Hybrid Bus Study
SARTA and Stark State College
Kenneth A. Buie, Principle Investigator Christopher M. Madrigal, Data Analysis
SARTA and Stark State College Hybrid Bus Study
Contents Introduction .................................................................................................................................................. 1
History of SARTA……………………………………………………………………………………………………………………………………..4
Baseline Emissions ........................................................................................................................................ 5
Diesel and Biodiesel Fuel ............................................................................................................................ 12
Hybrid Technology ...................................................................................................................................... 20
Conclusion…………………………………………………………………………………………………………………………………………….23
Citations ...................................................................................................................................................... 24
1
SARTA and Stark State College Hybrid Bus Study
Introduction SARTA has a long history of commitment to the local community and has a reputation of safe, responsive and efficient transportation for all citizens of Stark County. SARTA can now add environmentally responsible to its list of achievements. With the addition of four hybrid-electric buses to its fleet of 38 conventional buses, SARTA is on the path to reducing operating costs through fuel savings and reduced maintenance expenses all while making the world a less polluted place.
Beginning on January 1, 2010 and ending December 31, 2010, the Stark Area Regional Transit Authority (SARTA) and Stark State College (SSC) conducted an environmental impact and cost analysis study of SARTA's transit bus fleet which included 38 conventional Gillig buses and 4 new Gillig diesel-electric hybrid transit buses. In this study we had the unique opportunity to pull two buses out for an “apples-to-apples” comparison. We were able to compare a 2008 Gillig 29 foot non-hybrid bus (0873) to a 2009 Gillig 29 foot hybrid bus (0978). Fuel consumption data, maintenance costs, and miles driven were tracked and analyzed over a one year period. This report describes the evaluation process and details the results of that study. In the Stark county area, SARTA is one of the biggest users of diesel fuel using 367,832.01 gallons in 2010 in the transit buses involved in this one-year study. The typical person drives a car an average of 15,000 miles a year. If that car gets 20 MPG, approximately 750 gallons of gasoline will be used in one year to travel 15,000 miles. The 750 gallons of gasoline put into the gas tank of that 20 MPG car will dump 14,550 pounds of carbon dioxide (CO2) into the atmosphere. If more people ride in the car, the CO2 output and the fuel used over 15,000 miles of driving gets distributed among the other persons in the vehicle. This is the reason many cities have HOV (High Occupancy Vehicle) lanes. This is an incentive to have more persons travel per mile in one vehicle to lower fuel consumption and reduce air pollution. The chart below takes the passenger car scenario from the previous paragraph and adds numbers to the per-person impact of fuel consumption and CO2 emissions. The transit bus data in the chart comes from the “apples-to-apples” comparison of SARTA buses 0873 and 0978 that is included in this study.
Vehicle Miles
Driven Fuel Used
MPG CO2 Emitted
In Pounds Persons in
Vehicle CO2 per Person
Gallons of Fuel per Person
Passenger Car 15,000 750
Gallons 20 14,550
1 2 3 4
14,550 7,275 4,850 3,637
750 375 250 188
Conventional Bus (0873)
15,000 3,018.1 4.97 67,002
4 5
10 15 20
16,751 13,400 6,700 4,467 3,350
755 604 302 201 151
Hybrid Bus (0978)
15,000 2,279.6 6.58 50,607
4 5
10 15 20
12,652 10,121 5,061 3,374 2,530
561 456 228 152 114
Fig. 1.1 Data Comparisons at 15,000 Miles
2
SARTA and Stark State College Hybrid Bus Study
In the chart above, we can see that during 15,000 miles of driving, the conventional SARTA bus with four
riders is within 5 gallons of the fuel consumption of the sample car that has one person in it. The same
conventional bus is actually able to beat the per-person fuel consumption and the per-person CO2
output of the one-person car with just five bus riders.
The hybrid bus is even more energy efficient per person by beating the one-person car’s fuel consumption and CO2 output with just four riders. SARTA bus riders, and bus riders all over the nation, are helping to reduce our country’s dependence on imported oil all while helping to reduce CO2 emissions. This per-person footprint of fuel consumption and CO2 emissions follows us everywhere we go with any mode of motorized travel.
Fig. 1.2 CO2 and Gallon of Fuel Per Person SARTA understands that burning less fuel saves money and reduces pollution at the same time. By investing in fuel-efficient and emissions-friendly buses, SARTA is setting the standard for environmental responsibility and good economic sense. Transit systems around Ohio and the nation are joining SARTA by putting hybrid buses into service. A hybrid bus costs more than a conventional bus but there is more to putting a hybrid bus on the road than just to save money on fuel costs. There are emission and fuel economy standards enacted by the EPA that will only be able to be met with hybrid buses and new diesel fuels. There have been laws for many years that have set standards on automobile and light-truck pollution emissions and fuel economy. On May 21, 2010, a Presidential Memorandum1 directed the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Transportation (DOT) to create the first-ever National Policy to increase fuel efficiency and decrease greenhouse gas (GHG) pollution from medium-duty trucks, heavy-duty trucks, and vocational vehicles (transit buses). In another address to
1 P r e s i d e n t o b a m a d i r e c t s a d m i n i s t r a t i o n t o c r e a t e f i r s t - e v e r n a t i o n a l e f f i c i e n c y a n d e m i s s i o n s s t a n d a r d s f o r m e d i u m - a n d h e a v y - d u t y t r u c k s . ( 2 0 1 0 , M a y 2 1 ) . R e t r i e v e d f r o m
h t t p : / / w w w . w h i t e h o u s e . g o v / t h e - p r e s s - o f f i c e / p r e s i d e n t - o b a m a - d i r e c t s - a d m i n i s t r a t i o n - c r e a t e -
f i r s t - e v e r - n a t i o n a l - e f f i c i e n c y - a n d - e m
http://www.whitehouse.gov/the-press-office/president-obama-directs-administration-create-first-ever-national-efficiency-and-emhttp://www.whitehouse.gov/the-press-office/president-obama-directs-administration-create-first-ever-national-efficiency-and-em
3
SARTA and Stark State College Hybrid Bus Study
the nation on June 15, 20102, the president stated, “Our addiction to foreign oil and fossil fuels puts our economy, our national security, and our environment at risk”. The new HD vehicle emission and fuel economy standards proposed in May of 2010 were not even in place when this study began. In order to meet these new pollution standards, new diesel fuels are needed. Beginning December 1, 2010, all highway diesel fuel must be ultra low sulfur diesel (ULSD). After much debate and several revisions, the Energy Independence and Security Act of 2007 (EISA) enacted legislation late in November 2010 that sets percentage standards on renewable fuel volume to non-renewable fuel volume (gasoline and diesel) requiring that 8% of all fuel used in 2011 to come from renewable sources3. As you will see in this study, SARTA is ahead of the curve to meet these new EPA guidelines for transit buses and diesel fuels. In November of 2010, SARTA began their fleet-wide conversion to B-20 biodiesel by adding a 20,000 gallon in-ground fuel tank to store the locally-produced B-20 biodiesel. On March 15, 2011, the transition to B-20 was completed and all SARTA buses began using B-20 biodiesel. This study will share all of the information learned in the SARTA hybrid-bus study and use it to educate the community on environmental issues that impact our economy and the air we breathe. Special thanks go to the following individuals for their contributions of technical expertise: Mark Finnicum, SARTA Director of Maintenance John Ferrell, SARTA Maintenance Supervisor Matt Buca, Stark State College, GM-STC Stark State College Christopher Madrigal, Stark State College
2 W h i t e h o u s e . ( 2 0 1 0 , J u n e 1 5 ) . E n e r g y & e n v i r o n m e n t . R e t r i e v e d f r o m h t t p : / / w w w . w h i t e h o u s e . g o v / i s s u e s / e n e r g y - a n d - e n v i r o n m e n t 3 E P A . ( 2 0 1 0 , D e c e m b e r 2 1 ) . R e n e w a b l e f u e l s : r e g u l a t i o n s & s t a n d a r d s . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o t a q / f u e l s / r e n e w a b l e f u e l s / r e g u l a t i o n s . h t m
http://www.whitehouse.gov/issues/energy-and-environmenthttp://www.epa.gov/otaq/fuels/renewablefuels/regulations.htm
4
SARTA and Stark State College Hybrid Bus Study
History of SARTA
SARTA was established in 1997 as a county-wide
transit agency for Stark County. SARTA is primarily
funded by a 0.25 percent sales tax in Stark County,
which generated approximately $11 million in 2010 with a total budget of $14 million. SARTA operates
34 buses on Mondays through Saturdays. The total ridership in 2010 was 2.1 million. Most of the
routes are operated between 6 AM and 9 PM, with three late night loops that operate after 10
PM. SARTA’s system is focused on the Cornerstone Transit Center in downtown Canton, but has three
other major transfer points in the three other major developed areas of Stark County, in downtown
Massillon, Alliance, and the Belden Village area north of Canton, where a new transit center is scheduled
to open in 2011. Routes connect the four transfer centers as well as Akron-Canton airport and
downtown Akron. About 24% of Stark County’s land area is within ½ mile of a SARTA route, but the
routes are within walking distance of about 80% of the county’s population.
The routes with the highest ridership are those that connect Massillon, Alliance, and North
Canton/Belden Village with downtown Canton. Those with the lowest serve neighborhoods in Massillon
and Alliance, and the more remote areas of Stark County. The highest ridership routes are generally
also the most productive in terms of riders per hour, with some exceptions.
SARTA’s paratransit service, Proline, provides door to door transportation for qualifying passengers to
anywhere in Stark County. Proline operates six days a week (Monday through Saturday) between the
hours of 5:00 AM and 1:30 AM. SARTA typically operates 39 Proline vehicles on weekdays and 16 on
Saturday. Customers must apply to use the service based on disability, and must make reservations in
advance. Trips from residential areas of the county to shopping and medical locations in the Belden
Village area make up a large proportion of Proline trips.
SARTA Mission: The purpose of Stark Area Regional Transit Authority (SARTA) is to provide safe,
responsive and efficient transportation for all citizens of Stark County.
5
SARTA and Stark State College Hybrid Bus Study
Baseline Emissions On average, each of us breathes in over 3,000 gallons of air each day. If that air contains pollutants,
there’s a strong possibility we will begin to have health problems. In order to keep our air breathable
and safe, the Clean Air Act was established in 1963 to provide funding for the study and for the cleanup
of air pollution. A much stronger Clean Air Act was enacted by congress in 1970 with the creation of the
Environmental Protection Agency (EPA). The EPA is empowered to make and enforce laws to control air
pollution. There have been many amendments made to the 1970 Clean Air Act to give us the emission
standards we have today.
The EPA’s Hit List of Air Pollutants
Pollution from mobile sources like cars, trucks, and buses accounts for 80% of the carbon monoxide (CO)
emissions found in the atmosphere4 . The EPA looks at the six most common air pollutants and calls
them “criteria pollutants”5. The six pollutants that make up the EPA-monitored criteria pollutants list
are:
Carbon Monoxide (CO)
Lead (Pb)
Nitrogen Oxide (NOx)
Sulfur Dioxide (SO2)
Particulate Matter (PM)
Ground-Level Ozone (a combination of NOx and VOCs)
o VOC stands for Volatile Organic Compound6
VOCs include the hydrocarbon (HC) fuels: gasoline and diesel fuel
The six pollutants listed above do not just come from cars, trucks, and buses (mobile sources); they are
also emitted from power plants and factories (stationary sources) that burn fossil fuels.
Five of the six pollutants listed above, SO2, NOx, VOCs, CO, and lead emissions, originate solely from
human activity7. Although, PM emissions can come from wildfires, waste burning, and fireplaces, the
biggest source of PM emissions are in the form of sulfates (SOx) that originate from burning fossil fuels
like coal, gasoline and diesel fuel8.
Certain areas of the U.S. have higher concentrations of air pollution than other areas due to geographic
reasons that can trap air pollutants. Other areas can have higher concentrations of factories and vehicle
4,5,7,8 E P A . ( 2 0 1 0 , A p r i l 0 1 ) . O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / a i r t r e n d s / 2 0 1 0 / ( D o w n l o a d P g . 6 )
5 O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 ( D o w n l o a d Pg. 8)
6 E P A . ( 2 0 0 9 , N o v e m b e r 0 4 ) . V o l a t i l e o r g a n i c c o m p o u n d s . R e t r i e v e d f r o m
h t t p : / / w w w . e p a . g o v / a i r / e m i s s i o n s / v o c . h t m 7 O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 ( D o w n l o a d Pg. 5)
8 O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 ( D o w n l o a d Pg. 24)
http://www.epa.gov/airtrends/2010/http://www.epa.gov/air/emissions/voc.htm
6
SARTA and Stark State College Hybrid Bus Study
traffic causing more air pollution in a particular area. Individually these six pollutants are health and
environmental hazards, but when some of them combine; they produce even more hazardous
pollutants. The two pollutants listed below are formed when multiple criteria pollutants mix together in
the atmosphere and create new atmospheric pollutants.
Ground-Level Ozone
Ground-level ozone is a man-made pollution
that is caused when two of the EPA’s Criteria
Pollutants, NOx and VOCs, come in contact with
sunlight and heat.
Ground-level ozone is the primary component
of smog and is monitored by the EPA due to its
harmful effects to human health. The EPA’s Air
Quality Index (AQI)9 rates air samples in all
major U.S. cities with a rating of 0-50 for good
up to a rating of 301-500 for hazardous.
Fig. 3.1
Particle Pollution
Particle pollution, also known as particulate
matter (PM) is not totally a man-made pollutant.
Some PM comes from naturally occurring fires;
the other PM comes from burning fossil fuels.
PM is classified into two sizes; fine (PM2.5) and
course (PM10). PM2.5 is more harmful to human
health and is found in greater concentrations
than PM10. The main source of PM2.5 is from the
burning of fossil fuels. The sulfur in diesel fuel is a
big contributor to the production of PM in diesel
exhaust.
Fig. 3.2
9 A I R N o w . ( 2 0 1 1 , M a y 0 5 ) . L o c a l a i r q u a l i t y c o n d i t i o n s a n d f o r e c a s t s . R e t r i e v e d f r o m h t t p : / / w w w . a i r n o w . g o v /
http://www.airnow.gov/
7
SARTA and Stark State College Hybrid Bus Study
Ohio ranks 47th in the nation for PM2.5 air quality10 and the chart below shows just how much Ohio
contributed to the annual emissions of criteria pollutants.
Annual Emissions of Criteria Pollutants in Ohio
Pollutant Annual Emissions (Tons) Transportation Sector Contribution
Carbon Monoxide (CO) 3,398,644 88.8%
Nitrogen Oxide (NO2) 18,286,537 58.3%
Particulate Matter Total 711,887 4.5%
PM 2.5 155,003 9.5%
PM 10 556,884 3.1%
Volatile Organic Compounds (VOCs) 15,966,101 43.6%
Fig. 3.3 11
It is the responsibility of the EPA to monitor air pollution and to regulate the sources of pollution from
factories to motor vehicles. Each source of emissions is treated differently due to the nature of the
pollutants and the extent of how much is emitted. For example, factories and power plants are
stationary and usually emit pollutants in the same geographic area high into the air. Mobile sources like
cars, trucks, and buses travel around and emit their pollutants at ground level, close to people. Since the
early 1970’s, passenger car emissions have been increasingly regulated by the EPA. HD trucks and buses
are now beginning to be regulated by the EPA for exhaust emissions.
Transit Bus EPA-Regulated Emission Standards
Even though trucks and buses both have diesel engines, they fall into different EPA emissions categories
due to the nature of how these vehicles are used. There are 8 different classifications for trucks and
buses from Light-Duty (Class 1 and 2), Medium Heavy-Duty (Classes 3 through 6), and Heavy-Duty
(Classes 7 and 8). Transit buses fall into the Heavy-Duty Class-7 category and are also given an additional
classification as vocational vehicles. A Heavy-Duty tractor-trailer vehicle that is primarily driven on the
highway all day with very few stops and starts will have an entirely different emissions profile than a city
bus that possibly never reaches 50 MPH and stops at every intersection.
The following emissions data is exclusive to transit buses. As emissions standards get tighter, the only
way transit buses will be able to comply with the EPA standards is by using electric-hybrid powertrain
systems, advanced after-combustion emission devices, and newly formulated diesel fuels.
10
A m e r i c a ' s H e a l t h R a n k i n g s , . ( 2 0 1 1 , M a y 0 5 ) . S t a t e h e a l t h s t a t s . R e t r i e v e d f r o m h t t p : / / s t a t e h e a l t h s t a t s . a m e r i c a s h e a l t h r a n k i n g s . o r g / , E P A . ( 2 0 1 1 , J a n u a r y 3 1 ) . A i r e x p l o r e r . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / a i r e x p l o r e r /
11 O h i o C l e a n F u e l s . ( 2 0 1 0 ) . T h e 6 r ' s o f d i e s e l c l e a n u p . R e t r i e v e d f r o m h t t p : / / w w w . c l e a n f u e l s o h i o . o r g / i n d e x . p h p ? o p t i o n = c o m _ c o n t e n t & v i e w = a r t i c l e & i d = 2 7 2 & I t e m i d = 2 7
0 ( D o w n l o a d P g . 4 )
http://statehealthstats.americashealthrankings.org/http://www.epa.gov/airexplorer/http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270
8
SARTA and Stark State College Hybrid Bus Study
The following chart lists many of the same pollutants found in the EPA’s Criteria Pollutants list. These are
the emissions standards that the EPA sets for new vehicles based on the year of vehicle production.
These standards are used to certify that the vehicle meets all federal EPA guidelines for tailpipe
emissions. Charts like this are also produced for passenger cars and light trucks. This chart shows the
standards set for urban buses, there are similar standards in place for heavy-duty trucks as well.
Remember that HC falls into the VOC category which is basically unburned diesel fuel.
Urban Bus Engine Emission Standards (g/bhp-hr)
M.Y. NOx HC CO PM NOx + HC
1998* 10.7 1.3 15.5 0.6
1990 6 1.3 15.5 0.6
1991 5 1.3 15.5 0.25
1993** 5 1.3 15.5 0.1
1994 5 1.3 15.5 0.07
1996 5 1.3 15.5 0.05***
1998 4 1.3 15.5 0.05
2004 (EPA ’04): Option 1 15.5 0.05 2.40
2004 (EPA ’04): Option 2 15.5 0.01 2.50
2007 0.2 0.14 15.5 0.01
2010 0.2 0.14 15.5 0.01
* Prior to 1998, only smoke standards applied to heavy-duty diesel engines.
** In 1993, urban buses assigned separate, more stringent emission standard.
*** In 1996, PM certification set at 0.05, but in-use level remained at 0.07.
Fig. 3.4 12
Carbon Dioxide CO2
One gas noticeably missing from the criteria emissions and from the transit bus emissions chart is
carbon dioxide (CO2). Atmospheric carbon dioxide has a direct link to the burning of fossil fuels; gasoline
and diesel fuel are a fossil fuels. Data provided by the EPA shows that fossil fuel combustion contributed
to almost 94% of total CO2 emissions in 200713. The main reason that CO2 is not on the criteria pollutant
list is that it is really not harmful to humans. So why do we hear so much about CO2? It has to do with its
global warming potential as a Green House Gas (GHG). In May of 2010, new EPA regulations were
introduced to set limits on CO2 emissions from trucks and buses.
12 U S E P A , . ( 2 0 1 1 , J a n u a r y 0 7 ) . H e a v y - d u t y h i g h w a y c o m p r e s s i o n - i g n i t i o n e n g i n e s a n d u r b a n b u s e s -- e x h a u s t e m i s s i o n s t a n d a r d s . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / s t a n d a r d s / h e a v y - d u t y / h d c i -e x h a u s t . h t m 13 US E P A . ( 2 0 1 0 , A p r i l 0 1 ) . O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / a i r t r e n d s / 2 0 1 0 / ( D o w n l o a d P g . 6 )
http://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/airtrends/2010/
9
SARTA and Stark State College Hybrid Bus Study
Since CO2 has never been regulated before, the EPA needed to develop a proposed baseline for CO2
output for Class-7 vocational vehicles (transit buses). The EPA certifies all Heavy-Duty engines for
emissions output and fuel economy using the Federal Test Procedure (FTP)14. An FTP baseline was
established and proposed a 2010 baseline of 660 g CO2/bhp-hr15 for CO2 output and a fuel consumption
of 7.43 gal/100 bhp-hr16.
Since the FTP only certifies the engine, the EPA along with NHTSA concluded that reductions in GHG
emissions and improvements in fuel economy would require addressing both the engine and the
vehicle. Since vocational vehicles are not driven like cars, or even like over-the-road HD trucks, setting
MPG standards for fuel economy and CO2 output based on miles driven would not be a realistic
comparison. For vehicle-related emissions the EPA and NHTSA are proposing standards for chassis
manufacturers that would be expressed in moving a ton of payload over one mile. In the final proposal,
the EPA will set standards for CO2 in terms of (g/ton-mile), and NHTSA will have a standard for fuel
consumption of (gal/1,000 ton-mile).
Proposed EPA Standards for Transit Bus CO2 Emissions
The following charts represent the proposed FTP Vocational Diesel Engine Standards and the Proposed
Vocational Vehicle Standards and Percent Reductions.17 18
Model Year Proposed Vocational Diesel Engine CO2 Standards
Over the FTP Cycle
Heavy-Duty
Diesel
Baseline
2010-2013
CO2 Standard (g/bhp-hr)…………………………………………………………….
Voluntary Fuel Consumption Standard (gallon/100 bhp-hr)……..…
660
7.43
2014-2016 CO2 Standard (g/bhp-hr)…………………………………………………………….
Voluntary Fuel Consumption Standard (gallon/100 bhp-hr)……..…
567
5.57
2017 and Later CO2 Standard (g/bhp-hr)…………………………………………………………….
Fuel Consumption (gallon/100 bhp-hr)…………………………….…………
555
5.45
Fig. 3.5
14 US E P A . ( 2 0 0 9 , S e p t e m b e r 1 7 ) . E p a f e d e r a l t e s t p r o c e d u r e ( f t p ) . R e t r i e v e d f r o m
h t t p : / / w w w . e p a . g o v / O M S / s t a n d a r d s / l i g h t - d u t y / f t p . h t m
15 I C C T . ( 2 0 1 1 , J a n u a r y 1 9 ) . E p a / n h t s a g r e e n h o u s e g a s e m i s s i o n s . R e t r i e v e d f r o m h t t p : / / w w w . t h e i c c t . o r g / p u b s / I C C T _ p o l i c y u p d a t e 1 0 _ H D V s t d s . p d f 16 E P A , . ( 2 0 1 1 , J a n u a r y 0 7 ) . H e a v y - d u t y h i g h w a y c o m p r e s s i o n - i g n i t i o n e n g i n e s a n d u r b a n b u s e s - - e x h a u s t e m i s s i o n s t a n d a r d s . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / s t a n d a r d s / h e a v y - d u t y / h d c i -e x h a u s t . h t m 17 US E P A . ( 2 0 1 1 , j a n u a r y 0 6 ) . E p a a n d n h t s a p r o p o s e f i r s t - e v e r p r o g r a m t o r e d u c e g r e e n h o u s e g a s e m i s s i o n s a n d i m p r o v e f u e l e f f i c i e n c y o f m e d i u m - a n d h e a v y - d u t y v e h i c l e s : r e g u l a t o r y a n n o u n c e m e n t . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / c l i m a t e / r e g u l a t i o n s / 4 2 0 f 1 0 9 0 1 . h t m 18 U.S. F e d e r a l G o v e r n m e n t , . ( 2 0 1 0 , D e c e m b e r 2 9 ) . F e d e r a l r e g i s t e r / v o l . 7 5 , n o . 2 4 9 / w e d n e s d a y , d e c e m b e r 2 9 , 2 0 1 0 / p r o p o s e d r u l e s . R e t r i e v e d f r o m h t t p : / / w w w . c o p y r i g h t . g o v / f e d r e g / 2 0 1 0 / 7 5 f r 8 1 9 5 2 . p d f
http://www.epa.gov/OMS/standards/light-duty/ftp.htmhttp://www.theicct.org/pubs/ICCT_policyupdate10_HDVstds.pdfhttp://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/oms/climate/regulations/420f10901.htmhttp://www.copyright.gov/fedreg/2010/75fr81952.pdf
10
SARTA and Stark State College Hybrid Bus Study
Model Year Proposed Vocational Vehicle CO2 Standards
and Percent Reductions
Heavy Chassis
Heavy-Duty
Baseline
2010-2013
Fuel Consumption Baseline (gallon/1,000 ton-mile) ……………………
CO2 Baseline (grams CO2/ton-mile) …………………………………………….
11.3
115
Model Year
2014-2016
Fuel Consumption Standard (gallon/1,000 ton-mile) ………………….
CO2 Standard (grams CO2/ton-mile) …………………………………………..
10.7
109
Model Year
2017 and Later
Fuel Consumption Standard (gallon/1,000 ton-mile) ………………….
CO2 Standard (grams CO2/ton-mile) …………………………………………..
10.5
107
Percent Reduction from 2010 Baseline in 2014 Model Year 5%
Percent Reduction from 2010 Baseline in 2017 Model Year 7%
Fig. 3.6
Calculating CO2 output
For purposes of this study we are using the EPA formulas19 to establish CO2 emission outputs for the
buses used in the SARTA study. Many methods of scientific testing and validation have determined that
one gallon of gasoline will produce 19.4 pounds of CO2, one gallon of regular diesel fuel will produce
22.2 pounds of CO2, and one gallon of B-20 diesel fuel will emit 17.9 pounds of CO2 per gallon20 of fuel.
If you want to dig deeper into the science and chemistry of how one gallon of gasoline or diesel fuel can
produce around 20 pounds of CO2, follow this link http://fueleconomy.gov/Feg/co2.shtml
When less fuel is burned, the there will be less CO2 and less criteria pollutants produced. Less CO2 can
also be accomplished by changing the composition of the fuel to burn cleaner and more efficiently.
Alternatives to traditional diesel fuel are ultra low sulfur diesel (ULSD), biodiesel (B-5, B-20), and natural
(CNG) gas. Alternative fuels are also capable of producing less CO2 and less criteria pollutants.
After-combustion devices that mount to the exhaust system are designed to lower many of the criteria
pollutants found in diesel exhaust, but do less to control CO2 emissions. Automobiles have had catalytic
converters since the mid-70’s. When catalytic converters were added to cars, the gasoline had to change
from leaded fuel to unleaded fuel. The new “catalytic converters” used on buses act in the similar way
that a gasoline-engine catalytic converter does by reducing criteria pollutants in the tailpipe after
combustion takes place in the engine. The bus after-combustion devices also require new diesel fuels
that are lower in sulfur. Just as lead in gasoline clogged catalytic converters, sulfur clogs diesel
converters.
19
US E P A . ( 2 0 1 1 , A p r i l 1 2 ) . E m i s s i o n f a c t s : a v e r a g e c a r b o n d i o x i d e e m i s s i o n s r e s u l t i n g f r o m g a s o l i n e
a n d d i e s e l f u e l . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / c l i m a t e / 4 2 0 f 0 5 0 0 1 . h t m
20 U . S . E n e r g y I n f o r m a t i o n S y s t e m . ( 2 0 1 1 , J a n u a r y 3 1 ) . V o l u n t a r y r e p o r t i n g o f g r e e n h o u s e g a s e s p r o g r a m . R e t r i e v e d f r o m h t t p : / / w w w . e i a . d o e . g o v / o i a f / 1 6 0 5 / c o e f f i c i e n t s . h t m l
http://fueleconomy.gov/Feg/co2.shtmlhttp://www.epa.gov/oms/climate/420f05001.htmhttp://www.eia.doe.gov/oiaf/1605/coefficients.html
11
SARTA and Stark State College Hybrid Bus Study
In 2008, SARTA began using Diesel Particulate Filters (DPF) on their new buses. This required the use of
ULSD fuel to keep the DPFs clean. According to EPA studies21, DPFs used on vehicles burning ULSD can
reduce PM emissions by 85-95% and also reduce HC emissions by 85-95%, and reduce CO emissions by
50-90%.
In 2011, SARTA will begin using buses that will be equipped with DPFs and Selective Catalyst Reduction
(SCR) converters. The same EPA study mentioned above shows that an SCR will reduce harmful NOx
emissions by up to 75%. This will make the SARTA fleet the cleanest diesel fleet in the history of SARTA.
21
U S E P A . ( 2 0 1 1 , M a r c h 0 8 ) . T e c h n o l o g i e s . R e t r i e v e d f r o m h t t p : / / e p a . g o v / c l e a n d i e s e l / t e c h n o l o g i e s / r e t r o f i t s . h t m
http://epa.gov/cleandiesel/technologies/retrofits.htm
12
SARTA and Stark State College Hybrid Bus Study
Diesel and Biodiesel Fuel Fossil-Fuel Powered
All of the emissions that come out the tailpipe of a bus come from the fuel that went into the fuel tank.
Different fuels will create different levels of emissions. If less fuel is burned, fewer emissions are
created. The pollutant NOx does not come from a fossil fuel but it is formed when any fossil fuel is
burned. The two pollutants SO2 (sulfur dioxide) and PM (particulate matter) are both a direct result from
burning diesel fuel. If we lower the level of sulfur in the fuel, SO2 and PM are also reduced.
The U.S. imported 4.25 billion barrels of oil in 2010 at the cost of $337 billion22. In a report published by
the Clean Fuels Ohio, Ohio consumed about 5.2 million gallons of diesel fuel per day in 200823. The same
report goes on to state that the Ohio transportation sector emits 32,060 tons of particulate matter (PM),
10,654,693 tons of nitrogen oxide, and 6,955,360 tons of volatile organic compounds (VOCs) per year24.
Unlike factory smokestacks that emit their pollutants high up in the air, buses emit their pollutants at
ground level and usually near high concentrations of people in an urban environment. The diesel
exhaust pollutant that has the biggest adverse effect on human health is particulate matter (PM).
Regular diesel fuel contains high levels of sulfur, and sulfur has a direct correlation to particulate matter.
The more sulfur in the diesel fuel, the more PM in the exhaust. The relationship between PM and sulfur
has been tied to a ratio that for every 100-ppm reduction in sulfur, there will be a 0.16% corresponding
reduction in PM emissions in light duty vehicles and a 87% reduction in heavy duty applications25.
Even by reducing sulfur in diesel fuel it is still not enough to lower PM emissions to acceptable and safe
levels. Another big diesel exhaust pollutant that must be brought under control is NOx. Ground-level
ozone is formed when NOx and VOCs come in contact with heat and sunlight. The production of NOx is
not so much related to the diesel fuel as it is to the way the diesel engine operates. When a diesel
engine is operating at peak power, NOx is at its highest output.
In order to meet the new EPA mandates for PM and NOx reduction, a three-pronged approach of new
diesel fuels, engine modifications, and after-combustion devices are needed. Engine modifications can
lower NOx but those modifications increase PM output. Diesel Particulate Filters (DPFs) can be added to
the diesel engine’s exhaust to bring PM emissions under control but DPFs require newly-formulated
22
P i c k e n s , T . ( 2 0 1 1 , A p r i l 1 3 ) . O i l i m p o p r t n e w s . R e t r i e v e d f r o m h t t p : / / w w w . p i c k e n s p l a n . c o m / t h e p l a n 2 / o i l i m p o r t s / http://www.pickensplan.com/oilimports/
23 O h i o C l e a n F u e l s . ( 2 0 1 0 ) . T h e 6 r ' s o f d i e s e l c l e a n u p . R e t r i e v e d f r o m h t t p : / / w w w . c l e a n f u e l s o h i o . o r g / i n d e x . p h p ? o p t i o n = c o m _ c o n t e n t & v i e w = a r t i c l e & i d = 2 7 2 & I t e m i d = 2 7
0 ( D o w n l o a d P g . 2 )
24 O h i o C l e a n F u e l s . ( 2 0 1 0 ) . T h e 6 r ' s o f d i e s e l c l e a n u p . R e t r i e v e d f r o m h t t p : / / w w w . c l e a n f u e l s o h i o . o r g / i n d e x . p h p ? o p t i o n = c o m _ c o n t e n t & v i e w = a r t i c l e & i d = 2 7 2 & I t e m i d = 2 7
0 ( D o w n l o a d P g . 4 )
25 A D B . ( 2 0 0 3 ) . P o l i c y g u i d e l i n e s f o r r e d u c i n g v e h i c l e e m i s s i o n s i n a s i a . R e t r i e v e d f r o m
w w w . a d b . o r g / d o c u m e n t s / g u i d e l i n e s / v e h i c l e _ e m i s s i o n s / c l e a n e r _ f u e l s . p d f ( D o w n l o a d P 1 4 )
http://www.pickensplan.com/oilimports/http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270
13
SARTA and Stark State College Hybrid Bus Study
diesel fuels or they will clog up and block the exhaust system. Since 2008, SARTA has equipped their bus
fleet with DPFs lowering their PM emissions.
New Diesel Fuels
Prior to 1993, diesel fuel contained an average of 5,000 ppm of sulfur. From 1993 to 2007 low sulfur
diesel (LSD) was introduced to lower PM in diesel exhaust and its sulfur content was lowered to 500
ppm. On January 1, 2007 ultra low sulfur diesel (ULSD) fuel was introduced that only contained 15 ppm
of sulfur. The EPA mandated that beginning January 1, 2010, only ULSD would be sold for on-road diesel
applications.
Biodiesel Fuel
Biodiesel is a renewable fuel refined from domestically grown vegetable oils, used restaurant fryer oil, or
animal fats. The most common stock to make biodiesel from is vegetable oil but can be made from any
biomass that is a renewable energy source. Most studies that validate the environmental impact of
biodiesel use biodiesel made from vegetable oils or biomass. Biodiesel can be 100% refined vegetable oil
or blended with regular diesel fuel to form a biodiesel blend.
Biodiesel fuels are identified by a capital “B” followed by the percentage of the renewable vegetable oil.
B-100 is 100% biodiesel made from a domestic, renewable, non-petroleum source. B-5 is 5% biodiesel
mixed with 90% regular diesel fuel and B-20, currently the most popular biodiesel, is a mixture of 20%
biodiesel and 80% diesel fuel.
With the enactment of the Energy Independence and Security Act in November of 2010, 8% of all fuels
sold in the US must be bio-based fuels beginning in 2011.
SARTA B-20 biodiesel
Biodiesel fuels burn cleaner than regular diesel fuels and have an added plus in the reduction of CO2
from the fact that the biomass used to produce the biodiesel absorbed CO2 from the atmosphere during
its time as a plant. B-20 biodiesel burns cleaner than regular diesel and ULSD fuel. When SARTA
converted over to locally produced B-20 biodiesel, they already began to make their carbon footprint
smaller by shrinking the CO2 output of every bus using B-20 biodiesel.
14
SARTA and Stark State College Hybrid Bus Study
CO2 Emissions Diesel Fuel and B-20 Biodiesel
CO2 Emissions Diesel CO2 Emissions B-20
All Buses 8,165,870.62 6,580,514.66
Conv. Buses Only 7,491,897.71 6,037,389.64
Hybrid Buses Only 673,972.91 543,125.01
Conv. Bus 0873 209,151.75 168,546.16
Hybrid Bus 0978 171,928.79 138,549.82
Fig 3.7
Fig. 3.8
SARTA has continued to decrease its carbon and criteria emissions output and have saved money in the
process. Beginning in September 2011, production will begin on the next SARTA fleet of compressed
natural gas (CNG) buses. These buses will burn domestically-produced CNG; reducing our dependence
on imported oil. In a U.S. Department of Energy report26, testing was performed on transit buses
equipped with CNG and results showed that the CNG buses produced 49% lower NOx emissions and
84% lower PM emissions than an equivalent bus running on diesel fuel.
SARTA will also be constructing the first public compressed natural gas (CNG) station in Stark County.
This station will be used to fuel a third to half of SARTA’s buses as vehicles are replaced. SARTA was
awarded a $15 million grant from the Ohio Department of Transportation (ODOT) for the construction of
26
U S D e p a r t m e n t o f E n e r g y . ( 2 0 1 1 , J a n u a r y 0 8 ) . A l t e r n a t i v e f u e l s & a d v a n c e d v e h i c l e d a t a c e n t e r . R e t r i e v e d f r o m h t t p : / / w w w . a f d c . e n e r g y . g o v / a f d c / v e h i c l e s / n a t u r a l _ g a s _ e m i s s i o n s . h t m l
http://www.afdc.energy.gov/afdc/vehicles/natural_gas_emissions.html
15
SARTA and Stark State College Hybrid Bus Study
a Bus Rapid Transit (BRT) corridor along the Mahoning Road area. This is part of a nearly $40 million
redevelopment effort in the City of Canton.
16
SARTA and Stark State College Hybrid Bus Study
Data Methodology
The year-long environmental impact study and cost analysis of the SARTA transit bus fleet included 38
conventional transit buses and four new diesel-electric hybrid transit buses. Along with compiling data
for the entire SARTA fleet, one conventional bus and one new hybrid bus, were pulled out for an in-
depth, first-year-of-operation “apples-to-apples” comparison study. The buses were the same identical
size and style of bus except one has a diesel-electric hybrid propulsion system (bus 0978) and the other
bus has a conventional diesel drive system (bus 0873).
After analyzing fuel usage, miles traveled, and maintenance records of the SARTA hybrid and non-hybrid
bus fleet, the following results reveal the cost analysis reflected against the accountability of mandated
environmental regulations. This study is a balance between cost savings and emissions reductions. EPA
guidelines were thoroughly followed to calculate CO2 emissions based on fuel consumption.
The following data is a detailed analysis of the SARTA bus fleet’s miles driven, diesel fuel usage, fuel
costs, and CO2 emissions released into the atmosphere.
2010 Total Fuel Used in All
Transit Buses
2010 Total Miles Driven All
Transit Buses
MPG 2010 All Transit Buses
Combined
2010 Total CO2 Emissions All
Transit Buses
2010 Total Fuel Costs
All Transit Buses
367,832.01 gal 1,854,082 Miles 5.04 MPG 8,165,870.62 Lbs. $846,013.62*
2010 Total Fuel Used in
Conventional Transit Buses
2010 Total Miles Driven Conventional Transit Buses
MPG 2010 All Conventional
Transit Buses Combined
2010 Total CO2 Emissions Conventional Transit Buses
2010 Total Fuel Costs
Conventional Transit Buses
337,472.87 gal 1,680,166 Miles 4.98 MPG 7,491,879.71 Lbs. $776,187.60*
2010 Total Fuel Used in
Hybrid Transit Buses
2010 Total Miles Driven
Hybrid Transit Buses
MPG 2010 All Hybrid Buses
Combined
2010 Total CO2 Emissions
Hybrid Transit Buses
2010 Total Fuel Costs
Hybrid Transit Buses
30,359.14 gal 173,916 Miles 5.73 MPG 673,972.91 Lbs. $69,826.02*
2010 Total Fuel Used in 0873 Conventional Bus
2010 Total Miles Driven 0873 Conventional Bus
MPG 2010 Number 0873
Conventional Bus
2010 Total CO2 Emissions 0873
Conventional Bus
2010 Total Fuel Costs
0873 Conventional Bus
9,421.25 gal 46,780 Miles 4.97 MPG 209,151.75 Lbs. $21,668.88*
2010 Total Fuel Used in
0978 Hybrid Bus
2010 Total Miles Driven
0978 Hybrid Bus
MPG 2010 Number 0978
Hybrid Bus
2010 Total CO2 Emissions
0978 Hybrid Bus
2010 Total Fuel Costs
0978 Hybrid Bus
7,744.54 gal 50,965 Miles 6.58 MPG 171,928.79 Lbs. $17,812.44*
Fig. 4.1 * Fuel cost for 2010 at $2.30 per gallon
The total miles driven by the SARTA bus fleet in 2010 is close to four trips to the moon and back and
took 367,832.01 gallons of diesel fuel at a cost of $846,013.62* to travel those miles in one year. The
space shuttle, on the other hand, uses 835,985 gallons of fuel during takeoff at a cost of $450 million to
17
SARTA and Stark State College Hybrid Bus Study
launch into space27. The hybrid bus 0978 actually drove more miles than its conventional sister bus
during 2010. When both buses reached the distance of 30,000 miles on their odometers, the hybrid bus
had already saved SARTA $3,396.99 in fuel costs at the 2010 fuel cost of $2.30 per gallon.
MPG
The combined miles per gallon (MPG) for every
bus in the study came out to 5.04 MPG. The
conventional buses had a combine MPG of
4.98, while the hybrid buses reached a
combine MPG of 5.73. The conventional bus
(0873) selected for the comparison had an
average MPG of 4.97 for 2010 and the selected
hybrid bus (0978) had an average of 6.68 MPG
for the same year.
CO2 Emissions
Using the EPA-validated formula28 of 22.2
pounds of CO2 emissions from one gallon of
regular diesel fuel, calculations were made on
the SARTA fleet’s diesel fuel usage. A
passenger car running on gasoline emits 19.4
pounds of CO2 per gallon. In March of 2011,
SARTA converted its entire fleet over to B-20
biodiesel fuel. B-20 biodiesel has a CO2
emissions factor of 17.89 pounds29 per gallon.
This will greatly reduce SARTA’s carbon
emissions over the coming years.
27 N A S A . ( 2 0 0 8 , F e b r u a r y 2 4 ) . F a q s p a c e s h u t t l e a n d i n t e r n a t i o n a l s p a c e s t a t i o n . R e t r i e v e d f r o m
h t t p : / / w w w . n a s a . g o v / c e n t e r s / k e n n e d y / a b o u t / i n f o r m a t i o n / s h u t t l e _ f a q . h t m l # 1 0
28 U S E P A . ( 2 0 1 1 , A p r i l 1 2 ) . E m i s s i o n f a c t s : a v e r a g e c a r b o n d i o x i d e e m i s s i o n s r e s u l t i n g f r o m g a s o l i n e a n d d i e s e l f u e l . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / c l i m a t e / 4 2 0 f 0 5 0 0 1 . h t m 29 U S E n e r g y I n f o r m a t i o n S y s t e m . ( 2 0 1 1 , J a n u a r y 3 1 ) . V o l u n t a r y r e p o r t i n g o f g r e e n h o u s e g a s e s
p r o g r a m . R e t r i e v e d f r o m h t t p : / / w w w . e i a . d o e . g o v / o i a f / 1 6 0 5 / c o e f f i c i e n t s . h t m l # t b l 2
http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#10http://www.epa.gov/oms/climate/420f05001.htmhttp://www.eia.doe.gov/oiaf/1605/coefficients.html#tbl2
18
SARTA and Stark State College Hybrid Bus Study
Maintenance Costs
Just as it costs money to fill the fuel tanks on 42 buses, it costs money to keep these buses in tip-top
shape. In 2010, SARTA spent $225,381.76 in total maintenance costs for all 42 transit buses. Total
maintenance costs for a transit bus include mechanical and non-mechanical repairs. Mechanical repairs
are maintenance operations like oil changes, engine repairs, tires, and brake system inspections and
repairs. Non-mechanical repairs include body damage, paint repairs, wheel chair lift inspections, fare
box inspections, light bulbs, windows, etc. Typically, fleets look at yearly maintenance costs using a cost
per mile calculation to smooth out the highs and lows of repair costs over a one year period.
The first-year maintenance records for the two sample buses in this study were looked at and the results
show that the hybrid bus was driven 5,975 miles more than the conventional bus in 2010 yet operated
at a cost of $0.0663 per mile less than the conventional bus. Six cents per mile may not sound like much
but it adds up to $712.35 saved for 2010. Essentially, the hybrid bus drove more miles while operating at
a 15% lower cost than conventional bus.
Total Miles Driven
Total Maintenance
Cost
Non-Mechanical Maintenance
Cost
Mechanical Maintenance Cost
Hybrid Bus 0978 29,383 $4,130.19 $2,935.49 $1,194.70
Hybrid Bus 0978 Cost Per Mile
29,383 $0.1406 Per Mile
$0.0999 Per Mile
$0.046 Per Mile
Conv. Bus 0873 23,408 $4,842.54 $2,894.83 $1,947.71
Conv. Bus 0873 Cost Per Mile 23,408
$0.2069 Per Mile
$0.1237 Per Mile
$0.0832 Per Mile
Fig. 4.4
19
SARTA and Stark State College Hybrid Bus Study
Fig. 4.5
SARTA’s investment in hybrid technology was driven by several factors; government mandates to lower
tailpipe emissions, ever-increasing fuel costs, and environmental responsibility. The apples-to-apples
comparison of the two buses has shown that the hybrid bus (0978) operated with 15% lower
maintenance costs, 17% lower fuel costs, and emitted 18% less CO2 than its conventional counterpart,
conventional bus (0873).
20
SARTA and Stark State College Hybrid Bus Study
Hybrid Technology
The hybrid buses in the SARTA fleet are manufactured in the USA by the Gillig Bus Company and are
powered by the General Motors Allison H40EP30 hybrid drive system. The hybrid propulsion system is
capable of producing 350 HP on acceleration with power coming from the 600 volt nickel metal hydride
(NiNH) roof-mounted battery pack. The Allison hybrid drive system is connected to a Cummins ISB 280
(280 HP) diesel engine capable of 900 LB-FT of torque. As a quick comparison, a 2009 Ford F-150 pickup
truck with a 4.6L V-8 is rated at 292 HP and produces 320 LB-FT of torque compared to 900 LB-FT from
the bus.
Fig. 5.1 Conventional Drive System Fig. 5.2 Allison H40EP Drive System
The only real noticeable difference between the two buses used as our apples-to-apples comparison in
this study is the green paint scheme on the hybrid bus and the extra compartment on the roof that
contains the battery pack and the power inverter.
The hybrid drive system looks just like a regular bus transmission
and bolts to the engine just like a regular transmission. The
diesel engine and the hybrid drive system are configured to
operate similar to a passenger car hybrid system but the Allison
Hybrid system uses a split parallel architecture, meaning there is
a pure mechanical and a pure electrical path and can act as a
parallel or a series hybrid to gain the most efficiency.
Fig. 5.3 Allison H40EP1
30 A l l i s o n T r a n s m i s s i o n , . ( 2 0 1 1 ) . A l l i s o n h y b r i d t r a n s m i s s i o n . R e t r i e v e d f r o m
h t t p : / / w w w . a l l i s o n t r a n s m i s s i o n . c o m / c o m m e r c i a l / t r a n s m i s s i o n s / h y b r i d - b u s /
http://www.allisontransmission.com/commercial/transmissions/hybrid-bus/
21
SARTA and Stark State College Hybrid Bus Study
This means that the diesel engine and the electric motor can both power the bus at the same time or
operate independently to power the bus. The fuel savings, emissions reduction, and reduced drive line
wear and tear are all possible by the way the diesel engine and the electric motor work together.
5.4 Conventional Drive System Fig. 5.5 Allison H40EP Drive System
On acceleration, the electric motor assists the diesel engine, lessening the work required by the diesel
motor, thus, reducing fuel consumption and the heavier exhaust emissions that are produced during
acceleration. The hybrid propulsion system also helps reduce noise compared to traditional buses. At a
sound level of 79 db at 30 feet, the hybrid equipped buses approach the sound level of a passenger
car.31
On deceleration and stopping, the electric motor acts like an electric brake, reducing wear and tear on
the braking system. Some transit systems using the Allison hybrid system are reporting brake life of up
to 170,000 to 250,000 miles3 before needing brake replacement. SARTA’s older fleet of Phantom buses
requires an average of 4 to 5 brake jobs a year. A rear brake job has an average cost of $545.19 and a
front brake job averages $476.46. After one full year of service, hybrid bus 0978 required a minor brake
system repair costing $57.18. SARTA is expecting a brake system service life of two to three years for the
hybrid buses.
Also during deceleration and stopping, the electric
motor charges the 600 volt NiMH high-voltage
battery pack, preparing it for the next acceleration
cycle. The diesel engine can also be “tuned” to
operate more efficiently now that there is an
electric motor ready to jump in and help power the
bus, again saving on fuel and reducing exhaust emissions. The first Allison hybrid systems were put into
31, 3, 4,5 A l l i s o n T r a n s m i s s i o n , I n i t i a l s . ( 2 0 1 0 ) . A l l i s o n h 4 0 e p h 5 0 e p . R e t r i e v e d f r o m h t t p : / / w w w . a l l i s o n t r a n s m i s s i o n . c o m / s e r v l e t / D o w n l o a d F i l e ? D i r = p u b l i c a t i o n s / p u b s & F i l e T o G e t = S A 5 98 3 E N . p d f
http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=SA5983EN.pdfhttp://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=SA5983EN.pdf
22
SARTA and Stark State College Hybrid Bus Study
service in 2003 and since that time Allison equipped hybrid buses have traveled over 100 million miles4
without a single “end-of-life” battery failure.
The SARTA technicians that service the buses have received special training on the hybrid propulsion
system. The hybrid system contains extensive computer controls to operate the diesel engine and the
hybrid system as a seamless unit. The drivers of the hybrid buses have also received additional driver
training to understand better the efficiencies and driving characteristics of the hybrid propulsion system.
23
SARTA and Stark State College Hybrid Bus Study
Conclusion
This study has shown that a hybrid transit bus with just four riders has the same carbon footprint as a
passenger car with just one driver. There is a cost to new technology and there is a payback as well. We
all share the same planet and breathe the same air. Our transportation choices are one of the biggest
impacts that we, as individuals, make on the environment. Cars, trucks, and buses are cleaner than any
time in history but it has taken government mandates and investments in technology to reach this
milestone. Many of the government regulations covered in this study we not even in place when this
project began. The need for new biodiesel fuels and the need for new emission control devices have
helped spark investments in new technologies, creating new jobs. The biodiesel fuel used in SARTA
buses in produced in Ohio. The natural gas that will power the new generation of SARTA buses is
domestically produced.
This paper began with reference to a Presidential Memorandum to increase the efficiency and lower the
emissions of trucks and buses. There was also reference to a Presidential statement that, “Our addiction
to foreign oil and fossil fuels puts our economy, our national security, and our environment at risk”.
There is a commitment and a direction from the federal government to keep the environment clean
through new technologies. SARTA was awarded a $15 million grant from the Ohio Department of
Transportation to build a Bus Rapid Transit (BRT) corridor as part of a $40 million redevelopment effort
in the City of Canton. Investments are being made, commitments are established, and the leadership of
SARTA is focused on the future of the greater Stark County area.
According to Kirt Conrad, SARTA’s CEO, “Our experience with hybrid buses has shown an increase of about 17% in fuel economy. It also showed a significant reduction in green house gas emissions and
other particulate matter. Our riders like them because they are quieter and cleaner”.
24
SARTA and Stark State College Hybrid Bus Study
Citations
1 P r e s i d e n t o b a m a d i r e c t s a d m i n i s t r a t i o n t o c r e a t e f i r s t - e v e r n a t i o n a l e f f i c i e n c y a n d e m i s s i o n s s t a n d a r d s f o r m e d i u m - a n d h e a v y - d u t y t r u c k s . ( 2 0 1 0 , M a y 2 1 ) . R e t r i e v e d f r o m
h t t p : / / w w w . w h i t e h o u s e . g o v / t h e - p r e s s - o f f i c e / p r e s i d e n t - o b a m a - d i r e c t s - a d m i n i s t r a t i o n - c r e a t e -
f i r s t - e v e r - n a t i o n a l - e f f i c i e n c y - a n d - e m
1 W h i t e h o u s e . ( 2 0 1 0 , J u n e 1 5 ) . E n e r g y & e n v i r o n m e n t . R e t r i e v e d f r o m h t t p : / / w w w . w h i t e h o u s e . g o v / i s s u e s / e n e r g y - a n d - e n v i r o n m e n t 1 E P A . ( 2 0 1 0 , D e c e m b e r 2 1 ) . R e n e w a b l e f u e l s : r e g u l a t i o n s & s t a n d a r d s . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o t a q / f u e l s / r e n e w a b l e f u e l s / r e g u l a t i o n s . h t m
1,5,7,8 E P A . ( 2 0 1 0 , A p r i l 0 1 ) . O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / a i r t r e n d s / 2 0 1 0 / ( D o w n l o a d P g . 6 )
1 O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 ( D o w n l o a d Pg. 8)
1 E P A . ( 2 0 0 9 , N o v e m b e r 0 4 ) . V o l a t i l e o r g a n i c c o m p o u n d s . R e t r i e v e d f r o m
h t t p : / / w w w . e p a . g o v / a i r / e m i s s i o n s / v o c . h t m 1 O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 ( D o w n l o a d Pg. 5)
1 O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 ( D o w n l o a d Pg. 24)
1 A I R N o w . ( 2 0 1 1 , M a y 0 5 ) . L o c a l a i r q u a l i t y c o n d i t i o n s a n d f o r e c a s t s . R e t r i e v e d f r o m h t t p : / / w w w . a i r n o w . g o v / 1 A m e r i c a ' s H e a l t h R a n k i n g s , . ( 2 0 1 1 , M a y 0 5 ) . S t a t e h e a l t h s t a t s . R e t r i e v e d f r o m
h t t p : / / s t a t e h e a l t h s t a t s . a m e r i c a s h e a l t h r a n k i n g s . o r g / , E P A . ( 2 0 1 1 , J a n u a r y 3 1 ) . A i r e x p l o r e r . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / a i r e x p l o r e r /
1 O h i o C l e a n F u e l s . ( 2 0 1 0 ) . T h e 6 r ' s o f d i e s e l c l e a n u p . R e t r i e v e d f r o m h t t p : / / w w w . c l e a n f u e l s o h i o . o r g / i n d e x . p h p ? o p t i o n = c o m _ c o n t e n t & v i e w = a r t i c l e & i d = 2 7 2 & I t e m i d = 2 7
0 ( D o w n l o a d P g . 4 )
1 U S E P A , . ( 2 0 1 1 , J a n u a r y 0 7 ) . H e a v y - d u t y h i g h w a y c o m p r e s s i o n - i g n i t i o n e n g i n e s a n d u r b a n b u s e s - - e x h a u s t e m i s s i o n s t a n d a r d s . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / s t a n d a r d s / h e a v y - d u t y / h d c i -e x h a u s t . h t m 1 US E P A . ( 2 0 1 0 , A p r i l 0 1 ) . O u r n a t i o n ' s a i r - s t a t u s a n d t r e n d s t h r o u g h 2 0 0 8 . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / a i r t r e n d s / 2 0 1 0 / ( D o w n l o a d P g . 6 )
1 US E P A . ( 2 0 0 9 , S e p t e m b e r 1 7 ) . E p a f e d e r a l t e s t p r o c e d u r e ( f t p ) . R e t r i e v e d f r o m
h t t p : / / w w w . e p a . g o v / O M S / s t a n d a r d s / l i g h t - d u t y / f t p . h t m
1 I C C T . ( 2 0 1 1 , J a n u a r y 1 9 ) . E p a / n h t s a g r e e n h o u s e g a s e m i s s i o n s . R e t r i e v e d f r o m h t t p : / / w w w . t h e i c c t . o r g / p u b s / I C C T _ p o l i c y u p d a t e 1 0 _ H D V s t d s . p d f 1 E P A , . ( 2 0 1 1 , J a n u a r y 0 7 ) . H e a v y - d u t y h i g h w a y c o m p r e s s i o n - i g n i t i o n e n g i n e s a n d u r b a n b u s e s - - e x h a u s t e m i s s i o n s t a n d a r d s . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / s t a n d a r d s / h e a v y - d u t y / h d c i -e x h a u s t . h t m 1 US E P A . ( 2 0 1 1 , j a n u a r y 0 6 ) . E p a a n d n h t s a p r o p o s e f i r s t - e v e r p r o g r a m t o r e d u c e g r e e n h o u s e g a s e m i s s i o n s a n d i m p r o v e f u e l e f f i c i e n c y o f m e d i u m - a n d h e a v y - d u t y v e h i c l e s : r e g u l a t o r y a n n o u n c e m e n t . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / c l i m a t e / r e g u l a t i o n s / 4 2 0 f 1 0 9 0 1 . h t m
http://www.whitehouse.gov/the-press-office/president-obama-directs-administration-create-first-ever-national-efficiency-and-emhttp://www.whitehouse.gov/the-press-office/president-obama-directs-administration-create-first-ever-national-efficiency-and-emhttp://www.whitehouse.gov/issues/energy-and-environmenthttp://www.epa.gov/otaq/fuels/renewablefuels/regulations.htmhttp://www.epa.gov/airtrends/2010/http://www.epa.gov/air/emissions/voc.htmhttp://www.airnow.gov/http://statehealthstats.americashealthrankings.org/http://www.epa.gov/airexplorer/http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/airtrends/2010/http://www.epa.gov/OMS/standards/light-duty/ftp.htmhttp://www.theicct.org/pubs/ICCT_policyupdate10_HDVstds.pdfhttp://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/oms/standards/heavy-duty/hdci-exhaust.htmhttp://www.epa.gov/oms/climate/regulations/420f10901.htm
25
SARTA and Stark State College Hybrid Bus Study
1 U.S. F e d e r a l G o v e r n m e n t , . ( 2 0 1 0 , D e c e m b e r 2 9 ) . F e d e r a l r e g i s t e r / v o l . 7 5 , n o . 2 4 9 / w e d n e s d a y , d e c e m b e r 2 9 , 2 0 1 0 / p r o p o s e d r u l e s . R e t r i e v e d f r o m h t t p : / / w w w . c o p y r i g h t . g o v / f e d r e g / 2 0 1 0 / 7 5 f r 8 1 9 5 2 . p d f 1 US E P A . ( 2 0 1 1 , A p r i l 1 2 ) . E m i s s i o n f a c t s : a v e r a g e c a r b o n d i o x i d e e m i s s i o n s r e s u l t i n g f r o m g a s o l i n e
a n d d i e s e l f u e l . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / c l i m a t e / 4 2 0 f 0 5 0 0 1 . h t m
1 U . S . E n e r g y I n f o r m a t i o n S y s t e m . ( 2 0 1 1 , J a n u a r y 3 1 ) . V o l u n t a r y r e p o r t i n g o f g r e e n h o u s e g a s e s p r o g r a m . R e t r i e v e d f r o m h t t p : / / w w w . e i a . d o e . g o v / o i a f / 1 6 0 5 / c o e f f i c i e n t s . h t m l
1 U S E P A . ( 2 0 1 1 , M a r c h 0 8 ) . T e c h n o l o g i e s . R e t r i e v e d f r o m
h t t p : / / e p a . g o v / c l e a n d i e s e l / t e c h n o l o g i e s / r e t r o f i t s . h t m 1 P i c k e n s , T . ( 2 0 1 1 , A p r i l 1 3 ) . O i l i m p o p r t n e w s . R e t r i e v e d f r o m
h t t p : / / w w w . p i c k e n s p l a n . c o m / t h e p l a n 2 / o i l i m p o r t s / http://www.pickensplan.com/oilimports/
1 O h i o C l e a n F u e l s . ( 2 0 1 0 ) . T h e 6 r ' s o f d i e s e l c l e a n u p . R e t r i e v e d f r o m h t t p : / / w w w . c l e a n f u e l s o h i o . o r g / i n d e x . p h p ? o p t i o n = c o m _ c o n t e n t & v i e w = a r t i c l e & i d = 2 7 2 & I t e m i d = 2 7
0 ( D o w n l o a d P g . 2 )
1 O h i o C l e a n F u e l s . ( 2 0 1 0 ) . T h e 6 r ' s o f d i e s e l c l e a n u p . R e t r i e v e d f r o m h t t p : / / w w w . c l e a n f u e l s o h i o . o r g / i n d e x . p h p ? o p t i o n = c o m _ c o n t e n t & v i e w = a r t i c l e & i d = 2 7 2 & I t e m i d = 2 7
0 ( D o w n l o a d P g . 4 )
1 A D B . ( 2 0 0 3 ) . P o l i c y g u i d e l i n e s f o r r e d u c i n g v e h i c l e e m i s s i o n s i n a s i a . R e t r i e v e d f r o m
w w w . a d b . o r g / d o c u m e n t s / g u i d e l i n e s / v e h i c l e _ e m i s s i o n s / c l e a n e r _ f u e l s . p d f ( D o w n l o a d P 1 4 ) 1 U S D e p a r t m e n t o f E n e r g y . ( 2 0 1 1 , J a n u a r y 0 8 ) . A l t e r n a t i v e f u e l s & a d v a n c e d v e h i c l e d a t a c e n t e r .
R e t r i e v e d f r o m h t t p : / / w w w . a f d c . e n e r g y . g o v / a f d c / v e h i c l e s / n a t u r a l _ g a s _ e m i s s i o n s . h t m l
1 N A S A . ( 2 0 0 8 , F e b r u a r y 2 4 ) . F a q s p a c e s h u t t l e a n d i n t e r n a t i o n a l s p a c e s t a t i o n . R e t r i e v e d f r o m
h t t p : / / w w w . n a s a . g o v / c e n t e r s / k e n n e d y / a b o u t / i n f o r m a t i o n / s h u t t l e _ f a q . h t m l # 1 0
1 U S E P A . ( 2 0 1 1 , A p r i l 1 2 ) . E m i s s i o n f a c t s : a v e r a g e c a r b o n d i o x i d e e m i s s i o n s r e s u l t i n g f r o m g a s o l i n e a n d d i e s e l f u e l . R e t r i e v e d f r o m h t t p : / / w w w . e p a . g o v / o m s / c l i m a t e / 4 2 0 f 0 5 0 0 1 . h t m 1 U S E n e r g y I n f o r m a t i o n S y s t e m . ( 2 0 1 1 , J a n u a r y 3 1 ) . V o l u n t a r y r e p o r t i n g o f g r e e n h o u s e g a s e s
p r o g r a m . R e t r i e v e d f r o m h t t p : / / w w w . e i a . d o e . g o v / o i a f / 1 6 0 5 / c o e f f i c i e n t s . h t m l # t b l 2
1 A l l i s o n T r a n s m i s s i o n , . ( 2 0 1 1 ) . A l l i s o n h y b r i d t r a n s m i s s i o n . R e t r i e v e d f r o m
h t t p : / / w w w . a l l i s o n t r a n s m i s s i o n . c o m / c o m m e r c i a l / t r a n s m i s s i o n s / h y b r i d - b u s /
1, 3, 4,5 A l l i s o n T r a n s m i s s i o n , I n i t i a l s . ( 2 0 1 0 ) . A l l i s o n h 4 0 e p h 5 0 e p . R e t r i e v e d f r o m h t t p : / / w w w . a l l i s o n t r a n s m i s s i o n . c o m / s e r v l e t / D o w n l o a d F i l e ? D i r = p u b l i c a t i o n s / p u b s & F i l e T o G e t = S A 5 98 3 E N . p d f
http://www.copyright.gov/fedreg/2010/75fr81952.pdfhttp://www.epa.gov/oms/climate/420f05001.htmhttp://www.eia.doe.gov/oiaf/1605/coefficients.htmlhttp://epa.gov/cleandiesel/technologies/retrofits.htmhttp://www.pickensplan.com/oilimports/http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.cleanfuelsohio.org/index.php?option=com_content&view=article&id=272&Itemid=270http://www.afdc.energy.gov/afdc/vehicles/natural_gas_emissions.htmlhttp://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#10http://www.epa.gov/oms/climate/420f05001.htmhttp://www.eia.doe.gov/oiaf/1605/coefficients.html#tbl2http://www.allisontransmission.com/commercial/transmissions/hybrid-bus/http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=SA5983EN.pdfhttp://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=SA5983EN.pdfTop Related