1
EMFAC2017An update to California On-road Mobile Source Emission Inventory
November 9, 2017
Mobile Source Analysis BranchAir Quality Planning and Science Division
California Air Resources Board
2
Outline
• Background
• EMFAC Updates Timeline
• EMFAC2017 Public Process Overview
• Overview of Proposed Changes
• Emissions Impact
• Next Steps
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• California Air Quality Planning USEPA approves EMFAC for use in California’s SIPs and for
Conformity Analyses Can utilize California-specific MPO vehicle activity Accounts for unique, California-specific regulations and emission
factors as well as Federal regulations impacting CA fleets The 2016 Statewide SIP Strategy is based on EMFAC2014
• Rulemaking Used to develop rule-specific Criteria Pollutant emission inventories
• Climate Change Planning SB375 Scoping Plan
Background
4
EMFAC Updates
EMFAC2011Released: Sep. 2011
EMFAC2014Released: Dec. 2014
EMFAC2017To be released: Dec 2017
EMFAC202xNext
Integrating In-Use Diesel Regulations
Modular approach
Single Package Reflects Advanced Clean Cars, 2014
Amendments to Truck and Bus Rule, and Heavy duty GHG Regulations
3-Year Cycle An extension of the EMFAC2014 framework Reflecting measures adopted before 2018
Re-design the system to support both simplifications and/or enhancements, depending on program needs
Reflecting measures adopted before 202x
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• Workshops 1st Workshop (Methodology) – June 1, 2017
2nd Workshop (Emissions Impact) – TODAY
• Releases Alpha Release –September 2017
Beta Release – November 2017
Public Release – December 2017 (expected)
EMFAC2017 Public Process
Final Release
+US EPA
Approval
2017 2018
June July August Sep Oct Nov Dec March
Public Release
EMFACWorkshop
#2
BetaRelease
AlphaRelease
EMFACWorkshop
#1
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EMFAC2017 Support Tools
• Web database tool for emissions and emission rates http://www.arb.ca.gov/emfac/
• Web-based training Second Quarter of 2018
• User’s Guide
• Technical documentation
• Project Level Handbook
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EMFAC2017 Major Updates
Fleet Characterization Updated vehicle population based on most recent DMV and IRP
vehicle registration data
In-Use Emissions Extensive emission testing (on-road and chassis dynamometer) of
both light and heavy duty vehicles
Activity Profiles California Household Travel Survey (2010 – 2012) – LDVs Heavy Duty Activity Data Collection (2016) – HDVs
GHG and Transit Modules
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Regulations Reflected in EMFAC2017
• Federal Phase 2 GHG Standards for MHD/HHD
• California Phase 2 GHG (February 2018)
• Amendments to Opacity (Spring 2018)
• Amendments to Warranty (Spring 2018)
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Outline
• Transit Bus Module – Zhen Dai
• Natural Gas Trucks – Ehsan Hosseini
• Truck and Bus Compliance – Sherrie Sala-Moore
• Heavy Duty Emission Rates and Deterioration – Lei Zhou
• Advanced Clean Cars– Hang Liu
• GHG Module – Guihua Wang
• Emissions Impacts of EMFAC2017 – Chandan Misra
• Next Steps and Q&A – Sam Pournazeri
• Demo – Hang Liu
BREAK
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Transit Bus Module
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Need for New Module
• To improve characterization of the urban transit fleets, including the diversity in fuel type, body type, and weight class, and the regional differences
• To support existing and proposed regulations
• To reflect latest knowledge of diesel and CNG bus emission rates and fleet composition
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Summary of Data Sources
• Historical population and VMT: 2000~2015 NTD Annual data
• Future growth: MPO RTP/SCS forecast or county population growth
• Future attrition: assumed a specific lifetime based on empirical data
o Cutaways and buses with GVWR under 14,000 lbs:10 years
o Other buses: 14 years
• Base emission rates and speed correction factors
o New test data for heavy duty diesel and CNG buses
• Other parameters : EMFAC2017 latest assumptions
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Historical Data
• Data Source: National Transit Database (NTD) https://www.transit.dot.gov/ntd• Provides California Transit Data for CY2000 – CY2015
• All transit agencies receiving or benefit from federal §5307 or §5311 grants are required to report data to NTD
• Provides fleet inventory data delineated by vehicle type, service mode, manufacturer, model, seating capacity, etc.
• Consistent with EMFAC classification: school bus, motor coach and all other buses categories are excluded
• CY2015 used as base year for forecasting future population
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CY2015 Base YearTransit Bus Inventory
0
2,000
4,000
6,000
8,000
10,000
12,000
Articulated Bus Bus Cutaway
Popu
latio
n Zero Emission Bus (ZEB)
Natural Gas
Diesel
Gasoline
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Forecasted Population and VMT
• Year-to-year iterative process where new purchase is calculated as the difference between current year’s population and last year’s population after attrition
• Regional annual growth rates based on MPO Regional Transportation Plans (RTPs) , or human population growth for non-MPO areas
• New purchase split between diesel and natural gas based on regional assumption as specified in EMFAC2014
• Assuming 50% of future new purchase of diesel buses are hybrids
• In the absence of any regulatory framework, assuming no new purchase of zero emission buses
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0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
LPG
LNG
GAS_HYB
GAS
FCEB
DSL_HYB
DSL
CNG
BEB
Transit Buses Population Forecast
New Transit Bus Purchase Assumptions:• Gas: 100% conventional• Diesel: 50% conventional & 50% hybrid• CNG: 100% conventional
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Transit Bus Emissions Testing
• WVU Integrated Bus Information System (IBIS)• 29 diesel buses of 1986-2003 MY• 10 CNG buses of 2005-2008 MY
• CARB testing for Valley Transit Agency• 2 diesel buses of 2011 MY (SCR)• 3 CNG buses of 2011-2012 MY (TWC)
• Altoona Bus Research and Testing Center funded by Federal Transportation Agency• 8 diesel buses of 2010-2015 MY (SCR)• 10 CNG buses of 2010-2015 MY (TWC)
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Diesel Transit Bus Emission Rate
Model YearEMFAC2014a EMFAC2017b
NOx (g/mi)
PM (mg/mi)
CO2 (g/mi)
NOx (g/mi)
PM (mg/mi)
CO2 (g/mi)
Pre-2003 31.0 1,210 2,610 27.6 319 2,697
2003 14.0 116 2,41712.6 12.6 2,358
2004-2006 3.83 116 2,417
2007-20092.04 13.9 2,417
8.13 12.6 2,432
2010+ 1.70 6.0 2,029
a. Based on CBD
b. Based on OCBC
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CNG Transit Bus Emission Rate
Model YearEMFAC2014a EMFAC2017b
NOx (g/mi)
PM (mg/mi)
CO2 (g/mi)
NOx (g/mi)
PM (mg/mi)
CO2 (g/mi)
Pre-2003 21.6 42.5 2,394 20.3 21.7 2,325
2003-2006 15.4 23.0 2,39417.1 15.1 2,048
20070.65 1.3 2,305
2008+ 0.61 5.0 2,237
a. Based on CBD
b. Based on OCBC
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Emission Rates Assumptions
Weight Class
Fuel Type Data Source and Assumption
MHDT &
HHDT
CNG HHD based on new test; MHD scaled from HHD
DieselHHD based on new test; MHD scaled from HHD, apply 85% PM emission reduction on older buses starting 2010 to account for PM filter retrofit
BEB and FCEB Zero tailpipe emissions
Gasoline Same as EMFAC2014 gasoline UBUS
Diesel Hybrids 25% fuel efficiency improvement based on DSL
Gasoline Hybrids Same as EMFAC2014 Gasoline
LNG Same as CNG
LPG Same as CNG
Low NOx CNG 90% lower NOx emission rate based on CNG UBUS
Low NOx Diesel 90% lower NOx emission rate based on diesel UBUS
LHDT
CNG, DSL, LNG, LPG Same as EMFAC2017 diesel LHDT2 emission rates
Diesel Hybrids 25% fuel efficiency improvement based on DSL LHDT2Gasoline, Gasoline
HybridsSame as EMFAC2017 gasoline LHDT2 emission rates
BEB and FCEB Zero tailpipe emissions
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VMT Comparison
0
0.5
1
1.5
2
2.5
3
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
VMT
(milli
on m
iles
per d
ay)
Calendar Year
VMT -STATEWIDE - Transit Buses
EMFAC2014 EMFAC2017
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EMFAC2017 Inventory - NOx
0
10
20
30
40
50
60
70
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Emis
sion
s (tp
d)
Calendar Year
NOx - STATEWIDE - Transit Buses
EMFAC2014 EMFAC2017
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EMFAC2017 Inventory – PM2.5
0
0.2
0.4
0.6
0.8
1
1.2
1.4
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Emis
sion
s (tp
d)
Calendar Year
Tailpipe PM2.5 - STATEWIDE - Transit Buses
EMFAC2014 EMFAC2017
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EMFAC2017 Inventory –HC
0
2
4
6
8
10
12
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Emis
sion
s (tp
d)
Calendar Year
HC - STATEWIDE – Transit Buses
EMFAC2014 EMFAC2017
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EMFAC2017 Inventory – CO2
0
1000
2000
3000
4000
5000
6000
7000
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Emis
sion
s (tp
d)
Calendar Year
CO2 - STATEWIDE - Transit Buses
EMFAC2014 EMFAC2017
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Caveats
• Like in EMFAC2014, urban buses do not report extended idling emissions since idling is included in the test cycle and accounted for in their running emissions
• EMFAC2017 does not report evaporative emissions for CNG urban buses due to data limitation
• EMFAC2017 does not report start emissions for heavy heavy duty and medium heavy diesel and CNG urban buses due to data limitation
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Natural Gas Trucks
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Forecasting Penetration of Regional HD NG Vehicles within California
Methodology
• Processed DMV data to obtain counts of heavy duty (HD) natural gas (NG) trucks within California by region and fleet type
• Aggregated the DMV data into air district levels• Local rules and incentive programs are designed at air district levels• Larger sample size per region
• Modeled growth of HD NG fleet as a function of model year using a linear growth and two 8 and 5 year flat rate prediction classes for each GAI/air district.
• Considered impacts of local rules and regulations, specifically South Coast AQMD Rules 1191-1196,on future penetration of NG vehicles in the fleet.
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Forecasting Penetration of Regional HD NG Vehicles within California
Sample Modeling Results
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Forecasting Penetration of Regional HD NG Vehicles within California
Modeling Results
Penetration of HD NG Vehicles in California (GVWR>14,000 lbs)
% H
D N
G V
ehic
les
Calendar Year
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Natural Gas Module
• EMFAC2014 was the first version of the EMFAC model that reflected the impact of natural gas transit buses and solid waste collection vehicles
• With EMFAC2017, staff expanded the natural gas module to cover most of the heavy duty fleet categories such as public fleet, school buses, etc.
• Due to lack of emission test data on natural gas trucks, for EMFAC2017, staff assumed that natural gas trucks have same emission rates as their diesel counterpart (except for transit buses and refuse trucks). As a result of this assumption, reflecting natural gas trucks did not change the overall NOx
and PM inventories. There are several on-going efforts to collect emission data from natural gas trucks and
buses
• EMFAC2017 will also provide users with natural gas fuel consumptions in the unit of Diesel Gallons Equivalent (DGE)
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Lead Staff Contact
Ehsan Hosseini, PhD
Air Pollution Specialist
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Truck and Bus Compliance
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Updated CY2016 Base Year & Fleet Average Age
• Updated CY2016 Base Year in EMFAC2017, as compared to EMFAC2014, reflects:• Higher new sales for vehicles meeting the 2010 Engine Standard
• But less than 100% T&B Rule compliance which has occurred
Fleet Group CY2012* Average Age CY2016** Average Age
T6 Instate 9.1 11.3
T7 Instate Single 12.6 13.9
T7 Instate Tractor 9 8.6
CA IRP 6.2 5.8
Out of State*** 4 4.9
*Base Year for EMFAC2014
**Base Year for EMFAC2017***Out of State IRP Registration is not specific to travel within CA
(older vehicles are not as likely to travel to CA)
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CARB Enforcement Report
https://www.arb.ca.gov/enf/reports/2016_enf_annual_report.pdf
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Updated Compliance Assumptions
• EMFAC2014 assumed 100% compliance with T&B Rule
• EMFAC2017 future year forecasts assume that by CY2023, 100% compliance with the T&B Rule will be achieved• Enforcement has ongoing audits & can place registration
holds
• SB1 requires development of a registration hold system at DMV for vehicles that are out of compliance
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Impact of UpdatedCompliance Assumptions
• Increased proportion of MY2007 and older vehicles• With a decreased rate of installed DPF Retrofits
• Decreased proportion of vehicles that are MY2008-MY2010 (with OEM DPFs)
• Decreased proportion of T6 Instate vehicles that are MY2011+ (meet 2010 Engine Std.)
• Increased proportion of T7 Instate vehicles that are MY2011+ (meet 2010 Engine Std.) due to: • Less vehicle exemptions claimed (NOx exempt areas)
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Updated MY2007 and Older Instate Vehicle Assumptions
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Updated DPF Retrofit Assumptions
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Updated MY2008-2010 Instate Vehicle Assumptions
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Updated 2010 Std. Engine Vehicle Assumptions
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T&B Compliance Summary
• EMFAC2014 assumed 100% compliance with T&B Rule
• Less DPF retrofits and truck replacements have occurred than was forecasted in EMFAC 2014
• EMFAC2017 assumes 100% T&B Rule compliance will be achieved by CY2023
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Lead Staff Contact
Sherrie Sala-Moore
Air Resources Engineer
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Emission RatesHeavy Duty Vehicles
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Summary of June 2017 Workshop HDV Emission Rates
• Heavy duty trucks and buses with GVWR of 14,001 lbs. and higher referred to as medium- and heavy-heavy duty vehicles
• Update to truck running exhaust emission rates and speed correction factors based on dynamometer test data
• Update to truck start and idle emission rates based on PEMS test data
• Update to diesel and CNG bus emission rates based on dynamometer test data
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Update to Truck Running Exhaust Emission Rates
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New Test Data from CARB Truck and Bus Surveillance Program
• 5 additional 2013+ MY HD diesel trucks tested since June workshop
• Test runs over UDDS, Near Dock Drayage, Local Drayage, 40-mph Cruise, 62-mph Cruise
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UDDS NOx Emission Rate for 2013+ MY HD Diesel Trucks
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Zero-Mile Rate and Deterioration Rate
• Average emission rate (ERavg) is average of test results over UDDS cycle
• ERavg is then back-projected to “zero-mile rate (ZMR)” using emission impact rate (EIR)
ZMR = ERavg / (1 + EIR × Odoavg )
• Deterioration rate (DR) is rate of emission increase with mileage
DR = (ERavg− ZMR)/Odoavg
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Emission Deterioration of HD Diesel Trucks
• Emission deterioration of trucks is caused by tampering, mal-maintenance, and malfunction (TM&M) of emission controls
• Emission deterioration is quantified by emission impact rate (EIR), which is a function of Frequency of occurrence of TM&M
Emissions increase due to TM&M
52
Frequency of NOx Related TM&M:Effect of Extended Emission Warranty
• Many trucks have emission warranty beyond 100,000 miles CARB survey: ~40% of Classes 4-8 trucks have emission
warranty equal to their respective engine useful life
CARB estimate based on industry source: ~75% of remaining 60% of Class 8 have warranty extended to 250,000 miles
• TM&M frequency at 100,000 mi is now applied to weighted mileage of extended warranties
53
Revision of TM&M Frequency: NOx
NOx Related TM&M
TM&M Frequency at 1,000,000 Miles
EMFAC2014 EMFAC2017
2010-12 MY 2013+ MY 2010-12 MY 2013+ MY
SCR Malfunction 50% 33% 40% 27%
NOx Sensor #1 Malfunction
45% 30% 36% 24%
NOx Sensor #2 Malfunction
2.3% 1.5% 1.8% 1.2%
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PM Emissions vs. Opacity(NREL PM-Opacity Study)
55
Fraction of Trucks Exceeding 3% Opacity from CARB Roadside Inspections
TM&M frequency in EMFAC is for 1,000,000 miles
56
Revision of TM&M Frequency: PM
PM Related TM&M
TM&M Frequency at 1,000,000 Miles
EMFA2014 EMFA2017
2007-09 MY
2010-12 MY
2013+MY
2007-09 MY
2010-12 MY
2013+MY
DPF Leak 37.6% 37.6% 26.3% 38% 10% 6.7%
DPF Disabled
2% 2% 1.3% -- -- --
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T&M Emission Increase Based on OBD Demonstration Reports
TM&MEMFAC2014 EMFAC2017
NOx PM NOx PM
SCR Malfunction 300% 15% 300% 15%
NOx Sensor #1 Malfunction 200% 0% 200% 0%
NOx Sensor #2 Malfunction 200% 0% 200% 0%
DPF Leak 0% 600% 0% 4,800%
DPF Leak - increases by an order of magnitude Reflects ~0.001 g/bhp-hr cert vs 0.01 g/bhp-hr standard Leaking DPFs emit at ~0.05 g/bhp-hr and thus 50x increase
58
Comparison of Zero-Mile Rates
EngineModel Year
EMFAC2014 EMFAC2017
NOx (g/mi)
PM (mg/mi)
NOx (g/mi)
PM (mg/mi)
2010-12 2.33 4.4 2.72 2.5
2013+ 1.89 4.4 2.68 2.5
All NOx and PM rates normalized to pre-Clean Diesel fuel for EMFAC model
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NOx Emissions Deterioration
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PM Emissions Deterioration
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Speed Correction Factors for HD Trucks
• Running exhaust emission rate vary by speed
• SCF is based on test data from multiple test cycles with different speeds
ERMY = (ZMR + DR × OdoMY ) × SCF
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NOx Speed Correction Factor
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PM Speed Correction Factor
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Plan for Updating HD Deterioration Assumption
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Plan for Updating HD Deterioration
• Focus on utilizing OBD data to update TM&M frequency of 2013+ MY
• Revise rates of TM&M emission increase
Random Roadside Extramural Contract EMA Study
CARB has acquired eight new OBD scan tools
Enforcement staff trained on scan tools
Staff will collect OBD data on voluntary basis
$200k to update frequencies and EIR methodology
Staff in discussion with potential contractors
EMA/Ramboll OBD data from 3,000 trucks
Rambolldeveloping study plan with CARB
66
Federal Phase 2 GHG Regulation
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Federal Phase 2 GHG Reflected in EMFAC2017
• U.S. EPA/NHTSA Final Rulemaking (FRM) published October 2016
• For Phase 2, EMFAC2017 incorporates:• Increased stringency of standards for combination
tractors, vocational vehicle and trailer
• Chassis container category introduced
• Implementation:• 2018-2027 for trailers
• 2021-2027 for all other segments
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Lead Staff Contact
Lei ZhouStaff Air Pollution Specialist
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Advanced Clean Cars
70
Technology Penetration
• Staff updated the light duty vehicle technology penetration assumptions in EMFAC2017 using latest: a. Data from NMOG reports
b. Information from Advanced Clean Cars Midterm Review
• The updated technology fractions presents higher penetration of Partial Zero Emission Vehicles (PZEVs) in earlier years, and less zero emission vehicles in future years.
71
Technology PenetrationEMFAC2014
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Vehi
cle
Mile
s Tr
avel
led
Calendar Year
EMFAC2014 Technology Penetration
EVeq
SULEV20
PZEV/SULEV/SULEV30Pre-2004
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Technology PenetrationEMFAC2017
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Vehi
cle
Mile
s Tr
avel
led
Calendar Year
EMFAC2017 Technology Penetration
Pre-2004
PZEV/SULEV/SULEV30
SULEV20
EVeq
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ZEV Compliance AssumptionsEMFAC2014
• The 2012 ZEV rulemaking assumed that by 2025, 15.4% of light duty vehicle sales will be ZEV (BEV, FCEV, or PHEV)
• At the time, staff assumed that ZEVs will only appear in passenger cars
• To reflect the rulemaking assumption, EMFAC2014 assumed that by 2025, 15.7% of passenger car sales will be Electric Vehicle (EV) equivalent*
*Electric Vehicle Equivalent = BEVs + FCEVs + UF × PHEVs
(UF stands for the utility factor. EMFAC2014 used a utility factor of 40% for PHEVs) 0.1%1.0%
2.1%
6.0%
9.7%
13.0%
15.7%
0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
% S
ales
of E
V-Eq
Pass
enge
r Car
s
Model Year
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ZEV Compliance AssumptionsACC Midterm Review
• According to Appendix A of ACC Midterm Review, staff are expecting a ZEV penetration of approximately 7.5% in light duty vehicle new sales by 2025.
This number is equivalent to 5.7% of EV equivalent in 2025.
• Unlike EMFAC2014, EMFAC2017 assumes that ZEVs will appear in all different light duty weight classes – from passenger cars to medium duty vehicles (≤8,500 lbs. GVWR).
0%1%2%3%4%5%6%7%8%
Perc
ent Z
EV S
ales
in L
D S
ecto
r
Model Year
BEV FCEV PHEV
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ZEV Compliance AssumptionsEMFAC2017
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
6.0%
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
Perc
ent S
ales
of
EV E
quiv
alen
t
Model Year
Passenger Cars LDT1 LDT2 MDV
• Similar to EMFAC2014, EMFAC2017 models emissions from ZEVs using EV-equivalent VMT
• EMFAC2017 assumes that ZEVs are being spread throughout the whole LDV fleet rather than just passenger cars
• Although in EMFAC2014, a utility factor of 40% was assumed for all PHEVs, as part of the ACC MTR, this factor was gradually increased from 46% to 59% in 2025+.
• For years prior to 2017, the actual ZEV populations from DMV will be used.
76
ZEV VMT assumptions
• EMFAC2014 assumed that electric vehicles have an annual mileage accrual rates similar to that of conventional vehicles. • For example, a new electric vehicle in EMFAC2014 was assumed to drive
approximately 21,000 miles a year.
• Analysis of OEM data on current short range BEVs (Appendix G of ACC MTR) indicates that on average electric vehicles drives ~ 11,000 miles.
• Our new assessment of BAR Smog check data shows that conventional vehicles (ICEs) have an annual mileage accrual rates of about 15,000 miles.
• In EMFAC2017, staff assumes that electric vehicle will drive at ~ 11,000 miles/year and as average new BEV range increase, this annual mileage gradually increase to that of ICEs by 2025
77
Regional Distribution of ZEVs
• EMFAC2014 assumed that ZEV penetration will be similar in all regions. For example, EMFAC2014 assumed that in 2025, 15.7% of passenger car sales in all counties were EV.
• For EMFAC2017, staff are exploring new methods to reflect the regional variability in ZEV penetration using DMV vehicle registration data and information on regional ZEV infrastructure development, human population growth, etc.
• Results presented in this workshop are all based on the existing methodology
78
Lead Staff Contact
Hang Liu, Ph.D.Air Pollution Specialist
79
GHG Module
80
Background
• CO2 emissions can be estimated in EMFAC2014 or prior, but they do not represent CARB’s official GHG inventory.
• CH4 is estimated in EMFAC2014, using organic gas speciation profiles.
• N2O is not included in EMFAC2014 or prior versions.
• No CO2 equivalent (CO2e) is provided in EMFAC2014 or prior.
81
Major updates to the GHG part of EMFAC2017
• GHG estimation is improved in EMFAC2017 in order to align with and support official CARB efforts.
• EMFAC2017 includes 3 GHGs: CO2, CH4, and N2O.
• CO2 is calculated based on complete combustion of fuel.
• Fuel consumption is matched to BOE fuel sales for historical years (i.e., 2000-2016).
• Fuel efficiency (FE) assumptions have been updated based on federal FE data.
• The latest vehicle testing data are used to estimate CH4 and N2O.
82
CO2 calculation approach
• EMFAC2014 and prior calculate only tailpipe CO2 emissions, using g/mi emission rates from vehicle testing data.
• EMFAC2017 will calculate CO2 emissions based on complete combustion of fuel.
• Uses BOE, MRR, CEC, U.S. EPA data sources.
• EMFAC2017 fuel consumption for historical years is matched to BOE numbers to ensure CO2 estimates aligned with real-world official on-road mobile fuel sales in California.
83
Fleet average fuel efficiency and CO2 emission rates
• Identify the fuel efficiency rating for California’s vehicle fleet:
• Decode VIN numbers in DMV registration data to obtain make, model, and other vehicle attributes
• Match make, model, and vehicle attributes to a record in fueleconomy.gov to obtain EPA rated fuel efficiency for each individual vehicle.
• The EPA rated fuel efficiency values are then used to calculate the California fleet average fuel efficiency and CO2 emission rates.
84
Comparison of fleet average CO2
emission rates
0
100
200
300
400
500
600
700
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
2022
2024
2026
2028
CO
2E
mis
sion
Rat
e (g
/mil
e)
Model Year
P - EMFAC2014
LDT - EMFAC2014
P - EMFAC2017
LDT- EMFAC2017
• Updated fleet average CO2 emission rates by model year are lower in EMFAC2017.• Forecasted fuel efficiencies are based on Midterm Evaluation of Light-Duty Vehicle Greenhouse
Gas Emissions Standards for Model Years 2022-2025.
85
CH4 calculation approach
• CH4 currently calculated in EMFAC2014 and prior from HC, using speciation profiles.
• EMFAC2017 will • estimate gasoline CH4 as a function of HC emissions based
on the latest vehicle testing data.
• continue using speciation profiles to estimate diesel and natural gas CH4 emissions.
86
N2O calculation approach
• N2O is not estimated in EMFAC2014 or prior.
• EMFAC2017 will
• estimate gasoline N2O as a function of NOx emissions.
• estimate diesel N2O using fuel consumption and an improved fuel-based emission factor.
• Analysis of HD testing data indicates diesel N2O emission factors significantly higher than previously thought.
• CARB, WVU, and SCAQMD testing data, UC Berkeley study
• Utilize the latest available vehicle testing data:
• CARB Vehicle Surveillance Data (LDV) and “Cross California” campaign data (HD)
87
CO2 equivalent and annual estimates
• GHGs will also be provided in EMFAC2017 in units of CO2e, i.e., CO2 equivalent.
• Use 100-year time horizon GWPs (IPCC AR4).
• Consistent with CARB’s latest official GHG inventory.
• Weekday output and annual equivalent.
88
GHG and Fuel estimates are reported in a separate output
89
GHG module’s report structure
• Report CO2, CH4, N2O, and Fuel in a single output file.
• At the same level of detail as the criteria pollutants output.
90
CO2 estimates comparison of EMFAC2017 vs. EMFAC2014
• Estimated CO2 emissions from GAS and (DSL+NG)
Note: EMFAC output with default VMT
91
CH4 estimates comparison of EMFAC2017 vs. EMFAC2014
• Estimated CH4 emissions from GAS and (DSL+NG)
Note: EMFAC output with default VMT
92
N2O estimation in EMFAC2017
• Estimated N2O emissions from GAS and (DSL+NG)
Note: EMFAC output with default VMT
93
Fuel estimates comparison of EMFAC2017 vs. EMFAC2014
• Estimated annual fuel use: GAS and DSL
Note: EMFAC output with default VMT
94
Summary and inventory impact
• The GHG module is a new addition to EMFAC, with methodology consistent with CARB’s official GHG inventory.
• EMFAC2017 includes 3 GHGs from on-road mobile sources: CO2, CH4, and N2O (as well as CO2e).
• Statewide CO2 and CH4 emissions are anticipated to be slightly higher in EMFAC2017 than EMFAC2014.
• Diesel HD N2O emissions are anticipated to play an increasingly important role, as gasoline LDV N2O emissions are expected to drop in future years.
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Lead Staff Contact
Guihua Wang, Ph.D. Air Resources Engineer
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Emissions ImpactEMFAC2014 versus EMFAC2017
Prelim
inary -Draft
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VMT Data
• Inventory results presented in this workshop are based on VMT data from 2015 FSTIP which was also used for 2016 Statewide SIP Strategy Document
• EMFAC2017 model will be released with “default” VMT
• Similar to EMFAC2014, EMFAC2017 will also provide users with the capability of using their own VMT through the “Custom Activity” functionality of the model.
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Vehicle Category Definition
• Light Duty – All vehicles with Gross Vehicle Weight Rating (GVWR) of 8,500 lbs. or less. This includes passenger cars, light trucks, and motorcycles.
• Heavy Duty – All vehicles with GVWR of 8,501 lbs. or higher This includes light, medium and heavy duty trucks and buses
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Truck and Bus Rule: PM and NOx increase 2012 – 2022 due non-compliant trucks and buses
Heavy-Duty PM Deterioration update: PM increase
Heavy-Duty Emission Rates: PM increase and NOx increase in future years
Heavy Duty Start Emissions: NOx decrease
Heavy-Duty Idle emission factors: NOx increase, PM increase
Heavy-Duty Activity Profiles : NOx increase, PM increase
Transit Bus Emission Rate and Activity Update - NOx decrease, PM decrease
Light-duty Emission Rates: NOx increase
(1) New vehicles exhibit higher cold start and lower running emission
(2) With the updated technology penetration assumption there is a net NOx emissions increase
(EMFAC2017 vs EMFAC2014 using 2015 FSTIP activity data)Overview of Emissions Change
(Preliminary results - subject to change)
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VMT - Statewide
(Preliminary results - subject to change)
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Statewide Truck & Bus VMT
(Preliminary results - subject to change)
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VMT – South Coast
(Preliminary results - subject to change)
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VMT – San Joaquin Valley
(Preliminary results - subject to change)
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Statewide NOx Trend
(Preliminary results - subject to change)
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Statewide PM2.5 TrendExcludes Tire and Brake Wear
(Preliminary results - subject to change)
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Statewide ROG TrendIncludes Evaporative Emissions
(Preliminary results - subject to change)
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Detailed DifferencesEMFAC2017 vs EMFAC2014
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Statewide NOxHeavy- and Light-Duty
(Preliminary results - subject to change)
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Statewide NOx Trend
(Preliminary results - subject to change)
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South Coast NOxHeavy- and Light-Duty
(Preliminary results - subject to change)
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South Coast NOx Trend
(Preliminary results - subject to change)
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San Joaquin NOxHeavy- and Light-Duty
(Preliminary results - subject to change)
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San Joaquin NOx Trend
(Preliminary results - subject to change)
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Statewide PM2.5Heavy- and Light-Duty
Excludes Tire and Brake Wear
(Preliminary results - subject to change)
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Statewide PM2.5 TrendExcludes Tire and Brake Wear
(Preliminary results - subject to change)
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South Coast PM2.5Heavy- and Light-Duty
Excludes Tire and Brake Wear
(Preliminary results - subject to change)
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South Coast PM2.5 TrendExcludes Tire and Brake Wear
(Preliminary results - subject to change)
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SJV PM2.5Heavy- and Light-Duty
Excludes Tire and Brake Wear
(Preliminary results - subject to change)
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SJV PM2.5 TrendExcludes Tire and Brake Wear
(Preliminary results - subject to change)
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Statewide ROGHeavy- and Light-Duty
Includes Evaporative Emissions
(Preliminary results - subject to change)
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Statewide ROG TrendIncludes Evaporative Emissions
(Preliminary results - subject to change)
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South Coast ROGHeavy- and Light-Duty
Includes Evaporative Emissions
(Preliminary results - subject to change)
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South Coast ROG TrendIncludes Evaporative Emissions
(Preliminary results - subject to change)
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SJV ROGHeavy- and Light-Duty
Includes Evaporative Emissions
(Preliminary results - subject to change)
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SJV ROG TrendIncludes Evaporative Emissions
(Preliminary results - subject to change)
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Lead Staff
Chandan MisraStaff Air Pollution Specialist
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Next Steps
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Next Steps
• Beta Testing A completed version of the model will be released to CARB’s
designated beta testers for beta testing
• EMFAC2017 Release Updates from beta testing and public release by year end
• USEPA approval Submit the model to USEPA in March for approval
• Web based Training
• Technical Documentation
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Regulatory Support
• EMFAC2017 to be utilized for various upcoming rulemaking processes at CARB:• Amendments to Smoke Opacity
• Lengthening medium- and heavy-duty engine warranty
• Amendments to Heavy Duty OBD
• Comprehensive HD I/M
• Low NOx standards
• Innovative Clean Transit
• Advanced Clean Local Truck Rule
• Airport Shuttle Buses
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Looking ForwardEMFAC202x
• Coordinating with industry to share fleet representative data for future updates
• Collecting PHEV data to better reflect the emissions
• Emphasis on collecting OBD scan data to update MY2013+ TM&M frequencies
• Chassis/PEMS testing to continue to update emission rates
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Questions and Comments
• For questions and comments please contact us at:
[email protected]• You can also visit our website at:
https://www.arb.ca.gov/msei/msei.htm
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Demo