march2022 - 33

When we look at the actual cost of operations,
we found natural gas is about one-third the price
of diesel fuel today. It's a pretty inexpensive,
low-cost fuel source. Comparatively, hydrogen is
often multiples of the cost of diesel. And then electricity,
it obviously varies where you're sourcing
it, but it usually is also going to be more expensive
than diesel as well. As an example, if a fleet
buys diesel fuel at $3 per gallon and they get 7.5
mpg, then they are spending $0.40 on fuel per
mile. With electric, your electricity cost per mile
is equal to your electricity grid cost, which often
has peak usage fees associated. We recently spoke
with one group who expressed their peak electricity
pricing is $0.25 per kWh, which comes to
about $0.63 per mile.
While all electric vehicles are going to cost more
than diesel trucks, if you use a fuel source that costs
less than diesel, you have an ability to make this a
positive ROI for the fleet. If you use a fuel that's more,
you don't have that opportunity. And that's where
we see natural gas having the advantages there.
On the emissions side of things, there are so
many misconceptions. We like to look at emissions
from well to wheel. Where did your electricity
come from? What are the emissions that are
associated with that? A lot of our grid electricity
is coming from coal-fired power plants, natural
gas power plants, some coming from wind and
solar, and nuclear as well. But a lot of the different
sources have emissions associated with it.
When we use natural gas, we have the ability to
use renewable natural gas, and you can drive net
carbon-negative or below-zero emissions profiles.
CARB (California Air Resources Board) did a study
where they looked at carbon intensity (CI) scores,
and they found that the CI score of grid electricity
in California is in the low 80s. The CI score of
conventional fracked natural gas is in the high
70s. With RNG, you can get all the way down to
a -350 CI score. There is a huge opportunity for
emissions savings when using RNG.
FM: What are the major differences between
the Hybrid eX and the Hypertruck ERX?
TH: The best way to think about the Hybrid eX is
that it's like taking your semi-truck and making it
like a large Toyota Prius. You still have your diesel
or natural gas powertrain. Then we replace one of
the axles on the truck with an e-axle that can apply
power, apply torque, and can also do regen braking
to charge the batteries. It never needs to be plugged
in, and you're using your conventional vehicle.
This is a supplemental powertrain and a great
solution to move into electrification at a very low
risk and relatively low cost. We found that for
fleets that want to focus on ESG (Environmental,
Social, and Governance) and get into electrification,
it is a perfect stepping stone.
The 'end all, be all' is full electric-drive vehicles,
and that's where the Hypertruck ERX comes
into play. It has a full electric-drive powertrain but
uses onboard natural gas to recharge the batteries.
And we'll evolve the generator on the truck
eventually to a hydrogen-based solution. We're
positioned so that as infrastructure gets built
out, as cost of hydrogen comes down, we'll move
over when the time's right. But it starts today with
natural gas as a really smart solution.
We are already shipping Hybrid eX products to
fleets. It's at low volumes, but we're getting them
out there. We already have millions of miles
logged-real roadworthy miles. And that's been
invaluable for Hyliion because getting electric
solutions out there isn't easy. There's a lot of new
things to work through with fleets, and we've
already checked a lot of those boxes. As we go into
later this year, we're going to start controlled fleet
trials with the Hypertruck ERX. You'll see them
in fleet operations moving freight later this year.
FM: What do fleet maintenance departments
only familiar with diesel need to know about
servicing CNG systems?
TH: If you're just doing brake changes or tire
changes, there really is no difference. You just
turn the master switch of natural gas off, and
you're good to go.
If you're getting into fuel system overhauls and
things like that, you do need to have a facility that
is able to work on natural gas trucks. There are
facilities spread out across the U.S.; they're out
there. But it is not capital-intensive in order for a
fleet to upgrade their facility to be able to do that.
If you need work done on the actual fuel system,
you're going to bring that to a qualified dealer. For
the normal truck maintenance, it's really the same.
FM: Are there other maintenance considerations
when working on Hyliion solutions,
such as dealing with high voltages?
TH: One of the things we often get a question on
is, 'What about electrification? Do I need to train
all my technicians on how to work on batteries?'
In our approach, we've kept everything that is
high voltage pretty much isolated so that a technician
never has to deal with that. For instance, a
battery may fail out in the field. We've designed to
do a full battery pack swap as opposed to having
a technician opening up the battery and getting
close to the cells. From that standpoint, we don't
need to train people on how to deal with high-voltage
battery packs. It's more nuts and bolts of how
you unbolt the battery, bolt the new one up, and
then reconnect the wires.
The routine maintenance on our systems are
things like glycol changes, topping it off, or doing
a flush of the antifreeze, very similar to what
a truck normally goes through today.
FM: How do these hybrid-electric
powertrains affect wear items and
PM schedules?
TH: In the beginning, there are always
new learnings. There are always
things that don't go as expected, and
we've been faced with that as well.
Right now, we keep more of a whiteglove,
hands-on approach with these
vehicles just to ensure that we get any
of the bugs worked out of them.
As for the future, Tesla is a
great example. You don't have a
scheduled maintenance cycle;
you only bring this vehicle in for
service if something fails on the vehicle.
We want to adopt that sort of a solution or
something similar-maybe not quite to that extent
March 2022 | FleetMaintenance.com
33
but to where for any routine maintenance, we
schedule that in when that truck is already down
for a normal PM. And we don't envision that fleets,
in the long term, will need dedicated PMs just for
the electric system.
The one caveat there is if you are getting components
to their end of life. For instance, one of the
big concerns with the BEV plug-in vehicles is how
long the batteries are going to last. And it might
be that at 500,000 miles or 300,000 miles, you
need to change the battery pack on a BEV plug-in.
Our systems are a little different than a BEV
plug-in, which involves charging the batteries all
the way up, then depleting them all the way down,
and doing that daily.
With our solution, we have the batteries running
in the middle, and we're constantly charging them
as we go down the road. We found that we get a lot
longer life out of our battery pack. We expect our
battery solutions to be able to last the life of the
vehicle and not need to be replaced.
The way to think about a range extender vehicle
is you have a generator under the hood that is
producing electricity, but you want to keep that
operating at its absolute sweet spot.
With a normal diesel truck today, if you climb a
hill, that rpm of the engine is spiking up, your driver
is downshifting, and you're going to consume a
ton of fuel during that period. The flip side of that
is you're coasting down a hill, the engine is still
running, and you're not producing any power, but
you're still consuming fuel.
The generator always operates at a nominal,
peak performance. When you hit an uphill, when
you need a bunch of power, it's going to pull that
excess power out of your battery pack. When you
get back to flat terrain, you're going to be pulling
most of your power from the generator. When
you're going downhill, your generator is going to
be charging the batteries, and you're going to be in
a coast mode, or maybe even a regen mode where
the e-axles are charging the batteries as well.
From that standpoint, the load put on the generator
is much less than what goes to a diesel truck
because it has that battery as a buffer.
» The Class 8 Hyliion ERX solution comprises
a fully electric powertrain with an onboard
generator fueled by CNG for a
range of 1,000 miles.
Photo: John Hitch | Fleet
Maintenance
http://www.FleetMaintenance.com
march2022

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