Truck & Off-Highway Engineering - August 2022 - 5

TECHNICAL INNOVATIONS
" In commercial vehicles, there are
many things that are specialized, "
Reeser said. " Instead of using the 12V
system everyone designed to with ICE
vehicles, you might use 400V for a
wheelchair lift or the air conditioner;
400V is more efficient, you just need to
develop that wiring harness and the
CAN bus. "
While moving trucks and buses down
the road is a primary design focus, it may
not be the only engineering challenge.
Battery packs may be enlisted to help
support the nation's power grid and
avoid brownouts. Executives also noted
that California is exploring techniques for
using school bus batteries to help utility
companies when grids are strained.
Bus battery packs typically can be
charged at night, when utility rates and
demand both are low, and potentially
transfer energy back to the grid on
days when demand is high. That's especially
effective in summer and on weekends,
when buses often sit idle.
However, Bettis noted that this program
will take a lot of cooperation between
vehicle owners and utilities.
Supply-chain challenges
Regardless of how batteries are used,
supply-chain issues remain a major
challenge for production of both repowered
and new vehicles. Getting
chassis has been difficult, and many
components are in short supply.
" The challenges are multifold, "
Reeser said. " It's not just the chassis, it's
hard to get transmission control modules
and chips. It's also hard to get wiring
harnesses and connectors. I do
think in the next nine months we'll
come out of that. We've added new
suppliers and we've gone to vertical
integration. Making our own components
is being done out of necessity,
not because we necessarily wanted to. "
The need for new designs is fueling
expansion at Lightning's 1 million
square-foot facility in Loveland,
Colorado. The company added 60 engineers
and 15 service-team members
last year, bringing the total employee
count to around 250.
Terry Costlow
TRUCK & OFF-HIGHWAY ENGINEERING
FLOW CONTROL
Emerson supports scalability of fuel cell systems
To produce enough
hydrogen fuel cell
systems to supply fleets,
manufacturers need
to quickly scale up in
terms of resources,
factory extension and
procurement efficiency.
'Green' hydrogen is a promising fuel on
the path to decarbonizing the mobility
sector, proven by significant investments
in many transportation projects
and technologies. New fuel-cell electric
vehicle (FCEV) truck designs continue
to enter testing stages, with some manufacturers
planning to launch fleets as
early as this year. The technology is
even celebrating big milestones: In
January, an electric-hydrogen-powered
truck debuted in the 2022 Dakar Rally,
and in 2021, a hydrogen-powered fleet
drove over 1 million km (620,000 miles)
in 11 months using its 46 trucks.
Many in the commercial-vehicle market
see hydrogen fuel cells as a viable way to
decarbonize transportation around the
world. Unlike their battery-electric alternative,
hydrogen fuel cells are lightweight
and allow commercial trucks to maintain
relatively the same haul tonnage as their
diesel equivalent. Hydrogen fuel has a
high energy density and is stored at high
pressures, ensuring an advantage when it
comes to onboard storage footprint.
Hydrogen tanks can also be refueled in as
little as five minutes, minimizing transit
time for long-haul routes.
Even with so many advantages, some
manufacturers still worry about scalability,
while others are concerned
about the safety and efficiency of hydrogen
as a fuel source. The good news
is there are proven ways to scale up
production for hydrogen fuel cell technology,
as well as available solutions
that can improve system safety, reliability
and efficiency.
Controlling fuel flow
Due to its low ambient temperature
density, hydrogen gas has a low energy-per-unit
volume that requires the
element to be highly pressurized when
used as fuel. In onboard storage tanks,
the fuel is typically subject to pressures
of either 35 or 70 MPa (5,075 or 10,150
psi). These high pressures, combined
with the hydrogen molecule's small size,
make the gas very susceptible to leaks.
It is critical that fuel cell technology
safely, reliably and efficiently controls
the flow of the hydrogen fuel within
FCEVs. Regulators and proportional
valves engineered for hydrogen fuel cell
systems are being designed with safety
in mind to provide stable pressure
It is critical that fuel cell technology safely, reliably
and efficiently controls the flow of the hydrogen
fuel within FCEVs, said Emerson's Akilah Doyle.
August 2022 5
BOTH IMAGES: EMERSON
Truck & Off-Highway Engineering - August 2022

Table of Contents for the Digital Edition of Truck & Off-Highway Engineering - August 2022
