The results demonstrate almost 80 per cent of short-haul routes can be serviced by 100kW low-power charging and could avoid depot and grid upgrades

The U.S.-based National Renewable Energy Laboratory (NREL) in collaboration with utilities, Southern Company and Texas-based Oncor Electric Delivery Company, have released a new study examining the infrastructure, upgrades and costs required to support electrifying the global trucking industry.

By relying on data from the United States Census Bureau which shows that the majority — 80 per cent — of heavy-duty trucks operate in a 200 mile range; and leveraging operating data from NREL’s Fleet DNA clearinghouse, the research group was able to use simulations to apply load profiles to 36 real-world substations.

The study concludes, “In most cases the existing technology grid can accommodate truck charging at depots…This study shows that charging requirements could be met at power levels in line with current light-duty charging technology (≤100 kW/vehicle) for the fleets studied.”

Balancing supply and demand

The study found that the key, to depots and grids making the most out of their existing infrastructure and avoiding having to make costly and time consuming upgrade is by employing “smart” charging. This involves the vehicles charging at slower rates over the time they are parked and not in use. This would reduce peak energy demand.

By applying this method, fleet managers could find they get welcome results: “78 [per cent] to 86 [per cent] of real-world distribution substations studied are capable of supplying a fleet of 100 battery electric trucks with 100 kW/vehicle charging without upgrades,” reads the study.

“With slower managed charging, that number goes up to 90 [per cent].”

With many heavy-duty trucks dedicated to set usage routes and moving goods between warehouses and retail locations, the researchers conclude, “vehicles are often characterized by short, predictable routes and off-shift periods at central locations such as a vehicle depot, making them prime candidates for electrification.”

Overall, the report predicts, this will have a transformative effect on total cost of ownership for truck fleets. A 2020 BloombergNEF report estimates fuel costs make up more than half the expenditures.

“The switch to BEV fleets would offer a significant reduction in fuel costs and require less routine maintenance, another key advantage for fleets,” reads the NREL report.

Implications grid-side

The final phase of the study was to assess if grids will be able to support truck charging requirements. NREL, Southern Company and Oncor Electric Delivery Company performed simulation on 36 substations using NREL’s synthetic load predictions. The results demonstrate: “Most (~80 [per cent]) of the substations studied could supply the time-varying loads of 100 trucks charged at 100 kW/vehicle without any upgrades, and an additional 10 [per cent] of substations could avoid upgrades if fleets used “smart” charging.”

David Woody, Oncor’s senior manager in distribution planning and study co-author said in comments about the report, “This research is unique in that it paints a more complete picture of what it would look like to electrify these fleets…studies like this can help anticipate and prepare for the effects of this transition.”

NREL indicates their interest in running similar research simulations for last-mile and long-haul truck fleets, with the goal of understanding the evolving requirements for transitioning fleets and grids.

Source: NREL – Researchers Identify Near-Term Opportunity for Heavy-Duty Electric Trucks