energy efficiency
TRANSCRIPT
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Energy Efficiency and Energy Efficiency and Renewable EnergyRenewable Energy
G. Tyler Miller’sG. Tyler Miller’sLiving in the Living in the EnvironmentEnvironment1414thth Edition Edition
Chapter 18Chapter 18
Shohail Motahir ChoudhuryShohail Motahir Choudhury
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Key ConceptsKey Concepts
Improving energy efficiencyImproving energy efficiency
Types and uses of solar energyTypes and uses of solar energy
Types and uses of flowing waterTypes and uses of flowing water
Uses of wind energyUses of wind energy
Types and uses of biomassTypes and uses of biomass
Use of geothermal energyUse of geothermal energy
Use of hydrogen as a fuelUse of hydrogen as a fuel
Decentralized power systemsDecentralized power systems
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The Importance of Improving Energy EfficiencyThe Importance of Improving Energy Efficiency
Energy efficiencyEnergy efficiency
Fig. 18-3 p. 381Fig. 18-3 p. 381
Net energy efficiency Net energy efficiency (efficiency in steps of conversion)(efficiency in steps of conversion)
Least EfficientLeast Efficient
Incandescent lights Incandescent lights (5%)(5%)
Internal combustion engineInternal combustion engine(20-25%)(20-25%)
Nuclear power plants Nuclear power plants (14%)(14%)
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Energy EfficienciesEnergy Efficiencies
20-25%
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Ways to Improve Energy EfficiencyWays to Improve Energy Efficiency
CogenerationCogeneration
Efficient electric motors Efficient electric motors (in industries)(in industries)
High-efficiency lightingHigh-efficiency lighting
Increasing fuel economyIncreasing fuel economy
Alternative vehiclesAlternative vehicles
Insulation Insulation
Plug leaksPlug leaks
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Hybrid and Fuel Cell CarsHybrid and Fuel Cell Cars
Hybrid electric-internal combustion engine
Fuel cells(combines H2 and O2 to produce electricity)
Fig. 18-9 p. 385
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Using Solar Energy to Provide HeatUsing Solar Energy to Provide Heat
Passive solar heatingPassive solar heating
Active solar heatingActive solar heating
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Using Solar Energy to Provide High-Using Solar Energy to Provide High-Temperature Heat and ElectricityTemperature Heat and Electricity
Solar thermal systems
Photovoltaic (PV) cells
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Producing Electricity from Moving WaterProducing Electricity from Moving Water
Large-scale hydropower
Small-scale hydropower
Pumped-storage hydropower
Tidal power plant
Wave power plant
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Moderate to high net energy High efficiency (80%)
Large untapped potential
Low-cost electricity
Long life span
No CO2 emissions during operation May provide flood control below dam
Provides water for year-roundirrigation of crop land
Reservoir is useful for fishing and recreation
High construction costs
High environmental impact from flooding land to form a reservoir
High CO2 emissions from biomass decay in shallow tropical reservoirs
Floods natural areas behind dam
Converts land habitat to lake habitat
Danger of collapse
Uproots people
Decreases fish harvest below dam
Decreases flow of natural fertilizer (silt) to land below dam
Advantages Disadvantages
Trade-Offs
Large-Scale Hydropower
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Producing Electricity from WindProducing Electricity from Wind
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Moderate to highnet energy High efficiency
Moderate capital cost
Low electricity cost(and falling)
Very low environmentalimpact
No CO2 emissions Quick construction Easily expanded
Land below turbinescan be used to growcrops or graze livestock
Steady winds needed
Backup systems needed whenwinds are low
High land use for wind farm
Visual pollution
Noise when locatednear populated areas
May interfere in flights of migratory birds and kill birds of prey
Advantages Disadvantages
Trade-Offs
Wind Power
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Producing Energy from BiomassProducing Energy from Biomass
Biomass and biofuelsBiomass and biofuels
Biomass plantationsBiomass plantations
Crop residuesCrop residues
Animal manureAnimal manure
Biogas Biogas
Ethanol Ethanol
MethanolMethanol
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Geothermal EnergyGeothermal Energy
Geothermal heat pumpsGeothermal heat pumps(3 m depth 10-16 (3 m depth 10-16 ººC)C)
Geothermal exchangeGeothermal exchange
Dry and wet steamDry and wet steam
Hot waterHot water
Molten rock (magma)Molten rock (magma)
Hot dry-rock zonesHot dry-rock zones
22 Countries are producing 1% of the world’s electricity.
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The Hydrogen RevolutionThe Hydrogen Revolution
Extracting hydrogen efficientlyExtracting hydrogen efficiently
Storing hydrogenStoring hydrogen
Fuel cellsFuel cells
Environmentally friendly hydrogenEnvironmentally friendly hydrogen
2H2O= 2H2 + O2
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Can be produced from plentiful water
Low environmental impact
Renewable if producedFrom renewable energyresources
No CO2 emissions if produced from water Good substitute for oil Competitive price if environmental and social costs are included incost comparisons Easier to store than electricity Safer than gasoline and natural gas
Nontoxic
High efficiency (65-95%) in fuel cells
Not found in nature
Energy is needed to produce fuel
Negative net energy
CO2 emissions if produced fromcarbon-containing compounds
Nonrenewable if generated byfossil fuels or nuclear power
High costs (but expected to come down)
Will take 25 to 50 years to phase in
Short driving range for current fuel cell cars
No distribution system in place
Excessive H2 leaks may deplete ozone
Advantages Disadvantages
Trade-Offs
Hydrogen
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Utilization
Electric utility
Transportation
Commercial/Residential
Industrial
Storage
Gas and solids
Transport
Vehicles and pipeline
Photo-conversion
Electrolysis
Reforming
Hydrogen Production
Ele
ctri
city
G
ener
atio
n
Primary Energy Sources
Sunlight
Fossil fuels
Biomass
Wind
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Entering the Age of Decentralized MicropowerEntering the Age of Decentralized Micropower
Decentralized power systemsDecentralized power systems
Micropower systemsMicropower systems
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Bioenergy Power plants
Wind farm Small solar cellpower plants
Fuel cells
Solar cellrooftop systems
Commercial
MicroturbinesIndustrial
Transmissionand distributionsystem
Residential
Smallwindturbine
Rooftop solarcell arrays
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Solutions: A Sustainable Energy StrategySolutions: A Sustainable Energy Strategy
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Risk, Toxicology and Risk, Toxicology and Human HealthHuman Health
G. Tyler Miller’sG. Tyler Miller’sLiving in the Living in the EnvironmentEnvironment1414thth Edition Edition
Chapter 19Chapter 19
Shohail Motahir ChoudhuryShohail Motahir Choudhury
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