Carbon Footprint of the U.S. Population: Causes and Spatial-Temporal Pattern Class Project Me/ENV 449, 2007 Deniz Discioglu Fang-yun Chou Instructor: R. Husar ENERGY EFFICIENCY

Table of Contents 1.Introduction 2.Energy Efficiency trend 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: ( ) –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 Energy 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 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 cont’d Freight 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

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 ~ highways33 ~ around town5 Removing weight2 Unloading the roof5 Cleaning car7 Replacing clogged air filter10 Replacing oxygen sensor40 Keeping tires properly inflated3.3 Using recommended motor oil2 Driving less in cold weathers50

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 Administration –Passenger Cars, : U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics 1998, Table –All Other Data: • —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 04_22_m.html 04_22_m.html methods.cfm?attr%3d8

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