Truck & Off-Highway Engineering - February 2024 - 4

TECHNICAL INNOVATIONS
This GM Hydrotec fuel-cell power cube
contains more than 300 hydrogen fuel cells
and generates 77 kW, but the array of modular
power cubes for the Komatsu mining-truck
application will make up to 2 MW of electricity.
to these demanding applications. " He
added that trucks such as Komatsu's
require " immense amounts of energy "
and that the Hydrotec power cubes developed
for the Komatsu application
will have " substantially more power per
system " and likely will be in a different
form factor than the 77-kW power cube
GM recently showed as part of a jointdevelopment
agreement with commercial-truck
specialist Autocar.
Freese also offered some insight on the
possibilities and options for how hydrogen
fuel itself is deployed in the market, particularly
for potentially challenging worksites
such as remote mines. He said that
proton-exchange membrane (PEM) fuel
cell technology used for electrolysis that
generates hydrogen from water " seems to
be gaining traction in the industry. "
He added that the electrolysis industry
" hasn't been taking advantage of what's
been going on in the automotive space, "
but the process has promise for on-site
GM and Komatsu intend to test the first prototype in the mid-2020s at Komatsu's Arizona Proving
Grounds research-and-development facility.
generation of hydrogen in some applications.
If hydrogen can be manufactured
close to the point of use, " it unlocks even
more value, " Freese asserted.
Fuel cells for vocational vehicles
GM also announced in December 2023
that it entered a joint development agreement
with Alabama-based Autocar
Industries to build a range of all-electric
commercial trucks powered by electricity
generated from GM's Hydrotec hydrogen
fuel-cell systems GM calls " power cubes. "
In a video call with journalists, the companies
said production of electric trucks at
the Autocar Truck Plant in Birmingham,
Alabama, will begin in 2026.
" EV propulsion systems like GM's
Ultium Platform are great solutions for
electrifying passenger vehicles, but larger
vehicles like Autocar's Class 8 trucks,
refuse trucks and terminal tractors require
robust solutions that enable significant
energy-carrying capacity and fast
refueling times, " GM's Freese said in a
press release. " We want to enable zerotailpipe-emissions
solutions for the largest,
highest energy-consuming vehicles,
and fuel cells are ideal for the most energy-intensive
applications, " he added.
The power cube is comprised of 300plus
versions of GM's current, secondgeneration
fuel cells in a compact and
easily packaged footprint that also incorporates
power- and thermal-management
systems. GM said each power cube can
generate 77 kW " and is much quieter than
a conventional diesel propulsion system. "
The modular power cubes can be arrayed
in a multiple arrangement for vehicles
requiring more power. The power cubes
for the Autocar applications will be manufactured
by GM in Brownstown, Michigan.
During a press gathering in July 2023,
Freese intimated that the modular power
cube format is ideal for larger vehicles
that have high-energy demands. He
added that the second-generation fuel
cell design has markedly reduced loadings
of precious metals required for the
system's catalyst; the Gen 0 design used
about 80 grams of platinum, Gen 1 reduced
the amount to around 30 grams
- and the Gen 2 technology has cut the
amount to the 20-gram level.
Autocar DC-64D
dump truck at a
construction site.
4 February 2024
Zero-emissions, built to order
The JDA between GM and Autocar sees
fitment of the modular power cubes in
TRUCK & OFF-HIGHWAY ENGINEERING
CLOCKWISE FROM TOP LEFT: JIM FETS FOR GENERAL MOTORS; KOMATSU MINING CORP; AUTOCAR

Truck & Off-Highway Engineering - February 2024

Table of Contents for the Digital Edition of Truck & Off-Highway Engineering - February 2024