Six to seven seconds—that's the typical time between a pair of tractor-trailers traveling together at 65 mph. But, through the work of the Energy Department's National Renewable Energy Laboratory (NREL), and its partners in the medium- and heavy-duty truck market, that gap may be shrinking.
By narrowing the gap, a pair of trucks has a fuel-saving potential of up to 6.4%. Shorter following distances reduce aerodynamic drag, and the use of electronic coupling allows multiple vehicles to accelerate or brake simultaneously. The strategy is called semi-automated truck platooning, and it's just one of the many advances being tested and analyzed through NREL's collaboration with its partners in the trucking industry.
Working with Trucking Industry to Accelerate Technology Development
Recently, NREL hosted a landmark event for the trucking industry by bringing together members of the National Clean Fleets Partnership (NCFP) and the 21st Century Truck Partnership (21CTP) for the first time. The event supported a dialogue between fleet operators and truck manufacturers, allowing these closely tied industries to help the Energy Department and NREL identify and prioritize opportunities for high-impact collaboration in research, development, and deployment strategies.
21CTP is a partnership in the Energy Department's Vehicle Technologies Office that works with manufacturing partners in the medium- and heavy-duty trucks market, other federal agencies, and national laboratories to address national challenges related to improving vehicle efficiency and safety in on-road freight transportation.
NCFP is an initiative of the Energy Department's Clean Cities program that works with large, private-sector leaders to reduce petroleum use in their fleets. The partnership provides fleets with resources, expertise, networking opportunities, and support to successfully incorporate alternative fuels and fuel-saving measures into their operations. It was established to provide fleets with the ability to interact in a coordinated way with Clean Cities' nearly 100 coalitions with the support of technical resources provided at the federal level through the national labs.
More than 60 participants attended the event, representing a wide cross section of NREL's truck industry partners, including original equipment manufacturers, suppliers, fleets, national labs, Clean Cities coalitions, the Energy Department, the Federal Highway Administration, the U.S. Environmental Protection Agency (EPA), and the Army's Tank Automotive Research and Development Engineering Center.
"The meetings are part of an ongoing effort to facilitate collaboration with truck fleets and manufacturers to make sure NREL's capabilities are used in the best way possible," the Energy Department's Director of 21CTP Ken Howden said. "In particular, NREL has advanced data collection and analysis capabilities that can help fleets, manufacturers, and the Energy Department drive decision-making and improve efficiency, informing long-term, high-risk research such as the Energy Department's SuperTruck Initiative and supporting the EPA/NHTSA proposed new standards calling for as much as a 24% improvement in heavy-duty vehicle fuel efficiency.
Working Together to Meet Future Emissions and Fuel Efficiency Standards
One question on the minds of members of NCFP and 21CTP was the proposed EPA/National Highway Transportation Safety Administration (NHTSA) Phase 2 Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles. Matt Spears, center director for the EPA's Heavy-Duty Diesel Standards, remarked, "NREL's work has been informing the EPA regulations. EPA has an interagency agreement with NREL through the Energy Department to conduct analyses on several major issues, including the duty cycles used to challenge a vehicle and how to specify the duty cycles; how many duty cycles are needed in the regulation to cover the range of truck operations; and the weighting factors of these separate duty cycles."
Industry partners at the meeting emphasized the importance of working together to meet future emissions and fuel efficiency standards. "While many truck manufacturers invest in research and development, the economies of scale in the trucking industry don't allow for the same intensity of investment that you see in the car industry, said Susan Alt, senior vice president of public affairs for Volvo Group North America. "Partnerships like NCFP and 21CTP are incredibly important because they allow the industry to come together and discuss how we're going to meet future standards."
Mark Smith, vehicle technologies deployment manager for the Energy Department's Clean Cities program, added that "freight transportation demand is projected to grow to 30.2 billion tons by 2050, requiring ever-greater amounts of energy. Creative public-private partnering at the deployment stage presents great opportunities to increase sustainability on a grand scale."
For Kay Kelly, NREL's project lead for NCFP, coming together to share information and resources was a key outcome of the meeting. "NCFP is comprised of large, private fleets that often have the resources to experiment with new fuels and technologies in close cooperation with the trucking industry.
"At the local level, Clean Cites coalitions work with hundreds of small fleets to cut petroleum use and reduce emissions," Kay Kelly said. "Together, all of these locally based fleets make up a large percentage of the industry and can have a significant impact on petroleum use, but they often have more limited resources. Transferring knowledge, pooling resources, and connecting the dots between all of these different stakeholders are among the many ways that NREL can help to accelerate the market penetration of new transportation technologies."
Using Data to Drive Decision Making
NREL's fleet test and evaluation team conducts real-world performance evaluations of advanced medium- and heavy-duty fleet vehicles, technologies, and fuels. Like the work it did to demonstrate the fuel savings potential of truck platooning, the team evaluates vehicle performance and operating data to help reduce petroleum use and improve air quality.
"Our evaluation results help vehicle manufacturers and technology providers improve their designs and help fleet managers select fuel-efficient, low-emission vehicles that meet their bottom line and operational goals," NREL's Project Lead for Fleet Testing and Evaluations Ken Kelly said.
Through NCFP and 21CTP, NREL identifies fleets adopting new technologies and coordinates data collection that supports analysis and evaluation. The data is integrated into Fleet DNA, NREL's clearinghouse of commercial fleet vehicle operating data. The online tool provides data summaries and visualizations similar to real-world genetics for medium- and heavy-duty fleet vehicles operating in a variety of vocations.
These data summaries and visualizations help NREL and its partners understand the impacts of various technologies on the efficiency of the fleet, which is an integral part of identifying successful fleet technologies and sharing those technologies with other fleets.
Adam Duran, a research engineer at NREL, demonstrated to members of NCFP and 21CTP an example of NREL's data evaluation and decision support capabilities. Using data collected in collaboration with Shamrock Food Services, NREL has characterized how the food delivery fleet works from a data standpoint. With these data, NREL helps Shamrock investigate the impacts of different technologies, like improving aerodynamics of trucks or adding hybrid vehicles to the fleet.
In addition to enabling the visualization of individual fleet information, all data supplied to Fleet DNA are aggregated into anonymous, vehicle-category-specific reports and data sets. These publicly available data sets are useful tools—for researchers, regulators, original equipment manufacturers and developers, and other fleets—for understanding the typical use of the wide range of vehicle types and vocations in the medium- and heavy-duty vehicle arena.
One of the major benefits NREL communicated to members of NCFP and 21CTP was the depth of the data already in Fleet DNA. "While we are always looking to add additional partners to our data collection efforts, we are focused on discovering how we can best use the data we already have to help answer the critical questions posed by fleet operators and truck manufacturers," Duran said.