IEEE Electrification Magazine - March 2018 - 45

eventually achieve the stricter requirements already
adopted in the national code.
Insights from these experiences have recently informed national and international efforts for codes and
standards development. for example, the success of the
structure of California's modified accuracy tolerances
played a role in the national Institute of standards and
Technology modifying handbook 44 in 2017 to include an
accuracy class in national standards that more precisely
reflects available technology.
retail hydrogen fueling stations are also expected to
reliably, quickly, and safely transfer hydrogen gas from station-side storage to the vehicles' on-board tanks. Today's
fCeVs typically store 5-5.5 kg of hydrogen at 70 MPa. rapid
fueling of this amount of hydrogen at such a high pressure requires chilling the hydrogen to temperatures as low
as −40 °C. such low temperatures during the fill maintain
thermal stresses in the tanks within tolerances that
ensure longevity in the lifetime of the vehicle. Industrydeveloped standards through the society of automotive
engineers (sae J2601, J2799, and others) provide common
fueling protocols for equipment suppliers, station developers, and operators. Pressure ramp rates, temperature
limits of the fuel, targets for the final on-board tank pressure, vehicle-dispenser communications, and other fill
parameters are defined by these standards. In addition,
Csa hydrogen gas vehicle (hgV) 4.3 describes standardized test methods to validate a hydrogen fueling station's
compliance with the sae protocols.
California's developing hydrogen fueling network has
been a valuable resource for these performance and validation efforts. some of the earliest hydrogen fueling stations began operating when several of the sae protocols
were only technical information reports, i.e., the standards
were not yet fully vetted and finalized but provided early
guidance. Today, several of California's hydrogen stakeholders across industry and public agencies are actively
engaged in ongoing refinement. recent efforts from the
state seek to refine clarity and reduce ambiguity so that
future testing and certification authorities may be able to
complete assessments in a faster and increasingly predictable and standardized manner.
The state's involvement has largely been due to the
initiative of the hydrogen station equipment performance (hysteP) device and program to accelerate station
performance validation. during California's precommercial phase of hydrogen and fCeV deployment, individual
auto manufacturers tested new hydrogen stations' dispensers to determine compliance with fueling protocols.
oftentimes, each manufacturer would require several
trips to allow the station operator to make adjustments
based on results from earlier tests. The coordination and
logistical effort was cumbersome, placed burden on station developers, and significantly lengthened total station development time. To address this, the hysteP
device was designed and built by sandia national

laboratories, the national renewable energy laboratory,
and Powertech labs with funding provided by the doe's
fuel-Cell Technology office and its h2fIrsT program. The
device is able to perform validation tests specified by
Csa hgV 4.3 and is therefore able to replace much of the
testing of multiple auto manufacturers with a single visit
and a single device.
Today, the device is operated by CarB in cooperation
with several other state agencies and has been critical in
performance testing and validation of California's open
retail stations. station developers and operators have
been able to use the device's test results to refine their
station design and operation parameters. Potential variations in interpretation of protocol requirements and
ambiguous language have been identified through
observation of the various station developers' implementation of the standards. auto manufacturers have
been relieved of much of the burden of testing a station's
performance themselves.
These benefits have all contributed to the hydrogen
and fC industry and significantly advanced the state of
the science and focus for continued development. from
these combined efforts, a picture of the requirements and
expectations for retail hydrogen station performance has
emerged. In addition, complementary efforts have made
significant progress in further defining the retail customer
experience. The efforts include
x
communication with customers, e.g., public updates
when new hydrogen fueling stations open and the
real-time station operational status system operated
by the CafCP (https://m.cafcp.org)
x
equipment and station design for intuitive fueling
experiences
x
equipment reliability and station availability as perceived by customers
x
capability for stations to serve multiple customers'
hydrogen fueling needs in rapid succession, providing
the assurance of on-demand, rapid hydrogen fuel
availability similar to current gasoline stations.
There are still several refinements that are expected as
the hydrogen fueling network expands, but the stations
currently in operation are proving the promise today of
zero-compromise, zero-emission transportation through
hydrogen-powered fCeVs.

hydrogen's horizons
In the future, there are many indications for a shift in
emphasis on the scale of the hydrogen fueling and fCeV
markets and on the expansion of the hydrogen market
itself as an energy resource for applications across several industries. recent efforts by the CafCP provide a
vision for what this shift from market establishment to
a rapidly expanding scale may look like in California.
rapid growth in numbers of stations and deployed vehicles, the growth of hydrogen fueling station capacity to
and beyond 1,000 kg/day, and the design of stations with

IEEE Electrific ation Magazine / ma r c h 201 8

https://m.cafcp.org

Table of Contents for the Digital Edition of IEEE Electrification Magazine - March 2018