NREL, Freight Industry, Academia, and Technology Partners Develop Promising Solution
To Increase Trucking Energy Efficiency Without Large Capital Investments
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digital tools to optimize the energy efficiency of trucking fleets. Photo from Getty Images
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
energy efficiency. Photo from PACCAR
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.”
Learn more about NREL’s sustainable transportation and mobility research. And sign up for NREL’s quarterly transportation and mobility research newsletter, Sustainable Mobility Matters, to stay current on the latest news.
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