L
-
date post
12-Sep-2014 -
Category
Documents
-
view
762 -
download
0
description
Transcript of L
Transportation Issues
US Cars and Drivers
US Population:
300 million Licensed drivers
190 million Cars and light
trucks.
210 million
US Cars and Drivers
We spend $20 out of every $100 of household $$ on our cars.
Very little travel (2%) is by mass transit (buses and trains)
Problems
Air pollution Global Warming Oil Imports Gasoline Prices Future Oil Supplies
What can we do?
Transportation: Air Pollution
Air Pollution – Sources
Internal Combustion Engine
Pollutants
Photochemical Smog
Ozone
Acid Rain
Acid Rain
The Environmental Protection Agency
Clean Air Acts1955, 1963, 1970, 1990
Clean Air Act of 1990
Where are the problem areas?
How are emission standards achieved?
Catalytic Converter
Command and Control Strategy
Tailpipe Emissions Testingin Connecticut
EPA Strategies Have Worked for
Pollution Emission by cars.
Even though vehicle miles increased by 150%, emission have substantially decreased.
Cars also emit CO2
Global Warming
20 lb CO2 emitted for every gallon of gasoline consumed.
Transportation accounts for 25% of Global greenhouse gas emissions
Beyond Gasoline: Drive Less
Drive Less - Walk
Drive Less - Bicycle
Drive Less – Mass Transit
Drive Less - Subway
Drive Less - Carpool
Drive Less – Urban Planning
Drive Less – Summary
• Many people like flexibility and safety of cars
• Many people like suburbs.• Mass transit systems requires large $$
investments.• Will take many years to transform
suburbs into “new towns”• Part of the solution, but not the whole
solution.
Beyond Gasoline: Biofuels
Ethanol
Gasohol (E10)
E85 – alternate fuel
Flex Fuel Vehicle
Brazil
Sugar caneGas stations have E25 or E100
Ethanol from Cellulose
Biodiesel
Biodiesel FuelProcessed diesel fuel derived from biological sources. Used in unmodified diesel engines.
LimitationsB20 - unmodified diesel engines B100 - requires modificationsGelling problem
Beyond Gasoline: Concept Cars
EV
Electric Cars have not been successful.Large heavy batteriesShort driving rangeSlow refueling (recharging) process.
GM EV-1
Produced by GM from 1996-199.
Tesla
Tesla Roadster may represent a new direction.Uses new lighter batteries.Expensive.
GM Volt
Li-Ion batteries and a gasoline engine. The gasoline engine will run a
generator to recharge the batteries, but will not directly power the vehicle. (no gasoline motor)
Fuel Cell Vehicles
Internal Combustion Engine
Engine – 20% efficient
Only 20% of gasoline energy is converted to motion.
Fuel Cells and the Hydrogen Economy
Fuels Cells use hydrogen to produce electrical energy. They do not burn hydrogen.
2H2 +O2 2H2O + energy
Fuel cells could be used to power cars with hydrogen as the fuel.
Clean fuel
Barriers to Hydrogen Cars
Still in development
Expensive On-vehicle
storage of hydrogen fuel
Availability of hydrogen fuel
Infrastructure
Hydrogen Sources
Steam reforming of natural gas:
CH4 +2H2O CO2 + 4H2
Electrolysis:
2H2O + energy 2H2 + O2
Energy Source for Electrolyzer
Electrolysis requires energy.
Energy could come from Solar, Nuclear, or Wind.
In the short term, it would probably come from coal.
Beyond Gasoline: Fuel Economy
CAFE Standards
Corporate Average Fuel Economy
Mileage requirements for new vehicles
Current CAFE Standards
• 27.5 mpg for passenger automobiles
• 20.7 mpg for light trucks & SUVs
How do we make cars that use less gasoline?
Reduce wind drag
Reduce weight
More efficient engines and drive trains
Hybrid Electric Vehicle (HEV)
Gasoline Engine Electric motor Does not need to be recharged
Hybrid Electric Vehicle (HEV)
Some Examples of 2008 Fuel Efficient Models
Toyota Prius
Sedan $22,200 Hybrid 48 mpg 110 hp
Plug-In Hybrid (PHEV)
Honda Civic Hybrid
Sedan $22,600 Hybrid 45 mpg 110 hp
Toyota Yaris Liftback
Sedan $11,000 Gasoline 40 mpg 106hp
Honda Fit
5-Door $13,900 Gasoline 37 mpg 109 hp
Honda Civic EX
Sedan $18,700 Gasoline 37 mpg 140 hp
Ford Escape Hybrid
SUV $26,000 Hybrid 30 mpg 230 hp
How long does it take to change the US auto fleet?
• 210 million cars and light trucks in US• 19 million new cars and trucks each year• 200,000 new HEVs in 2005.• Vehicles last 140,000 miles or 10 years• Changing rolling stock takes several years.
Policies – Feebate
• Extra fee to buy a gasoline SUV• Rebate when buying a HEV
Nissan Armada: 13 mpg
Links
http://www.nrel.gov/learning/re_biofuels.htmlhttp://afdcmap2.nrel.gov/locator/FindPane.asphttp://gm-volt.com/http://world.honda.com/FuelCell/http://www.fueleconomy.gov/