Post on 30-Dec-2015
description
FINAL 1
Inventory, Emissions, and Population
July 2, 2003
AIR, Inc.
FINAL 2
Overview
• Exhaust Emissions
• Evaporative Emissions
• Populations
FINAL 3
Materials Received/Utilized from ARB
Population and Activity Memo April 14Hot soak RVP data April 15Evaporative Spreadsheets (preliminary) April 17Evaporative Emissions Memo April 21Tier 3 Exhaust Emission Factors May 1Lifetime emissions and cost effectiveness June 5Equipment Survey Data June 8Total inventories June 26Cost effectiveness model/assumptions June 30Inventories split by exhaust vs evaporative July 1Audit data analysis ??
FINAL 4
Exhaust Emissions
• Major comment is that the baseline does not reflect the Premium Program– baseline is used to determine cost effectiveness of proposed Tier 3
exhaust standards
FINAL 5
Premium Program
• What is it?
• Performance
• OFFROAD assumptions
• Lifetime emission impacts
• Summary
FINAL 6
What is it?
• 1999 exhaust proposal included Tier 2 and Tier 3– Tier 2 implemented in 2000, Tier 3 was to be implemented in 2004
• Final rule included Tier 2 and Premium Program– Premium Program covered the emission reductions of Tier 3
– Briggs and Stratton and Tecumseh were participants
FINAL 7
2002 Class 1 Engine Exhaust HC + NOx
0.00
2.00
4.00
6.00
8.00
10.00
12.00
Zero Hour Useful Life
HC
+ N
Ox
Preliminary Industry-Wide Estimate
ARB Emission Factor
FINAL 8
2002 Class 2 Engine Exhaust HC + NOx
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Zero Hour Useful Life
HC
+ N
Ox
Preliminary Industry-Wide Estimate
ARB Emission Factor
FINAL 9
Premium Program
• Data show 2002 emissions lower than assumed in some analyses
FINAL 10
OFFROAD Model
• Also does not include the effects of the Premium Program– Districts have not been able to book these reductions
FINAL 11
Tier 3 Lifetime HC + NOx Reductions Per Unit (lbs)
Equipment Without PremiumProgram
With PremiumProgram
Lawnmower 3.1 2.4
Commercial Turf 280.3 238.7
*AIR estimates of emission reductions for both cases
FINAL 12
Tier 3 Exhaust Cost Effectiveness
• Residential Lawnmower
• Assumes ARB standards implemented as proposed
• Exhaust cost increase: $54 (Briggs and Stratton)
• Preliminary estimate: $44,000 per ton of HC+NOx
FINAL 13
Summary - Exhaust Emissions
• ARB should revise its Tier 2 baseline for estimating proposed Tier 3 cost effectiveness
• OFFROAD model should be revised
FINAL 14
Evaporative Emissions
• Concerns:– Baseline and control diurnal and resting losses overestimated
– Baseline running loss deterioration too high
– RVP effect for hot soak and running losses too large
– Running loss reductions depend on technology used
FINAL 15
Diurnal and Resting Losses
• ARB definition of evap processes in OFFROAD model: they cannot overlap
• However, for ARB’s lifetime emission reductions and cost-effectiveness, they do overlap (“partial” diurnals)
• This results in some double-counting of emissions
• This will be addressed in soon-to-be released OFFROAD model, but is not yet addressed in ARB’s lifetime emissions, inventories, or cost/effectiveness– Small effect for residential equipment, significant for commercial
– Could not address magnitude of this effect for workshop
FINAL 16
Running Loss Deterioration
• Diurnal, resting loss and hot soak emissions for lawnmowers estimated on 23 lawnmowers– New, Used, Old
• Running losses estimated on only 4 lawnmowers
• Running loss deterioration not consistent with other evap components– One Alternative: use deterioration on other components to predict
running loss deterioration
• Similar concern for other equipment
FINAL 17
Ratio of Lawnmower Emissions at Different Ages to Emissions at Zero Hour
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
Diurnal Resting Hot Soak Running
Evap Component
Rat
io o
f E
mis
sio
ns
Zero Hour
Used
Old
FINAL 18
Hot Soak and Running Loss RVP Effect
• ARB developed RVP effect at 95F and is applying it at all temperatures
• Annual RVP assumed (8.1) may not reflect seasonal activity differences
• RVP does not have same effect at all temperatures• Increases baseline and controlled emissions by same
percentage (25%), so benefit of controls is also larger• One alternative is to eliminate this effect
FINAL 19
Running Loss Reductions
• ARB estimated at 50%– test data indicates 42%
• New lawnmower percent reduction will not apply when equipment older– Should use g/hr reduction on new engines at all ages
• Also, reductions depend on control technology used– Pressurized system with TPCV only gets permeation benefit,
because pressure controls have to be “open” when engine running
– Canister controls would get permeation + vapor benefit, since canister is connected to tank during engine operation - no data
FINAL 20
Baseline Evaporative HC Lifetime Emissions Per Unit (lbs)
Lawnmower(Class 1)
Commercial Turf(Class 2)
Current Approach 17.5 71.6
With modifiedrunning lossdeterioration
15.1 48.8
Without RVPeffect
14.3 41.3
FINAL 21
Tier 3 Evap HC Reductions Per Unit (lbs)
Lawnmower(Class 1)
Commercial Turf(Class 2)
Current 12.1 42.8
Revised 9.9 24.3
Revised: ARB method and assumptions, and includes changes to baseline, and smallerrunning loss reduction
FINAL 22
Population and Activity
• Evaluated population and activity changes
• Why discuss this?– Population/activityinventoriestargets for alternatives
– Activityproportion of evap vs exhaust
• Concern– Populations must be consistent with Census data
FINAL 23
Populations
• ARB conducted equipment survey
• Survey is being used to update populations
• Large proposed changes in populations– Lawnmowers: 2.4 million to 4 million
– Chainsaws: 0.6 million to 2.1 million
– Trimmers/edgers: 0.8 million to 2.8 million
• Inventories based on these new populations appear in the SCAQMD SIP
FINAL 24
Survey and Method
• 15,000 surveys sent– 2200 responded to survey (<15%)
– 220 agreed to use data loggers (<2%)
• Equipment populations were determined in the 2200 households
• Total California households were determined: 11.5 million
• Popstate = Popsuvey x 11.5 million/2200
• Problem: Survey overweighted single detached residences, which have a higher equipment ownership
FINAL 25
Fraction of Residence Types
Type ARB Survey 2000 Census, California
Single, detached 80% 57%
Single, attached 4% 8%
Multiple 12% 31%
Mobile Home 3% 3%
Boat, van, RV 1% 1%
FINAL 26
Equipment Per Residence
Residence Ratio, Equipment to Residences
Single, detached 1.07
Single, attached 0.07
Multiple 0.07
Mobile home 0.67
Boat/RV 0.67
FINAL 27
Survey
• These tables indicate that sample must be re-weighted by Census residence type fractions
• This will have a significant effect on populations, and therefore, inventories
FINAL 28
Summary - Population
• ARB proposed populations should be revised to match Census residence demographics
FINAL 29
Summary
• Exhaust– Tier 2 baseline emissions should include Premium Program
• Evaporative– Size of inventory and reductions uncertain
• Population– Too high