Energy Efficiency and Renewable Energy G. Tyler Miller’s Living in the Environment 14th Edition Chapter 18
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
Section 1: The Importance of Improving Energy Efficiency What is energy efficiency? How much energy do we waste? What is life cycle cost? What is net energy efficiency?
What is energy efficiency? Energy efficiency is the measure of the useful energy produced compared to the energy converted to low quality--- usually heat. Using energy to do work, not produce heat.
What is energy conservation? Implementing new technology to do same work using less energy. • Heating homes more efficiently • Driving more efficient cars • Lightning spaces more efficiently SAVES $$$, produces less pollution, reduces CO2
Energy Conservation • 84% of commercial electricity is wasted in U.S. • 41% of energy is automatically wasted due to 2nd Law Of Thermodynamics • 43% is wasted unnecessarily
The Importance of Improving Energy Efficiency • Energy efficiency • Net energy efficiency Least Efficient • Incandescent lights • Nuclear power plants • Internal combustion engine Fig. 18-3 p. 381
Life Cycle Costs Initial Cost plus the lifetime cost. Some energy efficient models may cost more up front, but save money in the long run. Civic Hybrid vs. Conventional Gas
Net Energy Efficiency Measure of how much useful energy we get from energy resource after subtracting the energy wasted. How much energy you get out given ALL the wasted energy.
Section 2: Ways to Improve Energy Efficiency Key Concepts How can we save energy in industry? How can we save energy in transportation? How can we design buildings to save energy? How can we save energy in existing buildings? Why are we still wasting so much energy?
Ways to Improve Energy Efficiency • Cogeneration • Efficient electric motors • High-efficiency lighting • Increasing fuel economy • Alternative vehicles • Insulation • Plug leaks
How can industry save energy? • Cogeneration – combining heat and power systems • Improving electric motor efficiency (consumes 1/4th of energy) • Improving light fixtures
How can we save energy in transportation? CAFÉ Standards need to be increased. Increase to 40 mpg in 10yrs would cut consumption in half (could eliminate imports from Middle East)
Hybrid and Fuel Cell Cars • Hybrid electric-internal combustion engine Hybrid-electric cars are powered by a battery and a small ICE that recharges the battery. Fig. 18-9 p. 385
Fuel Cell Cars Fuel cell cars run on hydrogen and produce little pollution. Combine hydrogen and oxygen to produce electricity and water vapor. Ford Focus Fuel Cell Car
GM’s prototype future fuel cell car. No engine noise, no pollution, no greenhouse gasses.
How can we Design More Efficient Buildings? Chicago’s Sears Tower uses more energy in a day than a city of 150,000 Atlanta’s Georgia Power Company uses 60% less energy than other buildings it size.
How can we Design More Efficient Buildings? We can save energy in buildings by • Getting heat from the sun • Insulating well • Using plants for shade and wind blockage
How can we Design More Efficient Buildings? Super insulated house: • Costs 5% more to build • Can use 90% less energy for heating and cooling Green Roofs: • Plants or gardens on roof help insulate from heat in summer and cold in winter
An infrared photo showing heat loss (red, white and orange) around windows, doors, roofs.
How can we save energy in existing buildings? We can save energy in existing buildings by: • insulating them • plugging leaks • using heating, electricity, cooling, appliances and lighting more efficiently
Insulate and plug leaks 1/3rd of heated air in U.S. homes is lost through windows, holes and cracks. Insulating and plugging holes is the easiest and cheapest ways to save energy.
Use Efficient Windows Double pained, insulating windows cost more, but can save money in the long run.
Heat House More Efficiently Using the most efficient heating system available. Some natural gas furnaces can reach 85-98% efficiency
Heat Water More Efficiently There are several new technologies to heat water more efficiently: • Tankless, instant heaters • Well insulated tank
Use Energy Efficient Lighting and Appliances Microwaves, refrigerators, washers, driers, lights all come with energy star labels ¼ of electricity bill is lighting
Cut Off Electrical Devises Not In Use When not using lights, computers, TV’s and other electrical devises they should be turned off.
Review Section 2 How can we save energy in industry? How can we save energy in transportation? How can we design buildings to save energy? How can we save energy in existing buildings? Why are we still wasting so much energy?
Section 3: Producing Energy With Solar Power: Key Ideas What are the main types of renewable energy? How can we use direct solar energy to heat and cool homes? How can we use solar energy to produce electricity? What are solar cells? What are advantages and disadvantages of solar cells?
What are the main types of renewable energy? The next several sections we will go through: • Solar Energy • Flowing Water • Wind • Biomass • Geothermal • Hydrogen • Other possible renewable energy sources.
What are the main types of renewable energy? • EU by 2020: 22% renewable • CA gets 12% from renewable (20% by 2020) • Union of Concerned Scientists study said 20% by 2020 is possible
Using Solar Energy to Provide Heat • Passive solar heating: absorbs and stores heat from the sun directly within the structure Has been used for thousands of years.