the HD GHG Phase 2 rulemaking, available at https://nepis.epa.gov/Exe/ZyPDF.cgi/P100P7NS.PDF?Dockey=P100P7NS.PDF.
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    In the HD GHG Phase 2 final rule, we included ZEV technologies in
our assessment of the suite of technologies for HD vocational vehicles
and tractors. However, in 2016, when the HD GHG Phase 2 rule was being
developed, we stated that ``adoption rates for these advanced
technologies in heavy-duty vehicles are essentially non-existent today
and seem unlikely to grow significantly within the next decade without
additional incentives.'' \388\ Thus, at that time, instead of including
ZEV technologies in the technology packages for setting the Phase 2
standards, we provided advanced technology credit multipliers to help
incentivize the development of ZEV technologies.
---------------------------------------------------------------------------

    \388\ 81 FR 73498 (October 25, 2016).
---------------------------------------------------------------------------

    Since the 2016 promulgation of the HD GHG Phase 2 final rule, as
discussed in Section I.C, a number of important factors have
contributed to changes in the HD landscape. Therefore, as detailed in
this Section II and DRIA Chapter 2, we now are proposing that BEV
technologies and FCEV technologies will be technically feasible for HD
vehicles and suitable for most applications, as assessed by vehicle
type and each Phase 3 MY. As further detailed in this Section II and
DRIA Chapter 2, we are also proposing that BEV and FCEV technologies
are feasible at the adoption rates included in the technology packages,
which vary depending on the respective vehicle type and Phase 3 MY, and
thus that the proposed revised standards for MY 2027 and proposed new
standards for MYs 2028 through 2032 are feasible and appropriate.
Similar to Phase 1 and Phase 2, the technology packages used to support
the standards in this proposal include a mix of technologies applied to
HD vehicles, and development of those technology packages included an
assessment of the projected feasibility of the development and
application of BEV, FCEV, and other technologies that reduce GHG
emissions from HD vehicles. While our analysis in this Section II.D
focuses on certain technologies in the technology packages to
demonstrate the feasibility of the proposed HD vehicle GHG emission
standards, there are other technologies as described in DRIA Chapter 1
that can reduce CO2 emissions. Under the proposed rule, manufacturers
may choose to produce the technologies that work best for their
business case and the operator's needs in meeting the proposed
standards, as the proposed standards are performance-based and do not
mandate any specific technology for any manufacturer or any vehicle
subcategory.
    EPA developed a bottom-up approach to estimate the operational
characteristics and costs of ZEV technologies for this proposal. This
approach takes into consideration concerns received on the HD2027 NPRM
concerning the proposed revised MY 2027 GHG vehicle standards' analysis
presented in the HD2027 NPRM. We developed a new technology assessment
tool, Heavy-Duty Technology Resource Use Case Scenario (HD TRUCS), to
evaluate the design features needed to meet the power and energy
demands of various HD vehicles when using ZEV technologies, as well as
costs related to manufacturing, purchasing and operating ICE and ZEV
technologies. HD TRUCS is described in more detail in Section II.D.5
and DRIA Chapter 2 but we briefly summarize the approach here.
    To build technology packages using HD TRUCS, we created 101
representative HD vehicles that cover the full range of weight classes
within the scope of this rulemaking (Class 2b through 8 vocational
vehicles and tractors). The representative vehicles cover many aspects
of work performed by the industry. This work was translated into energy
and power demands per vehicle type based on everyday use of HD
vehicles, ranging from moving goods and people to mixing cement. We
then identified the technical properties required for a BEV

or FCEV to meet the operational needs of a comparable ICE HD
vehicle.\389\
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    \389\ Heavy-duty vehicles are typically powered by a diesel-
fueled compression-ignition (CI) engine, though the heavy-duty
market includes vehicles powered by gasoline-fueled spark-ignition
(SI) engines and alternative-fueled ICEs. We selected diesel-powered
ICE vehicles as the baseline vehicle for the assessment in HD TRUCS
in our analysis because a diesel-fueled CI engine is broadly
available for all of the 101 vehicle types.
---------------------------------------------------------------------------

    Since batteries can add weight and volume to a vehicle,\390\ we
evaluated battery mass and physical volume required to package a
battery pack. If the performance needs of a BEV resulted in a battery
that was too large or heavy, then we did not consider the BEV for that
application in our technology package because of, for example, the
impact on payload and, thus, potential work accomplished relative to a
comparable ICE vehicle.\391\
---------------------------------------------------------------------------

    \390\ Smith, David et. al. ``Medium- and Heavy-Duty Vehicle
Electrification: An Assessment of Technology and Knowledge Gaps''.
U.S. Department of Energy: Oak Ridge National Laboratory and
National Renewable Energy Laboratory. December 2019. Available
online: https://info.ornl.gov/sites/publications/Files/Pub136575.pdf.
    \391\ This does not necessarily mean that a BEV with a large
battery weight and volume would not be technically feasible for a
given HD vehicle use, but rather this is an acknowledgement that we
considered impacts of increased battery size on feasibility
considerations like payload capacity as well as cost and payback
within the selection of HD vehicle technologies for the technology
packages.
---------------------------------------------------------------------------

    To evaluate costs, including costs of compliance for manufacturers
as well as user costs related to purchasing and operating ZEVs, we
sized vehicle components that are unique to ZEVs to meet the work
demands of each representative vehicle. We applied cost estimates to
each vehicle component based on sizing to assess the difference in
total powertrain costs between the ICE and ZEV powertrains. We
accounted for the IRA battery tax credit and vehicle tax credit, as
discussed in Section II.E.4. We also compared operating costs due to
fuel consumption as well as vehicle maintenance and repair, and we
included the cost to procure and install depot charging infrastructure
for BEVs. For FCEVs, similar to ICE vehicles' infrastructure and fuel
costs, we assumed hydrogen infrastructure costs were embedded in the
cost of hydrogen fuel.
    We relied on research and findings discussed in DRIA Chapters 1 and
2 to conduct this analysis. For MYs 2027 through 2029, we focused
primarily on BEV technology. Consistent with our analysis, research
shows that BEV technologies can become cost-competitive in terms of
total cost of ownership for many HD vehicles by the late 2020s, but it
would take longer for FCEVs.392 393 394 Given that there are
more BEV models available today compared to FCEV models (see, e.g.,
DRIA Chapters 1.7.5 and 1.7.6), we inferred that BEV adoption is likely
to happen sooner than the adoption of FCEV technology.
---------------------------------------------------------------------------

    \392\ Ledna et. al. ``Decarbonizing Medium- & Heavy-Duty On-Road
Vehicles: Zero-Emission Vehicles Cost Analysis''. U.S. Department of
Energy, National Renewable Energy Laboratory. March 2022. Available
online: https://www.nrel.gov/docs/fy22osti/82081.pdf.
    \393\ Hall, Dale and Nic Lutsey. ``Estimating the Infrastructure
Needs and Costs for the Launch of Zero-Emission Trucks''. White
Paper: The International Council on Clean Transportation. August
2019. Available online: https://theicct.org/wp-content/uploads/2021/06/ICCT_EV_HDVs_Infrastructure_20190809.pdf.
    \394\ Robo, Ellen and Dave Seamonds. Technical Memo to
Environmental Defense Fund: Investment Reduction Act Supplemental
Assessment: Analysis of Alternative Medium- and Heavy-Duty Zero-
Emission Vehicle Business-As-Usual Scenarios. ERM. August 19, 2022.
Available online: https://www.erm.com/contentassets/154d08e0d0674752925cd82c66b3e2b1/edf-zev-baseline-technical-memo-addendum.pdf.
---------------------------------------------------------------------------

    Starting in MY 2030, we also considered FCEV technology for select
applications. BEV technology is more energy efficient than FCEV
technology but may not be suitable for all applications, such as when
the performance needs result in additional battery mass that affects
payload. FCEVs are more energy efficient than diesel vehicles and can
have shorter refueling times than BEVs with large
batteries.395 396 We considered FCEVs in the technology
packages for applications that travel longer distances and/or carry
heavier loads (i.e., for those that may be sensitive to refueling times
or payload impacts). This included coach buses, heavy-haul tractors,
sleeper cab tractors, and day cab tractors.
---------------------------------------------------------------------------

    \395\ A technology is more energy efficient if it uses less
energy to do the same amount of work. Energy can be lost as it moves
through the vehicle's components due to heat and friction.
    \396\ Cunanan, Carlo et. al. ``A Review of Heavy-Duty Vehicle
Powertrain Technologies: Diesel Engine Vehicles, Battery Electric
Vehicles, and Hydrogen Fuel Cell Electric Vehicles''. Clean Technol.
Available online: https://www.mdpi.com/2571-8797/3/2/28.
---------------------------------------------------------------------------

    Though fuel cell technology is still emerging in HD vehicle
applications, FCEVs are a viable ZEV technology for heavy-duty
transportation 397 398 399 and will be available in the 2030
timeframe (see DRIA Chapter 1.7.5).400 401 402 403 Inclusion
of FCEVs in the technology packages starting in MY 2030 takes into
consideration additional lead time to allow manufacturers to design,
develop, and manufacture HD FCEV models. Fuel cell technology in other
sectors has been in existence for decades \404\ and has been
demonstrated to be technically feasible in heavy-duty
transportation.\405\ Interim research and development (R&D) technical
targets and projects (see DRIA Chapter 1.7.7) are in place to
facilitate necessary improvements in the performance, durability, and
costs of hydrogen-fueled long-haul HD tractors in 2030.\406\ With
substantial federal investment in low-GHG hydrogen production (see DRIA
Chapter 1.3.2), we project that the price of hydrogen fuel will drop
enough by 2030 to make HD FCEVs cost-competitive with comparable ICE
vehicles for some duty cycles. Hydrogen infrastructure is expected to
need the additional time prior to MY 2030 to further develop, as
discussed in greater detail in DRIA Chapter 1.8,407 408 but
we expect the

refueling needs can be met by MY 2030.\409\ We also recognize that
regulations, like this proposed rule, can further incentivize
technology and refueling infrastructure development and deployment.
Therefore, we included FCEVs in our technology assessment beginning in
MY 2030, which is our best projection after considering the IRA
incentives related to hydrogen as a transportation fuel and FCEVs,
DOE's hydrogen assessments, and other information discussed here in
Section II and in DRIA Chapter 1.
---------------------------------------------------------------------------

    \397\ Mihelic, Rick et. al. ``Making Sense of Heavy-Duty
Hydrogen Fuel Cell Tractors''. North American Council for Freight
Efficiency. December 16, 2020. Available online: https://nacfe.org/research/electric-trucks/making-sense-of-heavy-duty-hydrogen-fuel-cell-tractors/.
    \398\ Cunanan, Carlo et. al. ``A Review of Heavy-Duty Vehicle
Powertrain Technologies: Diesel Engine Vehicles, Battery Electric
Vehicles, and Hydrogen Fuel Cell Electric Vehicles''. Clean Technol.
Available online: https://www.mdpi.com/2571-8797/3/2/28.
    \399\ Cullen et. al. ``New roads and challenges for fuel cells
in heavy-duty transportation.'' Nature Energy. March 25, 2021.
Available online: https://www.nature.com/articles/s41560-021-00775-z.
    \400\ For example, California's Advanced Clean Fleets Regulation
requires that 10 percent of sleeper cab tractors and specialty
vehicles must be zero-emission by 2030. We note that although our
technology package consider FCEVs for specific HD applications, a
diverse range of technologies may be used to comply with the
proposed performance-based standards.
    \401\ California Air Resources Board. ``Advanced Clean Fleets
Regulation Summary''. October 27, 2022. Available online: https://ww2.arb.ca.gov/resources/fact-sheets/advanced-clean-fleets-regulation-summary (ACF 2030 goals).
    \402\ Adler, Alan. ``Hyundai's Xcient positioned for instant US
fuel cell truck leadership''. FreightWaves. November 29, 2022.
Available online: https://www.freightwaves.com/news/hyundais-xcient-positioned-for-instant-us-fuel-cell-truck-leadership.
    \403\ GNA. ``State of Sustainable Fleet: 2022 Market Brief--Fuel
Cell Electric Miniguide''. 2022. Available online: https://www.stateofsustainablefleets.com/.
    \404\ U.S. Energy Information Administration. ``Hydrogen
explained: Use of hydrogen''. Last updated January 20, 2022.
Available online: https://www.eia.gov/energyexplained/hydrogen/use-of-hydrogen.php.
    \405\ Toyota. ``Toyota, Kenworth Prove Fuel Cell Electric Truck
Capabilities with Successful Completion of Truck Operations for
ZANZEFF Project''. September 22, 2022. Available online: https://pressroom.toyota.com/toyota-kenworth-prove-fuel-cell-electric-truck-capabilities-with-successful-completion-of-truck-operations-for-zanzeff-project/.
    \406\ Marcinkoski, Jason et. al. ``DOE Advanced Truck
Technologies: Subsection of the Electrified Powertrain Roadmap--
Technical Targets for Hydrogen-Fueled Long-Haul Tractor-Trailer
Trucks. October 31, 2019. Available online: https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf.
    \407\ U.S. Department of Energy. ``Pathways to Commercial
Liftoff: Clean Hydrogen''. March 2023. Available online: https://liftoff.energy.gov/wp-content/uploads/2023/03/20230320-Liftoff-Clean-H2-vPUB.pdf.
    \408\ The proposed rule projects that hydrogen consumption from
FCEVs will be a small proportion of total low-GHG hydrogen
production expected in 2030: from 1.3% in 2030 to 8.3% in 2032.
    \409\ U.S. Department of Energy. ``DOE National Clean Hydrogen
Strategy and Roadmap''. Draft September 2022. Available online:
https://www.hydrogen.energy.gov/pdfs/clean-hydrogen-strategy-roadmap.pdf.
---------------------------------------------------------------------------

    After considering operational characteristics and costs in 2021
dollars, we determined the payback period, which is the number of years
it would take to offset any incremental cost increase of a ZEV over a
comparable ICE vehicle. Lastly, technology adoption rates for BEVs or
FCEVs for the technology packages were selected based on the payback
period. We request comment on this approach and any supporting data on
the potential for these and additional technologies to be available in
the HD market in the MY 2027 through MY 2032 timeframe.
5. EPA's HD TRUCS Analysis Tool
    For this proposal, EPA developed an analysis tool, HD TRUCS, to
evaluate the design features needed to meet the energy and power
demands of various HD vehicle types when using ZEV technologies. The
overarching design and functionality of HD TRUCS is premised on
ensuring each of the 101 ZEV types could perform the same work as its
ICE counterpart. We did this by sizing the BEV and FCEV components such
that they could meet the driving demands based on the 90th percentile
daily VMT for each application, while also accounting for the HVAC and
battery thermal conditioning load requirements in hot and cold weather
and any PTO demands for the vehicle. Furthermore, we accounted for the
fact that the usable battery capacity is less than 100 percent and that
batteries deteriorate over time. We also sized the ZEV powertrains to
ensure that the vehicles would meet an acceptable level of acceleration
from a stop and be able to maintain a cruise speed while going up a
hill at six-percent grade. In this subsection, we discuss the primary
inputs used in HD TRUCS. Additional details on HD TRUCS can be found in
DRIA Chapter 2. We welcome comment on all aspects of HD TRUCS.
i. Vehicles Analyzed
    We developed inputs for 101 different vehicle types for our
assessment in HD TRUCS. This encompasses 22 different applications in
the HD vehicle market, as shown in Table II-3. These vehicles
applications are further differentiated by weight class, duty cycle,
and daily vehicle miles traveled (VMT) for each of these vehicle
applications into 101 vehicle types. These 101 vehicle types cover all
33 of the heavy-duty regulatory subcategories, as shown in DRIA Chapter
<IP_ADDRESS>. The initial list of HD TRUCS vehicles contained 87 vehicle
types and was based on work the Truck and Engine Manufacturers
Association (EMA) and California Air Resources Board (CARB) conducted
for CARB's ACT rule.\410\ We consolidated the list; eliminated some of
the more unique vehicles with small populations like mobile
laboratories; and assigned operational characteristics that correspond
to the Urban, Multi-Purpose, and Regional duty cycles used in GEM. We
also added additional vehicle types to reflect vehicle applications
that were represented in EPA's certification data. Chapter 2.1 of the
DRIA summarizes the 101 unique vehicle types represented in HD TRUCS
and how they are categorized, each with a vehicle identifier, vehicle
application, vehicle weight class, MOtor Vehicle Emission Simulator
(MOVES) SourceTypeID and RegClassID,\411\ and GEM duty cycle category.
We request comment on our approach, including our categorization of
vehicle types and applications in the data, and whether there are
additional specific vehicle types we should include in our assessment.
---------------------------------------------------------------------------

    \410\ California Air Resources Board, Appendix E: Zero Emission
Truck Market Assessment (2019), available at https://ww2.arb.ca.gov/sites/default/files/barcu/regact/2019/act2019/appe.pdf (last
accessed on Sept. 26, 2022).
    \411\ MOVES homepage: https://www.epa.gov/moves (last accessed
October 2022).

        Table II-3--HD Vehicle Applications Included in HD TRUCS
------------------------------------------------------------------------

-------------------------------------------------------------------------
Ambulance.
Box Truck.
Cement Mixer.
Coach Bus.
Dump Truck.
Fire Truck.
Flatbed/Stake Truck.
Port Drayage Tracto.
Refuse Truck.
RV.
School Bus.
Shuttle bus.
Snow Plow.
Step Van.
Street Sweeper.
Tanker Truck.
Tow Truck.
Tractor, Day Cab.
Tractor, Sleeper Cab.
Transit Bus.
Utility Truck.
Yard Tractor.
------------------------------------------------------------------------

    Heavy-duty vehicles are typically powered by a diesel-fueled
compression-ignition (CI) engine, though the heavy-duty market also
includes vehicles powered by gasoline-fueled spark-ignition (SI)
engines and alternative-fueled ICE. We selected diesel-powered ICE
vehicles as the baseline vehicle for the assessment in HD TRUCS in our
analysis because a diesel-fueled CI engine is broadly available for all
of the 101 vehicle types and are more efficient than SI engines.
Chapter 2.2 of the DRIA includes the details we developed for each of
the baseline vehicles, including the size of the engine and the
transmission type. This information was used to determine the weight
and the cost of the ICE powertrains.
    In the analysis, for MYs 2027 through 2029, we focused primarily on
BEV technology. Starting in MY 2030, we also considered FCEV technology
for select applications that travel longer distances and/or carry
heavier loads. This included coach buses, heavy-haul tractors, sleeper
cab tractors, and day cab tractors that are designed to travel longer
distances. We request comment on our approach that focuses primarily on
BEVs, which currently are more prevalent in the HD vehicle market, and
whether there are additional vehicle types that should be evaluated as
FCEVs along with BEVs.
ii. Vehicle Energy Demand
    Vehicles require energy to perform the work required of the
vehicle. This work includes driving, idling, and providing heating and
cooling; in addition, some vehicles require energy to operate
equipment. Vehicles with regenerative braking systems have the
opportunity to recover some of the kinetic energy that would otherwise
be lost during braking. There are a wide variety of energy demands
across the heavy-duty sector, depending on the vehicle's application.
For example, some vehicles, such as long-haul tractors, spend the vast

majority of the time driving, a fraction of the time idling, and
require heating and cooling of the cabin, but do not require operation
of additional equipment. A transit bus typically operates at low
speeds, so it requires less energy for driving than a long-haul
tractor, but requires more energy for heating or cooling due to its
large amount of interior cabin volume. Unlike ICE vehicles where the
cabin heating is often provided by excess heat from the main ICE, BEVs
do not have excess heat from an ICE to utilize in this manner and thus
require more energy than ICE vehicles to heat the cabin and additional
energy to manage the temperature of the batteries. As another example
of the wide variety of energy demands for HD vehicles, a utility truck,
also known as a bucket truck, may only drive a few miles to a worksite
while idling for the majority of the day and using energy to move the
bucket up and down. The power to run the separate equipment on ICE
vehicles is typically provided by a PTO from the main engine. In HD
TRUCS, we determined the daily energy demand for each of the 101
vehicle types by estimating both the baseline energy demands that are
similar regardless of the powertrain configuration and the energy
demands that vary by powertrain. The baseline energy includes energy at
the axle to move the vehicle, energy recovered from regenerative
braking energy, and PTO energy. Powertrain-specific energy includes
energy required to condition the battery and heat or cool the cabin
using a heating, ventilation, and air conditioning (HVAC) system. We
discuss each of these in the following subsections.
a. Baseline Energy
    The amount of energy needed at the axle to move the vehicle down
the road is determined by a combination of the type of drive cycle
(such as urban or freeway driving) and the number of miles traveled
over a period of time. For each HD TRUCS vehicle type, we determined
the baseline energy consumption requirement that would be needed for
each of the ZEV applications. To do this, we used the drive cycles and
cycle weightings adopted for HD GHG Phase 2 for our assessment of the
energy required per mile for each vehicle type. EPA's GEM model
simulates road load power requirements for various duty cycles to
estimate the energy required per mile for HD vehicles. To understand
the existing heavy-duty industry, we performed an analysis on current
heavy-duty vehicles in the market in order to determine typical power
requirements and rates of energy consumption at the axle. These values
represent the energy required to propel a vehicle of a given weight,
frontal area, and tire rolling resistance to complete the specified
duty cycle on a per-mile basis, independent of the powertrain. In DRIA
Chapter 2.2.2, we describe the GEM inputs and results used to estimate
the propulsion energy and power requirements at the axle for ICE
vehicles on a per-mile basis. We also used these inputs, along with
some simple electric vehicle assumptions, to develop a model for
electric vehicles to calculate weighted percent of energy recovery due
to regenerative braking. Additional detail can be found in DRIA Chapter
<IP_ADDRESS>.3. We request comment on our approach, including other data we
should consider in our assessment of energy consumption.
    Some vocational vehicles have attachments that perform work,
typically by powering a hydraulic pump, which are powered by PTOs.
Information on in-use PTO energy demand cycles is limited. NREL
published two papers describing investigative work into PTO usage and
fuel consumption.412 413 These studies, however, were
limited to electric utility vehicles, such as bucket trucks and
material handlers. To account for PTO usage in HD TRUCS, we chose to
rely on a table described in California's Diesel Tax Fuel Regulations,
specifically in Regulation 1432, ``Other Nontaxable Uses of Diesel Fuel
in a Motor Vehicle,'' \414\ that covers a wider range of vehicles
beyond the electric utility vehicles in the referenced NREL studies.
This table contains ``safe-harbor'' percentages that are presumed
amounts of diesel fuel used for ``auxiliary equipment'' operated from
the same fuel tank as the motor vehicle. We used this source to
estimate PTO energy use as a function of total fuel consumed by vehicle
type, as discussed in DRIA Chapter <IP_ADDRESS>.4. We request additional
data that could be considered in our assessment of PTO loads in our
final rulemaking assessment.
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    \412\ NREL, Characterization of PTO and Idle Behavior for
Utility Vehicles, Sept 2017. Available online: https://www.nrel.gov/docs/fy17osti/66747.pdf.
    \413\ NREL, Fuel and Emissions Reduction in Electric Power Take-
Off Equipped Utility Vehicles, June 2016. Available online: https://www.nrel.gov/docs/fy17osti/66737.pdf.
    \414\ See Cal. Code Regs. tit. 18, Sec.  1432, ``Other
Nontaxable Uses of Diesel Fuel in a Motor Vehicle,'' available at
https://www.cdtfa.ca.gov/lawguides/vol3/dftr/dftr-reg1432.html.
---------------------------------------------------------------------------

    Within HD TRUCS, we calculated the total energy needed daily based
on a daily VMT for each vehicle type. We used multiple sources to
develop the VMT for each vehicle. Daily VMT for each vehicle came from
one of five Sources: the NREL FleetDNA database, a University of
California-Riverside (UCR) database, the 2002 Vehicle Inventory and Use
Survey (VIUS), the CARB Large Entity Report, or an independent source
specific to an application, as discussed in DRIA Chapter <IP_ADDRESS>.\415\
Each vehicle type was assigned a 50th percentile or average daily VMT
\416\ that was used to estimate operational costs, such as average
annual fuel, hydrogen, or electricity costs, and maintenance and repair
costs (see DRIA Chapters 2.3.4, 2.4.4, and 2.5.3). We also account for
the change in use of the vehicle over the course of its ownership and
operation in HD TRUCS by applying a MOVES-based VMT ratio based on
vehicle age to the 50th percentile VMT to arrive at a 10 year average
VMT, as described in more detail in DRIA Chapter <IP_ADDRESS>.2. We also
developed a 90th percentile daily VMT and used it in HD TRUCS to size
ZEV components, such as batteries, and estimate the size requirements
for EVSE. We selected the 90th percentile daily VMT data because we
project that manufacturers will design their BEVs to meet most daily
VMT needs, but not the most extreme operations. BEVs designed for all
daily VMT needs would be unnecessarily heavy and expensive for most
operations, which would limit their appeal in the broad market. Please
see DRIA Chapter <IP_ADDRESS> for the complete list of VMT for each of the
101 vehicle types. We request comment, including comment with data, on
our VMT assessments.
---------------------------------------------------------------------------

    \415\ NREL and EPA. Heavy-Duty Vehicle Activity for EPA MOVES.
Available at https://data.nrel.gov/submissions/168, last accessed on
October 15, 2022, which includes an assessment of both the NREL and
UC-Riverside databases; U.S. Census Bureau. 2002 Vehicle Inventory
and Use Survey. https://www.census.gov/library/publications/2002/econ/census/vehicle-inventory-and-use-survey.html, last accessed on
October 15, 2022. CARB. Large Entity Reporting. Available at https://ww2.arb.ca.gov/our-work/programs/advanced-clean-trucks/large-entity-reporting.
    \416\ We used the 50th percentile as a proxy for average VMT
from the NREL FleetDNA database and the UC-Riverside database. The
NREL and UC-Riverside databases each contained a selection of
vehicles that we used to calculate 50th and 90th percentile daily
VMT. When each database had a VMT value, the values were averaged to
get VMT for a specific market segment. See DRIA Chapter <IP_ADDRESS> for
further details.
---------------------------------------------------------------------------

b. Powertrain-Specific Energy
    Heating, ventilation, and air conditioning (HVAC) requirements vary
by vehicle type, location, and duty cycle. The HVAC energy required to
heat and cool interior cabins is considered separately from the
baseline energy in HD TRUCS, since these energy loads are not required
year-round or in

all regions of the country. Nearly all commercial vehicles are equipped
with heat and basic ventilation and most vehicles are equipped with air
conditioning (A/C). In ICE vehicles, traditional cabin heating uses
excess thermal energy produced by the main ICE. This is the only source
of cabin heating for many vehicle types. Additionally, on ICE vehicles,
cabin A/C uses a mechanical refrigerant compressor that is engine belt-
driven.
    For BEVs, the energy required for thermal management is different
than for ICE vehicles. First, the loads for HVAC are different because
the vehicle is not able to be heated from excess heat from the engine.
In this analysis, we project HD BEVs would be equipped with either a
positive temperature coefficient (PTC) electric resistance heater with
traditional A/C, or a full heat pump system, as described in DRIA
Chapter 1. The vehicle's battery is used to power either system, but
heat pumps are many times more efficient than PTC heaters. Given the
success and increasing adoption of heat pumps in light-duty EVs, we
believe that heat pumps will be the more commonly used technology and
thus assume the use of heat pumps in HD TRUCS.
    To estimate HVAC energy consumption of BEVs in HD TRUCS, we
performed a literature and market review. Even though there are limited
real-world studies, we agreed with the HVAC modeling-based approach
described in Basma et. al.\417\ This physics-based cabin thermal model
considers four vehicle characteristics: the cabin interior, walls,
materials, and number of passengers. The authors modeled a Class 8
electric transit bus with an HVAC system consisting of two 20-kW
reversible heat pumps, an air circulation system, and a battery thermal
management system. We used their estimated HVAC power demand values as
a function of temperature, resembling a parabolic curve, where hotter
and colder temperatures require more power with the lowest power demand
between 59 to 77 [deg]F.
---------------------------------------------------------------------------

    \417\ Basma, Hussein, Charbel Mansour, Marc Haddad, Maroun
Nemer, Pascal Stabat. ``Comprehensive energy modeling methodology
for battery electric buses''. Energy: Volume 207, 15 September 2020,
118241. Available online: https://www.sciencedirect.com/science/article/pii/S0360544220313487.
---------------------------------------------------------------------------

    The power required for HVAC in HD TRUCS is based on a Basma et. al
study that determined the HVAC power demand across a range of ambient
temperatures.\418\ We created three separate ambient temperature bins:
one for heating (less than 55 [deg]F), one for cooling (greater than 80
[deg]F), and one for a temperature range that requires only ventilation
(55-80 [deg]F). In HD TRUCS, we already accounted for the energy loads
due to ventilation in the axle loads, so no additional energy
consumption is applied here for the ventilation-only operation. We then
weighted the power demands by the percent HD VMT traveled at a specific
temperature range. The results of the VMT-weighted HVAC power demand
for a Class 8 Transit Bus are shown in Table II-4. We request comment
on and data to support other approaches to quantify the HVAC energy
demand in BEVs, including the ambient temperature ranges where heating
and cooling are utilized.
---------------------------------------------------------------------------

    \418\ It should be noted that Basma model has discrete values in
Celsius and MOVES data has discrete values in Fahrenheit. The Basma
discrete values in the Basma model is fitted to a parabolic curve
and converted into Fahrenheit to best fit the VMT distribution that
is available in MOVES.

Table II-4--HD TRUCS VMT-Weighted HVAC Power Demand of a Class 8 Transit
                                   Bus
------------------------------------------------------------------------
                                            Temperature     Consumption
                                             ([deg]F)          (kW)
------------------------------------------------------------------------
Heating.................................             <55            5.06
Ventilation.............................           55-80            0.00
Cooling.................................             >80            3.32
------------------------------------------------------------------------

    Lastly, HVAC load is dependent on cabin size--the larger the size
of the cabin, the greater the HVAC demand. The values for HVAC power
demand shown in Table II-4 represent the power demand to heat or cool
the interior of a Class 8 Transit bus. However, HD vehicles have a
range of cabin sizes; therefore, we developed scaling ratios relative
to the cabin size of a Class 8 bus. Each vehicle's scaling factor is
based on the surface area of the vehicle compared to the surface area
of the Class 8 bus. For example, a Class 4-5 shuttle bus has a cabin
size ratio of 0.6, in this case, the heating demand for the vehicle
will be 3.04 kW and the cooling demand would be 1.99 kW. The adjustment
ratio for buses and ambulances are between 0.3-0.6, while the cabin
size for remaining HDVs have a similar cabin to a mid-size light duty
vehicle and therefore, a single average scaling factor of 0.2 was
applied to all remaining vehicle types.\419\ We welcome data to support
these or other cabin size scaling factors.
---------------------------------------------------------------------------

    \419\ The interior cabin where the driver and passengers sit are
heated while where the cargo is stored is not heated.
---------------------------------------------------------------------------

    Fuel cell stacks produce excess heat during the conversion of
hydrogen to electricity, similar to an ICE during combustion. This
excess heat can be used to heat the interior cabin of the vehicle. In
HD TRUCS, we already accounted for the energy loads due to ventilation
in the axle loads, so no additional energy consumption is applied to
FCEV for heating operation. Therefore, for FCEV energy consumption in
HD TRUCS, we only include additional energy requirements for air
conditioning (i.e. not for heating).\420\ As described in DRIA Chapter
<IP_ADDRESS>.1, we assigned a power demand of 3.32 kW for powering the air
conditioner on a Class 8 bus. The A/C loads are then scaled by the
cabin volume for other vehicle applications in HD TRUCS and applied to
the VMT fraction that requires cooling, just as we did for BEVs.
---------------------------------------------------------------------------

    \420\ FCEVs use waste heat from the fuel cell for heating, and
that ventilation operates the same as it does for an ICE vehicle.
---------------------------------------------------------------------------

    BEVs have thermal management systems to maintain battery core
temperatures within an optimal range of approximately 68 to 95 degrees
Fahrenheit (F).\421\ In HD TRUCS, we accounted for the battery thermal
management energy demands as a function of ambient temperature based on
a Basma et. al study.\422\ As described in DRIA Chapter <IP_ADDRESS>.3, we
determined the amount of energy consumed to heat the battery with cabin
air when it is cold outside (less than 55 [deg]F) and energy consumed
to cool the battery when it is hot outside (greater than 80 [deg]F)
with refrigerant cooling. For the ambient temperatures between these
two regimes, we agreed with Basma, et. al that only ambient air cooling
is required for the batteries, which requires no additional load. We
first determined a single VMT-weighted power consumption value for
battery heating and a value for battery cooling based on the MOVES HD
VMT distribution, based on the same method used for HVAC. Then, we
determined the energy required for battery conditioning required for
eight hours of daily operation and expressed it in terms of percent of
total battery size. Table II-5 shows the energy consumption for battery
conditioning for both hot and cold ambient temperatures, expressed as a
percentage of battery capacity, used in HD TRUCS. We request additional
data on the battery thermal management loads for HD BEVs.
---------------------------------------------------------------------------

    \421\ Basma, Hussein, Charbel Mansour, Marc Haddad, Maroun
Nemer, Pascal Stabat. ``Comprehensive energy modeling methodology
for battery electric buses''. Energy: Volume 207, 15 September 2020,
118241. Available online: https://www.sciencedirect.com/science/article/pii/S0360544220313487.
    \422\ Ibid.

           Table II-5--Battery Conditioning Energy Consumption
------------------------------------------------------------------------
                                              Ambient         Energy
                                            temperature     consumption
                                             ([deg]F)           (%)
------------------------------------------------------------------------
Battery Heating.........................             <55             1.9
Battery Cooling.........................             >80             4.2
------------------------------------------------------------------------

iii. BEV Component Sizing and Weight
    We used HD TRUCS to determine the size of two of the major
components in a BEV--the battery and the motor. The size of these
components is determined by the energy needs of the specific vehicle to
meet its daily operating requirements. In this subsection, we also
discuss our method to evaluate the payload and packaging impact of the
battery.
a. Battery
    First, in HD TRUCS, we based the size of the battery on the daily
demands on the vehicle to perform a day's work, based on the 90th
percentile VMT (sizing VMT). As described in the Vehicle Energy Demand
subsection, this daily energy consumption is a function of miles the
vehicle is driven and the energy it consumes because of: (1) moving the
vehicle per unit mile, including the impact of regenerative braking,
and PTO energy requirements and (2) battery conditioning and HVAC
energy requirements. Then we also accounted for the battery efficiency,
depth of discharge, and deterioration in sizing of the batteries for
BEVs in HD TRUCS.
    The daily energy consumption of each BEV in HD TRUCS is determined
by applying efficiency losses to energy consumption at the axle, as
described in DRIA Chapter <IP_ADDRESS>.3. We have accounted for these losses
in the battery, inverter, and e-motor before the remaining energy
arrives at the axle, as shown in Table II-6. We request comment,
including data, on our approach and the results for our assessment of
system efficiencies for HD BEV components.

                                                 Table II-6--BEV Component Efficiencies Used in HD TRUCS
--------------------------------------------------------------------------------------------------------------------------------------------------------
                        Component                           MY 2027 (%)     MY 2028 (%)     MY 2029 (%)     MY 2030 (%)     MY 2031 (%)     MY 2032 (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Battery.................................................              95              95              95              95              95              95
Inverter................................................            97.0            97.0            97.0            97.5            97.5            97.5
E-Motor.................................................            94.5            94.5            94.5            95.0            95.0            95.0
Total System Efficiency.................................              87              87              87              88              88              88
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Next, we oversized the battery to account separately for the
typical usable amount of battery and for battery deterioration over
time. We sized the battery limiting the battery to a maximum depth of
discharge of 80 percent, recognizing that manufacturers and users
likely would not allow the battery capacity to be depleted beyond 80
percent of original capacity. We also accounted for deterioration of
the battery capacity over time by oversizing the battery by 20 percent,
assuming only 80 percent of the battery storage is available throughout
its life. Therefore, the battery sizes we used in our assessment are
conservative because they could meet 100 percent of the daily operating
requirement using the 90th percentile VMT at the battery end of life.
This is described in greater detail in DRIA Chapter <IP_ADDRESS> and
<IP_ADDRESS>. We request comment on approach and results for the useable
battery range and battery deterioration for HD BEVs that we could
consider for our final rule analysis.
b. Motor
    We determined the size of the motor for each BEV based on the peak
power of the transient cycle and highway cruise cycles, the vehicle's
ability to meet minimum performance targets in terms of acceleration
rate of the vehicle, and the ability of the vehicle to maintain speed
going up a hill. As described in DRIA Chapter <IP_ADDRESS>, we estimated a
BEV motor's peak power needs to size the e-motor, after considering the
peak power required during the ARB transient cycle \423\ and
performance targets included in ANL's Autonomie model \424\ and in
Islam et al.,\425\ as indicated in Table II-7. We assigned the target
maximum time to accelerate a vehicle from stop to 30 mph and 60 mph
based on weight class of each vehicle. We also used the criteria that
the vehicle must be able to maintain a specified cruise speed while
traveling up a road with a 6 percent grade, as shown in Table II-7. In
the case of cruising at 6 percent grade, the road load calculation is
set at a constant speed for each weight class bin on a hill with a 6
percent incline. We determined the required power rating of the motor
as the greatest power required to drive the vehicle over the ARB
transient test cycle, at 55 mph and 65 mph constant cruise speeds, or
at constant speed at 6 percent grade, and then applied losses from the
e-motor. We request comment on our approach using these performance
targets.
---------------------------------------------------------------------------

    \423\ EPA uses three representative duty cycles for calculating
CO2 emissions in GEM: transient cycle and two highway
cruise cycles. The transient duty cycle was developed by the
California Air Resources Board (CARB) and includes no grade--just
stops and starts. The highway cruise duty cycles represent 55-mph
and 65-mph vehicle speeds on a representative highway. They use the
same road load profile but at different vehicle speeds, along with a
percent grade ranging from -5 percent to 5 percent.
    \424\ Islam, Ehsan Sabri. Ram Vijayagopal, Ayman Moawad, Namdoo
Kim, Benjamin Dupont, Daniela Nieto Prada, Aymeric Rousseau, ``A
Detailed Vehicle Modeling & Simulation Study Quantifying Energy
Consumption and Cost Reduction of Advanced Vehicle Technologies
Through 2050,'' Report to the U.S. Department of Energy, Contract
ANL/ESD-21/10, October 2021. See previous reports and analysis:
2021. Available online: https://vms.taps.anl.gov/research-highlights/u-s-doe-vto-hfto-r-d-benefits/.
    \425\ Islam, Ehsan Sabri, Ram Vijayagopal, Aymeric Rousseau. ``A
Comprehensive Simulation Study to Evaluate Future Vehicle Energy and
Cost Reduction Potential'', Report to the U.S. Department of Energy,
Contract ANL/ESD-22/6, October 2022. Available online: https://vms.taps.anl.gov/research-highlights/u-s-doe-vto-hfto-r-d-benefits/.

                                                           Table II-7--ANL Performance Targets
--------------------------------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Vocational
                                                                Tractors
--------------------------------------------------------------------------------------------------------------------------------------------------------
Weight Class Bin..................................            2b-3              4-5              6-7                8                7                8
0-30 mph Time (s).................................               7                8               16               20               18               20
0-60 mph Time (s).................................              25               25               50              100               60              100

Cruise Speed (mph) @ 6% grade.....................              65               55               45               25               30               30
--------------------------------------------------------------------------------------------------------------------------------------------------------

c. Battery Weight and Volume
    Performance needs of a BEV can result in a battery that is so large
or heavy that it impacts payload and, thus, potential work accomplished
relative to a comparable ICE vehicle. We determined the battery weight
and physical volume for each vehicle application in HD TRUCS using the
specific energy and energy density of the battery for each battery
capacity. As described in DRIA Chapter 2.4.2, to determine the weight
impact, we used battery specific energy, which measures battery energy
per unit of mass. While battery technologies have made tremendous
advancements in recent years, it is well known that current automotive
batteries add mass to the vehicle. Our values for the specific energy
of battery packs with lithium-ion cell chemistries are based on
Autonomie.\426\ The values we used in HD TRUCS are shown in Table II-8.
---------------------------------------------------------------------------

    \426\ Islam, Ehsan Sabri. Ram Vijayagopal, Ayman Moawad, Namdoo
Kim, Benjamin Dupont, Daniela Nieto Prada, Aymeric Rousseau, ``A
Detailed Vehicle Modeling & Simulation Study Quantifying Energy
Consumption and Cost Reduction of Advanced Vehicle Technologies
Through 2050,'' Report to the U.S. Department of Energy, Contract
ANL/ESD-21/10, October 2021. See previous reports and analysis:
2021. Available online: https://vms.taps.anl.gov/research-highlights/u-s-doe-vto-hfto-r-d-benefits/.

                                           Table II-8--Battery Pack-Level Specific Energy in HD TRUCS (Wh/kg)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                    Model year                            2027             2028             2029             2030             2031             2032
--------------------------------------------------------------------------------------------------------------------------------------------------------
Specific Energy (Wh/kg)...........................             199              203              208              213              218              223
--------------------------------------------------------------------------------------------------------------------------------------------------------

    To evaluate battery volume and determine the packaging space
required for each HD vehicle type, we used battery energy density. We
also estimated the battery's width using the wheelbase and frame
depths.
    Battery energy density (also referred to as volumetric energy
density) measures battery energy per unit of volume. This value was not
available as a part of the Autonomie; however, the overall trend of
energy density shows a linear correlation with specific energy. In this
analysis, we determined the energy density is 2.5 times that of
specific energy, as shown in Table II-9.

                                            Table II-9--Battery Pack Level Energy Density in HD TRUCS (Wh/L)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                       Model year                              2027            2028            2029            2030            2031            2032
--------------------------------------------------------------------------------------------------------------------------------------------------------
Specific Energy (Wh/L)..................................             496             508             521             533             545             557
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We request comment on our approach and results as well as comment
and data on current and projected levels of battery-specific energy and
battery-specific density values for HD vehicles.
    Heavy-duty vehicles are used to perform work, such as moving cargo
or carrying passengers. Consequently, heavy-duty vehicles are sensitive
to increases in vehicle weight and carrying volume. To take this into
account, we also evaluated BEVs in terms of the overall impact on
payload-carrying ability and battery packaging space. The results of
this analysis can be found in DRIA Chapters 2.4.2 and 2.8.1. We found
that the extra weight of the batteries for applications such as coach
buses and tractors that travel long distances could have an impact on
operations of these vehicles as BEVs. Therefore, for applications where
our analysis showed that BEVs impacted the payload capacity by over 30
percent, we assessed fuel cell technology. In this proposal we are
using a single technology package that supports the feasibility of the
proposed standards, but we recognize the potential of BEVs in the
applications where we evaluate FCEVs, as demonstrated by the
development of a long-haul battery electric tractor by Tesla.
iv. Charging Infrastructure for BEVs
    Charging infrastructure represents a key element required for HD
BEV operation. More charging infrastructure will be needed to support
the growing fleet of HD BEVs. This will likely consist of a combination
of (1) depot charging--with infrastructure installed in parking depots,
warehouses, and other private locations where vehicles are parked off-
shift (when not in use), and (2) en-route charging, which provides
additional electricity for vehicles during their operating hours.
    In draft RIA Chapters 2.6 and 2.7.7 we describe how we accounted
for charging infrastructure in our analysis of HD BEV technology
feasibility and adoption rates for MYs 2027-2032. For this analysis, we
estimate infrastructure costs associated with depot charging to fulfill
each BEV's daily charging needs off-shift with the appropriately sized
electrical vehicle supply equipment.\427\ This approach reflects our
expectation that many heavy-duty BEV owners will opt to purchase and
install EVSE at depots; accordingly, we explicitly account for all of
these upfront costs in our analysis. By contrast, we do not estimate
upfront hardware and installation costs for public and other en-route
electric charging infrastructure because the BEV charging needs are met
with depot charging in our analysis. Discussion of private sector
infrastructure investments and charging deployment projects is included
in DRIA Chapter 1.6.2. We request comment on this analytical approach.
---------------------------------------------------------------------------

    \427\ We sized EVSE to meet vehicles' daily electricity
consumption (kWh/day) based on the 90th percentile VMT.
---------------------------------------------------------------------------

    Vehicle owners with return-to-base operations who choose to install
depot charging equipment have many options from which to select. This
includes AC

or DC charging, power level, as well as the number of ports and
connectors per charging unit, connector type(s), communications
protocols, and additional features such as vehicle-to-grid capability
(which allows the vehicle to supply energy back to the grid). Many of
these selections will impact EVSE hardware and installation costs, with
power level as one of the most significant drivers of cost. While
specific cost estimates vary across the literature, higher-power
charging equipment is typically more expensive than lower-power units.
For this reason, we have chosen to evaluate infrastructure costs
separately for four different, common charging types in our depot
charging analysis: AC Level 2 (19.2 kW) and 50 kW, 150 kW, and 350 kW
DC fast charging (DCFC).
    How long a vehicle is off-shift and parked at a depot, warehouse,
or other home base each day is a key factor for determining which
charging type(s) could meet its needs. The amount of time available at
the depot for charging (dwell time) will depend on a vehicle's duty
cycle. For example, a school bus or refuse truck may be parked at a
depot in the afternoon and remain there until the following morning
whereas a transit bus may continue to operate throughout the evening.
Even for a specific vehicle, off-shift dwell times may vary between
weekends and weekdays, by season, or due to other factors that impact
its operation. The 101 vehicle types in our analysis span a wide range
of vehicle applications and duty cycles, and we expect their off-shift
dwell times at depots to vary accordingly. As described in DRIA Chapter
<IP_ADDRESS>, in order to better understand what an average depot dwell time
might look like, we examined a dataset with engine start and off times
for 564 commercial vehicles. We used the longest time the vehicle
engine was off each day as a rough proxy for depot dwell time, finding
the average across all 564 vehicles to be over 14 hours, with proxy
dwell times for most of the seven vehicle categories examined rounding
to 12 hours or longer. However, assigning specific dwell times for each
of the 101 vehicle types in our analysis is challenging due a lack of
comprehensive datasets on parking times and locations, and, as further
detailed in DRIA Chapter <IP_ADDRESS>, we acknowledge limitations in the
approach and dataset we examined. Given these uncertainties, we used an
off-shift dwell time for all vehicle types of 12 hours for the purpose
of selecting charging equipment at depots in our analysis.
v. FCEV Component Sizing
    To compare diesel-fueled HD ICE vehicles and HD FCEV technology
costs and performance in HD TRUCS, this section explains how we define
HD FCEVs based on the performance and use criteria in DRIA Chapter 2.2
(that we also used for HD BEVs, as explained in Section D.5.ii). We
determined the e-motor, fuel cell stack, and battery pack sizes to meet
the power requirements for each of the eight FCEVs represented in HD
TRUCS. We also estimated the size of the onboard fuel tank needed to
store the energy, in the form of hydrogen, required to meet typical
range and duty cycle needs. See DRIA Chapter 2.5 for further details.
We request comment, including data, on our approach and results from
our assessment of HD FCEV component sizing.
a. E-Motor
    As discussed in DRIA Chapter <IP_ADDRESS>, the electric motor (e-motor)
is part of the electric drive system that converts the electric power
from the battery or fuel cell into mechanical power to move the wheels
of the vehicle. In HD TRUCS, the e-motor was sized for a FCEV like it
was sized for a BEV--to meet peak power needs of a vehicle, which is
the maximum power to drive the ARB transient cycle, meet the maximum
time to accelerate from 0 to 30 mph, meet the maximum time to
accelerate from 0 to 60 mph, and maintain a set speed up a six-percent
grade. Additional power was added to account for e-motor efficiency
losses using the same e-motor efficiency losses calculated and applied
for BEVs, as discussed in DRIA Chapter <IP_ADDRESS>.3.
b. Fuel Cell Stack
    Vehicle power in a FCEV comes from a combination of the fuel cell
(FC) stack and the battery pack. The FC stack behaves like the internal
combustion engine of a hybrid vehicle, converting chemical energy
stored in the hydrogen fuel into useful work. The battery is charged by
power derived from regenerative braking, as well as excess power from
the FC stack. Some FCEVs are designed to primarily rely on the fuel
cell stack to produce the necessary power, with the battery exclusively
used to capture energy from regenerative braking. Other FCEVs are
designed to store more energy in a battery to meet demand during
situations of high-power need.428 429
---------------------------------------------------------------------------

    \428\ Note that ANL's analysis defines a fuel cell hybrid EV as
a battery-dominant vehicle with a large energy battery pack and a
small fuel cell, and a fuel cell EV as a fuel cell-dominant vehicle
with a large fuel cell and a smaller power battery. Ours is a
slightly different approach because we consider a fuel cell-dominant
vehicle with a battery with energy cells. We took this approach
because energy cell batteries are less expensive to manufacture than
power cell batteries.
    \429\ Islam, Ehsan Sabri, Ram Vijayagopal, Aymeric Rousseau. ``A
Comprehensive Simulation Study to Evaluate Future Vehicle Energy and
Cost Reduction Potential'', Report to the U.S. Department of Energy,
Contract ANL/ESD-22.6. October 2022. See Full report. Available
online: https://vms.taps.anl.gov/research-highlights/u-s-doe-vto-hfto-r-d-benefits/.
---------------------------------------------------------------------------

    While much of FCEV design is dependent on the use case of the
vehicle, manufacturers also balance the cost of components such as the
FC stack, the battery, and the hydrogen fuel storage tanks. For the
purposes of this HD TRUCS analysis, we focused on proton-exchange
membrane (PEM) fuel cells that use energy battery cells, where the fuel
cell and the battery were sized based on the demands of the vehicle. In
HD TRUCS, the fuel cell stack was sized either to reach the 90th
percentile of power required for driving the ARB transient cycle or to
maintain a constant highway speed of 75 mph. The 90th percentile power
requirement was used to size the fuel cells of vocational vehicles. For
sleeper and day cabs, the fuel cell was sized using the power required
to drive at 75 mph with 80,000-pound gross combined vehicle weight
(GCVW).
    To avoid undersizing the fuel cell stack, we applied efficiency
values to account for losses that take place before the remaining
energy arrives at the axle. The same battery and inverter efficiencies
from Table II-10 were used for the FCEV calculations. Fuel cell stack
efficiency losses are due to the conversion of onboard hydrogen to
electricity. The DOE technical targets for Class 8 long-haul tractor-
trailers are to reach 68 percent peak efficiency by around 2030 (this
is the interim target; the ultimate target is to reach 72 percent
efficiency).430 431 Table II-10 shows the fuel cell
efficiency values that we used for MYs 2027-2032 in HD TRUCS, which are
slightly more conservative yet include expected improvements over time.
We averaged the high-tech peak efficiency estimates with low-tech peak
efficiency estimates from ANL's 2022 Autonomie \432\ for 2025, 2030,
and 2035

for available vehicle types. We then linearly interpolated these
averaged values to calculate values for each year.
---------------------------------------------------------------------------

    \430\ According to DOE, ultimate targets are ``based on 2050
simple cost of ownership assumptions and reflects anticipated
timeframe for market penetration''.
    \431\ Marcinkoski, Jason et. al. ``DOE Advanced Truck
Technologies: Subsection of the Electrified Powertrain Roadmap--
Technical Targets for Hydrogen-Fueled Long-Haul Tractor-Trailer
Trucks. October 31, 2019. Available online: https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf.
    \432\ Islam, Ehsan Sabri, Ram Vijayagopal, Aymeric Rousseau. ``A
Comprehensive Simulation Study to Evaluate Future Vehicle Energy and
Cost Reduction Potential'', Report to the U.S. Department of Energy,
Contract ANL/ESD-22.6. October 2022. See Medium- and heavy-duty
vehicles (assumptions). Available online: https://vms.taps.anl.gov/research-highlights/u-s-doe-vto-hfto-r-d-benefits/.

                            Table II-10--FCEV Fuel Cell Efficiencies for MY 2027-2032
----------------------------------------------------------------------------------------------------------------
                   Component                     2027 (%)   2028 (%)   2029 (%)   2030 (%)   2031 (%)   2032 (%)
----------------------------------------------------------------------------------------------------------------
Fuel Cell.....................................      64.5       64.5       64.5       66.0       66.0       66.0
----------------------------------------------------------------------------------------------------------------

c. Battery Pack
    As described in DRIA Chapter <IP_ADDRESS>.3, in HD TRUCS, the battery
power accounts for the difference between the power demand of the e-
motor at any moment and the maximum power output of the fuel cell
stack. We sized the battery to meet these power needs in excess of the
fuel cell stack's capability only when the fuel cell cannot provide
sufficient power. In our analysis, the remaining power needs are
sustained for a duration of 10 minutes (e.g., to assist with a climb up
a steep hill).
d. Onboard Hydrogen Storage Tank
    A FCEV is re-fueled like a gasoline or diesel-fueled vehicle. We
determined the capacity of the onboard hydrogen energy storage system
using an approach like the BEV methodology for battery pack sizing in
DRIA Chapter <IP_ADDRESS>, but we based the amount of hydrogen needed on the
daily energy consumption needs of a FCEV.
    As described in DRIA Chapter <IP_ADDRESS>, we converted FCEV energy
consumption (kWh) into hydrogen weight using an energy content of 33.33
kWh per kg of hydrogen. In our analysis, 95 percent of the hydrogen in
the tank (``usable H2'') can be accessed. This is based on targets for
light-duty vehicles, where a 700-bar hydrogen fuel tank with a capacity
of 5.9 kg has 5.6 kg of usable hydrogen.\433\ Furthermore, we added an
additional 10 percent to the tank size in HD TRUCS to avoid complete
depletion of hydrogen from the tank.
---------------------------------------------------------------------------

    \433\ U.S. Department of Energy, US Drive. ``Target Explanation
Document: Onboard Hydrogen Storage for Light-Duty Fuel Cell
Vehicles''. 2017. Available online: https://www.energy.gov/sites/prod/files/2017/05/f34/fcto_targets_onboard_hydro_storage_explanation.pdf.
---------------------------------------------------------------------------

E. Technology, Charging Infrastructure, and Operating Costs

    In the following subsections, we first discuss BEV technology
(Section II.E.1) and associated EVSE technology costs (Section II.E.2)
and FCEV technology costs (Section II.E.3). DRIA Chapter 2.4.3. (for
BEVs) and DRIA Chapter 2.5.2 (for FCEVs) includes the cost estimates
for each of the 101 applications. We then discuss the Inflation
Reduction Act tax credits we quantified in our analysis in Section
II.E.4. Our assessment of operating costs including the fuel or
electricity costs, along with the maintenance and repair costs, are
presented in Section II.E.5. This subsection concludes with the overall
payback analysis in Section II.E.6. DRIA Chapter 2.8.2 includes the
vehicle technology costs, EVSE costs, operating costs, and payback
results for each of the 101 HD applications. The technology costs
aggregated into MOVES categories are also described in detail in DRIA
Chapter 3.1.
1. BEV Technology Costs
    The incremental cost of a BEV powertrain system is calculated as
the cost difference from the comparable vehicle powertrain with an ICE.
The ICE vehicle powertrain cost is a sum of the costs of the engine
(including the projected cost of the HD2027 standards), alternator,
gearbox (transmission), starter, torque converter, and final drive
system.
    Heavy-duty BEV powertrain costs consist of the battery, electric
motor, inverter, converter, onboard charger, power electronics
controller, transmission or gearbox, final drive, and any electrical
accessories. DRIA Chapter 2.4.3 contains additional detail on our cost
projections for each of these components. We request comment, including
additional data, on our analysis for consideration in the final rule
regarding current and projected BEV component costs.
    Battery costs are widely discussed in the literature because they
are a key driver of the cost of a HD electric vehicle. The per unit
cost of the battery, in terms of $/kWh, is the most common metric in
determining the cost of the battery as the final size of the battery
may vary significantly between different applications. The total
battery pack cost is a function of the per unit kWh cost and the size
(in terms of kWh) of the pack.
    There are numerous projections for battery costs and battery
pricing in the literature that cover a range of estimates. Sources do
not always clearly define what is included in their cost or price
projections, nor whether the projections reflect direct manufacturing
costs incurred by the manufacturer or the prices seen by the end-
consumer. Except as noted, the values in the literature we used were
developed prior to enactment of the Inflation Reduction Act. For
example, BloombergNEF presents battery prices that would reach $100 per
kWh in 2026.\434\ In 2021, ANL developed cost projections for heavy-
duty vehicle battery packs in their benefit analysis (BEAN) model, that
ranged from $225 per kWh to $175 per kWh in 2027 and drop to $150 per
kWh to $115 per kWh in 2035.\435\ In a recent update to BEAN, released
after the IRA was passed, ANL now projects heavy-duty battery pack
costs in the range of $95 per kWh to $128 per kWh in 2025 and a drop to
between $70 per kWh and $90 per kWh in 2035.\436\ The direct
manufacturing battery cost for MY 2027 used in HD TRUCS is based on a
literature review of costs of zero-emission truck components conducted
by the International Council on Clean Transportation (ICCT).\437\ As
described in detail in DRIA Chapter <IP_ADDRESS>, we considered this source
to be a comprehensive review of the literature at the time of the HD
TRUCS analysis for the cost of battery packs in the

absence of the IRA, which may mean that it presents higher costs than
will be realized with the incentives in the IRA, even when accounting
for the battery tax credit described in Section II.E.4. In 2025, the
average cost is estimated to be $163.50/kWh (2019$) and, in 2030, the
average cost is projected to fall to $100 (2019$). We applied a linear
interpolation of these values that yields an estimated cost of $138/kWh
(2019$) for MY 2027. We then projected the costs to MY 2032 by using an
EPA estimate of market learning related to battery production and the
respective reduction in battery costs over this period of time, as
shown in Table II-11. We request comment, including data, on our
approach and projections for battery pack costs for the heavy-duty
sector, including values that specifically incorporate the potential
impacts of the IRA.
---------------------------------------------------------------------------

    \434\ Bloomberg NEF. ``Battery Pack Prices Fall to an Average of
$132/kWh, But Rising Commodity Prices Start to Bite.'' November 30,
2021. https://about.bnef.com/blog/battery-pack-prices-fall-to-an-average-of-132-kwh-but-rising-commodity-prices-start-to-bite/.
    \435\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
August 2022).
    \436\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
December 2022).
    \437\ Sharpe, Ben and Hussein Basma. ``A meta-study of purchase
costs for zero-emission trucks''. The International Council on Clean
Transportation, Working Paper 2022-09 (February 2022). Available
online: https://theicct.org/publication/purchase-cost-ze-trucks-feb22/.

                     Table II-11--Direct Manufacturing Pack-Level Battery Costs in HD TRUCS
                                                     [2021$]
----------------------------------------------------------------------------------------------------------------
                  Model year                       2027       2028       2029       2030       2031       2032
----------------------------------------------------------------------------------------------------------------
Battery Cost ($/kWh)..........................       145        134        126        120        115        111
----------------------------------------------------------------------------------------------------------------

    Batteries are the most significant cost component for BEVs and the
IRA section 13502, ``Advanced Manufacturing Production Credit,'' has
the potential to significantly reduce the cost of BEVs whose batteries
are produced in the United States. As discussed in Section II.E.4, we
thus then also accounted for the IRA Advanced Manufacturing Production
Credit, which provides up to $45 per kWh tax credits (with specified
phase-out in calendar years (CYs) 2030-2033) for the production and
sale of battery cells and modules, and additional tax credits for
producing critical minerals such as those found in batteries, when such
components or minerals are produced in the United States and other
criteria are met.
    An electric drive (e-drive)--another major component of an electric
vehicle--includes the electric motor, an inverter, a converter, and
optionally, a transmission system or gearbox. The electric energy in
the form of direct current (DC) is provided from the battery; an
inverter is used to change the DC into alternating current (AC) for use
by the motor. The motor then converts the electric power into
mechanical or motive power to move the vehicle. Conversely, the motor
also receives AC from the regenerative braking, whereby the converter
changes it to DC to be stored in the battery. The transmission reduces
the speed of the motor through a set of gears to an appropriate speed
at the axle. An emerging trend is to replace the transmission and
driveline with an e-axle, which is an electric motor integrated into
the axle, e-axles are not explicitly covered in our cost analysis.\438\
We request data on e-axle costs that we could consider for the final
rule.
---------------------------------------------------------------------------

    \438\ E-axles are an emerging technology that have potential to
realize efficiency gains because they have fewer moving parts.
---------------------------------------------------------------------------

    Similar to the battery cost, there is a range of electric drive
cost projections available in the literature. One reason for the
disparity is differences across the literature is what is included in
each for the ``electric drive''; some cost estimates include only the
electric motor and others present a more integrated model of e-motor/
inverter/gearbox combination. As described in detail in DRIA Chapter
<IP_ADDRESS>.1, EPA's MY 2027 e-drive cost, shown in Table II-12, comes from
ANL's 2022 BEAN model and is a linear interpolation of the average of
the high- and low-tech scenarios for 2025 and 2030, adjusted to
2021$.\439\ We then calculated MY 2028-2032 values, also shown in Table
II-12, using an EPA estimate of market learning shown in DRIA Chapter
3.2.1. We welcome comment, including data, on our assessment of e-drive
costs.
---------------------------------------------------------------------------

    \439\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
December 2022).

                           Table II-12--E-Drive Direct Manufacturing Costs in HD TRUCS
                                                 [$/kW] [2021$]
----------------------------------------------------------------------------------------------------------------
                  Model year                       2027       2028       2029       2030       2031       2032
----------------------------------------------------------------------------------------------------------------
E-Drive Cost ($/kW)...........................        20         18         17         16         16         15
----------------------------------------------------------------------------------------------------------------

    Gearbox and final drive units are used to reduce the speed of the
motor and transmit torque to the axle of the vehicle. In HD TRUCS, the
final drive unit direct manufacturing cost is $1,500 per unit, based on
the ``Power Converter'' average cost in ANL's BEAN model.\440\ The cost
of the gearbox varies depending on the vehicle weight class and duty
cycle. In our assessment, all light heavy-duty BEVs would be direct
drive and have no transmission and therefore no cost, consistent with
ANL's BEAN model. We then mapped BEAN gearbox costs for BEVs to the
appropriate medium heavy-duty and heavy heavy-duty vehicles in HD
TRUCS. Gearbox and final drive costs for BEVs are in DRIA Chapter
<IP_ADDRESS>.
---------------------------------------------------------------------------

    \440\ Ibid.
---------------------------------------------------------------------------

    Power electronics are another electrification component (along with
batteries and motors) where a DC-DC converter transitions high battery
voltage to a common 12V level for auxiliary uses. EPA's power
electronics and electric accessories costs of $6,000 per unit came from
ANL's BEAN model.\441\ See DRIA Chapter <IP_ADDRESS>.2 for further details.
---------------------------------------------------------------------------

    \441\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
August 2022).
---------------------------------------------------------------------------

    When using a Level 2 charging plug, an on-board charger converts AC
power from the grid to usable DC power via an AC-DC converter. When
using a DC fast charger (DCFC), any AC-DC converter is bypassed, and
the high-voltage battery is charged directly. As further discussed in
DRIA Chapter <IP_ADDRESS>, EPA's on-board charger costs, as shown in Table
II-13, come from ANL's BEAN model and we averaged the low-tech and
high-tech values for 2025 and 2030, and then MY

2027 was linearly interpolated and adjusted to 2021$.\442\ We then
calculated the MY 2028-2032 costs using the learning curve shown in
DRIA Chapter 3.2.1.
---------------------------------------------------------------------------

    \442\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
August 2022).

                      Table II-13--On-Board Charger Direct Manufacturing Costs in HD TRUCS
                                                     [2021$]
----------------------------------------------------------------------------------------------------------------
                  Model year                       2027       2028       2029       2030       2031       2032
----------------------------------------------------------------------------------------------------------------
On-Board Charger Cost ($/unit)................        38         35         33         31         30         29
----------------------------------------------------------------------------------------------------------------

    The total upfront BEV direct manufacturing cost is the summation of
the per-unit cost of the battery, motor, power electronics, on-board
charger, gearbox, final drive, and accessories. The total direct
manufacturing technology costs for BEVs for each of the 101 vehicle
types in HD TRUCS can be found in DRIA Chapter <IP_ADDRESS> for MY 2027 and
MY 2032.
2. Charging Infrastructure Costs
    In our analysis of depot charging infrastructure costs, we account
for the cost to purchasers to procure both EVSE (which we refer to as
the hardware costs) as well as costs to install the equipment. These
installation costs typically include labor and supplies, permitting,
taxes, and any upgrades or modifications to the on-site electrical
service. We developed our EVSE cost estimates from the available
literature, as discussed in DRIA Chapter 2.6.
    Both hardware and installation costs could vary over time. For
example, hardware costs could decrease due to manufacturing learning
and economies of scale. Recent studies by ICCT assumed a 3 percent
reduction in hardware costs for EVSE per year to
2030.443 444 By contrast, installation costs could increase
due to growth in labor or material costs. Installation costs are also
highly dependent on the specifics of the site including whether
sufficient electric capacity exists to add charging infrastructure and
how much trenching or other construction is required. If fleet owners
choose to install charging stations at easier, and therefore, lower
cost sites first, then installation costs could rise over time as
stations are developed at more challenging sites. One of the ICCT
studies found that these and other countervailing factors could result
in the average cost of a 150 kW EVSE port in 2030 being similar (~3
percent lower) to that in 2021.\445\ After considering the uncertainty
on how costs may change over time, we keep the combined hardware and
installation costs per EVSE port constant. We request comment on this
approach.
---------------------------------------------------------------------------

    \443\ Minjares, Ray, Felipe Rodriguez, Arijit Sen, and Caleb
Braun. ``Infrastructure to support a 100% zero-emission tractor-
trailer fleet in the United States by 2040''. ICCT, September 2021.
Available online: https://theicct.org/sites/default/files/publications/ze-tractor-trailer-fleet-us-hdvs-sept21.pdf.
    \444\ Bauer, Gordon, Chih-Wei Hsu, Mike Nicholas, and Nic
Lutsey. ``Charging Up America: Assessing the Growing Need for U.S.
Charging Infrastructure Through 2030''. The International Council on
Clean Transportation, July 2021. Available online: https://theicct.org/wp-content/uploads/2021/12/charging-up-america-jul2021.pdf.
    \445\ Ibid.
---------------------------------------------------------------------------

    Our infrastructure analysis centered around four charging types for
heavy-duty depot charging. As shown in Table II-14, the EVSE costs we
used in our analysis range from about $10,000 for a Level 2 port to
over $160,000 for a 350 kW DCFC port. As described in Chapter 2.6, in
our analysis, we allow up to two vehicles to share one DCFC port if
there is sufficient depot dwell time for both vehicles to meet their
daily charging needs.\446\ In those cases, the EVSE costs per vehicle
are halved. We request comment, including data, on our approach and
assessment of current and future costs for charging equipment and
installation.
---------------------------------------------------------------------------

    \446\ We note that for some of the vehicle types we evaluated,
more than two vehicles could share a DCFC port and still meet their
daily electricity consumption needs. However, we choose to limit
sharing to two vehicles pending market developments and more robust
depot dwell time estimates.

 Table II-14--Combined Hardware and Installation EVSE Costs, per Vehicle
                                 [2021$]
------------------------------------------------------------------------
              Charging type                    Cost            Cost
------------------------------------------------------------------------
                                          (1 Vehicle per    (2 Vehicles
                                               port)         per port)
------------------------------------------------------------------------
Level 2 (19.2 kW).......................         $10,541  Not Applicable
DCFC-50 kW..............................          31,623         $15,811
DCFC-150 kW.............................          99,086          49,543
DCFC-350 kW.............................         162,333          81,166
------------------------------------------------------------------------

    EPA acknowledges that there may be additional infrastructure needs
and costs beyond those associated with charging equipment itself. While
planning for additional electricity demand is a standard practice for
utilities and not specific to BEV charging, the buildout of public and
private charging stations (particularly those with multiple high-
powered DC fast charging units) could in some cases require upgrades to
local distribution systems. For example, a recent study found power
needs as low as 200 kW could trigger a requirement to install a
distribution transformer.\447\ The use of onsite battery storage and
renewables may be able to reduce the need for some distribution
upgrades; station operators may also opt to install these to mitigate
demand charges associated with peak

power.\448\ However, there is considerable uncertainty associated with
future distribution upgrade needs, and in many cases, some costs may be
borne by utilities rather than directly incurred by BEV or fleet
owners. Therefore, we do not model them directly as part of our
infrastructure cost analysis. We welcome comments on this and other
aspects of our cost analysis.
---------------------------------------------------------------------------

    \447\ Borlaug, B., Muratori, M., Gilleran, M. et al, ``Heavy-
duty truck electrification and the impacts of depot charging on
electricity distribution systems,'' Nat Energy 6, 673-682 (2021).
Accessed on January 11, 2023, at https://doi.org/10.1038/s41560-021-00855-0.
    \448\ Matt Alexander, Noel Crisostomo, Wendell Krell, Jeffrey
Lu, Raja Ramesh,'' Assembly Bill 2127: Electric Vehicle Charging
Infrastructure Assessment,'' July 2021, California Energy
Commission. Accessed March 9, 2023, at https://www.energy.ca.gov/programs-and-topics/programs/electric-vehicle-charging-infrastructure-assessment-ab-2127.
---------------------------------------------------------------------------

    As discussed in Section V, we model changes to power generation due
to the increased electricity demand anticipated in the proposal as part
of our upstream analysis. We project the additional generation needed
to meet the demand of the heavy-duty BEVs in the proposal to be
relatively modest (as shown in DRIA Chapter 6.5). As the proposal is
estimated to increase electric power end use by heavy-duty electric
vehicles by 0.1 percent in 2027 and increasing to 2.8 percent in 2055.
The U.S. electricity end use between the years 1992 and 2021, a similar
number of years included in our proposal analysis, increased by around
25 percent \449\ without any adverse effects on electric grid
reliability or electricity generation capacity shortages. Grid
reliability is not expected to be adversely affected by the modest
increase in electricity demand associated with HD BEV charging.
---------------------------------------------------------------------------

    \449\ Annual Energy Outlook 2022, U.S. Energy Information
Administration, March 3, 2022 (https://www.eia.gov/outlooks/aeo/narrative/introduction/sub-topic-01.php).
---------------------------------------------------------------------------

    A GAO report noted that the private sector and the government share
responsibility for the reliability of the U.S. electric power grid. The
report stated, ``Most of the electricity grid--the commercial electric
power transmission and distribution system comprising power lines and
other infrastructure--is owned and operated by private industry.
However, Federal, state, local, Tribal, and territorial governments
also have significant roles in enhancing the resilience of the
electricity grid.'' \450\ For instance, at the Federal level, the
Department of Homeland Security (DHS) coordinates Federal efforts to
promote the security and reliability of the nation's energy sector; the
Department of Energy (DOE) leads Federal efforts including research and
technology development; and the Federal Energy Regulatory Commission
(FERC) regulates the interstate electricity transmission and is
responsible for reviewing and approving mandatory electric Reliability
Standards, which are developed by the North American Electric
Reliability Corporation (NERC).\451\ NERC is the federally designated
U.S. electric reliability organization which ``develops and enforces
Reliability Standards; annually assesses seasonal and long[hyphen]term
reliability; monitors the bulk power system through system awareness;
and educates, trains, and certifies industry personnel.'' \452\ These
efforts help to keep the U.S. electric power grid is reliable. We also
consulted with FERC and EPRI staff on bulk power system reliability and
related issues.
---------------------------------------------------------------------------

    \450\ Federal Efforts to Enhance Grid Resilience. General
Accounting Office, GAO-17-153, 1/25/2017. https://www.gao.gov/assets/gao-17-153.pdf.
    \451\ Electricity Grid Resilience. General Accounting Office,
GAO-21-105403, 9/20/2021, https://www.gao.gov/assets/gao-21-105403.pdf.
    \452\ North American Electric Reliability Corporation. ``About
NERC''. Available online: https://www.nerc.com/AboutNERC/Pages/default.aspx.
---------------------------------------------------------------------------

    U.S. electric power utilities routinely upgrade the nation's
electric power system to improve grid reliability and to meet new
electric power demands. For example, when confronted with rapid
adoption of air conditioners in the 1960s and 1970s, U.S. electric
power utilities successfully met the new demand for electricity by
planning and building upgrades to the electric power distribution
system. Likewise, U.S. electric power utilities planned and built
distribution system upgrades required to service the rapid growth of
power-intensive data centers and server farms over the past two
decades. U.S. electric power utilities have already successfully
designed and built the distribution system infrastructure required for
1.4 million battery electric vehicles.\453\ Utilities have also
successfully integrated 46.1 GW of new utility-scale electric
generating capacity into the grid.\454\
---------------------------------------------------------------------------

    \453\ U.S. DOE Alternative Fuels Data Center, Maps and Data--
Electric Vehicle Registrations by State, https://afdc.energy.gov/data/.
    \454\ EIA, ``Electric Power Annual 2021'', November 2022.
Available online: https://www.eia.gov/electricity/annual/html/epa_01_01.html.
---------------------------------------------------------------------------

    When taking into consideration ongoing upgrades to the U.S.
electric power grid, and that the U.S. electric power utilities
generally have more capacity to produce electricity than is
consumed,\455\ the expected increase in electric power demand
attributable to vehicle electrification is not expected to adversely
affect grid reliability due to the modest increase in electricity
demand associated with electric vehicle charging. The additional
electricity demand from HD BEVs will depend on the time of day that
charging occurs, the type or power level of charging, and the use of
onsite storage and vehicle-to-grid (V2G) or other vehicle-grid-
integration (VGI) technology, among other considerations, as discussed
in DRIA Chapter 1.6.4. As noted by Lipman et al.,\456\ a wide variety
of organizations are engaged in VGI research, including the California
Energy Commission,\457\ California Public Utilities Commission,\458\
California Independent System Operator,\459\ the Electric Power
Research Institute, as well as charging providers, utilities (e.g.,
SCE, PG&E, SDG&E), and automakers. Electric Island, a truck charging
station deployed by Daimler Trucks North America and Portland General
Electric which is planned to eventually include megawatt-level
charging, will offer an opportunity to test energy management and VGI
with heavy-duty BEVs. Future plans for Electric Island also include the
use of onsite solar generation and battery storage.\460\
---------------------------------------------------------------------------

    \455\ EIA, ``Electric Power Annual 2021'', November 2022.
Available online: https://www.eia.gov/electricity/annual/html/epa_01_01.html.
    \456\ Lipman, Timothy, Alissa Harrington, and Adam Langton.
2021. ``Total Charge Management of Electric Vehicles.'' California
Energy Commission.'' Publication Number: CEC-500-2021-055. Available
online: https://www.energy.ca.gov/sites/default/files/2021-12/CEC-500-2021-055.pdf.
    \457\ Chhaya, S., et al., ``Distribution System Constrained
Vehicle-to-Grid Services for Improved Grid Stability and
Reliability,'' Publication Number: CEC-500-2019-027, 2019. Available
online: https://www.energy.ca.gov/sites/default/files/2021-06/CEC-500-2019-027.pdf.
    \458\ Order Instituting Rulemaking to Continue the Development
of Rates and Infrastructure for Vehicle Electrification. California
Public Utilities Commission, Rulemaking 18-12-006, 12/21/2020.
    \459\ California Independent System Operator (CAISO),
``California Vehicle-Grid Integration (VGI) Roadmap: Enabling
vehicle-based grid services,'' February 2014.
    \460\ PGE, ``Daimler Trucks North America, Portland General
Electric open first-of-its-kind heavy-duty electric truck charging
site,'' April 21, 2021. Available online: https://portlandgeneral.com/news/2021-04-21-daimler-portland-general-electric-open-electric-charging-site.
---------------------------------------------------------------------------

    Finally, we note that DOE is engaged in multiple efforts to
modernize the grid and improve resilience and reliability. For example,
in November 2022, DOE announced $13 billion in funding opportunities
under the BIL to support transmission and distribution infrastructure.
This includes $3 billion for smart grid grants with a focus on PEV
integration among other topics.\461\
---------------------------------------------------------------------------

    \461\ DOE, ``Biden-Harris Administration Announces $13 Billion
to Modernize and Expand America's Power Grid,'' November 18, 2022.
Available online: https://www.energy.gov/articles/biden-harris-administration-announces-13-billion-modernize-and-expand-americas-power-grid.

---------------------------------------------------------------------------

3. FCEV Technology Costs
    FCEVs and BEVs include many of the same components such as a
battery pack, e-motor, power electronics, gearbox unit, final drive,
and electrical accessories. Therefore we used the same costs for these
components across vehicles used for the same applications; for detailed
descriptions of these components, see DRIA Chapter 2.4.3. In this
subsection and DRIA Chapter 2.5.2, we present the costs for components
for FCEVs that are different from a BEV. These components include the
fuel cell stack and hydrogen fuel tank. The same energy cell battery
costs used for BEVs are used for fuel cell vehicles, but the battery
size of a comparable FCEV is smaller. We request comment, including
data, on our approach and cost projections for FCEV components.
i. Fuel Cell Stack Costs
    The fuel cell stack is the most expensive component of a heavy-duty
FCEV. Fuel cells for the heavy-duty sector are expected to be more
expensive than fuel cells for the light-duty sector because they
operate at higher average continuous power over their lifespan, which
requires a larger fuel cell stack size, and because they have longer
durability needs (i.e., technology targets are for 25,000 to 30,000
hours for a truck versus 8,000 hours for cars).\462\
---------------------------------------------------------------------------

    \462\ Marcinkoski, Jason et. al. ``DOE Advanced Truck
Technologies: Subsection of the Electrified Powertrain Roadmap--
Technical Targets for Hydrogen-Fueled Long-Haul Tractor-Trailer
Trucks. October 31, 2019. Available online: https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf.
---------------------------------------------------------------------------

    Projected costs vary widely in the literature. They are expected to
decrease as manufacturing matures. Larger production volumes are
anticipated as global demand increases for fuel cell systems for HD
vehicles, which could improve economies of scale.\463\ Costs are also
anticipated to decline as durability improves, which could extend the
life of fuel cells and reduce the need for parts replacement.\464\
Burke et al. compared estimates from the literature and chose values of
$240 per kW in 2025 for a high case in their analysis, based on 1,000
heavy-duty fuel cell units produced per year, and $145 per kW for both
a low case in 2025 and a high case in 2030, based on 3,000 units
produced per year.\465\
---------------------------------------------------------------------------

    \463\ Deloitte China. ``Fueling the Future of Mobility: Hydrogen
and fuel cell solutions for transportation, Volume 1''. 2020.
Available online: https://www2.deloitte.com/content/dam/Deloitte/cn/Documents/finance/deloitte-cn-fueling-the-future-of-mobility-en-200101.pdf.
    \464\ Deloitte China. ``Fueling the Future of Mobility: Hydrogen
and fuel cell solutions for transportation, Volume 1''. 2020.
Available online: https://www2.deloitte.com/content/dam/Deloitte/cn/Documents/finance/deloitte-cn-fueling-the-future-of-mobility-en-200101.pdf.
    \465\ U.S. Department of Energy. ``DOE National Clean Hydrogen
Strategy and Roadmap''. Draft September 2022. Available online:
https://www.hydrogen.energy.gov/pdfs/clean-hydrogen-strategy-roadmap.pdf.
---------------------------------------------------------------------------

    The interim DOE cost target for Class 8 tractor-trailer fuel stacks
is $80 per kW by 2030. Their ultimate target is $60 per kW in 2050, set
to ensure that costs are comparable to those of advanced diesel engines
and other factors. These targets are based on 100,000 units per year
production volume. They pointed to analysis that suggests that 2019
costs at a manufacturing volume of 1,000 units per year were around
$190 per kW.\466\ In BEAN model updates, ANL estimated a range based on
vehicle type of between $156 per kW and $174 per kW in 2025, and from
$65 per kW to $99 per kW by 2035.\467\
---------------------------------------------------------------------------

    \466\ Marcinkoski, Jason et. al. ``DOE Advanced Truck
Technologies: Subsection of the Electrified Powertrain Roadmap--
Technical Targets for Hydrogen-Fueled Long-Haul Tractor-Trailer
Trucks. October 31, 2019. Available online: https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf. https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf.
    \467\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
December 2022).
---------------------------------------------------------------------------

    A Sharpe and Basma meta-study of other reports found 2025 costs
ranging from $750 per kW to $50 per kW. The authors stated that they
expect fuel cell costs to drop by about 30 percent between 2025 and
2030 due to manufacturer learning, improved materials and performance,
and economies of scale.\468\ Like the approach we took for BEV battery
costs, we averaged the 2025 cost values from the Sharpe and Basma meta-
study, averaged the 2030 values, and then linearly interpolated to get
MY 2027 values and adjusted to 2021$; we then applied the learning
curve shown in DRIA Chapter 3.2.1 to calculate MY 2028-2032 values. The
resulting fuel cell stack direct manufacturing costs are shown in Table
II-15.\469\
---------------------------------------------------------------------------

    \468\ Sharpe, Ben and Hussein Basma. ``A meta-study of purchase
costs for zero-emission trucks''. The International Council on Clean
Transportation, Working Paper 2022-09 (February 2022). Available
online: https://theicct.org/publication/purchase-cost-ze-trucks-feb22/.
    \469\ IRA section 13502 provides tax credits for 10 percent of
the cost of producing applicable critical materials, including those
found in fuel cells (providing that the minerals meet certain
specifications), when such components or minerals are produced in
the U.S. We did not include a detailed cost breakdown of fuel cells
quantitatively in our analysis, but the potential impact of the tax
credit on fuel cells may be significant because platinum (an
applicable critical mineral commonly used in fuel cells) is a major
contributor to the cost of fuel cells.

                           Table II-15--HD Fuel Cell Stack Direct Manufacturing Costs
                                                     [2021$]
----------------------------------------------------------------------------------------------------------------
                  Model year                       2027       2028       2029       2030       2031       2032
----------------------------------------------------------------------------------------------------------------
$/kW..........................................       242        223        210        200        192        185
----------------------------------------------------------------------------------------------------------------

ii. Hydrogen Fuel Tank Costs
    Hydrogen storage cost projections also vary widely in the
literature. Sharpe and Basma reported costs ranging from as high as
$1,289 per kg to $375 per kg of usable hydrogen in 2025. They expect
hydrogen tank costs to drop by 21 percent between 2025 and 2030 due to
lighter weight and lower cost carbon fiber-reinforced materials,
technology improvements, and economies of scale.\470\
---------------------------------------------------------------------------

    \470\ Sharpe, Ben and Hussein Basma. ``A meta-study of purchase
costs for zero-emission trucks''. The International Council on Clean
Transportation, Working Paper 2022-09 (February 2022). Available
online: https://theicct.org/publication/purchase-cost-ze-trucks-feb22/.
---------------------------------------------------------------------------

    The interim DOE target for Class 8 tractor-trailers is $300 per kg
of hydrogen by 2030. Their ultimate target is $266 per kg (2016$) by
2050. They include all components necessary to support the tank and are
based on a production volume of 100,000 tanks per year. They point to
analysis that suggests that 2019 costs for 700-bar tanks at a
manufacturing volume of 1,000 tanks per year were roughly $1,200 per
kg.\471\ For reference, the Kenworth ``beta'' fuel cell truck holds

six 10-kg hydrogen storage tanks at 700 bar.\472\
---------------------------------------------------------------------------

    \471\ Marcinkoski, Jason et al. ``DOE Advanced Truck
Technologies: Subsection of the Electrified Powertrain Roadmap--
Technical Targets for Hydrogen-Fueled Long-Haul Tractor-Trailer
Trucks. October 31, 2019. Available online: https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf.
    \472\ https://www.kenworth.com/media/voffdzok/ata-fuel-cell-flyer-08-25-2021-v2.pdf and https://www.greencarreports.com/news/1120765_toyota-and-kenworth-to-build-10-fuel-cell-semis-for-la-port-duty.
---------------------------------------------------------------------------

    Like the approach we took for battery and fuel cell stack costs, we
averaged all of the 2025 cost values in the Sharpe and Basma meta-
study, averaged all of the 2030 values, and then linearly interpolated
to determine the MY 2027 value, adjusted to 2021 dollars. We applied
the learning curve shown in DRIA Chapter 3.2.1 to calculate MY 2028-
2032 values. The hydrogen fuel tank direct manufacturing costs are
shown in Table II-16.

                           Table II-16--Hydrogen Fuel Tank Direct Manufacturing Costs
                                                     [2021$]
----------------------------------------------------------------------------------------------------------------
                                            MY 2027     MY 2028     MY 2029     MY 2030     MY 2031     MY 2032
----------------------------------------------------------------------------------------------------------------
$/kg H2.................................        801         738         694         660         634         612
----------------------------------------------------------------------------------------------------------------

4. Inflation Reduction Act Tax Credits
    The IRA,\473\ which was signed into law on August 16, 2022,
includes a number of provisions relevant to vehicle electrification.
There are two provisions of the IRA we included within our quantitative
analysis in HD TRUCS. First, Section 13502, ``Advanced Manufacturing
Production Credit,'' provides up to $45 per kWh tax credits for the
production and sale of battery cells and modules when such components
are produced in the United States and other qualifications are met.
Second, Section 13403, ``Qualified Commercial Clean Vehicles,''
provides for a vehicle tax credit applicable to HD vehicles if certain
qualifications are met. Beyond these two tax credits described in
sections 13403 and 13502 of the IRA, there are numerous provisions in
the IRA and the BIL \474\ that may impact HD vehicles and increase
adoption of HD ZEV technologies. These range from tax credits across
the supply chain, to grants which may help direct ZEVs to communities
most burdened by air pollution, to funding for programs to build out
electric vehicle charging infrastructure, as described in Section I of
this preamble and DRIA Chapter 1.3.2. We welcome comment on our
assessment of how the IRA will impact the heavy-duty industry, and how
EPA could consider reflecting those impacts in our assessment for
establishing the HD GHG standards under this proposal, including
comment on methods to appropriately account for these provisions in our
assessment.
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    \473\ Inflation Reduction Act of 2022, Public Law 117-169, 136
Stat. 1818 (2022) (``Inflation Reduction Act'' or ``IRA''),
available at https://www.congress.gov/117/bills/hr5376/BILLS-117hr5376enr.pdf.
    \474\ United States, Congress. Public Law 117-58. Infrastructure
Investment and Jobs Act of 2021. Congress.gov, www.congress.gov/bill/117th-congress/house-bill/3684/text. 117th Congress, House
Resolution 3684, passed 15 Nov. 2021.
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    Regarding the first of the two provisions, IRA section 13502,
``Advanced Manufacturing Production Credit,'' provides up to $45 per
kWh tax credits for the production and sale of battery cells (up to $35
per kWh) and modules (up to $10 per kWh) and 10 percent of the cost of
producing critical minerals such as those found in batteries, when such
components or minerals are produced in the United States and other
qualifications are met. These credits begin in CY 2023 and phase down
starting in CY 2030, ending after CY 2032. As further discussed in DRIA
Chapter <IP_ADDRESS>, we recognize that there are currently few
manufacturing plants for HD vehicle batteries in the United States. We
expect that the industry will respond to this tax credit incentive by
building more domestic battery manufacturing capacity in the coming
years, in part due to the BIL and IRA. For example, Proterra recently
announced its first heavy-duty battery manufacturing plant in the
United States,\475\ Tesla is expanding its facilities in Nevada to
produce its Semi BEV tractor and battery cells,\476\ and Cummins has
entered into an agreement with Arizona-based Sion Power to design and
supply battery cells for commercial electric vehicle applications.\477\
In addition, DOE is funding through the BIL battery materials
processing and manufacturing projects to ``support new and expanded
commercial-scale domestic facilities to process lithium, graphite and
other battery materials, manufacture components, and demonstrate new
approaches, including manufacturing components from recycled
materials.'' \478\ Thus, we model this tax credit in HD TRUCS such that
HD BEV and FCEV manufacturers fully utilize the battery module tax
credit and gradually increase their utilization of the cell tax credit
for MY 2027-2029 until MY 2030 and beyond, when they earn 100 percent
of the available cell and module tax credits. The battery pack costs
and battery tax credits used in our analysis are shown in Table II-17.
We request comment on our approach to modeling this tax credit,
including our projection that the full value of the tax credit earned
by the manufacturer is passed through to the purchaser because market
competition would drive manufacturers to minimize their prices.
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    \475\ Proterra. ``First Proterra Powered commercial EV battery
produced at new Powered 1 battery factory''. January 12, 2023.
Available online: https://www.proterra.com/press-release/first-battery-at-powered1-factory/.
    \476\ Sriram, Akash, Aditya Soni, and Hyunjoo Jin. ``Tesla plans
$3.6 bln Nevada expansion to make Semi truck, battery cells.''
Reuters. January 25, 2023. Last accessed on March 31, 2023 at
https://www.reuters.com/markets/deals/tesla-invest-over-36-bln-nevada-build-two-new-factories-2023-01-24/.
    \477\ Sion Power. ``Cummins Invests in Sion Power to Develop
Licerion[supreg] Lithium Metal Battery Technology for Commercial
Electric Vehicle Applications''. November 30, 2021. Available
online: https://sionpower.com/2021/cummins-invests-in-sion-power-to-develop-licerion-lithium-metal-battery-technology-for-commercial-electric-vehicle-applications/.
    \478\ U.S. Department of Energy. ``Bipartisan Infrastructure
Law: Battery Materials Processing and Battery Manufacturing &
Recycling Funding Opportunity Announcement--Factsheets''. October
19, 2022. Available online: https://www.energy.gov/sites/default/files/2022-10/DOE%20BIL%20Battery%20FOA-2678%20Selectee%20Fact%20Sheets%20-%201_2.pdf.

           Table II-17--Pack-Level Battery Direct Manufacturing Costs and IRA Tax Credits in HD TRUCS
                                                     [2021$]
----------------------------------------------------------------------------------------------------------------
                  Model year                       2027       2028       2029       2030       2031       2032
----------------------------------------------------------------------------------------------------------------
Battery Pack Cost ($/kWh).....................        145        134        126        120        115        111

IRA Cell Credit ($/kWh).......................       8.75      17.50      26.25      26.25      17.50       8.75
IRA Module Credit ($/kWh).....................      10.00      10.00      10.00       7.50       5.00       2.50
IRA Total Battery Credit ($/kWh)..............      18.75      27.50      36.25      33.75      22.50      11.25
Battery Pack Cost Less IRA Total Battery           126.25     106.50      89.75      86.25      92.50      99.75
 Credit ($/kWh)...............................
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    Regarding the second of the two provisions, IRA section 13403
creates a tax credit applicable to each purchase of a qualified
commercial clean vehicle. These vehicles must be on-road vehicles (or
mobile machinery) that are propelled to a significant extent by a
battery-powered electric motor. The battery must have a capacity of at
least 15 kWh (or 7 kWh if it is Class 3 or below) and must be
rechargeable from an external source of electricity. This limits the
qualified vehicles to BEVs and plug-in hybrid electric vehicles
(PHEVs). Additionally, fuel cell electric vehicles (FCEVs) are
eligible. The credit is available from calendar year (CY) 2023 through
2032, which overlaps with the model years for which we are proposing
standards (MYs 2027 through 2032), so we included the tax credit in our
calculations for each of those years in HD TRUCS.
    For BEVs and FCEVs, the tax credit is equal to the lesser of: (A)
30 percent of the BEV or FCEV cost, or (B) the incremental cost of a
BEV or FCEV when compared to a comparable ICE vehicle. The limit of
this tax credit is $40,000 for Class 4-8 commercial vehicles and $7,500
for commercial vehicles Class 3 and below. For example, if a BEV costs
$350,000 and a comparable ICE vehicle costs $150,000,\479\ the tax
credit would be the lesser of: (A) 0.30 x $350,000 = $105,000 or (B)
$350,000 - $150,000 = $200,000. In this example, (A) is less than (B),
but (A) exceeds the limit of $40,000, so the tax credit would be
$40,000.
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    \479\ Sharpe, B., Basma, H. ``A meta-study of purchase costs for
zero-emission trucks''. International Council on Clean
Transportation. February 17, 2022. Available online: https://theicct.org/wp-content/uploads/2022/02/purchase-cost-ze-trucks-feb22-1.pdf.
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    We included this tax credit in HD TRUCS by decreasing the
incremental upfront cost a vehicle purchaser must pay for a ZEV
compared to a comparable ICE vehicle following the process explained in
the previous paragraph. The calculation for this tax credit was done
after applying a retail price equivalent to our direct manufacturing
costs. We did not calculate the full cost of vehicles in our analysis,
instead we determined that all Class 4-8 ZEVs could be eligible for the
full $40,000 (or $7,500 for ZEVs Class 3 and below) if the incremental
cost calculated compared to a comparable ICE vehicle was greater than
that amount. In order for this determination to be true, all Class 4-8
ZEVs must cost more than $133,333 such that 30 percent of the cost is
at least $40,000 (or $25,000 and $7,500, respectively, for ZEVs Class 3
and below), which seems reasonable based on our assessment of the
literature.\480\ As in the calculation described in the previous
paragraph, both (A) and (B) are greater than the tax credit limit and
the vehicle purchaser may receive the full tax credit. The incremental
cost of a ZEV taking into account the tax credits for each vehicle
segment in MY 2027 and MY 2032 are included in DRIA Chapter 2.8.2. We
welcome comment on how we included the IRA tax credits for HD vehicles
in our assessment.
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    \480\ Burnham, A., Gohlke, D., Rush, L., Stephens, T., Zhou, Y.,
Delucchi, M.A., Birky, A., Hunter, C., Lin, Z., Ou, S., Xie, F.,
Proctor, C., Wiryadinata, S., Liu, N., Boloor, M. ``Comprehensive
Total Cost of Ownership Quantification for Vehicles with Different
Size Classes and Powertrains''. Argonne National Laboratory. April
1, 2021. Available at https://publications.anl.gov/anlpubs/2021/05/167399.pdf.
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5. Operating Costs
    Operating costs for HD vehicles encompass a variety of costs, such
as labor, insurance, registration fees, fueling, maintenance and repair
(M&R), and other costs. For this analysis, we are primarily interested
in costs that would differ for a comparable diesel-powered ICE vehicle
and a ZEV.\481\ These operational cost differences are used to
calculate an estimated payback period in HD TRUCS. We expect fueling
costs and M&R costs to be different for ZEVs than for comparable
diesel-fueled ICE vehicles, but we do not anticipate other operating
costs, such as labor and insurance, to differ significantly, so the
following subsections focus on M&R and fueling costs. Operating costs
are averaged over a 10-year time period of the annual M&R cost and
annual fuel cost.
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    \481\ For diesel-fueled ICE vehicles, we also estimated the cost
of the diesel exhaust fluid (DEF) required for the selective
catalytic reduction aftertreatment system. See DRIA Chapter <IP_ADDRESS>
for DEF costs.
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i. Maintenance and Repair Costs
    M&R costs contribute to the overall operating costs for HD
vehicles. To establish a baseline cost for maintenance and repair of
diesel-fueled ICE vehicles, we relied on the research compiled by
Burnham et al. and used equations found in the ANL's BEAN
model.482 483 Burnham et al. used data from Utilimarc and
the American Transportation Research Institute (ATRI) to estimate
maintenance and repair costs per mile for multiple heavy-duty vehicle
categories over time. We selected the box truck curve to represent
vocational vehicles and short-haul tractors, and the semi-tractor curve
to represent long-haul tractors.\484\ Additional details regarding this
analysis can be found in DRIA Chapter <IP_ADDRESS>. Averaging the M&R costs
for years 0-9 yields about 67 cents per mile for vocational vehicles
and short-haul tractors and about 25 cents per mile for long-haul
tractors, after adjusting to 2021$. We welcome comment, including
additional data, on our approach and assessment of HD ICE vehicle M&R
costs.
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    \482\ Burnham, A., Gohlke, D., Rush, L., Stephens, T., Zhou, Y.,
Delucchi, M.A., Birky, A., Hunter, C., Lin, Z., Ou, S., Xie, F.,
Proctor, C., Wiryadinata, S., Liu, N., Boloor, M. ``Comprehensive
Total Cost of Ownership Quantification for Vehicles with Different
Size Classes and Powertrains''. Argonne National Laboratory. Chapter
3.5.5. April 1, 2021. Available at https://publications.anl.gov/anlpubs/2021/05/167399.pdf.
    \483\ Argonne National Lab, Vehicle & Mobility Systems Group,
BEAN, found at: https://vms.taps.anl.gov/tools/bean/ (accessed
August 2022).
    \484\ Short haul tractors and vocational vehicles are
represented by the same M&R equation because they have duty cycles
and annual VMT that are similar.
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    Data on real-world M&R costs for HD ZEVs is limited due to limited
HD ZEV technology adoption today. We expect the overall maintenance
costs to be lower for ZEVs compared to a comparable ICE vehicles for
several reasons. First, an electric powertrain has fewer moving parts
that accrue wear or need regular adjustments. Second, ZEVs do not
require fluids such as engine oil or diesel exhaust fluid (DEF), nor do
they require exhaust filters to reduce

particulate matter or other pollutants. Third, the per-mile rate of
brake wear is expected to be lower for ZEVs due to regenerative braking
systems. Several literature sources propose applying a scaling factor
to diesel vehicle maintenance costs to estimate ZEV maintenance
costs.485 486 487 We followed this approach and applied a
maintenance and repair cost scaling factor of 0.71 for BEVs and 0.75
for FCEVs to the maintenance and repair costs of diesel-fueled ICE
vehicles. The scaling factors are based on an analysis from Wang et al.
that estimates a future BEV heavy-duty truck would have a 29 percent
reduction, and a future FCEV heavy-duty vehicle would have a 25 percent
reduction, compared to a diesel-powered heavy-duty
vehicle.488 489 We welcome comment on our approach and these
projections.
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    \485\ Burnham, A., Gohlke, D., Rush, L., Stephens, T., Zhou, Y.,
Delucchi, M.A., Birky, A., Hunter, C., Lin, Z., Ou, S., Xie, F.,
Proctor, C., Wiryadinata, S., Liu, N., Boloor, M. ``Comprehensive
Total Cost of Ownership Quantification for Vehicles with Different
Size Classes and Powertrains''. Argonne National Laboratory. April
1, 2021. Available online: https://publications.anl.gov/anlpubs/2021/05/167399.pdf.
    \486\ Hunter, Chad, Michael Penev, Evan Reznicek, Jason
Lustbader, Alicia Birkby, and Chen Zhang. ``Spatial and Temporal
Analysis of the Total Cost of Ownership for Class 8 Tractors and
Class 4 Parcel Delivery Trucks''. National Renewable Energy Lab.
September 2021. Available online: https://www.nrel.gov/docs/fy21osti/71796.pdf.
    \487\ Burke, Andrew, Marshall Miller, Anish Sinha, et. al.
``Evaluation of the Economics of Battery-Electric and Fuel Cell
Trucks and Buses: Methods, Issues, and Results''. August 1, 2022.
Available online: https://escholarship.org/uc/item/1g89p8dn.
    \488\ Wang, G., Miller, M., and Fulton, L.'' Estimating
Maintenance and Repair Costs for Battery Electric and Fuel Cell
Heavy Duty Trucks, 2022. Available online: https://escholarship.org/content/qt36c08395/qt36c08395_noSplash_589098e470b036b3010eae00f3b7b618.pdf?t=r6zwjb.
    \489\ Burnham, A., Gohlke, D., Rush, L., Stephens, T., Zhou, Y.,
Delucchi, M.A., Birky, A., Hunter, C., Lin, Z., Ou, S., Xie, F.,
Proctor, C., Wiryadinata, S., Liu, N., Boloor, M. ``Comprehensive
Total Cost of Ownership Quantification for Vehicles with Different
Size Classes and Powertrains''. Argonne National Laboratory. April
1, 2021. Available online: https://publications.anl.gov/anlpubs/2021/05/167399.pdf.
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    In our payback analysis in HD TRUCS, we did not account for
potential diesel engine rebuild costs for ICE vehicles, potential
replacement battery costs for BEVs, or potential replacement fuel cell
stack costs for FCEVs because our payback analysis typically covers a
shorter period of time than the expected life of these components.
Typical battery warranties being offered by HD BEV manufacturers range
between 8 and 15 years today.\490\ A BEV battery replacement may be
practically necessary over the life of a vehicle if the battery
deteriorates to a point where the vehicle range no longer meets the
vehicle's operational needs. We believe that proper vehicle and battery
maintenance and management can extend battery life. For example,
manufacturers will utilize battery management system to maintain the
temperature of the battery \491\ as well active battery balancing to
extend the life of the battery.492 493 Likewise, pre-
conditioning has also shown to extend the life of the battery as
well.\494\ Furthermore, research suggests that battery life is expected
to improve with new batteries over time as battery chemistry and
battery charging strategies improve, such that newer MY BEVs will have
longer battery life. We request comment on this approach for both ICE
vehicles and ZEVs, in addition to data on battery and fuel stack
replacement costs, engine rebuild costs, and expected component
lifetime periods.
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    \490\ Type C BEV school bus battery warranty range five to
fifteen years according to https://www.nyapt.org/resources/Documents/WRI_ESB-Buyers-Guide_US-Market_2022.pdf. The Freightliner
electric walk-in van includes an eight year battery warranty
according to https://www.electricwalkinvan.com/wp-content/uploads/2022/05/MT50e-specifications-2022.pdf.
    \491\ Basma, Hussein, Charbel Mansour, Marc Haddad, Maroun
Nemer, Pascal Stabat. ``Comprehensive energy modeling methodology
for battery electric buses''. Energy: Volume 207, 15 September 2020,
118241. Available online: https://www.sciencedirect.com/science/article/pii/S0360544220313487.
    \492\ Bae, SH., Park, J.W., Lee, S.H. ``Optimal SOC Reference
Based Active Cell Balancing on a Common Energy Bus of Battery''
Available online: http://koreascience.or.kr/article/JAKO201709641401357.pdf.
    \493\ Azad, F.S., Ahasan Habib, A.K.M., Rahman, A., Ahmed I.
``Active cell balancing of Li-Ion batteries using single capacitor
and single LC series resonant circuit.'' https://beei.org/index.php/EEI/article/viewFile/1944/1491.
    \494\ ``How to Improve EV Battery Performance in Cold Weather''
Accessed on March 31, 2023. https://www.worktruckonline.com/10176367/how-to-improve-ev-battery-performance-in-cold-weather.
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ii. Fuel, Electricity, and Hydrogen Costs
    The annual fuel cost for operating a diesel-fueled ICE vehicle is a
function of its yearly fuel consumption and the cost of diesel fuel.
The yearly fuel consumption is described in DRIA Chapter <IP_ADDRESS>. We
used the DOE Energy Information Administration's (EIA) Annual Energy
Outlook (AEO) 2022 transportation sector reference case projection for
diesel fuel for on-road use for diesel prices.\495\ This value includes
Federal and State taxes but excludes county and local taxes. The
average annual fuel cost is averaged over a 10-year period.
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    \495\ U.S. Energy Information Administration. Annual Energy
Outlook 2022. Last accessed on 9/28/2022 at https://www.eia.gov/
outlooks/aeo/data/browser/#/?id=3-
AEO2022&cases=ref2022~highmacro~lowmacro~highprice~lowprice~highogs~l
owogs~hirencst~lorencst~aeo2019ref&sourcekey=0.
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    The annual electricity cost for operating a HD electric vehicle is
a function of the electricity price, daily energy consumption of the
vehicle, and number of operating days in a year. In HD TRUCS, we used
the DOE EIA AEO 2022 reference case commercial electricity end-use rate
projection.\496\ We selected this value instead of the transportation
end use prices in AEO because those are similar to the prices for the
residential sector, which implies they may be more relevant to light-
duty vehicle charging than commercial truck charging.
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    \496\ U.S. Department of Energy, Energy Information
Administration. Annual Energy Outlook 2022, Table 8: Electricity
Supply, Disposition, Prices, and Emissions. September 21, 2022.
Available online: https://www.eia.gov/outlooks/aeo/data/browser/#/?id=8-AEO2022&cases=ref2022&sourcekey=0.
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    For the purposes of the HD TRUCS analysis, rather than focusing on
depot hydrogen fueling infrastructure costs that would be incurred
upfront, we included infrastructure costs in our per-kilogram retail
price of hydrogen. The retail price of hydrogen is the total price of
hydrogen when it becomes available to the end user, including the costs
of production, distribution, storage, and dispensing at a fueling
station. This price per kilogram of hydrogen includes the amortization
of the station capital costs. This approach is consistent with the
method we use in HD TRUCS for ICE vehicles, where the equivalent diesel
fuel costs are included in the diesel fuel price instead of accounting
for the costs of fuel stations separately.
    We acknowledge that this market is still emerging and that hydrogen
fuel providers will likely pursue a diverse range of business models.
For example, some businesses may sell hydrogen to fleets through a
negotiated contract rather than at a flat market rate on a given day.
Others may offer to absorb the infrastructure development risk for the
consumer, in exchange for the ability to sell excess hydrogen to other
customers and more quickly amortize the cost of building a fueling
station. FCEV manufacturers may offer a ``turnkey'' solution to fleets,
where they provide a vehicle with fuel as a package deal. These
uncertainties are not reflected in our hydrogen price estimates
presented in the DRIA.
    As discussed in DRIA Chapter 1.3.2 and 1.8, large incentives are in
place to reduce the price of hydrogen production, particularly from
electrolytic sources. In June 2021, DOE launched a Hydrogen Shot goal