H2Tech - Q2 2022 - 30

SPECIAL FOCUS HYDROGEN INFRASTRUCTURE DEVELOPMENT
Demonstration of system capabilities.
A mobile trailer configuration of
this
technology has been operational
since 2020, and separate refueling demonstrations
were performed in 2021 at
Stark Area Regional Transit Authority
(SARTA) and SunLine Transit Agency
(SunLine). FIG. 2 summarizes the results
of these demonstrations.
The SARTA demonstration. The
system was deployed at SARTA, located
in Canton, Ohio, from February 2021-
June 2021: it operated for 4 mos following
a 1-mos permitting, setup and commissioning
period, and had an average
specific energy demand of < 0.35 kWh/
kg H2
total of 3,700 kg of H2
dispensed. The system delivered a
to in-service fuel
cell buses over 118 individual fueling
events and with 100% system availability;
the typical filling time for an empty bus
with a 40-kg tank was 10.1 min, and the
average and peak fueling rates over the
course of the demonstration were 3.4 kg/
min and 7.1 kg/min, respectively. The
fills delivered were J2601-compliant.
The demonstration concluded with an
endurance test in which 52 consecutive
fills, totaling 1,322 kg of dispensed H2
,
were delivered over an 11.5-hr period.4
The SunLine demonstration. The
system was deployed at SunLine's Division
II facility in Thousand Palms, California,
from October 2021-February 2022. As
with SARTA, a 1-mos permitting, setup
and commissioning period preceded operation.
The system operated at Sunline for
3 mos, delivering a total of 4,838 kg of H2
to in-service fuel cell buses over the course
of 230 individual fueling events, most
of them with the system in unattended
mode. System availability was once again
100%, and system performance (including
fill rates and specific energy use) was
consistent between both demonstrations.
When the numbers from qualification
testing in 2020 and the two 2021 demonstrations
are combined, the system has
pumped 20 metric t of LH2
and accumuFIG.
2. Mobile trailer refueling demonstrations at two transit agencies, SARTA and SunLine.
Photo: refueling in progress at SunLine.
Economics of modular deployment
Conventional deployment
= Portable
Hub-and-spoke network
Modular
deployment
Fleet size
(number of vehicles)
Backbone network (along a traffic corridor)
Network growth
= Permanent
lated more than 1 yr of operating experience.
This experience, and the use of a
simulation trailer to mimic 60-kg, 90-kg
and 120-kg fills during qualification testing,
indicated that the system offers comparable
performance for fuel cell trucks as
for transit buses-Class 8 fuel cell trucks
require between 60 kg and 120 kg per fill,
and the current time standard for refueling
diesel trucks is up to 30 min.
Scalable deployment for truck fleets.
Refueling stations, regardless of fuel type,
are typically built at their full service capacity.
In a mature ecosystem with large
numbers of vehicles in service, this enables
the station to immediately operate
at maximum capacity; in an ecosystem
where the vehicle fleet is small but growing,
however, station utilization will initially
be low. This makes capital recovery
more difficult, forming the crux of the
" chicken-and-egg " investment problem
facing H2
fuel cell vehicles today.
A modular approach to station deployFIG.
3. A staged approach to network deployment using modular refueling stations (top left).
The capital expenditure for conventional deployment is higher than the staged approach
available from modular deployment (right and bottom).
30 Q2 2022 | H2-Tech.com
ment, as illustrated in FIG. 3, avoids this
problem by unlocking a staged deployment
path for the transition period during
which fleets are growing. Smaller, portable
modules can be deployed initially
while the number of fuel cell vehicles on
a route is low, and then be replaced with
larger, permanent stations as traffic grows.
The portable nature of the smaller modCapital
costs
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