1. Energy Efficiency and Renewable Energy
Chapter 16
G. Tyler Miller’s
Living in the Environment
13th Edition

2. Key Concepts Improving energy efficiency Solar energy
Hydropower (flowing water)
Wind
Biomass
Hydrogen fuel
Geothermal
Decentralized power systems

3. Doing more with less Energy efficiency
is the percentage of total energy input into an energy conversion device or system that
does useful work and
is not converted to low-quality heat.

4. The Importance of Improving Energy Efficiency
84% of all commercial energy produced in the U.S. is wasted!
Fig p. 381

5. The Importance of Improving Energy Efficiency
Lower life cycle cost
Initial cost plus lifetime operating cost
Net energy efficiency
Total amount of useful energy available minus the amount of energy
used (First Law of Thermodynamics)
automatically wasted (Second Law of Thermodynamics)
unnecessarily wasted.
Least Efficient
Incandescent light bulb (5%)
Internal combustion engine (10-15%)
Nuclear power plants (8-14%)

6. REDUCING 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.

7. Efficiencies (fig p. 382)

8. Electricity from Nuclear Power Plant
95%
Waste
heat
Uranium
mining
(95%)
54%
Waste
heat
Uranium processing
and transportation
(57%)
17%
Waste
heat
Power
plant
(31%)
Waste
heat
14%
Transmission
of electricity
(85%)
14%
Resistance
heating
(100%)
Uranium
100%
Electricity from Nuclear Power Plant
Passive Solar
Sunlight
100%
90%
Waste
heat
Energy
Efficiency

9. Could we save energy by recycling energy?No
Second Law of Thermodynamics

10. Ways to Improve Energy Efficiency
In Our Homes
Insulation
Eliminate air leaks
Air-to-air heat exchangers
Industry
Cogeneration
Two useful sources of energy are produced from the same fuel source
Efficient electric motors
High efficiency lighting
Increased fuel economy

11. Saving 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 17-11

12. WAYS TO IMPROVE ENERGY EFFICIENCY
Average fuel economy of new vehicles sold in the U.S. between
The government Corporate Average Fuel Economy (CAFE) has not increased after 1985.
Figure 17-5

14. Increased Fuel Economy
Rechargeable battery systems
Hybrid electric-internal combustion engine
Fuel cells

15. Hybrid Car (Electric – Internal Combustion Engine)
Fuel tank B
Electric motor C
Battery bank D B
Regulator E D
Transmission F E F A C
Fuel
Electricity

16. Fuel Cell Cars A B C D E Fuel Electricity Fuel cell stack Fuel tank
Turbo compressor B D
Traction inverter D E
Electric motor /
transaxle C E A
Fuel
Electricity

17. H2 O2 H2O 1 3 1 2 2 3 4 4 Cell splits H2 into protons Hydrogen gas
and electrons. Protons flow
across catalyst membrane.
Hydrogen gas 3 1 O2 2
React with oxygen (O2). 2 3
Produce electrical
energy (flow of electrons) to power car. 4
H2O 4
Emits water
(H2O) vapor.

18. The Solar-Hydrogen Revolution
Extracting hydrogen efficiently
Storing hydrogen
Fuel cells

19. Fuel Cells Advantages Energy efficiencies of 65-90% No moving parts
Quiet
Emit only water and heat
More reliable
Disadvantage
Cost

20. Using Solar Energy to Provide Heat and Electricity
Passive solar heating
Active solar heating

21. Using Solar Energy to Provide High-Temperature Heat and Electricity
Solar thermal systems

22. Using Solar Energy to Provide High-Temperature Heat and Electricity
Photovoltaic (PV) cells

23. Using Solar Energy to Provide High-Temperature Heat and Electricity

24. Producing Electricity from Moving Water
Large-scale hydropower
Small-scale hydropower
Pumped-storage hydropower

25. Producing Electricity from Moving Water
Tidal power plant
Wave power

26. Producing Electricity from Heat Stored in Water
Ocean thermal energy conversion (OTEC)
Saline solar ponds
Freshwater solar ponds

28. Producing Electricity from Wind
Fig p. 402
Fig p. 402

30. Producing Energy from Biomass
Biofuels
Biomass plantations
Crop residues
Animal manure
Biogas
Ethanol
Methanol

31. Geothermal Energy Geothermal reservoirs Dry steam Wet steam Hot water
Fig p. 409
Dry steam
Wet steam
Hot water
Molten rock
Hot dry-rock zones

32. Geothermal Reservoirs
Fig p. 410

33. Entering the Age of Decentralized Micropower
Current Centralized power systems
Future Decentralized power systems
Micropower systems
Fig p. 411
Fig
p. 411

34. Solutions: A Sustainable Energy Strategy