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

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

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

Energy Efficiencies (Fig p. 381)

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

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.

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.

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.

Hybrid and Fuel Cell Cars  Hybrid electric-internal combustion engine  Fuel cells Fig p. 385

Octane 120 Octane lbs of CO 2 per gallon! This breaks bonds to make energy

0 lbs of CO 2 per gallon! This makes bonds to release energy! 2 H 2 1 O 2 2 H 2 O

Using Solar Energy to Provide Heat  Passive solar heating  Active solar heating Fig p. 391

Using Solar Energy to Provide High- Temperature Heat and Electricity  Solar thermal systems  Photovoltaic (PV) cells Fig p. 394 Fig p. 395

Producing Energy from Biomass  Biomass and biofuels  Biomass plantations  Crop residues  Animal manure  Biogas  Ethanol  Methanol Fig p. 398

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

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

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

Producing Electricity from Wind Fig p. 396Fig p. 397

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

The Hydrogen Revolution  Extracting hydrogen efficiently  Storing hydrogen  Fuel cells  Environmentally friendly hydrogen

The Hydrogen Revolution Fig p. 403

Entering the Age of Decentralized Micropower  Decentralized power systems  Micropower systems Fig p. 405

Solutions: A Sustainable Energy Strategy Fig p. 407