Research looks at cost benefits of electric trucks

It may be time to start investing in electric semi-trailer trucks, Carnegie Mellon University researchers say.

A new research paper undertaken at the Pittsburgh, Pennsylvania institute has compared the cost of traditional diesel semi-trucks to electrically powered ones.

The paper, Quantifying the Economic Case for Electric Semi-Trucks

, by assistant professor Venkat Viswanathan and PhD student Shashank Sripad suggests the initial cost to invest in electric semi-trucks may be worth paying.

Overall, the research says a number of targets need to be met to help with the transition to electric semi-trucks.

First, the vehicle design needs to reduce the battery pack size and meet the payload requirements of about 38,000 pounds.

Second, the pack price should be reduced to less than US$150 per kilowatt hour to encourage people to invest in electric semi-trucks.

Third, a cost of electricity below US$0.20 per kilowatt hour with a peak power of over 500kW per truck would ensure a fast re-charging without incurring a loss of valuable time.

Finally, the battery pack cycle life will have to be improved so that the trucks will require fewer battery pack replacements over their lifetime.

While a few unfavorable scenarios do not allow a meaningful payback period, in favorable scenarios, the period is around three years or lower.

“When the Tesla semi-truck was announced, it was important to understand how far it could go and what types of payload it could carry … We decided to use the framework we had previously developed for electric commercial vehicles and apply it to semi-trucks,” Viswanathan says.

The research examined the initial investment and the operating cost of a fleet of electric semi-trucks that can travel 500 miles compared with a fleet of diesel semi-trucks.

Electric trucks have a lower operational cost because they have increased energy efficiency for mobility along with a comparable or lower cost per unit of electricity compared to diesel.

However, the initial price of the lithium-ion battery pack used to power the trucks has raised questions.

“In spite of those initial concerns, there seems to be an economic case for transitioning to electric semi-trucks,” Sripad says.

“However, to ensure favorable economics, certain, important aspects like the low-battery pack cost, high cycle life and low electricity price need to be ensured.”