NREL Expertise Contributes to Customizable Ready-To-Deploy Tool Package To Improve Fleet Efficiency

NREL, Freight Industry, Academia, and Technology Partners Develop Promising Solution To Increase Trucking Energy Efficiency Without Large Capital Investments

Picture a truck delivering goods on the highway. Although you are seeing only a single vehicle, it represents just one component in a highly intricate system. That truck is specialized machinery, operated by a person, part of a larger fleet delivering shipments across a particular region-with these logistics managed by other people directing where the trucks go and when.

The complexity of the trucking network makes it possible for us to get our goods quickly, but it also makes decarbonizing the sector challenging. And with medium- and heavy-duty trucks contributing about one-quarter of all transportation greenhouse gas emissions, answering urgent questions such as "What aspects can we make more efficient?" or "How will one choice impact other aspects of the trucking system?" have become paramount to making progress.

Researchers at the National Renewable Energy Laboratory (NREL) looked for answers to these complex questions through the Co-Optimization of Vehicles and Routes (CoVaR) project, alongside partners PACCAR and its subsidiary Kenworth, The Ohio State University, Valence (now Kopius), and Esri. Through the CoVaR project, the researchers explored an all-in-one technology package that could allow fleet managers to optimize different aspects of fleet operations to improve their energy efficiency by 25%-all using ready-to-deploy tools and software that could be on vehicles now.

"These tools are a near-term win," said NREL's Andrew Kotz, a senior commercial vehicle technologies researcher. "CoVaR has the opportunity and ability to impact emissions substantially, today."

A Deployable, Cohesive Package of Technologies

Vehicle and battery manufacturers are making significant strides toward electrifying the next generation of heavy-duty vehicles. Further progress will rely on advances that are yet to be made in developing charging equipment and batteries that can handle the power and reliability demands of trucks. Besides that, the transition to electric fleets can require capital investments that some fleets may not be able to make yet. The CoVaR tool package addresses other aspects of trucking that could increase efficiencies today, while future vehicle technologies are still in development.

"Optimizing the use of existing fleet vehicles through the CoVaR tool package is appealing as an immediate solution for energy savings," said NREL's Jake Holden, a senior decarbonized vehicle systems researcher.

"If a fleet can't currently transition to electric due to expense or lack of available charging infrastructure, for example on long-haul routes, CoVaR is an alternative that finds the middle ground of energy-efficient options that are still time efficient and sustainable for drivers," added Setayesh Fakhimi, another NREL commercial vehicle technologies researcher on the project.

Here is how it works.

Vehicle Configuration Optimizer

As part of the CoVaR tool package, The Ohio State University developed a vehicle configuration optimizer that would calculate the most energy-efficient vehicles for the routes and duty cycles the fleet would be subject to. The duty cycle calculations account for elements like how long each delivery trip is, how many shifts per day the truck is operated, and more. The optimizer then recommends a combination of different truck powertrains across a fleet, like diesel, electric, and hybrid. Fleet managers could use this tool to understand their options for adjusting their fleets using powertrain technologies that make the most economic and operational sense for them.

Eco-Routing

The CoVaR tool package can provide fleet managers with speedy recommendations for which vehicles to route to what locations to achieve the highest energy efficiency. NREL researchers combined their advanced tool capabilities with project partner Esri's mapping software to develop a map and routing framework that fleet managers and truck operators could use to identify the most efficient routes for their operations based on the vehicles being driven. Through this project, Esri, the developer of ArcGIS and other mapping and analytics software, incorporated energy use into its routing planning algorithms for the first time.

NREL researchers contributed existing, real-world fleet vehicle energy use data from the laboratory's FleetREDI analysis pipeline and the Fleet DNA data platform. In addition, NREL's FASTSim and Route Energy Prediction Model (RouteE) tools can estimate the energy required by specific vehicles traveling on entered routes. The tools can be integrated into an application to present data in a user-friendly format and timeframe, perfect for fleet managers working on tight timelines.

"If you want to calculate energy requirements on your phone, you don't want to wait for a very complex model to run. You want it to happen right away," Kotz said. "That's the power of these tools."

Through developing the CoVaR tool package, the NREL team boosted the capabilities of RouteE. Previously, the tool only calculated vehicle energy consumption over given routes for light-duty vehicles like cars and pickup trucks. Now, with a new integration feeding cleaned and validated FleetREDI data to RouteE, RouteE can model energy requirements for heavy-duty vehicles, too.

Driver Coaching

Drivers would encounter the CoVaR system through a tablet mounted on their truck's dashboard. In fact, this simple device is already being deployed by some vehicle manufacturers to allow fleet managers to send down route information to a driver.

The software on the truck's tablet would not only provide route information but also provide a coaching platform that could help drivers most efficiently operate their vehicles. Using second-by-second data collected by the tablets on PACCAR's model fleet, NREL researchers analyzed route and fuel consumption data. They used FASTSim to simulate energy use impacts of different driver behaviors to alter driving speed, acceleration, idling, and more. These analyses could inform recommendations to drivers. A coaching system could prompt operators to change their driving style based on the vehicle they are operating-while considering that with every shift, the driver could be moving different amounts of weight, impacting the handling of the vehicle.

Fleet Performance Dashboard

In a real-world setting, fleet managers would visualize the vehicles in their fleet using a digital dashboard to identify the most energy-efficient combination of vehicles to send out on a given day. Valence (now Kopius) developed the user interface. It combines the vehicle configuration optimizer and eco-routing technology so fleet managers could plan their vehicles' routes to enhance energy efficiency across the fleet and then send those route directions to drivers.

Adaptability Is Key

The CoVaR tool package serves up a variety of options to fleet managers, allowing them to decide for themselves what energy efficiency goals they want to achieve and the choices they want to make for their fleet operations.

"A one-size-fits-all solution is all but impossible," Holden said. "CoVaR addresses this challenge by studying fleet priorities and behaviors that might impact energy consumption and presenting the range of efficiency improvements that are possible."

And improvements are indeed possible. Holden said the research team was able to achieve a 25% energy efficiency improvement in a modeling environment through the four interventions of vehicle configuration optimization, eco-routing, driver coaching, and a fleet performance dashboard. Deployment in an actual fleet could provide real-world validation and assess the package's performance in edge cases and for different fleet sizes.

"The impact of different interventions on energy savings is dependent on the operations of the fleet," Fakhimi said. "Reducing idling may have the biggest impact for one fleet, whereas lowering the maximum driving speed may be the most effective behavior change for another."

While the CoVaR tool package must be validated and commercially launched to become available to fleet managers, the NREL team sees this as a near-term possibility. The researchers and other project partners have demonstrated that the package is viable for improving energy efficiency today simply by aligning different elements of fleet operations and improving existing tools.

But the NREL team does not just see CoVaR as a stopgap solution to be phased out when the trucking sector is decarbonized.

"Even in an eventual all-electric future, the system could be used to further recapture and minimize wasted energy," Kotz said. "And we can adapt CoVaR to different vehicle types, like transit buses-another powerful catalyst for the broader decarbonization of heavy-duty vehicles."

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