewable and biodiesel fuels, are key available solutions that can deliver big impacts today. The considerable benefits of using low-carbon renewable biobased diesel fuels becomes clearer from this analysis. As these fuels can be used in all diesel vehicles today, fueling the diesel vehicles in the study with 100 percent renewable diesel resulted in three times larger cumulative GHG reductions by 2032 than the EV scenarios. Using B20 (a 20-percent blend of biodiesel with 80-percent

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petroleum diesel), provided about the same cumulative GHG reduction. “All eyes seem to be focused on electrification as the best if not the only strategy for the future fuel and technology in the transportation sector,” stated Gary Yowell, automotive engineer at Stillwater Associates. “This work has illuminated that’s overly simplistic; that there are significant, less expensive, and more available emissions reduction strategies for these workhorse vehicles which can enable greater emission reductions to be delivered more rapidly.” Beyond GHG emissions, the research also highlighted impacts of an advanced diesel vs. electrification strategy on regional air quality as well, finding that the business-as-usual case replacing pre-2007 model year diesel vehicles which lacked diesel particulate filters with advanced technology diesel vehicles provided the largest particulate matter (PM) reduc-

tion. This is due to new technology diesel engines’ 98-percent PM reductions compared to EVs’ 95 percent PM reduction assuming power from the U.S. Grid Mix. As for nitrogen oxides (NOx) emissions, EVs have 98.5 percent lower NOX than pre-2007 diesel vehicles on a per mile basis, and 2010 and later MY vehicles have 79 percent less NOx emissions than a 2007 diesel model. However, when replacing a diesel medium and heavy-duty vehicle with an EV and evaluated on an annual miles driven basis, the NOx benefit is diminished. EVs are generally deployed on shorter routes and have a shorter range of operation than that of a comparable diesel vehicle, with about 87 percent of the mileage on a daily basis. Given this mileage difference, NOx emission reductions for a fleet transitioning to EV will be less than the business-as-usual turnover from older generation diesel to