MOBILE6 Input Commands Basics and Guidance

1
MOBILE 6 Input Requirements and the
NONROAD MODEL-2002
Dale Aspy Region 4
2
Overview

• Introduce the range of commands except output
  commands
• Demonstrate that MOBILE6 is flexible
• Local data encouraged, default data provided

3
Input Guidance

• Current M6 User Guide contains no guidance on
  appropriate input assumptions
• Chap. 5 contains useful information for
  converting M5 input assumptions to M6
• Guidance has been issued
• Most new input options are for special cases
• Some will require new data in the long run, but
  we will provide interim options such as national
  defaults that can be used near-term.

4
Required Commands

• MOBILE6 INPUT FILE
• MOBILE6 BATCH FILE is alternative
• RUN DATA
• marks beginning of run section
• MIN/MAX TEMPERATURE
• HOURLY TEMPERATURE is alternative
• can be in run or scenario sections
• FUEL RVP
• can be in run or scenario sections
• SCENARIO RECORD
• labels and marks start of new scenario
• CALENDAR YEAR
• specifies calendar year of scenario
• END OF RUN
• separate multiple runs in input files

5
Simplest Input File Example

• MOBILE6 INPUT FILE
• RUN DATA
• MIN/MAX TEMP 64. 92.
• FUEL RVP 7.0
• SCENARIO REC Scenario Title Text
• CALENDAR YEAR 2010
• END OF RUN

6
Header Commands

• POLLUTANTS
• specifies which pollutants (HC, CO, NOx) are
  included in output file
• default is all three
• REPORT FILE
• allows user to specify a name for an output file
  in descriptive format
• default is name of input file with extension
  .TXT
• DATABASE OUTPUT
• directs MOBILE6 to produce database output
• default is descriptive output
• will be covered elsewhere

7
Header Commands Example

• MOBILE6 INPUT FILE
• POLLUTANTS HC NOX
• REPORT FILE filename.txt
• RUN DATA
• MIN/MAX TEMP 64. 92.
• FUEL RVP 7.0
• SCENARIO REC No CO
• CALENDAR YEAR 2010
• END OF RUN

8
Temperature

• A required input, with two options
• Affects temperature corrections to exhaust and
  evap emissions and temperature of dispensed fuel
  for refueling emissions
• MIN/MAX TEMP
• User supplies minimum and maximum daily ambient
  temperature
• Model creates daily temp profile with low at 6 am
  and high at 3 pm
• Local data can be obtained from National Climatic
  Data Center
• Preferred choice for most modeling
• HOURLY TEMP
• User supplies 24 hourly temperatures
• Optional for most applications

9
ABSOLUTE HUMIDITY

• Used to determine A/C usage
• Much more important than in MOBILE5
• Guidance
• Users should supply local data
• Local data (relative humidity) can be obtained
  from National Climatic Data Center
• Will supply information on conversion from
  relative humidity to absolute

10
Other Weather Conditions

• These also affect A/C usage
• Defaults for all are worst case conditions
• Guidance
• Optional for most applications
• Commands
• CLOUD COVER
• PEAK SUN
• SUNRISE/SUNSET

11
Evaluation Year and Month

• Must be in Scenario section
• CALENDAR YEAR
• Required command
• EVALUATION MONTH
• January (1) or July (7)
• Default is January
• Only affects fleet composition and RFG program
• No effect on temperature, RVP, etc.
• Other months can be estimated by interpolation
  between January and July runs

12
External Conditions Example

• MOBILE6 INPUT FILE
• RUN DATA
• MIN/MAX TEMP 64. 92.
• ABSOLUTE HUMIDITY 115.0
• FUEL RVP 7.0
• SCENARIO REC Its not the heat...
• CALENDAR YEAR 2010
• EVALUATION MONTH 7
• ALTITUDE 2
• END OF RUN

13
Fleet Characteristics

• Commands that identify characteristics of the
  vehicle fleet such as vehicle age, power source,
  and activity level
• 2 fuel types gas and diesel
• Natural gas handled separately
• 16 vehicle types
• 25 ages within each type

14
New Vehicle Types

• MOBILE6 vehicle types more closely match
  classification used for vehicle standards than
  MOBILE5

MOBILE5 MOBILE6
LDV LDV
LDT1 LDT1
LDT1 LDT2
LDT2 LDT3
LDT2 LDT4
15
New Vehicle Types
MOBILE5 MOBILE6
HDV HDV2B
HDV HDV3
HDV HDV4
HDV HDV5
HDV HDV6
HDV HDV7
HDV HDV8A
HDV HDV8B
HDV HDBS
HDV HDBT
MC MC
16
Fleet Guidance

• Areas are unlikely to have local data for all new
  vehicle types
• Should use the local data they do have to account
  for MOBILE5 vehicle types
• Can use national defaults for new vehicle types
• We will work with DOT and others to develop new
  methods for local data

17
Age Distribution

• EPA recommends use of local data
• Determines the fleet turnover rate
• Wide local variation
• Command is REG DIST
• Data usually come from registration lists
• Must be in Run section
• Requires an external data file
• File consists of registration fractions for each
  of 25 ages, representing the fraction of vehicles
  of that age in July
• Can enter any of 16 vehicle types (combined gas
  and diesel)

18
Age Distribution

• Chapter 5 of User Guide provides a method for
  applying MOBILE5 registration distributions to
  new MOBILE6 sub-classes
• Assumes no differences among sub-classes
• A reasonable approach until we have local data
• VIN decoders could help with new LDT classes
• New HDV classes are a more difficult problem

19
Diesel Fractions

• Allows user to specify fraction of diesel
  vehicles for 14 vehicle types
• Urban/transit buses are 100 diesel
• Motorcycles are 100 gas
• Not an important local input
• Local variation smaller than age distribution
• Command is DIESEL FRACTIONS
• Can be in Run or Scenario sections
• If selected, user must supply fractions for every
  age in every class 350 separate fractions

20
Annual Mileage Accumulation

• Annual mileage accumulation rate varies by
  vehicle age and vehicle class
• EPA recommends use of national default data in
  MOBILE6
• Difficult to develop accurate local data
• Command is MILE ACCUM RATE
• Must be in Run Section
• User enters rates by age
• Not all vehicle classes are required
• External data file required

21
Natural Gas Vehicle Fractions

• Allows user to specify fraction of natural gas
  vehicles by model year and vehicle class
• Not necessary for most applications
• Default is zero
• Command is NGV FRACTION
• Must be in Run section
• External data file required
• User must enter NGV fractions for each vehicle
  type and model year from 1994 through 2050

22
Fleet Characteristics Example

• MOBILE6 INPUT FILE
• RUN DATA
• MIN/MAX TEMP 64. 92.
• FUEL RVP 7.0
• REG DIST REGDATA.D
• SCENARIO REC Alternate reg. dist.
• CALENDAR YEAR 2010
• EVALUATION MONTH 7
• ALTITUDE 2
• END OF RUN

23
Activity Commands

• Allow users to allocate vehicle travel by vehicle
  class, time of day, day of week, type of road,
  speed, etc.
• Many new options add flexibility for meso- and
  microscale analysis
• Most would not be required for typical SIP or
  conformity submission

24
VMT Fractions

• MOBILE6 produces both separate emissions factors
  for each vehicle class as well as aggregate
  emissions by groupings (all vehicles, HDDV, etc.)
• This command allows users to specify how MOBILE
  allocates VMT by vehicle type to calculate
  aggregate emissions
• EPA expects that states and MPOs would use local
  data for VMT fractions
• Command is VMT FRACTIONS
• Can be in Run or Scenario sections
• User must enter fractions for 16 vehicle types

25
VMT Fractions

• Chapter 5 of User Guide provides a method for
  applying MOBILE5 VMT fractions to new MOBILE6
  sub-classes
• Method uses default national data for each
  vehicle type by model year to allocate local data
  to MOBILE6 sub-classes
• A reasonable approach in the near term
• What are long-term prospects for new data?
• More detailed counts?
• Use of registration data?

26
VMT Fractions Example

• MOBILE6 INPUT FILE
• RUN DATA
• MIN/MAX TEMP 64. 92.
• FUEL RVP 7.0
• REG DIST REGDATA.D
• VMT FRACTIONS
• 0.354 0.089 0.297 0.092 0.041 0.040 0.004 0.003
• 0.002 0.008 0.010 0.012 0.040 0.002 0.001 0.005
• SCENARIO REC Alternate VMT fractions
• CALENDAR YEAR 2010
• EVALUATION MONTH 7
• ALTITUDE 2
• END OF RUN

27
VMT BY HOUR

• Allows users to allocate the fraction of VMT that
  occurs at each hour of the day
• Encourage areas to use this, especially if
  results will be used for photochemical modeling
• If hourly activity is not known but peak vs.
  off-peak activity is, allocate peak activity to
  peak hours and vice versa
• Command requires input of 24 VMT fractions

28
VMT BY FACILITY

• Allows users to allocate VMT to roadway types by
  vehicle class
• Encourage states and MPOs to use this
• Default assumes the same distribution for all
  vehicle classes
• Command requires external data file
• File includes VMT distribution across 4 roadway
  types for each of 24 hours for each vehicle class
  the user chooses

29
VMT BY FACILITY

• Full use of this command will be difficult due to
  lack of data
• Guidance
• Need to develop methodology for getting from
  current data whats needed for MOBILE6
• If hourly activity is not known but peak vs.
  off-peak activity is, allocate peak activity to
  peak hours and vice versa
• For link-based modeling of one particular
  facility type, VMT BY FACILITY can be set to 100
  of that type for each hour of the day

30
Comparison of VMT BY HOUR and VMT BY FACILITY

• Difference from VMT BY FACILITY (example)
• VMT BY FACILITY estimate for 9 am
• 40 of LDV VMT is on freeways
• 30 is on arterials
• 20 is on local streets
• 10 is on ramps
• Distribution varies by hour and vehicle class
• VMT BY HOUR
• 10 of total daily fleet VMT occurs at 9 am
• 9 of VMT occurs at 10 am, etc.

31
Speeds

• In MOBILE5, users entered average speeds
• In MOBILE6, users can enter a speed distribution
• Allows users to enter the data behind the average
  speed
• Example - modeling an area with 3 roads and 3
  speeds
• In MOBILE5, do three runs, one at each speed, and
  calculate weighted average of results
• In MOBILE6, do one run with distribution of VMT
  at each speed

32
Speeds

• Can run MOBILE6 for a single speed by creating a
  run distribution with only one or two values
• Can now run a MOBILE5 type average speed in the
  latest release of MOBILE6
• Chapter 5 provides more information on the
  conversion of MOBILE5 input to MOBILE6
• Guidance
• Areas should use local speed distributions
• Command is SPEED VMT
• Requires external data file
• File contains VMT fractions in 14 speed bins for
  each hour of day

33
Operating Modes

• MOBILE5 allowed user input of percent of VMT in
  hot and cold start modes
• MOBILE6 uses number of engine starts and soak
  duration distributions to control effects of
  engine starts
• Guidance
• not necessary for many applications

34
Operating Modes

• Chapter 5 of User Guide gives details of
  conversion from MOBILE5 to MOBILE6 input
• Two commands
• STARTS PER DAY
• must be in Run section
• estimate of number of trips
• requires 56 values - one weekday and one weekend
  average number of starts for each of 28 vehicle
  types
• SOAK DISTRIBUTION
• must be in Scenario section
• measure of time engine is not running
• requires 3,360 values - 70 soak durations for
  each hour of day

35
Additional Activity Commands

• START DIST
• Allocates engine starts by hour of the day
• Requires 48 values - percentage of starts for
  each hour for weekdays and weekends
• HOT SOAK ACTIVITY
• Specifies a hot soak duration distribution
• Evap emissions that occur after a hot vehicle has
  shut down
• Distribution is number of vehicles with a hot
  soak of 1-60 minutes, by minute, for each hour of
  the day
• Day is broken up into 14 time periods (night
  hours are lumped together)

36
Additional Activity Commands

• DIURN SOAK ACTIVITY
• Specifies a diurnal soak time distribution
• Evap emissions that occur when a vehicle is
  parked longer than 1 hour to a max of 72 hours
• Distribution of the length of time vehicles have
  been soaking for each hour of day
• Day is broken up into 18 periods (night hours are
  lumped together)

37
Additional Activity Commands

• Weekday and weekend trip length distributions
• Specifies fraction of VMT that occurs during
  trips of different durations
• Affects running loss evap emissions
• Requires distribution of trip lengths (6 ranges)
  for 14 hours
• WE DA TRI LEN DI does weekday distributions
• WE EN TRI LEN DI does weekend distributions
• Use weekend vehicle activity
• Directs MOBILE6 to apply weekend activity
  information
• Default is weekday activity
• Command is WE VEH US

38
Additional Activity Commands

• Guidance
• Activity commands increase flexibility of MOBILE6
• Better able to do meso- and microscale modeling
• Encourage areas to develop data over the long
  term that improves accuracy of emissions modeling
• Areas should use commands if they have the data
• Use of these commands is not required if the data
  are not available

39
Fuel Commands

• Allow users to model impacts of various gasoline
  fuel parameters

40
FUEL RVP

• A required input that affects both exhaust and
  evap emissions
• Can be based on mandated limits or on survey data
  as described in previous guidance
• OXYGENATED FUELS and FUEL PROGRAM commands may
  affect FUEL RVP input

41
FUEL PROGRAM

• Allows users to specify fuel program
• Options
• Conventional Gas East (1)
• Default setting
• Post-1999 sulfur levels for most of country
• Conventional Gas West (3)
• Post-1999 sulfur levels in five western states
• Reformulated Gas (2 N or 2 S)
• Effects of RFG program (1995)
• User must specify north or south region
• Overrides RVP
• User-Supplied Gasoline Sulfur Levels (4)
• Specifies post-1999 average and maximum sulfur
  levels

42
Gasoline Sulfur Content

• Allows users to specify gasoline sulfur content
  for calendar years through 1999
• Default is 300 ppm
• Guidance will need to define acceptable sources
  of data
• Command is SULFUR CONTENT
• Must be in Scenario section
• Enter sulfur values between 30 and 600 ppm

43
OXYGENATED FUELS

• Allows users to model an oxy fuels program
• Users enter
• Market shares of ether and alcohol blends
• Average oxygen content of ether and alcohol
  blends
• Whether a RVP waiver has been granted to allow
  splash blending of alcohol-based oxygenates

44
SEASON

• Identifies season for the RFG calculation
• Summer (1)
• Winter (2)
• Default
• Season is based on EVALUATION MONTH
• SEASON flag allows winter RFG in July
• Only needed if RFG is specified and user needs to
  interpolate results to an intermediate month

45
Stage II Programs

• Allows users to model impact of Stage II vapor
  recovery system requirement on refueling
  emissions
• Stage II reductions depend on efficiency of the
  program, whether or not vehicles have onboard
  vapor recovery systems, fuel RVP, and fuel
  temperature
• Command is STAGE II REFUELING
• Must be in the Run section
• User must input program start year, number of
  phase-in years, and efficiency of the program on
  light and heavy duty vehicles

46
Fuel Commands Example

• MOBILE6 INPUT FILE
• RUN DATA
• MIN/MAX TEMP 64. 92.
• FUEL RVP 7.0
• FUEL PROGRAM 2 S
• STAGE II REFUELING 89 4 80. 60.
• SCENARIO REC southern RFG Stage II
• CALENDAR YEAR 2000
• EVALUATION MONTH 7
• END OF RUN

47
NO CLEAN AIR ACT

• Allows users to model vehicle emissions as if the
  Clean Air Act Amendments of 1990 had not been
  implemented
• Needed for Rate of Progress calculations
• Disables
• All exhaust standards after Tier 0
• Enhanced evap test benefits
• SFTP
• OBD, I/M240, and ASM benefits
• Detergent additives
• Fuel sulfur levels lower than 300 ppm
• Cold CO benefits

48
Modified Output Formats

• Eliminate most existing options
• Descriptive (120 column) output
• Electronic (tab delimited) databaseoutput

49
Database Output Fields

• File
• Run
• Scenario
• Vehicle Type
• Pollutant
• Hour
• Age
• Facility (Roadway) Type
• Emission Type

• Grams per mile
• Grams per hour
• Starts
• Ends
• Miles
• Miles per Gallon
• Hourly VMT fraction
• Facility VMT fraction
• Registration Distribution
• Vehicle Count
• Ambient Temperature
• Diurnal Temperature

50
Key Points

• MOBILE6 provides much flexibility, can do area
  wide emissions down to a particular project.
• Local data is suggested when available.
• Default data provided, based on national trends.

51
Reporting Requirements
Non-attainment areas
Consolidated Emission Reporting Requirements
are due June 1, 2004 VMT by roadway class for
all counties in the state
Includes PM2.5 and NH3
52
EPA Nonroad Emissions Inventory Model(NONROAD)

• EPA NONROAD Emissions
• Inventory Model-2002
• (NONROAD)

53
Evolution of Nonroad Emission Inventory
Development

• Pre-1991-92
• AP-42 Compilation of Air Pollutant Emission
  Factors, Volume II Mobile Sources
• Post 1991-92
• Volume IV Procedures for Emission Inventory
  Preparation
• Nonroad Engine Vehicle and Emissions Study (NEVES)

54
Evolution of Nonroad Emission Inventory
Development

• June 1998
• Release of first draft version of NONROAD Model
• 2000
• Release of revised draft

55
National Nonroad Inventories Changing

• June 1998 Draft NONROAD vs. NEVES
• VOC 25
• NOx 25
• PM Down - 5
• Final NONROAD model emissions estimates are
  expected to be different from June 1998 draft
  version of model

56
NONROAD vs NEVES Why Inventories Are
Different

• VOC and NOx
• Updated NONROAD database has higher equipment
  populations for some equipment categories as well
  as additional equipment categories not included
  in NEVES
• PM
• Database has additional equipment, but lower
  emission factors

57
NONROAD Model Overview

• Graphical User Interface (Visual Basic)
• Define scenario
• Core Model (Fortran)
• Perform calculations
• Reporting Utility (Microsoft Access)
• Output results

58
Equipment Categories

• Airport service
• Agricultural
• Commercial
• Construction
• Industrial
• Lawn garden
• Logging
• Railroad maintenance

• Recreational equipment
• Recreational marine
• More than 80 basic and 260 specific categories.
• (Use Volume IV for commercial marine,
  locomotives, and aircraft.)

59
Pollutants Reported

• HC (THC, TOG, NMOG, NMHC, VOC)
• Non-exhaust HC by Mode (diurnal, refueling,
  crankcase)
• HC not reported (hot soak, running
  loss, resting loss)

• NOx
• CO
• CO2
• SOx
• PM (PMtot , PM10, PM2.5)
• Fuel Consumption

60
Geographic Coverage

• US Total
• State
• County
• Option to add sub-county data for nonattainment
  area analysis

61
Temporal Coverage

• Estimates of past, present and future year
  emissions
• Annual, seasonal, monthly, or daily emissions
• Daily emissions distinguished by season and
  weekday/weekend day

62
Inputs Default Data

• Equipment Population
• Useful Life and Scrappage
• Activity (hours/year)
• Load Factors
• Emission Factors

• Emission Deterioration Factors
• Growth Rates
• Geographic Allocation
• Temporal Allocation

63
Control Programs

• RFG Fuel parameters can be specified
• RVP and percent oxygen
• Stage II
• Percent of equipment refueled at pumps with Stage
  II controls

64
Control Programs

• Phase 1 and 2 Small Spark-Ignition Engine
• Under 25 hp or 19 kWts Emission Standards
• Tier I, II, and III Compression-Ignition Emission
  Standards
• Since the Tier III rulemaking is not yet
  finalized, the benefit estimates of Tier III may
  change.

65
Growth Rates

• EPA will provide guidance with the final model on
  regional growth rates

66
Report Options

• County
• Equipment Category
• Equipment Type/SCC
• Horsepower
• Fuel Consumption

67
Reporting Utility Output Format Options

• ASCII File
• Pre-formatted ACCESS Reports
• ACCESS not required
• ACCESS Database
• Excel Spreadsheet
• NET File (final version)

68
Scenario Input Options

• Year
• Temporal Period (Season, Month, Weekday/Weekend
  Day)
• Geographic Area
• Equipment Type
• Fuel Characteristic

69
Inputs Sensitivity

• Population and activity are local inputs with the
  greatest effect on emissions
• Geographic allocation indicators, RVP,
  temperature, and percent oxygen also affect
  emissions at the state and county level
• States are encouraged to test the model
  sensitivity to variations in their own local
  inputs

70
Inputs Using Local Data

• EPA recommends that states only change population
  and activity simultaneously
• Not changing these inputs simultaneously could
  result in distorted emissions estimates

71
New SCCs

• A/C Refrigeration Equipment
• Used on truck trailers for perishable cargo
• SCC 22xx003060
• Oil Field Equipment
• SCC 22xx010010
• Underground Mining Equipment
• SCC 22xx009010

72
New SCCs

• Lawn and Garden Residential / Commercial
  Equipment
• SCC 22xx004010 / 22xx004011
• Irrigation Sets
• SCC 22xx005060
• Railroad Maintenance Equipment
• SCC 228500x015

73
New SCCs

• Personal Water Craft
• SCC 22xx005015
• Inboard and Sterndrive Pleasure Craft Engines
  (combined)
• SCC 22820x0005

74
Basis for Comparison

• Time Period Calendar Year 1999
• HDD 2007 national estimates using June-2000
  version with national defaults
• current publicly available version
• NR 2002 national estimates from 1999 NEI, final
  version 2
• sums of county inventories
• recently released to states

75
Inventory Comparison VOC
National Estimates for 1999
76
Inventory Comparison CO
National Estimates for 1999
77
Inventory Comparison NOx
National Estimates for 1999
78
Inventory Comparison SOx
National Estimates for 1999
79
Inventory Comparison PM10
National Estimates for 1999
80
Inventory ComparisonDiesel Fuel Consumption
National Estimates for 1999
81
Inventory Comparison SI Diesel
National Estimates for 1999
82
Inventory Comparison SI Diesel
National Estimates for 1999
83
NONROAD Web Sitehttp//www.epa.gov/oms/nonrdmdl.h
tm

• Other Electronic Information Sources
• Listserver
• Subscriber instructions on nonroad web page
• Email nonroad_at_epa.gov