Chapter 20: Sustainable Energy

20.1 Conservation

• There are many ways to save energy • Green buildings can cut energy costs by half• Transportation could be far more efficient• Cogeneration produces both electricity and

heat

Urban Sprawl

• Steamboat suburbs, 1830’s• Railroad suburbs by 1850’s• “Commuter, “ 1865• Planned suburbs, late 1800’s• Streetcars and Interurban railroads

Wisconsin Interurban Railroads

Midwest Interurban Railroads

Interurban Rail, Los Angeles

Los Angeles Streetcar Lines

Los Angeles doesn’t sprawl because it has freeways

--Los Angeles built freeways

because it sprawls

The Downside of Light Rail

• Lines were very unprofitable• Owners invested in real estate– Ironically, light rail created urban sprawl

• Sometimes built amusement parks at the end of the line

• Lines frequently serviced owners’ developments and bypassed others

End of the Urban Rail Era

• A Cartel of Oil, Rubber and Auto Companies Bought up and dismantled urban rail lines in the 1930’s and 1940’s

• Not To Sell Cars, But Buses• Cartel Was Fined But By That Time The

Systems Were Dismantled

1883 Stationary Gas Engine

Early Motorcycle, 1885

1889 Daimler Auto

1902 Daimler Roadster

Mercedes Jellinek

World War I

• Railroads insufficient for Army’s needs• Army turned to truck convoys• Civilians found convoy routes featured such

revolutionary innovations as:–Route Markings–Regular Maintenance– Snow Removal

Pershing’s Map, 1922

The Interstate Highway System

If You Think Cars Pollute, Consider Horses

• New York City generated thousands of tons of horse manure a day

• Horses often cruelly overworked• 15,000 horses a year died on the streets of

New York each year• Many were just abandoned

20.2 Tapping Solar Energy

• Solar collectors can be passive or active• Storing solar energy is problematic

20.3 High Temperature Solar Energy

• Simple solar cookers can save energy • Utilities are promoting renewable energy • Photovoltaic cells capture solar energy • Electrical energy is difficult and expensive to

store

20.4 Fuel Cells

• All fuel cells have similar components • Several different electrolytes can be used in

fuel cells

20.5 Energy From Biomass

• We can burn biomass • Methane from biomass is clean and efficient • Ethanol and biodiesel can contribute to fuel

supplies • Cellulosic ethanol seems to offer hope for the

future • Can Biofuels Be Sustainable? • Could algae be a hope for the future?

The Math of Ethanol

• U.S. Uses 7 billion barrels of oil a year• Equals 293 billion gallons• Ethanol Equivalent = 439 billion gallons• 2.8 gallons/bushel of corn = 157 billion

bushels• U.S. Corn Production 2010 = 13 billion bushels

20.6 Energy From The Earth’s Forces

• Falling water has been used as an energy source since ancient times

• Wind energy is our fastest growing renewable source

• Wind could meet all our energy needs • Geothermal heat, tides, and waves could be

valuable resources • Ocean thermal electric conversion might be

useful