Background
The engine compartment on today’s
heavy trucks is a hot and crowded place.
Pumps, alternators, compressors, and
other engine accessories all give off heat
as they compete for space and for the
energy they need from the engine. These
accessories have little effect individually
on engine power, but together – via belts
and pulleys – they can rob a diesel
engine’s fuel efficiency. As fuel prices
continue to rise, truck and fleet owners
need ways to reduce their fuel use in
order to stay profitable. Now, thanks to a
collaboration launched in 2000 between
private industry and the U.S. Department
of Energy (DOE), truck and fleet owners
will have more fuelsaving options avail-
able to them. That’s because a DOE
project called the “More Electric Truck”
has introduced new technology that takes
a big load off truck engines by replacing
mechanically driven accessories with
electrically powered accessories. More
Electric Trucks use less fuel, are more
reliable, and require less maintenance.
The Technology
The DOE More Electric Truck concept
incorporates accessories powered by a
generator located inside the flywheel
housing, which also serves as the starter
motor. Researchers converted the
following accessories to
electrical power on this
research demonstration
vehicle: the heating, venti-
lating, and airconditioning
(HVAC), brake air compressor,
and oil and water pumps.
Once they are validated, these
and future electrically driven
components will become
commercially available to the
trucking industry.
The More Electric Truck
features an electrically driven
HVAC module and a high-
efficiency 30 kW switched
reluctance (SR) generator. The HVAC
module incorporates scroll technology
that previously was available only on
stationary HVAC units. Other features
include an integrated auxiliary power
unit (APU) and a “shore power” feature
that permits the truck to plug in like a
recreational vehicle at a campground.
Shore power is available at select truck
stop demonstration sites in the U.S.,
where drivers don’t have to