NACFE: Modest Gains Seen So Far from Variable Engine-Driven Accessories

[kscarbel2]

Heavy Duty Trucking  /  February 27, 2017

The Technology and Maintenance Council and The North American Council for Freight Efficiency (NACFE) go together like peas and carrots, as a certain cinematic shrimp entrepreneur likes to say. So it's no surprise that NACFE operational leader Mike Roeth chose the TMC meeting here to release the organization's findings and a Confidence Report on the fuel efficiency of Variable Engine-Driven Accessories that many OEMs are evaluating today as possible fuel economy enhancement systems on future powertrains.

These technologies include waste heat recovery systems and high voltage electrical systems, which OEMs and component suppliers are currently evaluating and have been testing on various OEM SuperTruck incarnations.

NACFE Confidence Reports are painstakingly researched by truck industry technology leaders and examine existing or emerging technology to give North American fleets baseline information on how a technology works,and what kind of fuel economy benefit or ROI they can expect to see whne using it in real-world operations.

The Variable Engine-Driven Confidence Report is NACFE's second look at an emerging trucking technology, coming on the heels of its Two-Truck Platooning report last year.

Because the technology is so new, and very much in early stages of development, Roeth said initial findings were modest in terms of eventual deployment and the potential for fuel savings and ROI. But, he stressed, much work was being done to improve these systems and advised fleets to continue to review advances in this area of powertrain development as further advances possible.

That said, the NAFCE's current report found the following on Variable Engine-Driven Accessories:

• Fuel economy gains are modest
• Fleets are concerned about complexity and reliability
• Payback is currently insufficient for high levels of adoption
• High voltage and waste heat recovery systems offer the best potential now for improved ROI

Additionally, Roeth said NACFE is recommending the following policies as development of Variable Engine-Driven Accessories continues:

• Fleets should continue to review and study these systems
• Manufacturers should continue to develop these systems
• Fleets should monitor the improvements driven by Greenhouse Gas Regulations
• High voltage systems will enable payback -- but accessories will not be the driver for higher voltage systems

The entire NACFE Variable Engine-Driven Accessory Confidence Report can be dowloaded here.

[kscarbel2]

Engine driven accessories bring modest fuel savings

Jim Mele, Fleet Owner  /  February 27, 2017

Switching from belt- or gear-driven engine accessories to variably driven ones has the potential to reduce heavy-truck fuel consumption by 3% to 5%, according to the latest Confidence Report released by the North American Council for Freight Efficiency (NACFE) and the Carbon War Room.  However at this stage of development, “variable engine driven accessories present relatively small opportunities for gains in fuel efficiency, but they may provide better payback with further development,” said Michael Roeth, NACFE executive director and IdeaXchange columnist for Fleet Owner.

Introduced at the annual Technology and Maintenance Council meeting, the report was the 15^th report issued by the two groups as part of their efforts to double freight efficiency by providing objective evaluations of technology and operating strategies.

The newest report examined eight technologies that are all currently in development including 2-speed cooling fans, variable speed water pumps, clutched air compressors, high-efficiency alternators, smart air dryers, dual displacement power steering pumps, electrically driven A/C compressors and other electrically driven accessories.  

The research team interviewed component manufacturers, truck and engine builders, teams involved in the various Super Truck projects, the Dept. of Energy and fleets “in an effort to provide a foundational understanding” of the eight new accessory technologies, some of which might become part of efforts to meet upcoming greenhouse gas emissions standards for heavy trucks.

At the current state of development, the conclusion is that “the fuel economy gains are pretty modest and could even decline” as fleets move to reduce operating engine speeds with downspeeding powertrains,” Roeth said. Fleets are concerned about reliability of new accessory system that add complexity, and the payback on investment in those systems from fuel savings “is insufficient for high levels of adoption at present,” he noted.

Despite that conclusion, the report urges fleets to continue reviewing variable engine-driven accessories and for manufacturers to continue development work. Current work on high voltage and waste-heat recovery systems could potentially lead to improved payback, and greenhouse gas benefits might also drive future adoption, Roeth said.