Carbon Footprint of the U.S. Population: Causes and Spatial-Temporal Pattern

Class Project

Me/ENV 449, 2007Deniz Discioglu

Fang-yun Chou

Instructor: R. Husar

ENERGY EFFICIENCY

Table of Contents

1. Introduction

2. Energy Efficiency trend 1960-2003

3. Effect on carbon emissions

4. Parameters influencing energy efficiency

5. Suggestions to improve energy efficiency

Introduction

• Energy Efficiency = (Fuel Efficiency)-1

– Energy Efficiency in Btu/mile– Inverse Fuel Efficiency in Gal/mile

• Inverse fuel efficiency in gal/mile: (1960-2003)– Passenger cars– Trucks (heavy trucks)– Other 2-axel 4-tire vehicles (light trucks)

• Approach:– Converted data by: Gal/mile = (mile/gal)-1 = 1 / [(Total miles traveled)/(Total gallons consumed)] – Data from:

• 1 main source• 1 additional source (for cars and light trucks)

– Error between sources < 5%– Use data on heavy trucks from additional source

Introduction cont’d • Findings:

– Trend of mil/gal for each type of vehicle– Effects of fuel efficiency on carbon emissions– Parameters influencing fuel efficiency

• Results:– Confirmed finding by two sources and obtained usable data– Cars have the highest fuel efficiency– Trucks are the least fuel efficiency vehicles– Fuel efficiency:

• increased for cars and light trucks• decreased for heavy trucks

Energy Efficiency Trend 1960-2003Energy efficiency:• Cars:

– 35% increase in efficiency– Highest fuel efficiency– Steady increase after 1970s

• due to the high efficiency of newly manufactured cars• Light trucks:

– 38% increase in energy efficiency– Steady increase after 1975

Energy Efficiency Trend 1960-2003 cont’d

Energy efficiency:• Heavy trucks:

– Fluctuated over the years– Overall increase in efficiency : 19%– Increasing for the recent years– Least energy efficient vehicles

Energy Efficiency Trend 1960-2003 cont’dFreight Energy Efficiency (Btu/freight ton-mile)• Cars : – highest energy efficiency

– increase before 1970 & unsteady decrease after 1970• Light Trucks: – steady decrease

– least efficient before 1970• Heavy Trucks: – increase until 1970 & steady decrease after 1970

– least efficient after 1970

Inverse Fuel Efficiency

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Year

Gal/

Frigh

t m

ile

Passenger CarOther 2-axle 4- tire vehicleHeavy Trucks

Effect on Carbon Emissions

• Energy efficiency is found by converting gal/mile to Btu/mile

• Results were confirmed through 2 different sources

• Data is used to estimate carbon emissions

• Overall energy efficiency contributes as a decreasing factor to the carbon emissions

Parameters influencing energy efficiency

• The main parameter : type of vehicle

• Some vehicles are more energy efficiency (hybrids)

• Second parameter : age of car

• Newest cars are more energy efficient

Parameters influencing energy efficiency cont’d

Type of activity % efficiency

Driving sensibly ~ highways 33

~ around town 5

Removing weight 2

Unloading the roof 5

Cleaning car 7

Replacing clogged air filter 10

Replacing oxygen sensor 40

Keeping tires properly inflated 3.3

Using recommended motor oil 2

Driving less in cold weathers 50

Suggestions to improve energy efficiency

• Avoid big cars/vans • Do not buy cars manufactured before 1980s• Compare efficiencies of different vehicles and hybrids before purchase• Drive sensibly:

– avoid rapid acceleration and braking– do not exceed speed limit.

• Use cruise control and highest gear on highways • Avoid idling • Remove extra weight from car • Do not pack extra items on top of the car • Keep the car clean and well maintained• Change oil frequently• Keep filters clean• Use recommended fuel type and octane level • Reduce the amount of time AC is on.• Drive less in cold weather or use a heater to warm the coolant

Suggestions to improve energy efficiency cont’d

• Fuel efficiency standards are determined by Corporate Average Fuel Economy (CAFE) standards– market incentives and education programs

should be increased to educate the public about CAFE standards

– hybrid and fuel cell cars should be improved to replace less energy efficient cars.

References

• Energy Information Administrationhttp://www.eia.doe.gov/emeu/mer/pdf/pages/sec1_17.pdfhttp://www.eia.doe.gov/emeu/aer/pdf/pages/sec2_23.pdf

– Passenger Cars, 1990-1994: U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics 1998, Table 4-13.

– All Other Data: 1949-1994—Federal Highway Administration (FHWA), � Highway Statistics Summary to 1995, Table VM-201A. 1995 forward—FHWA, � Highway Statistics, annual reports, Table VM-1.

• Bureau of Transportation Statistics http://www.bts.gov/publications/national_transportation_statistics/html/table_04_22_m.html

• http://www.eia.doe.gov/emeu/rtecs/chapter4.html• http://www.fueleconomy.gov/feg/driveHabits.shtml• http://www.edmunds.com/reviews/list/top10/103164/article.html• http://www.ftc.gov/bcp/conline/pubs/alerts/fuelalrt.pdf• http://oee.nrcan.gc.ca/transportation/personal/driving/autosmart-methods.cfm?

attr%3d8

QUESTIONS??