Transcript Document
Energy Efficiency and
Renewable Energy Resources
Solutions:We have the answers!
Energy Efficiency!
43% of energy in the US is wasted
unnecessarily
• Incandescent bulb=5% efficient
Fluorescent bulb=20% efficient
• Auto fleet standards = CAFE Standards
(Corporate Average Fuel Economy)
– 12.9 mpg in 1974
– 27.9 mpg today
– 40 mpg CAFE standard would cut gas use by 50%
Efficiencies
Ways to Improve Energy Efficiency
Insulation
Eliminate air leaks
Air to air heat exchangers
Efficient appliances
Efficient electric motors
High-efficiency lighting
Increasing fuel economy
Solutions:We have the answers!
Renewable Energy Resources!
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Biomass
Hydroelectric power
Geothermal
Solar—passive and active
Wind generation
Hydrogen power
Using Solar Energy to Provide Heat
and Electricity
Passive solar heating
Active solar heating
Using Solar Energy to Provide HighTemperature Heat and Electricity
Solar Cell Trade-Offs
Solar thermal systems
Photovoltaic (PV) cells
Producing Electricity from
Moving Water
Large-scale hydropower
Small-scale hydropower
50% of West Coast electricity
7% of US electricity
20% of World’s electricity
Major environmental impacts
High construction costs
Impacts of hydropower on salmon
and other riverine spp.
Pollution
Disruption of
water flow
Loss of
biodiversity
Invasive species
Impacts of hydropower on
Species and People_______________
Dams can provide many human benefits but:
• Disrupts ecological services rivers provide;
e.g. 119 dams on Columbia River have
caused a 94% drop in wild salmon; removing
hydroelectric dams will restore native
spawning grounds
• Displaces millions of people worldwide as
reservoirs flood traditional homelands
• No room for expansion in the US
Producing Electricity from Wind
Producing Energy from Biomass
Biofuels
Biomass plantations
Crop residues
Animal manure
Biogas
Ethanol
Methanol
The Solar-Hydrogen Revolution
Extracting hydrogen efficiently
Storing hydrogen
Fuel cells
Geothermal Energy
Geothermal reservoirs
Dry steam
Wet steam
Hot water
Molten rock
Hot dry-rock zones
Geothermal Reservoirs
Entering the Age of
Decentralized Micropower
Centralized power systems
Decentralized power systems
Micropower systems
Fig. 16-39
p. 411
Creating a Sustainable Energy Future
• Increase fuel efficiency standards for
vehicle, appliances, buildings
• Tax and other financial incentives for
energy efficiency
• Subsidize renewable energy use,
research and development
• Internalize externalities for fossil fuels
• By 2050:
– Increase renewable energy to 50%
– cut coal use by 50%
– phase out nuclear altogether
Solutions:
A Sustainable Energy Strategy