Alternative Method for Calculating Off-Cycle Credits for Mercedes-Benz Vehicles Under the Light-Duty Greenhouse Gas Emissions Program |
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Topics: Mercedes-Benz
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Byron Bunker
Environmental Protection Agency
October 1, 2013
[Federal Register Volume 78, Number 190 (Tuesday, October 1, 2013)]
[Notices]
[Pages 60275-60279]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-23964]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-9901-57-OAR]
Alternative Method for Calculating Off-Cycle Credits for
Mercedes-Benz Vehicles Under the Light-Duty Greenhouse Gas Emissions
Program
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: In the light-duty vehicle greenhouse gas rule for model year
2012 through 2016 vehicles, EPA established a program to allow
automobile manufacturers to generate ``off-cycle'' carbon dioxide
(CO2) credits by employing technologies that achieve
CO2 reductions in the real world but are not appropriately
captured on the test procedures used by manufacturers to demonstrate
compliance with the CO2 standards. Under one of the program
options, a manufacturer may develop and submit to EPA for approval an
alternative demonstration methodology justifying eligibility for off-
cycle credits and their amount. The regulations concerning off-cycle
credits require an opportunity for public comment as part of EPA's
review of such an alternative methodology. EPA is requesting comment on
an alternative methodology submitted by Mercedes-Benz for determining
off-cycle credits for the following technologies: engine stop-start,
high efficiency exterior lighting, infrared glazing, and active seat
ventilation. The application is only for off-cycle credits for
Mercedes-Benz vehicles for the 2012 through 2016 model years.
DATES: Comments must be received on or before October 31, 2013.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2013-0643, by one of the following methods:
On-Line at http://www.regulations.gov: Follow the On- Line
Instructions for Submitting Comments.
Email: a-and-r-docket@epa.gov.
Fax: (202) 566-1741.
Mail: Air and Radiation Docket, Docket ID No. EPA-HQ-OAR-
2013- 0643, U.S. Environmental Protection Agency, Mailcode: 6102T, 1200
Pennsylvania Avenue NW., Washington, DC 20460. Please include a total
of two copies.
Hand Delivery: EPA Docket Center, Public Reading Room, EPA
West Building, Room 3334, 1301 Constitution Avenue NW., Washington, DC
20460. Such deliveries are only accepted during the Docket's normal
hours of operation, and special arrangements should be made for
deliveries of boxed information.
On-Line Instructions for Submitting Comments: Direct your comments
to Docket ID No. EPA-HQ-OAR-2013- 0643. EPA's policy is that all
comments received will be included in the public docket without change
and may be made available online at http://www.regulations.gov,
including any personal information provided, unless the comment
includes information claimed to be Confidential Business Information
(CBI) or other information whose disclosure is restricted by statute.
Do not submit information that you consider to be CBI or otherwise
protected through http://www.regulations.gov or email.
The http://www.regulations.gov Web site is an ``anonymous access''
system, which means EPA will not know your identity or contact
information unless you provide it in the body of your comment. If you
send an email comment directly to EPA without going through http://www.regulations.gov, your email address will automatically be captured
and included as part of the comment that is placed in the public docket
and made available on the Internet. If you submit an electronic
comment, EPA recommends that you include your name and other contact
information in the body of your comment and with any disk or CD-ROM you
submit. If EPA cannot read your comment due to technical difficulties
and cannot contact you for clarification, EPA may not be able to
consider your comment. Electronic files should avoid the use of special
characters, any form of encryption, and be free of any defects or
viruses. For additional information about EPA's public docket visit the
EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
Materials relevant to this proceeding are contained in the Air and
Radiation Docket and Information Center, maintained in Docket ID No.
EPA-HQ- OAR-2013-0643. Publicly available docket materials are
available either electronically through http://www.regulations.gov or
in hard copy at the Air and Radiation Docket in the EPA Headquarters
Library, EPA West Building, Room 3334, located at 1301 Constitution
Avenue NW., Washington, DC. The Public Reading Room is open to the
public on all federal government work days from 8:30 a.m. to 4:30 p.m.;
generally, it is open Monday through Friday, excluding holidays. The
telephone number for the Reading Room is (202) 566-1744. The Air and
Radiation Docket and Information
[[Page 60276]]
Center's Web site is http://www.epa.gov/oar/docket.html. The electronic
mail (email) address for the Air and Radiation Docket is: a-and-r-docket@epa.gov, the telephone number is (202) 566-1742, and the fax
number is (202) 566-9744. An electronic version of the public docket is
available through the federal government's electronic public docket and
comment system. You may access EPA dockets at http://www.regulations.gov. After opening the http://www.regulations.gov Web
site, enter EPA-HQ-OAR-2013-0643 in the ``Enter Keyword or ID'' fill-in
box to view documents in the record. Although a part of the official
docket, the public docket does not include Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute.
EPA will keep the record open until October 31, 2013. All
information will be available for inspection at the EPA Air Docket No.
EPA-HQ-OAR-2013-0643. Persons with comments containing proprietary
information must distinguish such information from other comments to
the greatest extent possible and label it as ``Confidential Business
Information'' (``CBI''). If a person making comments wants EPA to base
its decision on a submission labeled as CBI, then a non-confidential
version of the document that summarizes the key data or information
should be submitted to the public docket. To ensure that proprietary
information is not inadvertently placed in the public docket,
submissions containing such information should be sent directly to the
contact person listed below and not to the public docket. Information
covered by a claim of confidentiality will be disclosed by EPA only to
the extent allowed, and according to the procedures set forth in 40 CFR
part 2. If no claim of confidentiality accompanies the submission when
EPA receives it, EPA will make it available to the public without
further notice to the person making comments.
FOR FURTHER INFORMATION CONTACT: Roberts French, Environmental
Protection Specialist, Office of Transportation and Air Quality,
Compliance Division, U.S. Environmental Protection Agency, 2000
Traverwood Drive, Ann Arbor, MI 48105. Telephone: (734) 214-4380. Fax:
(734) 214-4869. Email address: french.roberts@epa.gov.
SUPPLEMENTARY INFORMATION:
I. Background
In the model year (MY) 2012-2016 light-duty vehicle greenhouse gas
(GHG) rule, EPA established an option for manufacturers to generate
credits by employing technologies that achieve carbon dioxide
(CO2) reductions in the real world but are not captured on
the 2-cycle test procedures used to determine compliance with the fleet
average standards (i.e., ``off-cycle'' credits). EPA adopted the off-
cycle credit option to encourage the introduction of these types of
technologies, believing that off-cycle CO2 reductions should
be considered in determining a manufacturer's fleet average, and that a
credit mechanism is an effective way to achieve this.
The MY 2012-2016 rule provided two ways for manufacturers to
demonstrate the off-cycle emissions reduction capabilities of a
technology and generate off-cycle credits, either through 5-cycle
testing (which captures elements of real-world driving not captured by
the 2-cycle compliance tests, including high speeds, rapid
accelerations, and cold temperature operation) or an alternative
demonstration methodology developed by the manufacturer and approved by
EPA.\1\ The MY 2017-2025 light-duty GHG rule streamlined the off-cycle
credits program and provided a third pathway for credits, a pre-
determined credits list that may be used beginning in MY 2014.\2\
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\1\ 75 FR 25438-25440, May 7, 2010.
\2\ 77 FR 62832-62839, October 15, 2012.
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The first pathway for a manufacturer to demonstrate off-cycle
technology is to conduct 5-cycle emissions testing with and without the
technology applied to the vehicle.\3\ If the off-cycle emissions
benefit of the technology is able to be adequately captured through 5-
cycle testing, the manufacturer must conduct testing per the
regulations, and submit the data to EPA.\4\ This methodology was
proposed in detail in the rulemakings, which included an opportunity
for public comment, and therefore manufacturers' applications for
credits using the 5-cycle process do not undergo additional public
review.
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\3\ 40 CFR 86.1869-12(c).
\4\ 40 CFR 86.1869-12(c).
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The second pathway allows manufacturers to demonstrate off-cycle
emissions reduction technology using an alternative methodology
developed by the manufacturer in cases where the real world benefit of
the technology cannot be adequately demonstrated using the 5-cycle test
procedures.\5\ The regulations regarding the alternative methodology,
excerpted below, specify the data and information needed to support a
manufacturer's off-cycle credit application.\6\ The alternative
methodology must be approved by EPA prior to the manufacturer
generating credits. Also, as part of the EPA review, the alternative
methodology must be made available for public comment.\7\ EPA will
consider public comments as part of its final decision to approve or
deny the credit request.
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\5\ 40 CFR 86.1869-12(d).
\6\ 40 CFR 86.1869-12(d) and (e).
\7\ 40 CFR 86.1869-12(d)(2).
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The regulations for the alternative methodology provided at 40 CFR
86.1869-12(d)(1)(i)-(iv) specify that the alternative demonstration
program must be approved in advance by the Administrator and should be
based on modeling, on-road testing, on-road data collection, or other
approved analytical or engineering methods, and should be robust,
verifiable, and capable of demonstrating the real-world emissions
benefit of the technology with strong statistical significance.
Further, the alternative program should result in a demonstration of
baseline and controlled emissions over a wide range of driving
conditions and vehicles in order to minimize issues of data
uncertainty. Additionally, the regulations at 40 CFR 86.1869-
12(e)(1)(ii)-(iii) and (e)(2)(i)-(iv) provide specificity regarding the
data and information that must be submitted to EPA as part of an
application for credits using an alternative demonstration methodology.
As noted above, as part of the MY 2017-2025 rule, EPA adopted a
list of pre-approved off-cycle technologies and credits that
manufacturers can use beginning in MY 2014.\8\ This third option was
included in the MY 2017-2025 rule because certain types of off-cycle
credits are amenable to quantification without further demonstration,
and EPA's specification of these credits therefore significantly
streamlines the off-cycle credits program and reduces the testing and
data burden that the program otherwise entails. Manufacturers using the
pre-approved list only need to provide EPA at the time of certification
with information demonstrating that their technology meets applicable
definitions and qualifies for credits. There are no testing or other
requirements for demonstrating emissions reductions. Manufacturers may
however use the 5-cycle or alternative methodology pathways in MY 2014
and later to demonstrate that their technology achieves greater off-
cycle emissions reductions than are provided by the pre-defined list.
Also, manufacturers would need to use the 5-cycle or alternative
methodology pathways to demonstrate eligibility for credits for
technologies
[[Page 60277]]
that are not on the list, as well as the extent of the credits.
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\8\ 40 CFR 86.1869-12(a).
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Mercedes-Benz is applying for credits for model years prior to MY
2014 and for credits in excess of the credits on the pre-approved list.
The technologies cannot be adequately demonstrated over the 5-cycle
test and therefore Mercedes-Benz has applied for credits under the
alternative methodology approach discussed above.
II. Mercedes-Benz Off-Cycle Credit Application and Alternative
Methodology
Mercedes-Benz has applied for off-cycle credits using the
alternative demonstration methodology pathway for the following
technologies: engine stop-start, high efficiency exterior lighting,
infrared glazing, and active seat ventilation. The application covers
MY 2012-2016 vehicles. EPA has reviewed the application for
completeness and is now making the application available for public
review and comment per the regulations.\9\ The Mercedes-Benz off-cycle
credit application with confidential business information redacted has
been placed in docket EPA-HQ- OAR-2013-0643 and on EPA's Web site at
http://www.epa.gov/otaq/regs/ld-hwy/greenhouse/ld-ghg.htm.
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\9\ Sec. 86.1869-12(e)(3).
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A summary of Mercedes' alternative methodology for each of the four
technologies is provided below. For context and comparison, in
summarizing the Mercedes-Benz alternative methodology, EPA provides
some background on how the Mercedes-Benz methodology compares to that
developed by EPA in the MY 2017-2025 light-duty GHG rulemaking for the
pre-approved list of off-cycle credits, which is contained in the Joint
Technical Support Document (TSD), Chapter 5.\10\
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\10\ Joint Technical Support Document: Final Rulemaking for
2017-2025 Light-duty Vehicle Greenhouse Gas Emission Standards for
Corporate Average Fuel Economy Standards, United States
Environmental Protection Agency and National Highway Traffic Safety
Administration, August 2012, EPA-420-R-12-901.
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A. Engine Stop-Start
Mercedes-Benz is applying for engine idle stop-start credit
covering all of their MY 2012-2016 U.S. model product range (e.g.,
small/mid-size/large cars and light-duty trucks) (See Section II-III of
Mercedes-Benz Application). Mercedes-Benz is following a similar
methodology to the one EPA described in the TSD for the MY2017-2025
rule, but with unique inputs for idle time and stop-start system
effectiveness which includes parameters related to Mercedes' unique
control strategy for its stop-start system.\11\
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\11\ MY2017-2025 Technical Support Document, Chapter 5, Section
5.2.8.1.
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The basic methodology entails the following steps: estimate or
measure the total idle fraction as a percentage of all vehicle
operation in the real-world; estimate or measure the percentage of idle
fraction that the stop-start system is enabled out of all the available
idle time (i.e., eligible stop-start percentage or stop-start system
effectiveness); determine the benefit of the stop-start system in grams
per mile based on A-B testing (i.e., technology on and off); and
multiply the eligible real world stop-start time (relative to the 2-
cycle eligible time) by the stop-start system benefit to estimate the
engine idle stop-start credit.
In lieu of the EPA default idle time derived from the MOVES model,
Mercedes-Benz is proposing to apply a unique idle time specific to its
vehicles. To estimate the total idle time as a percentage of all
vehicle operation, Mercedes-Benz conducted a field study in calendar
years 2010-2011 including 29 instrumented customer vehicles, randomly
selected from the Mercedes-Benz customer base. The field study was
performed for a period of 13 months in eight states: California, New
York, New Jersey, Florida, Texas, Illinois, Virginia, and Arizona.
These eight states represented about 65% of the Mercedes-Benz sales
volume. The remaining 35% of the Mercedes-Benz sales fleet was
distributed in the other 42 states not included in the idle fraction
study. During the course of the study, the vehicles accumulated 311,118
miles. The 29 vehicle sample broadly represents the Mercedes-Benz
models equipped with stop-start technology sold in the United States.
Based on this study, Mercedes-Benz estimated that its vehicles have a
23.83% total idle fraction as a percentage of all vehicle operation.
To provide further support for its idle fraction estimate,
Mercedes-Benz acquired an independent estimate of idle fraction for its
vehicles from Progressive Insurance. Progressive Insurance has about
1.4 million vehicles in its ``Snapshot'' Program covering 44 states
(excluding California, North Carolina, Tennessee, Indiana, Arkansas,
and Hawaii), over a six month period.\12\ In the Progressive data set,
there are 17,484 Mercedes-Benz vehicles which are represented in
proportion to current industry sales shares. Based on the Progressive
data set, the Mercedes-Benz vehicles are estimated to have an idle
fraction of 23.9%. This is almost exactly the same as the 23.83% idle
fraction found in the Mercedes-Benz study discussed above and used by
Mercedes-Benz in their analysis. Further, since the Progressive
Insurance data covers 37 out of the other 42 states not included in the
Mercedes-Benz idle fraction study, this data implies that the other 35%
of the sales volume not represented by the Mercedes-Benz data has
consistent idle fractions. Mercedes indicated that none of the other 42
states, except for Pennsylvania, have equivalent sales volumes to the
states used in the idle fraction study. As such, Mercedes-Benz
concludes that the idle fraction for the other 35% of the sales volume,
if different, would not have significantly altered the idle fraction
estimate.
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\12\ Of these states, only California is a major market for
Mercedes-Benz.
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To estimate the percentage of idle fraction during which the stop-
start system is enabled, Mercedes-Benz used EPA's methodology in
Chapter 5 of the Technical Support Document (TSD) for the MY2017-2025
rule, with inputs specific to Mercedes-Benz vehicles and control
strategies.
The following background is provided to give some additional
context on how EPA derived off-cycle credits for stop-start systems for
the pre-approved menu in the MY 2017-2025 rulemaking. EPA constrained
stop-start system effectiveness based on three operating temperature
ranges: cold temperatures below 40 degrees Fahrenheit, mid-temperatures
between 40 and 80 degrees Fahrenheit, and hot temperatures above 80
degrees. For the cold temperature range, EPA assumed that passenger
demand for heat would reduce stop-start effectiveness unless the
vehicle possesses an electric heater circulation pump, or equivalent
system, that supplies sufficient heat during engine off operation. For
the hot temperature range, EPA assumed that passenger demand for air
conditioning (A/C) would render the stop-start system inoperable,
unless the manufacturer has some supplemental system to support cabin
cooling. For all the temperature ranges, EPA assumed that the stop-
start system always defaults on when the vehicle is keyed on. EPA
assumed the overall system effectiveness would be reduced to 87.75% due
to these temperature effects.
Mercedes Benz's stop-start system has several design features that
differ from those used by EPA for the pre-approved menu analysis. As
described in Section III of the Mercedes-Benz application, Mercedes-
Benz took these factors into account in analyzing its system
performance. First, the Mercedes-Benz stop-start system includes an
electric
[[Page 60278]]
heater circulation pump that maintains cabin heating in cold
temperatures, and thus enables stop-start capability when heat is
demanded. Second, the Mercedes-Benz system has a supplemental 12 volt
battery system that supplies power for all the electrical components
and accessories. This allows the main battery to support restarting and
also enables stop-start capability even when A/C is demanded. Mercedes-
Benz also made an adjustment to account for OBD and stop-start
interactions, which limits the availability of stop-start during the
first 170 seconds of vehicle operation. These adjustments resulted in
an estimated fraction of effectiveness (i.e., when the system is
active) of about 91.32%, compared to EPA's generic estimate of 87.75%.
In addition, the Mercedes-Benz system includes an ``EcoButton''
that allows customers to disable the stop-start system. An estimate of
the frequency of use of the EcoButton to disable the stop-start system
is included in the Mercedes-Benz calculations. Finally, the Mercedes-
Benz stop-start system has a maximum engine off duration of three
minutes; therefore, the stop-start system would not be active after an
idle period exceeds three minutes. Based on these features, Mercedes-
Benz reduced its eligible idle time of 23.83% to a total eligible idle
time of 21.22% using the 91.32% system effectiveness discussed above,
and an additional discount of 2.5% for EcoButton usage and idles
exceeding the Mercedes-Benz system's 3 minute engine off duration.
To determine the CO2 emissions benefit of the stop-start
system, Mercedes-Benz performed testing of Mercedes-Benz vehicles
equipped with stop-start in different vehicle categories with the stop-
start system on and off. Based on this testing, Mercedes-Benz measured
a benefit of: 9.8 g/mi CO2 for small size cars, 8.1 g/mi
CO2 for mid-size cars, 16.9 g/mi CO2 for large
size cars, and 15.2 g/mi CO2 for light-duty trucks (e.g.,
SUVs). These g/mile GHG improvement values reflect the operational
effectiveness of the Mercedes-Benz system during the 2-cycle testing.
The effectiveness (i.e., the time the engine is off compared to the
total idle time in the cycle) of the stop-start system over the 2-cycle
test ranged from 67.3% to 80.4%.
Based on the eligible stop-start idle fraction of 21.22%, compared
with 10% idle fraction over the 2-cycle tests, and the emissions
benefits measured above, Mercedes-Benz calculated an engine stop-start
credit of 11.0 g/mi CO2 for small size cars; 9.1 g/mi
CO2 for mid-size cars; 19.0 g/mi CO2 for large
size cars; and 17.1 g/mi CO2 for light-duty trucks (for
example, for small cars, these credits were derived as: (9.8 g/mi
CO2 x 0.2122/0.10) - 9.8 g/mi CO2 = 11.0 g/mi
CO2).
High Efficiency Exterior Lighting
Mercedes-Benz is applying for off-cycle credits for high efficiency
exterior lighting for their MY 2012-2016 U.S. model product range with
the following lighting elements: low beam head lights, high beam head
lights, parking/position, front turn signal, front side marker, tail
lights, rear turn signal, and license plate (See Section IV of the
Mercedes-Benz application). This list of lighting elements is
consistent with that specified by EPA for the pre-approved list in the
MY 2017-2025 rule.\13\
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\13\ 40 CFR 86.1869-12(a)(ii).
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To calculate the high efficiency exterior lighting credits,
Mercedes-Benz used the EPA methodology set forth in the TSD for the
MY2017-2025 rule.\14\ Specifically, Mercedes-Benz used the MY 2017-2025
rule baseline wattage values for each lighting element listed above and
the time of day (e.g., day time, night time) usage rates from a study
performed by Schoettle et al. \15\ and inserted the wattage values from
the Mercedes-Benz high efficiency exterior lighting to determine the
wattage savings for each lighting element. In most cases, the Mercedes-
Benz wattage savings for each lighting element exceeded the wattage
savings projected in the MY 2017-2025 rule (exceptions: parking/
position lights at 70% savings versus 78% in the MY 2017-2025 rule;
license plate light at 86% versus 90% in the MY 2017-2025 rule).
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\14\ MY2017-2025 Technical Support Document, Chapter 5, Section
5.2.3.
\15\ Schoettle, B., et al., ``LEDS and Power Consumption of
Exterior Automotive Lighting: Implications for Gasoline and Electric
Vehicles,'' University of Michigan Transportation Research
Institute, October, 2008. For the MY2017-2025 Rule, the high
efficiency exterior lighting wattage for one lighting element, low
beam head lights, was revised based on manufacturer comment.
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For the final credit amounts, Mercedes-Benz multiplied the wattage
savings times the usage rates and a constant of 0.032 g/mi
CO2/watt (based on data showing a 100 watt savings equates
to 3.2 g/mi CO2 savings) for a credit of 1.1 g/mi
CO2 total for all the high-efficiency exterior lighting
elements used over the range of Mercedes-Benz models. In comparison,
the default credit value for high efficiency exterior lighting in the
MY2017-2025 rule is 1.0 g/mi CO2.
Infrared Glazing
Mercedes-Benz is applying for off-cycle credits for infrared
glazing for the MY 2012-2013 S-Class, ML-Class and GL-Class vehicles
that utilize infrared glazing technology (See Section IV of Mercedes-
Benz's application). The infrared glazing technology absorbs and/or
reflects a percentage of the infrared solar energy emitted from the sun
and reduces the amount of solar heat load transmitted into the cabin;
this is termed ``total solar transmittance'' or ``Tts.'' The Tts is
usually expressed as a percentage and defined as the amount of solar
energy that passes through the glazing, including energy absorbed and
subsequently re-radiated to the interior, to the amount of solar energy
imparted on the surface of glazing.\16\ The higher this number, the
more solar energy is allowed to penetrate into the passenger cabin.
Therefore, a lower Tts number is better since less solar energy will
penetrate the passenger cabin and, consequently, the interior cabin
temperature is reduced. Infrared glazing technologies improve passenger
comfort, reducing the need for air conditioning (A/C) usage, which in
turn, reduces vehicle fuel consumption. EPA's analysis relied on a
study performed by the National Renewable Energy Laboratory (NREL)
demonstrating that a one degree centigrade reduction in cabin air
temperature results in a 2.2% reduction in CO2 emissions
resulting from a reduction in passenger compartment temperature and
reduced A/C usage.\17\
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\16\ Title 17 California Code of Regulations Sec. 95600-95605:
``Cool Car Standards and Test Procedures--2012 and Subsequent Model-
Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles.'';
Air Resources Board; May 8, 2009 (see:http://www.arb.ca.gov/regact/2009/coolcars09/coolcarsappa.pdf).
\17\ Rugh, J., Farrington, R. ``Vehicle Ancillary Load Reduction
Project Close-Out Report,'' National Renewable Energy Laboratory
Technical Report NREL/TP-540-42454, January, 2008.
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To calculate the infrared glazing credits, Mercedes-Benz used the
methods set forth in Chapter 5 of the TSD for the MY 2017-2025
rule.\18\ This method utilizes the International Organization for
Standardization's (ISO) standard 13837 for measuring the solar
transmittance of infrared glazing \19\ and a formula for estimating the
effect of the solar performance of glazing technologies developed by
EPA and California Air Resources Board with
[[Page 60279]]
input from the National Renewable Energy Laboratory (NREL) and the
Enhanced Performance Glass Automotive Association (EPGAA).
Specifically, the contribution of each glass/glazing location to the
overall interior temperature reduction is estimated using its measured
Tts, relative to a baseline level, and the area of the glass/glazing
location relative to the overall glass area. \20\
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\18\ MY2017-2025 Technical Support Document, Chapter 5, Section
5.2.10.
\19\ International Organization for Standardization's (ISO)
13837: ``Road vehicles--Safety glazing materials--Method for the
determination of solar transmittance,'' April 15, 2008.
\20\ 40 CFR 86.1869-12(b)(1)(viii)(A).
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The infrared glazing used by Mercedes-Benz has the same Tts
performance levels as the baseline Tts levels specified in the MY2017-
2025 rule: 62% for all glazing locations, except for rooflites and rear
side glazings of crossovers, SUVs, and minivans, which have a baseline
Tts of 40%. Based on the Tts levels for Mercedes Benz's infrared
glazing and the formula described above, Mercedes-Benz calculated a
credit of 0.8 to 1.7 g/mi CO2 for the infrared glazing used
over the range of Mercedes-Benz models. In comparison, the default
credit values for infrared glazing in the MY2017-2025 rule are scalable
depending on such factors as the amount of glass in the vehicle and the
performance of the glazing, up to a maximum of 2.9 g/mi CO2
for cars and 3.9 g/mi CO2 for trucks.
Active Seat Ventilation
Mercedes-Benz is applying for off-cycle credits for applicable
vehicles that have active seat ventilation on both the front row'
driver and passenger seats (See Section IV of Mercedes-Benz's
application).\21\ The Mercedes-Benz active seat ventilation technology
has the capability to both pull air away from and push air to the
seating surface.
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\21\ 40 CFR 86.1869-12(b)(4)(viii).
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To calculate the active seat ventilation credits, Mercedes-Benz
used the methods set forth in Chapter 5 of the MY 2017-2025 TSD.\22\
Based on the NREL study mentioned above, a 7.5% reduction in air
conditioning (A/C) related emissions could be achieved by lowering the
surface temperature of the vehicle seats.\23\
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\22\ MY2017-2025 Technical Support Document, Chapter 5, Section
5.2.11.
\23\ Ibid 12.
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Based on the seat location criteria, capability, and the
methodology described above, Mercedes-Benz estimated a credit of 1.0 g/
mi CO2 for cars and 1.3 g/mi CO2 for trucks for
the active seat ventilation technology used over the range of Mercedes-
Benz models. These values are identical to the default values in the
pre-approved off-cycle credit list in the MY 2017-2025 rule. Therefore,
Mercedes-Benz concludes that its active seat ventilation system
achieves equivalent performance to that assumed in the MY 2017-2025
rule. Mercedes-Benz could use the pre-approved list to claim these
credits beginning in MY 2014, but since they are seeking credits to
begin in MY 2012, and because these technologies are not measurable
through the 5-cycle testing pathway, Mercedes-Benz is applying for
these credits through this alternative technology pathway.
III. EPA Decision Process
EPA is providing a 30-day comment period on this application for an
alternative methodology for off-cycle credits, as specified by the
regulations. The manufacturer may submit a written rebuttal of comments
for EPA's consideration, or may revise its application in response to
comments; EPA would review a revised application as if it were a new
application.\24\ After reviewing any public comments and any rebuttal
of comments submitted by Mercedes-Benz, EPA will make a final decision
regarding the credit request. EPA will make its decision available to
the public by placing a decision document in the docket as specified in
the MY 2017-2025 rule.\25\ and on EPA's Web site at http://www.epa.gov/otaq/regs/ld-hwy/greenhouse/ld-ghg.htm.
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\24\ 40 CFR 86.1869-12(e)(3)(iii).
\25\ 40 CFR 86.1869-12(e)(4)(iii).
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An EPA decision to approve Mercedes Benz's off-cycle credit request
would only apply to the vehicles specified in the Mercedes-Benz
application for MYs 2012-2016. Such decision would not apply to other
Mercedes-Benz vehicles or vehicles from other manufacturers. While the
broad methodology used by Mercedes-Benz could potentially be used for
other vehicles and by other manufacturers, the vehicle specific data
needed to demonstrate the off-cycle emissions reductions would likely
be different. In such cases, a new application would be required,
including an opportunity for public comment.
Dated: September 20, 2013.
Byron Bunker,
Director, Compliance Division, Office of Transportation and Air
Quality, Office of Air and Radiation.
[FR Doc. 2013-23964 Filed 9-30-13; 8:45 am]
BILLING CODE 6560-50-P