Comparative Analysis of Fuel Source Consumption and Economic Costs

of Razorback Transit Among Alternative Fuel Sources Todd K. Knobbe

University of Arkansas Department of Geosciences, Fulbright College of Arts and Sciences, Fayetteville, Arkansas.

Capstone for Sustainability Minor

Fuel Source Data Economic Evaluation

Sustainability

Razorback Transit is the public transit system of the

University of Arkansas-Fayetteville. This transit system serves

the University of Arkansas community (population ca. 25,000)

and residents of Fayetteville, AR (population ca. 75,000) with

public transportation around the university campus and the

city of Fayetteville throughout the year. This case study was a

comparative analysis of fuel source consumption and

economic costs for the University of Arkansas Razorback

Transit System. Presently, Razorback Transit consists of 23

transit buses powered by diesel fuel. The FY 2012 diesel fleet

was compared to scenarios replacing the current fleet fuel with

B20 biodiesel, B100 biodiesel, Compressed Natural Gas,

Liquefied Petroleum Gas, and Diesel-Electric Hybrids. The

study had two primary foci: 1) fuel source data and 2)

economic evaluation. Analyses of fuel source data included 1)

Fuel Consumption, 2) Green House Gas Emissions (GHG),

and 3) Fuel Efficiency and GHG Emissions per capita. Current

and alternative fuels were compared in diesel gallon

equivalency (DGE). Energy and GHG emissions per capita

were compared using ridership data obtained from Razorback

Transit. The second component of this study was an economic

evaluation of the current transit system comparing economy of

current fuel to alternative fuel sources. This economic

evaluation examined average market prices (in diesel gallon

equivalency), fuel cost of Razorback Transit, conversion costs,

and cost per capita. Within this part of the study, the

conducted analysis compared the current fuel cost to those of

the proposed alternatives. Fuel costs were based on annual

fuel expenditures relative to fuel source. All data used in the

economic evaluation were from FY 2012. The data obtained

and presented in this study can be used to evaluate the

current diesel transit system and how it compares to alternate

fuel sources, serving as a preliminary step in moving the

University of Arkansas towards a more resilient and

sustainable public transit system.

In FY 2012 Razorback Transit provided transportation for

1,980,283 people. 457,025 people (23%) were non U of A

students. 128,387.11 gallons of diesel fuel were consumed

during the transportation process. This amounted to a

substantial $417,761.30 in diesel fuel costs. 1,296.12 Metric

Tons of Carbon Dioxide Equivalent (MTCDE) were emitted

into the atmosphere during the FY 2012 by Razorback

Transit. Alternative fuels are generally seen as greener

modes of transportationc. This case study was designed to

compare the current diesel powered transit system to

alternative fuels in search of a more sustainable and resilient

fuel source.

.

Methodology

Energy is the driving force of our world. This project compared

the current diesel powered transit system to 5 alternate fuel

scenarios. It incorporates the four major components of

sustainability: Built systems, Managed Systems, Social

Systems, and Nature Systems. This comparative analysis

provides preliminary information in search of a more resilient

and sustainable fuel source to power Razorback Transit.

Problem

ABSTRACT Results

0

0.5

1

1.5

2

2.5

3

3.5

4

Diesel B20 B100 Hybrid CNG LPG

Fu

el E

con

om

y

Fuel Source

Fuel Economy (DGE)

Diesel

B20

B100

Hybrid

CNG

LPG

12

96

.11

89

13

13

24

.86

54

15

14

38

.24

51

95

12

31

.06

89

45

13

07

.48

84

91

17

54

.09

04

6

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Diesel B20 B100 Diesel-Electric Hybrid

CNG LPG

Me

tric

s T

on

s o

f C

O2

e

Fuel Source (DGE)

Greenhouse Gas Emissions

Diesel

B20

B100

Diesel-Electric Hybrid

CNG

LPG

12

83

87

.11

13

10

96

.18

74

14

13

35

.82

37

10

70

61

.88

64

16

05

92

.82

96

19

79

57

.26

3

0

50000

100000

150000

200000

250000

Diesel B20 B100 Hybrid CNG LPG

Fu

el C

on

sum

pti

on

(D

GE

)

Fuel Source

Fuel Source Consumption (DGE)

Diesel

B20

B100

Hybrid

CNG

LPG

$4

17

,76

1.3

0

$5

38

,80

5.3

3

$6

51

,00

5.3

4

$3

47

,95

1.1

3

$3

74

,98

4.2

6

$8

37

,22

0.7

1

$0.00

$100,000.00

$200,000.00

$300,000.00

$400,000.00

$500,000.00

$600,000.00

$700,000.00

$800,000.00

$900,000.00

Diesel Biodiesel 20 Biodiesel 100 Hybrid CNG LPG

Tota

l Fu

el

Co

st (

$/D

GE)

Fuel Source (DGE)

Total Fuel Cost

Diesel

Biodiesel 20

Biodiesel 100

Hybrid

CNG

LPG

$0.00

$0.05

$0.10

$0.15

$0.20

$0.25

$0.30

$0.35

$0.40

$0.45

Diesel B20 B100 Hybrid CNG LPGT

ota

l F

ue

l C

ost

Pe

r C

ap

ita

Fuel Source

Total Fuel Cost Per Capita

Diesel

B20

B100

Hybrid

CNG

LPG

0

100

200

300

400

500

600

700

800

900

1000

Diesel B20 B100 Hybrid CNG LPG

Gra

ms

of

CO

2e

pe

r C

apit

a

Fuel Source

GHG Emissions Per Capita (C02e)

Diesel

B20

B100

Hybrid

CNG

LPG

U of A Mobile Combustion MTCDE U of A MTCDE

MTCDE 4,122.00 150,784.00

Razorback Transit MTCDE 1296.118913 1296.118913

Percent 31.44% 0.86%

Fuel Source Consumption • Each alternative fuel was converted into units of diesel gallon

equivalency (DGE) based on British Thermal Unit (BTU) ratios

and sources found in the literature.

• The initial fuel economy was adjusted to the DGE of each

alternative fuel.

•Total fuel consumption was based on the fuel economy of

each fuel in DGE and the total miles travelled in FY 2012.

•Greenhouse Gas Emission data for each fuel source was

obtained from literature published by the Environmental

Protection Agency (EPA). GHG emissions were reported in

Metric Tons of CO2e. This was correlated with Total Fuel

Consumption in each fuel scenario.

Economic Evaluation •Alternative fuel prices (in DGE) were obtained from the Clean

Cities Alternative Fuel Price Report published quarterly by the

U.S. Department of Energy in 2012. These prices were used

to calculate the total fuel cost based on total fuel consumption.

•Total Fuel Cost Per Capita is the result of total cost of each

fuel source divided by the number of RT riders in FY 2012.

•GHG Emissions Per Capita is the result of the total MTCDE

produced by each fuel source, in relation to DGE, and divided

by the number of RT riders in FY 2012.

•Razorback Transit GHG emissions were compared to the

Mobile Sector GHG emissions and the total MTCDE emitted

by the University of Arkansas for the FY 2012. This data was

provided by Sightlines.

Acknowledgements This research was supported by the University of Arkansas,

Razorback Transit, The Office of Sustainability and was

conducted under the direction of Dr. Stephen K. Boss,

Department of Geosciences, and Dr. Tahar Messadi, Fay

Jones School of Architecture.