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Energy Efficiency and Renewable Energy
Energy Efficiency and Renewable Energy
Chapter 16
G. Tyler Miller’sLiving in the Environment
13th Edition
Chapter 16
G. Tyler Miller’sLiving in the Environment
13th Edition
Key ConceptsKey Concepts
• Improving energy efficiencyImproving energy efficiency
• Solar energySolar energy
• Hydropower (flowing water)Hydropower (flowing water)
• WindWind
• BiomassBiomass
• Hydrogen fuelHydrogen fuel
• GeothermalGeothermal
• Decentralized power systemsDecentralized power systems
Doing more with lessDoing more with lessDoing more with lessDoing more with less
• Energy efficiencyEnergy efficiency– is the percentage of total energy is the percentage of total energy
input into an energy conversion input into an energy conversion device or system thatdevice or system that1)1) does useful work and does useful work and
2)2) is not converted to low-quality is not converted to low-quality heat.heat.
The Importance of Improving Energy EfficiencyThe Importance of Improving Energy Efficiency
• 84% of all 84% of all commercial commercial energy produced energy produced in the U.S. is in the U.S. is wastedwasted!!
Fig. 16-2 p. 381Fig. 16-2 p. 381
The Importance of Improving Energy EfficiencyThe Importance of Improving Energy Efficiency
• Lower life cycle costLower life cycle cost– Initial cost plus lifetime operating costInitial cost plus lifetime operating cost
• Net energy efficiencyNet energy efficiency– Total amount of useful energy available minus the Total amount of useful energy available minus the
amount of energyamount of energy• used (First Law of Thermodynamics)used (First Law of Thermodynamics)• automatically wasted (Second Law of Thermodynamics)automatically wasted (Second Law of Thermodynamics)• unnecessarily wasted.unnecessarily wasted.
Least Efficient• Incandescent light bulb (5%)Incandescent light bulb (5%)• Internal combustion engine (10-15%)Internal combustion engine (10-15%)• Nuclear power plants (8-14%)Nuclear power plants (8-14%)
REDUCING ENERGY WASTE AND IMPROVING ENERGY EFFICIENCYREDUCING ENERGY WASTE AND IMPROVING ENERGY EFFICIENCY
• Four widely used devices waste large amounts of energy:– Incandescent light bulb: 95% is lost as heat.– Internal combustion engine: 94% of the energy in
its fuel is wasted.– Nuclear power plant: 92% of energy is wasted
through nuclear fuel and energy needed for waste management.
– Coal-burning power plant: 66% of the energy released by burning coal is lost.
Efficiencies (fig. 16-4 p. 382)Efficiencies (fig. 16-4 p. 382)
Uranium100%
Electricity from Nuclear Power Plant
14%
Resistanceheating(100%)
90%
Wasteheat
Passive Solar
Sunlight100%
Wasteheat
14%
Transmissionof electricity
(85%)
17%
Wasteheat
Power plant(31%)
54%
Wasteheat
Uranium processingand transportation
(57%)
95%
Wasteheat
Uraniummining(95%)
Energy
Efficiency
Could we save energy by recycling energy?Could we save energy by recycling energy?
• NoNo• Second Law of ThermodynamicsSecond Law of Thermodynamics
Ways to Improve Energy EfficiencyWays to Improve Energy Efficiency
In Our HomesIn Our Homes InsulationInsulation Eliminate air leaksEliminate air leaks Air-to-air heat exchangersAir-to-air heat exchangers
IndustryIndustry CogenerationCogeneration
– Two useful sources of energy are produced from the same fuel Two useful sources of energy are produced from the same fuel sourcesource
Efficient electric motorsEfficient electric motors High efficiency lightingHigh efficiency lighting Increased fuel economyIncreased fuel economy
Saving Energy in Existing BuildingsSaving Energy in Existing Buildings
• About one-third of the heated air in typical U.S. homes and buildings escapes through closed windows and holes and cracks.
Figure 17-11Figure 17-11
WAYS TO IMPROVE ENERGY EFFICIENCYWAYS TO IMPROVE ENERGY EFFICIENCY
• Average fuel economy of new vehicles sold in the U.S. between 1975-2006.
• The government Corporate Average Fuel Economy (CAFE) has not increased after 1985.
Figure 17-5Figure 17-5
Increased Fuel EconomyIncreased Fuel EconomyIncreased Fuel EconomyIncreased Fuel Economy
Rechargeable battery systems Rechargeable battery systems Hybrid electric-internal combustion engine Hybrid electric-internal combustion engine Fuel cells Fuel cells
ElectricityFuel
Combustion engineCombustion engineAA
Fuel tankFuel tankBB
Electric motorElectric motorCC
Battery bankBattery bankDD
RegulatorRegulatorEE
TransmissionTransmissionFF
A
B
C
D
EF
Hybrid Car Hybrid Car (Electric – Internal (Electric – Internal
Combustion Engine)Combustion Engine)
A
C
E
D
B
ElectricityFuel
AA Fuel cell stackFuel cell stack
BB Fuel tankFuel tank
CC Turbo compressorTurbo compressor
DD Traction inverterTraction inverter
EE Electric motor /Electric motor /transaxletransaxle
Fuel Cell CarsFuel Cell Cars
1
2
3
4
1
2
3
4
H2
O2
H2O
Hydrogen gasHydrogen gas
Emits water Emits water (H(H22O) vapor.O) vapor.
Produce electrical Produce electrical energy (flow of energy (flow of electrons) to power car.electrons) to power car.
React with oxygen (OReact with oxygen (O22).).
Cell splits HCell splits H22 into protons into protons
and electrons. Protons flowand electrons. Protons flowacross catalyst membrane.across catalyst membrane.
The Solar-Hydrogen RevolutionThe Solar-Hydrogen Revolution
Extracting hydrogen efficientlyExtracting hydrogen efficientlyStoring hydrogenStoring hydrogenFuel cellsFuel cells
Fuel CellsFuel CellsFuel CellsFuel Cells
AdvantagesAdvantages• Energy efficiencies of 65-90%Energy efficiencies of 65-90%• No moving partsNo moving parts• QuietQuiet• Emit only water and heatEmit only water and heat• More reliableMore reliable
DisadvantageDisadvantage• CostCost
Using Solar Energy to Provide Heat and ElectricityUsing Solar Energy to Provide Heat and Electricity
Passive solar heating
Passive solar heating
Active solar heating
Active solar heating
Using Solar Energy to Provide High-Temperature Heat and Electricity
Using Solar Energy to Provide High-Temperature Heat and Electricity
Solar thermal systemsSolar thermal systems
Using Solar Energy to Provide High-Temperature Heat and Electricity
Using Solar Energy to Provide High-Temperature Heat and Electricity
Photovoltaic (PV) cellsPhotovoltaic (PV) cells
Using Solar Energy to Provide High-Temperature Heat and Electricity
Using Solar Energy to Provide High-Temperature Heat and Electricity
Producing Electricity from Moving WaterProducing Electricity from Moving Water
Large-scale hydropower
Small-scale hydropower
Pumped-storage hydropower
Large-scale hydropower
Small-scale hydropower
Pumped-storage hydropower
Producing Electricity from Moving WaterProducing Electricity from Moving Water
Tidal power plant
Wave power
Tidal power plant
Wave power
Producing Electricity from Heat Stored in WaterProducing Electricity from Heat Stored in Water
Ocean thermal energy conversion (OTEC) Ocean thermal energy conversion (OTEC)
Saline solar ponds Saline solar ponds
Freshwater solar ponds Freshwater solar ponds
Producing Electricity from WindProducing Electricity from WindFig. 16-28 p. 402Fig. 16-28 p. 402 Fig. 16-29 p. 402Fig. 16-29 p. 402
Producing Energy from BiomassProducing Energy from Biomass
BiofuelsBiomass plantationsCrop residuesAnimal manureBiogasEthanolMethanol
BiofuelsBiomass plantationsCrop residuesAnimal manureBiogasEthanolMethanol
Geothermal EnergyGeothermal Energy
Geothermal reservoirsGeothermal reservoirs
Dry steamDry steam
Wet steamWet steam
Hot waterHot water
Molten rockMolten rock
Hot dry-rock zonesHot dry-rock zones
Fig. 16-36p. 409
Fig. 16-36p. 409
Geothermal ReservoirsGeothermal Reservoirs
Fig. 16-37 p. 410
Entering the Age of Decentralized MicropowerEntering the Age of Decentralized Micropower
Current Centralized power systems Current Centralized power systems
Future Decentralized power systems Future Decentralized power systems
Micropower systems Micropower systems
Fig. 16-39p. 411
Fig. 16-40 p. 411Fig. 16-40 p. 411
Solutions:A Sustainable Energy StrategySolutions:A Sustainable Energy Strategy