Chapter 18 - Ali Taqi 1 AP Environmental Science Chapter...

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Ali Taqi 1 AP Environmental Science Chapter 18: Energy Efficiency and Renewable Energy 18-1: Importance of Improving Energy Efficiency A. What is Energy Efficiency? - It is a measure of the useful energy produced by an energy conversion device compared to the energy that ends up being converted to low-quality heat. - About 84% of United States commercial energy is wasted. - Life-cycle cost is the initial cost plus the lifetime operating costs (for installing solar panels is expensive at first but is paid off in years to come) - There are 4 devices that waste large amounts of energy the most: 1) Light Bulbs (95%) 2) Nuclear Power Plants (86%) 3) Motor Vehicles (75-80%) 4) Coal-Burning Plants (66%) B. What is Net Energy Efficiency? - It is a measurement of how much useful energy we get from an energy resource after subtracting energy used and waste. - Solar energy is 90% efficient. - There are two general principles for saving energy: 1) Keep number of steps in an energy conversion process as low as possible. 2) Strive to have highest possible energy efficiency for each step in a conversion process. 18-2: Ways to Improve Energy Efficiency A. Save Energy in Industry - Save by producing both heat and electricity. - Cogeneration is process in which two useful forms of energy are produced from the same fuel source. - Another way to save energy is to replace energy-wasting electric motors. - Third way is to switch from low-efficiency lighting to fluorescent lighting. B. Save in Transportation - Best way is to increase fuel efficiency of motor vehicles. - CAFE (Corporate Average Fuel Economy) regulated fuel efficiency on cars, which raised standards for fuel emissions. - If we raise MPG to 40, oil imports would cease and we would consume half as much oil. C. Hybrid-Electric Vehicles - They are powered by battery and small engine that charges battery. - More and more automakers are making transitions. D. Fuel-Cell Cars - Fuel cells are a device that combines hydrogen gas ( 2 H ) and oxygen gas ( 2 O ) to produce electricity and water vapor.
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Ali Taqi 2 - No Pollution. E. Building to Save Energy
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This note was uploaded on 04/10/2008 for the course ENVIRO 152 taught by Professor Fernandez during the Spring '08 term at Vanderbilt.

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Chapter 18 - Ali Taqi 1 AP Environmental Science Chapter...

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