With the use of electric delivery trucks starting to grow across the nation, fleet owners are seriously evaluating the possible advantages of the use of this form of delivery vehicle versus one powered by a diesel engine. What exactly do they need to be comparing though in order to answer the question of which one to go with? A new study from the Georgia Institute of Technology aims to help define that.
Researchers from Georgia Tech said it really comes down to three variables which should be compared – energy consumption, greenhouse gas emissions and total cost of ownership. In general,
in urban delivery routes with lots of stop-and-start driving, electric trucks are roughly 50 percent more efficient to operate than diesel trucks overall. That makes them at least 20 percent less expensive than diesel-fueled trucks, and reduces greenhouse gas emissions by roughly 50 percent. Where they are frequently stopped and started, the higher efficiency of the electric motor at low speeds and the regenerative braking systems in electrical vehicles help provide better efficiency.
However, electric delivery trucks lose their advantage in suburban routes that involve fewer stops and higher average speed. Electric vehicles have a limited daily range and top speed, and without a lot of stops, lose their regenerative braking advantage. Electric vehicles can cost more than their diesel counterparts under certain conditions, particularly if high-cost charging systems are used, if the battery must be replaced early, or if they are used mainly for highway driving.
Many factors came into play in evaluating electric trucks, including various vehicle efficiency associations and the sources of electricity used to charge the EVs. Wild cards in the study included the future costs of both diesel fuel and electricity, and the potential cost of replacing an electric truck’s battery pack if it has a shorter-than-expected lifetime.
“Over the life of the truck, there are many situations in which the total cost of operating an electric vehicle is less than operating a diesel vehicle,” noted Marilyn Brown, a co-author of the study and a professor in Georgia Tech’s School of Public Policy. “Our expectation was that the electric vehicle would provide environmental benefits, but at a cost. We found that particularly in urban settings and in locations with relatively low greenhouse gas emissions from electricity, electric delivery trucks both save money and have environmental benefits.”
For the purposes of comparison, researchers pitted a 2011 Smith Newton electric truck powered by a 120 kW electric motor, and a 2006 Freightliner truck powered by a Cummins diesel engine. The two trucks had approximately the same gross vehicle weight, curb weight and payload.