Energy Efficiency and Renewable Energy

1. Energy Efficiency and Renewable Energy G. Tyler Miller’s Living in the Environment 14th Edition Chapter 18

2. Key Concepts • Improving energy efficiency • Types and uses of solar energy • Types and uses of flowing water • Uses of wind energy • Types and uses of biomass • Use of geothermal energy • Use of hydrogen as a fuel • Decentralized power systems

3. The Importance of Improving Energy Efficiency • Energy efficiency useful vs. loses to low quality heat • Net energy efficiency Least Efficient • Incandescent lights • Nuclear power plants • Internal combustion engine • 84% of all U.S. energy is wasted Fig. 18-3 p. 381

4. Energy Efficiencies (Fig. 18-5 p. 381)

5. Ways to Improve Energy Efficiency • Cogeneration • Efficient electric motors • High-efficiency lighting • Increasing fuel economy • Alternative vehicles • Insulation • Plug leaks

6. Overview • Hydrogen is not a primary source of energy, unlike petroleum. Hydrogen is used to move energy. • The prospect of clean hydrogen fuel-cell vehicles creates a sustainable environment without compromising extreme personal mobility.

7. Overview • Fuel cells convert hydrogen gas into electricity cleanly, making possible nonpolluting vehicles powered by electric drive motors. • A chicken-and-egg problem exists: large numbers of fuel-cell vehicles require adequate fuel availability to support them, but the required infrastructure is hard to build unless there are significant numbers of fuel-cell vehicles on the roadways.

8. Despite steady improvements, today’s vehicles are only up to 25% efficient in converting the energy content of fuels into drive-wheel power. (expected to plateau around 30%) • Hydrogen fuel-cell vehicle is nearly twice as efficient, so it will require just half the fuel energy. • Of even more significance, fuel cells emit only water and heat as by-products. Finally, hydrogen gas can be extracted from various fuels and energy sources, such as natural gas, ethanol, water (via electrolysis using electricity) and, eventually, renewable energy systems.

9. Hybrid and Fuel Cell Cars • Hybrid electric-internal combustion engine • Fuel cells Fig. 18-9 p. 385

10. Octane 100 Octane 120 6 lbs of CO2 per gallon! This breaks bonds to make energy

11. 2 H2O 2 H2 1 O2 0 lbs of CO2 per gallon! This makes bonds to release energy!

14. Using Solar Energy to Provide Heat • Passive solar heating • Active solar heating Fig. 18-16 p. 391

15. Using Solar Energy to Provide High-Temperature Heat and Electricity Fig. 18-21 p. 395 • Solar thermal systems • Photovoltaic (PV) cells Fig. 18-20 p. 394

16. Producing Energy from Biomass • Biomass and biofuels • Biomass plantations • Crop residues • Animal manure • Biogas • Ethanol • Methanol Fig. 18-25 p. 398

17. Producing Electricity from Moving Water • Large-scale hydropower • Small-scale hydropower • Pumped-storage hydropower • Tidal power plant • Wave power plant

18. Reviewing the Trade-offs of Hydropower Dams Fig. 15-9 p. 313

19. Large-scale Hydroelectric Power: Trade-offs Fig. 18-22 p. 396

20. Producing Electricity from Wind Fig. 18-23 p. 396 Fig. 18-24 p. 397

21. Geothermal Energy • Geothermal heat pumps • Geothermal exchange • Dry and wet steam • Hot water • Molten rock (magma) • Hot dry-rock zones

22. The Hydrogen Revolution • Environmentally friendly hydrogen • Extracting hydrogen efficiently • Storing hydrogen • Fuel cells

23. The Hydrogen Revolution Fig. 18-31 p. 403

24. Entering the Age of Decentralized Micropower • Decentralized power systems • Micropower systems Fig. 18-32 p. 405

25. Solutions: A Sustainable Energy Strategy Fig. 18-35 p. 407