2019-24572. Alternative Methods for Calculating Off-Cycle Credits Under the Light-Duty Vehicle Greenhouse Gas Emissions Program: Applications From Nissan North America, Inc.

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice.

SUMMARY:

EPA is requesting comment on applications from Nissan North America, Inc. (“Nissan”) for off-cycle carbon dioxide (CO₂) credits under EPA's light-duty vehicle greenhouse gas emissions standards. “Off-cycle” emission reductions can be achieved by employing technologies that result in real-world benefits, but where that benefit is not adequately captured on the test procedures used by manufacturers to demonstrate compliance with emission standards. EPA's light-duty vehicle greenhouse gas program acknowledges these benefits by giving automobile manufacturers several options for generating “off-cycle” CO₂ credits. Under the regulations, a manufacturer may apply for CO₂ credits for off-cycle technologies that result in off-cycle benefits. In these cases, a manufacturer must provide EPA with a proposed methodology for determining the real-world off-cycle benefit. Nissan has submitted applications that describe methodologies for determining off-cycle credits from technologies described in their application. Pursuant to applicable regulations, EPA is making Nissan's off-cycle credit calculation methodologies available for public comment.

DATES:

Comments must be received on or before December 12, 2019.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2019-0588, to the Federal eRulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or withdrawn. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (i.e. on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit http://www2.epa.gov/​dockets/​commenting-epa-dockets.

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: [phone]. Fax: [phone]. Email address: [e-mail].

SUPPLEMENTARY INFORMATION:

I. Background

EPA's light-duty vehicle greenhouse gas (GHG) program provides three pathways by which a manufacturer may accrue off-cycle carbon dioxide (CO₂) credits for those technologies that achieve CO₂ reductions in the real world but where those reductions are not adequately captured on the test used to determine compliance with the CO₂ standards, and which are not otherwise reflected in the standards' stringency. The first pathway is a predetermined list of credit values for specific off-cycle technologies that may be used beginning in model year 2014.^[1] This pathway allows manufacturers to use conservative credit values established by EPA for a wide range of technologies, with minimal data submittal or testing requirements, if the technologies meet EPA regulatory definitions. In cases where the off-cycle technology is not on the menu but additional laboratory testing can demonstrate emission benefits, a second pathway allows manufacturers to use a broader array of emission tests (known as “5-cycle” testing because the methodology uses five different testing procedures) to demonstrate and justify off-cycle CO₂ credits.^[2] The additional emission tests allow emission benefits to be demonstrated over some elements of real-world driving not adequately captured by the GHG compliance tests, including high speeds, hard accelerations, and cold temperatures. These first two methodologies were completely defined through notice and comment rulemaking and therefore no additional process is necessary for manufacturers to use these methods. The third and last pathway allows manufacturers to seek EPA approval to use an alternative methodology for determining the off-cycle CO₂ credits.^[3] This option is only available if the benefit of the technology cannot be adequately demonstrated using the 5-cycle methodology. Manufacturers may also use this option for model years prior to 2014 to demonstrate off-cycle CO₂ reductions for technologies that are on the predetermined list, or to demonstrate reductions that exceed those available via use of the predetermined list.

Under the regulations, a manufacturer seeking to demonstrate off-cycle credits with an alternative methodology (i.e., under the third pathway described above) must describe a methodology that meets the following criteria:

• Use modeling, on-road testing, on-road data collection, or other approved analytical or engineering methods;
• Be robust, verifiable, and capable of demonstrating the real-world emissions benefit with strong statistical significance;
• Result in a demonstration of baseline and controlled emissions over a wide range of driving conditions and number of vehicles such that issues of data uncertainty are minimized;
• Result in data on a model type basis unless the manufacturer demonstrates that another basis is appropriate and adequate.

Further, the regulations specify the following requirements regarding an application for off-cycle CO₂ credits:

• A manufacturer requesting off-cycle credits must develop a methodology for demonstrating and determining the benefit of the off-cycle technology and carry out any necessary testing and analysis required to support that methodology.
• A manufacturer requesting off-cycle credits must conduct testing and/or prepare engineering analyses that demonstrate the in-use durability of the technology for the full useful life of the vehicle.
• The application must contain a detailed description of the off-cycle technology and how it functions to reduce CO₂ emissions under conditions not represented on the compliance tests.
• The application must contain a list of the vehicle model(s) which will be equipped with the technology.
• The application must contain a detailed description of the test vehicles selected and an engineering analysis that supports the selection of those vehicles for testing.
• The application must contain all testing and/or simulation data required under the regulations, plus any other data the manufacturer has considered in the analysis.

Finally, the alternative methodology must be approved by EPA prior to the manufacturer using it to generate credits. As part of the review process defined by regulation, the alternative methodology submitted to EPA for consideration must be made available for public comment.^[4] EPA will consider public comments as part of its final decision to approve or deny the request for off-cycle credits.

II. Off-Cycle Credit Applications

A. Variable Crankcase Suction Valve Technology in Denso AC Compressors

Using the alternative methodology approach discussed above, Nissan is applying for credits for an air conditioning compressor manufactured by Denso that results in air conditioning efficiency credits beyond those provided in the regulations. This request is for the 2017 and subsequent model years. This compressor, known as the Denso SAS compressor, improves the internal valve system within the compressor to reduce the internal refrigerant flow necessary throughout the range of displacements that the compressor may use during its operating cycle. The addition of a variable crankcase suction valve allows a larger mass flow under maximum capacity and compressor start-up conditions (when high flow is ideal), and then it can reduce to smaller openings with reduced mass flow in mid- or low-capacity conditions. The refrigerant exiting the crankcase is thus optimized across the range of operating conditions, reducing the overall energy consumption of the air conditioning system. EPA first approved credits for General Motors (GM) for the use of the Denso SAS compressor in 2015,^[5] and has subsequently approved such credits for BMW, Ford, and Hyundai.^[6]

The credits calculated for the Denso SAS compressor would be in addition to the credits of 1.7 grams/mile for variable-displacement A/C compressors already allowed under EPA regulations.^[7] However, it is important to note that EPA regulations place a limit on the cumulative credits that can be claimed for improving the efficiency of A/C systems. The rationale for this limit is that the additional fuel consumption of A/C systems can never be reduced to zero, and the limits established by regulation reflect the maximum possible reduction in fuel consumption projected by EPA. These limits, or caps, on credits for A/C efficiency, must also be applied to A/C efficiency credits granted under the off-cycle credit approval process. In other words, cumulative A/C efficiency credits for an A/C system—from the A/C efficiency regulations and those granted via the off-cycle regulations—must comply with the stated limits.

Nissan is requesting an off-cycle GHG credit of 1.1 grams CO₂ per mile for the Denso SAS compressor. Nissan cited the bench test modeling analysis referenced in the original GM application, which demonstrated a benefit of 1.1 grams/mile. Like other manufacturers, Nissan also ran vehicle tests using the AC17 test to confirm the credit amount. Seven tests were conducted, resulting in a calculated benefit of 4.4 grams/mile, thus substantiating the bench test results. Based on these results, Nissan is requesting a credit of 1.1 grams/mile for all Nissan vehicles equipped with the Denso SAS compressor with variable crankcase suction valve technology, starting with 2017 model year vehicles. Details of the testing and analysis can be found in the manufacturer's application.

B. Off-Cycle GHG Credits for Calsonic Kansei A/C Compressor Incorporating Flowpath Resistance Reduction Technology

Using the alternative methodology approach discussed above, Nissan is applying for credits for an air conditioning compressor manufactured by Calsonic Kansei that results in air conditioning efficiency credits beyond those provided in the regulations. This request is for the 2018 and subsequent model years. This compressor (the “Calsonic Kansei CR-Phase 4 compressor”), improves the efficiency of the compressor by changing the contours of the refrigerant flow path, reducing the pressure loss and improving the efficiency relative to previous versions of the system.

The credits calculated for the Calsonic Kansei compressor would be in addition to the credits of 1.7 grams/mile for variable-displacement A/C compressors already allowed under EPA regulations.^[8] However, it is important to note that EPA regulations place a limit on the cumulative credits that can be claimed for improving the efficiency of A/C systems. The rationale for this limit is that the additional fuel consumption of A/C systems can never be reduced to zero, and the limits established by regulation reflect the maximum possible reduction in fuel consumption projected by EPA. These limits, or caps, on credits for A/C efficiency, must also be applied to A/C efficiency credits granted under the off-cycle credit approval process. In other words, cumulative A/C efficiency credits for an A/C system—from the A/C efficiency regulations and those granted via the off-cycle regulations—must comply with the stated limits.

Nissan is requesting an off-cycle GHG credit of 1.1 grams CO₂ per mile for the Calsonic Kansei compressor. Nissan cited the bench test modeling analysis conducted by Calsonic Kansei, using the procedures contained in SAE standard J2765, which characterize a system's coefficient of performance. Nissan also ran six vehicle tests comparing compressors on the AC17 test protocol; these tests demonstrated a 1.7 gram/mile benefit. Finally, Calsonic Kansei used the LCCP model to estimate the benefits of the technology, and this modeling also supported a credit value of 1.1 grams/mile. Details of the bench testing, vehicle testing, and modeling are available in Nissan's application.

III. EPA Decision Process

EPA has reviewed the applications for completeness and is now making the applications available for public review and comment as required by the regulations. The off-cycle credit applications submitted by the manufacturer (with confidential business information redacted) have been placed in the public docket (see ADDRESSES section above) and on EPA's website at https://www.epa.gov/​vehicle-and-engine-certification/​compliance-information-light-duty-greenhouse-gas-ghg-standards.

EPA is providing a 30-day comment period on the applications for off-cycle credits described in this notice, as specified by the regulations. The manufacturers may submit a written rebuttal of comments for EPA's consideration, or may revise an application in response to comments. After reviewing any public comments and any rebuttal of comments submitted by manufacturers, EPA will make a final decision regarding the credit requests. EPA will make its decision available to the public by placing a decision document (or multiple decision documents) in the docket and on EPA's website at the same manufacturer-specific pages shown above. While the broad methodologies used by these manufacturers 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: November 1, 2019.

Byron J. Bunker,

Director, Compliance Division, Office of Transportation and Air Quality, Office of Air and Radiation.

Footnotes

1.  See 40 CFR 86.1869-12(b).

2.  See 40 CFR 86.1869-12(c).

3.  See 40 CFR 86.1869-12(d).

4.  See 40 CFR 86.1869-12(d)(2).

5.  “EPA Decision Document: Off-cycle Credits for Fiat Chrysler Automobiles, Ford Motor Company, and General Motors Corporation.” Compliance Division, Office of Transportation and Air Quality, U.S. Environmental Protection Agency. EPA-420-R-15-014, September 2015.

6.  EPA Decision Document: Off-cycle Credits for BMW Group, Ford Motor Company, and Hyundai Motor Company.” Compliance Division, Office of Transportation and Air Quality, U.S. Environmental Protection Agency. EPA-420-R-17-010, December 2017.

7.  See 40 CFR 86.1868-12.

8.  See 40 CFR 86.1868-12.