Presentation on theme: "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."— Presentation transcript:
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. 18-3 p. 381 Net energy efficiency Least Efficient Incandescent lights Internal combustion engine Nuclear power plants 84% of all U.S. energy is wasted
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. 18-9 p. 385
Octane 120 Octane 100 6 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