6. Non-Road Strategies
Non-road vehicles and equipment include railroads, marine vessels, airport ground support equipment, lawn and garden equipment, construction and agricultural equipment, and other mobile equipment. There are a wide range of technologies and operational strategies available to address these sources. The strategies presented below focus on policies and programs which can be implemented at the state and local level.
27. Locomotive Replacement or Repowering
Strategy Overview
Locomotives have long life, with some remaining in active use for more than 30 years. Typically, locomotives are overhauled about every eight years and repowered at least once. EPA has adopted emissions standards for locomotives that substantially reduce emissions compared to uncontrolled levels. The Tier 1 standards apply to original model years between 2002 through 2004; Tier 2 standards apply to original model years of 2005 and later. The standards result in a 45 percent reduction in NOx emissions for Tier I locomotives and a 59 percent reduction in NOx for Tier II locomotives, compared to baseline values. Thus, replacing or repowering pre-2002 locomotives with newer models tends to reduce emissions. Newer locomotives are also more fuel efficient, and therefore use less fuel and produce fewer emissions for a given level of power output.
Emissions Impacts
The level of emissions reduction will depend on the type of replacement locomotive or engine, the use of the locomotive (line haul, switcher, etc.), and the type of fuel used. In addition, combining locomotive replacement and/or repowers with idling reduction technologies and/or ULSD fuel can achieve additional emissions reductions beyond what is documented here.
Locomotives are a significant source of NOx and PM emissions53. Although switcher and passenger locomotives generate less overall emissions than line-haul freight locomotives, their emissions are also of concern because they are often geographically concentrated in urban rail yards. Locomotive replacement/repowering can result in reductions in NOX, PM, and VOCs, as shown below:
Table 6-1: Locomotive Replacement/Repowers - Expected Emissions Reductions
|
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH-3 |
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
(-) = Decrease expected, but not quantified in EPA guidance; N = No effect; not quantified in EPA guidance
General Considerations
Key factors affecting emissions include:
- The age and remaining useful life of the existing locomotive
- The level of use of the existing locomotive
- The age and expected use of the replacement/repowered locomotive
For locomotive replacement, a key factor affecting the level of emission reduction achieved by this strategy is the relative usage of the old and new locomotive. Newer locomotives are significantly more efficient than older locomotives, so railroads use them more intensively. Older line-haul locomotives are sometimes shifted to switch yard operation, where they are used less. If a replacement locomotive is operated more hours than the older locomotive it replaces, or if the older replaced locomotive is not retired but rather shifted to other uses, the calculation of emissions impact must account for this difference.
For EPA guidance on emission factors, see "Emission Factors for Locomotives," http://www.epa.gov/otaq/regs/nonroad/locomotv/frm/42097051.pdf
Sample Project
Repowering a 1987 Locomotive
A Class I railroad operator in California proposes to repower a 1987 line haul locomotive, replacing the original engine with a new 2006 (Tier 2) engine. It is assumed in this example that the locomotive consumes 75,000 gallons of fuel annually within the nonattainment area, with both the old and new engine, in the same type of line-haul service.
Locomotive emissions are calculated based on fuel consumption. Emission factors are often reported in grams per brake horsepower-hour (bhp-hr); they can be converted to grams per gallon by assuming 20.8 bhp-hr/gallon.
Step 1: Calculate annual baseline emissions.
= (Baseline emission factor) x (baseline fuel consumption rate) x (grams to tons conversion)
Baseline NOx = (178 g/gal)(75,000 gal/yr)(1 ton/907,200 g) = 14.7 ton/yr NOx
Baseline VOC = (10 g/gal)(75,000 gal/yr)(1 ton/907,200 g) = 0.83 ton/yr VOC
Baseline PM-10 = (6.7 g/gal)(75,000 gal/yr)(1 ton/907,200 g) = 0.55 ton/yr PM-10
Step 2: Calculate annual repowered locomotive emissions.
= (Repowered emission factor) x (repowered fuel consumption rate) x (grams to tons conversion)
Baseline NOx = (103 g/gal)(75,000 gal/yr)(1 ton/907,200 g) = 8.5 ton/yr NOx
Baseline VOC = (5.4 g/gal)(75,000 gal/yr)(1 ton/907,200 g) = 0.45 ton/yr VOC
Baseline PM-10 = (3.6 g/gal)(75,000 gal/yr)(1 ton/907,200 g) = 0.30 ton/yr PM-10
Step 3: Calculate emissions reductions.
= (Baseline emissions) - (repowered emissions)
NOx = (14.7 tons/yr) - (8.5 tons/yr) = 6.2 tons/yr
VOC = (0.83 tons/yr) - (0.45 tons/yr) = 0.38 tons/yr
PM-10 = (0.55 tons/yr) - (0.30 tons/yr) = 0.26 tons/yr
The impacts of implementing this strategy in 2010 would be similar the 2006. Table 6-2 summarizes the emissions impacts.
Table 6-2: Total Emissions Reductions (tons/year) from Locomotive Replacement Example
|
PM-2.5 |
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH-3 |
|---|---|---|---|---|---|---|---|
2006 |
0.26 |
0.26 |
0 |
6.2 |
0.38 |
NA |
NA |
2010 |
0.26 |
0.26 |
0 |
6.2 |
0.38 |
NA |
NA |
It is currently not possible to accurately estimate the impacts of this strategy implemented in 2020. EPA has announced its intent to propose more stringent emission standards for new locomotive diesel engines. The new standards are expected to be modeled after the 2007/2010 highway and Tier 4 non-road diesel engine programs, with an emphasis on achieving large reductions in emissions of PM and air toxics through the use of advanced emission control technology. Thus, a new locomotive in 2020 will likely have much lower emission rates than current new locomotives. But it is not possible to estimate emission factors 2020 locomotives.
28. Rail Electrification
Strategy Overview
Converting railways to electrical power would require installation of an overhead power distribution system along the converted tracks, in addition to restructuring of signaling systems, communication systems, bridges, and other structures to be electrically compatible. Diesel locomotives would also need to be replaced with self-propelled Electric Multiple Unit (EMU) trains, or electric locomotives pulling unpowered railcars similar to the present trains.
Emissions Impacts
Rail electrification should yield reduced emissions of all pollutants emitted by diesel engines.; Additional emissions benefits may be achieved if electrification results in increased train reliability, service frequency, and ridership gains. Electrification provides quick acceleration and deceleration, which allows for trains to run more frequently while fewer moving parts and less wear on the wheels decreases delays due to breakdowns and repairs.
Table 6-3. Rail Electrification Strategy - Overall Impact on Emissions
|
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH3 |
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
(-) = Decrease expected, but not quantified in EPA guidance
General Considerations
Factors affecting the level of emissions impact include:
- The local power generation source for the new electricity
- The type of service provided by the rail and locomotive being electrified
For EPA guidance on emission factors, see "Emission Factors for Locomotives," http://www.epa.gov/otaq/regs/nonroad/locomotv/frm/42097051.pdf
Sample Project
Electrification of Locomotives
This sample is based on an electrification project of CalTrain for the Metropolitan Transportation Commission in San Francisco, California. The project would replace the existing diesel locomotive fleet on a one-for-one basis with electric locomotives which would continue to haul the existing fleet of gallery cars. Details of the project are as follows:
- Power for the electric vehicles will be drawn from an overhead contact system (OCS) through a roof-mounted pantograph.
- The design locomotive for evaluation of the impacts of electrification is the ADtranz ALP-46.
- CalTrain is a commuter rail system in the San Francisco area covering a 77 mile corridor.
- 96 one-way train trips (weekday) and 30 one-way train trips (weekend)
- 260 operating days per year (weekday service) and 105 operating days per year (weekend service)
Step 1. Calculate miles traveled per year.
= (One-way train trips per day) x (length of one-way trip) x (operating days)
= [(96) x (77 mi) x (260)] + [(30) x (77 mi) x (105)]
= 2,164,470 miles traveled per year
Step 2. Calculate annual baseline emissions and convert to tons per year. Results indicate energy consumption by diesel locomotives that would be offset by electricity.
= (Miles traveled per year) x (fleet average emission factors for all locomotives54)
Step 3. Calculate emissions from electricity production and transmission, based on the California energy mix.
= (Miles traveled per year) x (electricity emission factors55)
Step 4. Calculate annual emissions reduced.
= (Baseline emissions) - (electricity emissions)
Table 6-4. Total Emissions Reductions (tons/year) from Rail Electrification Example
|
PM-2.5 |
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH-3 |
|---|---|---|---|---|---|---|---|
2006 |
93.6 |
93.6 |
296 |
2,603 |
148 |
97.3 |
NA |
2010 |
86.3 |
86.3 |
296 |
2,272 |
133 |
97.3 |
NA |
2020 |
71.7 |
71.7 |
296 |
1,939 |
116 |
97.3 |
NA |
29. Locomotive Idling Reduction
Strategy Overview
Locomotive operators, similar to heavy-duty truck operators, idle their engines to maintain battery charge, warmth of the engine coolant, fuel, oil, and water, and comfortable temperatures inside the operator cabs.Locomotives also idle to ensure the engine is readily available (avoiding unnecessary starting and shutting-down), and because of timing delays. Encouraging or implementing switching yard operational improvements and vehicle anti-idling technologies reduce emissions by increasing the efficiency of the existing rail system.
An idle reduction technology consists of the use of an alternative energy source in lieu of using the main switch yard line (SYL) engine or a device designed to reduce long duration idling. Some of these technologies are mobile and attach onto the SYL (mobile auxiliary power units (APUs)), and provide heat or electrical power. Another technology involves electrifying SYL parking spaces (stationary locomotive parking electrification) and modifying the SYL. In general, this involves installing electric powered heating systems on SYL which connect to the electrical grid and provide energy to operate on-board equipment.
Emissions Impacts
Rail idling reduction will result in reduced emissions of all pollutants emitted by diesel engines, as shown below:
Table 6-5: Locomotive Idling Reduction - Overall Impact on Emissions
|
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH3 |
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
(-) = Decrease expected, but not quantified in EPA guidance
General Considerations
Factors affecting emissions reductions include:
- The number of locomotives equipped with anti-idling technologies
- The average number of hours idling each day
- Implementation in conjunction with locomotive replacement or repower projects may offset some benefits.
- Installation of APU does not guarantee idle reduction. Operators may require training and monitoring in order to ensure that use of the main engine is minimized
For EPA guidance, see "Guidance for Quantifying and Using Long Durations Switch Yard Locomotive Idling Emissions reductions in State Implementation Plans," http://www.epa.gov/otaq/smartway/documents/420b04002.pdf. For more information, also see,
Sample Project
Switch Yard Locomotive APUs
This project would install auxiliary power units (APUs) on all switch yard locomotives. An APU consists of a small diesel engine that allows the locomotive engine to be shut down while maintaining the vital systems of the locomotive, such as heating and circulating the coolant and oil, charging the batteries, and powering the cab heaters. The sample project includes the following inputs, based on those provided in EPA guidance56 and a demonstration project.57
- 5 EMD switch yard locomotives
- Average 10 hours of long duration idling, daily
- APU engine is a 3-Cylinder, 27 hp EPA Tier 1 Certified Diesel Engine (Lister Petter LPWS 3)
- The APU operates at 10.2 brake horsepower
- 8 out of 10 hours of locomotive idling time to be eliminated
Step 1: Calculate the average annual emissions reduced.
= (Emissions factor for switch-yard locomotive) x (number of hours per day idle reduction technology is to be used) x (days in use per year) x (grams to tons conversion)
NOx = (777 g/hr) x (8 hrs/day) x (300 days/yr) x (1 ton/907,200 g) = 2.06 tons/yr
PM-10 = (20 g/hr) x (8 hrs/day) x (300 days/yr) x (1 ton/907,200 g) = 0.053 tons/yr
Step 2: Calculate the annual emissions from the APU.
= (Emissions factor for APU) x (average daily hp load for engine) x (daily operation hours) x (days in use per year) x (grams to tons conversion)
NOx = (12.6 g/bhp-hr) x (10.2 bhp) x (8 hr/day) x (300 days/yr) x (1 ton/907,200 g) = 0.340 tpy
PM-10 = (0.66 g/bhp-hr) x (10.2 bhp) x (8 hr/day) x (300 days/yr) x (1 ton/907,200 g) = 0.018 tpy
Step 3: Determine net NOx emissions reduction per locomotive.
= (Average annual locomotive emissions reduced) - (average annual emissions of APU)
NOx = (2.06 tons/yr) - (0.34 tons/yr) = 1.72 tons/yr
PM-10 = (0.053 tons/yr) - (0.018 tons/yr) = 0.035 tons/yr
Step 4: Determine sum of all emissions reductions for project.
= (Number of participating locomotives) x (net emission reduction)
NOx = (5) x (1.72 tons/yr) = 8.58 tons/yr
PM-10 = (5) x (0.035 tons/yr) = 0.18 tons/yr
The impacts of implementing this strategy in 2010 would be similar the 2006. The table below summarizes the emissions impacts.
Table 6-6: Total Emissions Reductions (tons/year) from Locomotive Idle Reduction Example
|
PM-2.5 |
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH3 |
|---|---|---|---|---|---|---|---|
2006 |
0.18 |
0.18 |
NA |
8.58 |
NA |
NA |
NA |
2010 |
0.18 |
0.18 |
NA |
8.58 |
NA |
NA |
NA |
According to EPA, most all diesel PM is submicron in size. Therefore, EPA believes it is reasonable to use the same idling emission factor for both PM2.5 and PM10.58 It is currently not possible to accurately estimate the impacts of this strategy implemented in 2020. EPA is expected to adopt more stringent emission standards for new locomotive diesel engines by that time, but details of those standards are not yet available.
30. Marine Vessel Replacement or Repowering
Strategy Overview
Marine vessel emissions can be reduced through accelerated retirement of existing vessels (replacement) or repowering, which involves replacing an older mechanical engine with a newer, electronic one. EPA recently established new emission standards for Category 1, 2, and 3 commercial marine engines, which take effect between 2004 and 2007. Use of these engines to replace older engines will reduce emissions of most pollutants. In addition, natural gas engines have recently entered the marine engine market with growing support, and can offer significant emissions benefits over diesel engines.
Emissions Impacts
Engine optimization modifications are evolving through land-based engines in response to the tightening of on-road and off-road regulatory requirements. Marine engines are expected to incorporate many of these improvements over time, including basic redesign of the combustion chambers, retarding the timing, improving high-pressure fuel injection systems, upgrading or adding aftercooling and turbocharging, injecting water into the air intake using humid air motors (HAM), and exhaust gas recirculation (EGR). The benefits of these technology improvements will be reflected through the certification of new engines with lower emission rates and adoption of the National Blue Skies Series Program standards. The level of emissions reduction will depend on the type of engine used in the replacement.
Table 6-7: Marine Replacement or Repower - Overall Impact on Emissions
|
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH3 |
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
N = No change; not quantified in EPA guidance; (-) = Decrease expected, but not quantified
General Considerations
The following factors may affect emissions impacts:
- Age and emissions characteristics of engine
- Annual hours of usage
- Any change in usage (type or hours) after the project
- Any change in engine horsepower
- Disposition of replaced vessel/engine (must be scrapped for full benefits)
Sample Project
Fishing Vessel Auxiliary Engine Repower
A charter fishing vessel owner wishes to repower a 125 horsepower 1985 auxiliary engine with a new 2005 model year 200 horsepower engine.59 The auxiliary engine is operated 900 hours per year. The old engine operates at a load factor of 0.43; the new engine operates at a load factor of 0.27. The following steps illustrate the calculation of the emissions benefits of this project.
Step 1: Calculate annual baseline emissions.
= (Baseline emissions factor) x (baseline horsepower) x (baseline engine load factor) x (baseline annual hours of operation) x (grams to tons conversion factor)
Baseline NOx = (10.2 g/bhp-hr) x (125 hp) x (0.43) x (900 hr/yr) x (1 ton / 907,200 g) = 0.54 ton/yr
Baseline VOC = (1.06 g/bhp-hr) x (125 hp) x (0.43) x (900 hr/yr) x (1 ton / 907,200 g) = 0.057 ton/yr
Baseline PM10 = (0.396 g/bhp-hr) x (125 hp) x (0.43) x (900 hr/yr) x (1 ton / 907,200 g) = 0.021 ton/yr
Step 2: Calculate annual repowered vessel emissions.
= (Repower emissions factor) x (repower horsepower) x (repower engine load factor) x (repower annual hours of operation) x (grams to tons conversion factor)
Repower NOx = (4.17 g/bhp-hr) x (200 hp) x (0.27) x (900 hr/yr) x (1 ton / 907,200 g) = 0.22 ton/yr
Repower VOC = (0.39 g/bhp-hr) x (200 hp) x (0.27) x (900 hr/yr) x (1 ton / 907,200 g) = 0.021 ton/yr
Repower PM10 = (0.14 g/bhp-hr) x (200 hp) x (0.27) x (900 hr/yr) x (1 ton / 907,200 g) = 0.008 ton/yr
Step 3: Calculate emissions reductions
= (Baseline emissions) - (repowered emissions)
NOx = (0.54 tons/yr) - (0.22 tons/yr) = 0.32 tons/yr
VOC = (0.057 tons/yr) - (0.021 tons/yr) = 0.036 tons/yr
PM10 = (0.021 tons/yr) - (0.008 tons/yr) = 0.013 tons/yr
The impacts of implementing this strategy in 2010 would be similar the 2006. The following table summarizes the emissions impacts.
Table 6-8: Total Emissions Reductions (tons/year) from Fishing Vessel Repower Example
|
PM-2.5 |
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH3 |
|---|---|---|---|---|---|---|---|
2006 |
NA |
0.01 |
NA |
0.32 |
0.04 |
NA |
NA |
2010 |
NA |
0.01 |
NA |
0.32 |
0.04 |
NA |
NA |
It is currently not possible to accurately estimate the impacts of this strategy implemented in 2020. EPA announced its intent to propose more stringent emission standards for all new Category 1 and 2 marine diesel engines. The new emission standards are expected to be modeled after the 2007/2010 highway and Tier 4 non-road diesel engine programs, with an emphasis on achieving large reductions in emissions of PM and air toxics through the use of advanced emission control technology. Thus, a new marine engine in 2020 will likely have much lower emission rates than current new engines, but it is not possible to estimate emission factors for 2020 marine engines.
31. Marine Vessel Operational Strategies
Strategy Overview
Several operational strategies are effective for reducing emissions from marine vessels. In general, four operating modes characterize ship calls on a port: hotelling at a berth, maneuvering around the berth area, maneuvering within the designated reduced speed zone (RSZ) between the berthing area and the breakwater, and cruising in open water. Vessel emissions from hotelling are due solely to the auxiliary engines used to provide power to the ship for climate control, pump operation, etc. while docked. Hotelling emissions can be reduced through "cold ironing", which uses shore power to replace operation of the vessel auxiliary engine. Reducing vessel speed is another strategy for reducing emissions. Ports can implement this strategy by expanding the reduced speed zone around a port.
Emissions Impacts
Marine vessel operational strategies have the potential to reduce emissions of all pollutants.
Table 6-9: Marine Operational Strategy - Overall Impact on Emissions
|
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH3 |
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
(-) = Decrease expected, but not quantified
General Considerations
Factors affecting emissions impact include:
- Type of vessels serving a port and number of vessels calls
- Type of fuel (and sulfur level) available for auxiliary engines
- Vessel power demands during hotelling time
Sample Project
Cold Ironing (Vessel Shore Power)
Cold ironing involves retrofitting ocean going vessels to allow them to receive shore power from the local grid to meet their energy needs while docked at the port, thus allowing them to shut off their auxiliary engines. These projects typically also require major improvements to the electrical infrastructure at a port. The effectiveness of the strategy is related to the hotelling time of the participating vessels, the annual number of calls on the port by each vessel, vessel generator load, and the pollutant emission factors of the auxiliary power supply.
Annual hotelling emissions for a given vessel are the product of the average time in hotelling mode, power used, emissions factors, and number of annual calls. To estimate the effect of cold ironing on emissions, it is important to first determine the number of vessels that are likely to participate. Very few vessels are currently equipped to use shore power for all hotelling needs, and retrofitting vessels is cost-effective only for those that have long hotelling times, multiple annual vessel calls, and high auxiliary power needs. For participating vessels, it can be assumed that all hotelling power is derived from shore power rather than auxiliary engine, so the only factor changed in calculating the effect of cold ironing is the emission factor.
Emissions factors for marine vessels are poorly understood. The development of the latest emission inventory for the Port of Los Angeles included collection of in-use emissions data and development of new vessel emission factors, and this study offers the most accurate values currently available.60 For Category 2 auxiliary engines, these factors are 19.71 g/hp-hr for NOx and 0.40 g/hp-hr for PM.
Accurately calculating emissions required obtaining, for each vessel, the number of annual calls, the time in hotelling mode, the power, and load factor. Emissions for each participating vessel can then be summed to determine total baseline emissions. Emission factors associated with electrical power generation for a specific region can be obtained from EPA's Emissions & Generation Resource Integrated Database (eGRID)61.
Step 1: Calculate baseline vessel emissions [to be repeated for each vessel type].
= (Annual calls on port) x (average time in hotelling mode) x (operating power in hotelling mode) x (load factor) x (emissions factor)
Containership NOx = (72 calls/yr) x (13.7 hotelling hrs/call) x (7,700 horsepower in auxiliary mode) x (0.17 load factor) x (19.71 g/hp-hr) = 28.1 tons/yr
Containership PM-10 = (72 calls/yr) x (13.7 hotelling hrs/call) x (7,700 horsepower in auxiliary mode) x (0.17 load factor) x (0.40 g/hp-hr) = 0.57 tons/yr
[Repeat for each ship type]
Step 2: Calculate vessel emissions using cold ironing.
= (Annual calls on port) x (average time in hotelling mode) x (operating power in hotelling mode) x (load factor) x (emissions factor for power generation)
Containership NOx with cold ironing = (72 calls/yr) x (13.7 hotelling hrs/call) x (7,700 hp) x (0.17 load factor) x (0.846 g/hp-hr) = 1.2 tons/yr
Containership PM=10 with cold ironing = (72 calls/yr) x (13.7 hotelling hrs/call) x (7,700 hp) x (0.17 load factor) x (0.017 g/hp-hr) = 0.024 tons/yr
Step 3: Calculate emission reduction.
= (Emissions without cold ironing) - (emissions with cold ironing)
NOx = 28.1 - 1.2 = 26.8 tons/yr
PM-10 = 0.57 - 0.024 = 0.54 tons/yr
The impacts of implementing this strategy in 2010 would be similar the 2006. The following table summarizes the emissions impacts.
Table 6-10: Total Emissions Reductions (tons/year) from Marine Operations Example
|
PM-2.5 |
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH-3 |
|---|---|---|---|---|---|---|---|
2006 |
NA |
0.54 |
NA |
26.8 |
NA |
NA |
NA |
2010 |
NA |
0.54 |
NA |
26.8 |
NA |
NA |
NA |
It is not possible to accurately quantify the impact of this strategy in 2020 because of the lack of emission factors for marine vessels in that year.
32. Transportation Related Equipment
Strategy Overview
While transportation construction and related equipment produces only short term impacts, they are also one of the only mobile emissions sources under the direct control of transportation agencies. Thus, these projects have little uncertainty and potentially fewer unknown implementation costs. Projects to replace or repower uncontrolled diesel engines in off-road equipment with lower-emitting, controlled diesel engines or alternative fueled engines can reduce emissions associated with transportation project construction.
Emissions Impacts
Emissions reductions are typically associated with NOx reductions, although this is dependant on the type of engine found in the heavy-duty transportation machinery.
Table 6-11. Transportation Related Equipment Strategy - Overall Impact on Emissions
|
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH-3 |
|---|---|---|---|---|---|---|
|
|
|
|
|
|
|
(-) = Decrease expected, but not quantified in EPA guidance; N = No effect; not quantified in EPA guidance
General Considerations
Factor affecting emissions impacts include:
- The number of engines estimated to be equipped with new technologies
- The age and emissions characteristics of the engine
- The activity life of the equipment on the construction project
- The remaining useful life of the equipment
For EPA guidance, see "Diesel Retrofits: Quantifying and Using Their Benefits in SIPs and Conformity," http://www.epa.gov/oms/stateresources/transconf/policy/420b06005.pdf.
Sample Project
A Scraper Repower
A city transportation construction department will purchase a new off-raod diesel engine rated at 300 hp (Tier 2 engine) to replaces a 1997 diesel engine rates at 300 hp (Tier 1) used in a construction scraper62.Project specifics are as follows:
- Baseline engine is a 300 hp 1997 (Tier 1)
- 1,000 hours annual operation
- New engine is 300 hp 2003 engine (Tier 2)
Step 1: Estimate baseline emissions based on hours of operation
= (Emissions factor) x (load factor) x (horsepower) x (annual hours of operation) x (1 ton/907,200 g)
= (6.0 g/bhp-hr) x (.72) x (300) x (1,000) x (1/907,200)
= 1.43 tons/year
Step 2: Estimate new emissions based on hours of operation
= (Emissions factor) x (load factor) x (horsepower) x (annual hours of operation) x (1 ton/907,200 g)
= (3.97 g/bhp-hr) x (.72) x (300) x (1,000) x (1/907,200)
= 0.94 ton/yr
Step 3: Calculate annual emissions reductions
= (Baseline emissions) - (new emissions)
= (1.43) - (0.94)
= 0.49 ton/year NOx
Table 6-12. Total Emissions Reductions (tons/year) from Transportation Equipment Example
|
PM-2.5 |
PM-10 |
CO |
NOx |
VOCs |
SOx |
NH-3 |
|---|---|---|---|---|---|---|---|
2006 |
NA |
.01 |
NA |
0.49 |
NA |
NA |
NA |
53.According to EPA, most all diesel PM is submicron in size. Therefore, EPA believes it is reasonable to use the same idling emission factor for both PM2.5 and PM10.
54 Emission factors can be found in EPA's "Technical Highlights: Emission Factors in Locomotives," http://www.epa.gov/OTAQ/regs/nonroad/locomotv/frm/42097051.pdf For SOx emission factors: http://www.energyconversions.com/locoemis.htm for SO2 emissions
55 Impacts for NOx, and SO2 obtained from The Emissions & Generation Resource Integrated Database (E-GRID2002), Version 1.0 files, 2000 data sheets, released December 2002, www.epa.gov/cleanenergy/energy-resources/egrid/archive.html, accessed 8/13/03. Impacts for CO and energy consumption obtained from Monterey County 21st Century General Plan Update Fact Sheet, http://www.co.monterey.ca.us/gpu/FactSheets/energy.htm, accessed 2/10/03 and from US DOE (1994) Evaluation of Electricity Consumption in the Manufacturing Division, http://www.eia.doe.gov/emeu/mecs/mecs94/ei/elec.html, accessed 2/10/03.
56 Guidance for Quantifying and Using Long Durations Switch Yard Locomotive Idling Emissions reductions in State Implementation Plans, available at: http://www.epa.gov.
57 Vancouver, WA Switchyard Locomotive Idle Reduction Project: Final Report to EPA, Southwest Clean Air Agency, October 18, 2005, available at http://www.westcoastdiesel.org/files/other/EPA%20Locomotive%20Case%20Study.pdf
58 See: EPA, Guidance for Quantifying and Using Long Durations Switch Yard Locomotive Idling Emissions reductions in State Implementation Plans.
59 This example taken from The Carl Moyer Program Guidelines, Part IV, California Air Resources Board, 2005.
60 Starcrest Consulting Group, Port-Wide Baseline Air Emissions Inventory, Prepared for the Port of Los Angeles, 2004.
61 Available at http://www.epa.gov/cleanenergy/egrid/index.htm
62 Documented in "The Carl Moyer Memorial Air Quality Standards Attainment Program Guidelines," for the California Air Resources Board, 2003.