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 43% is wasted unnecessarily 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

Advantages of Reducing Energy Waste

The Importance of Improving Energy Efficiency Net energy efficiency Least Efficient Incandescent lights Nuclear power plants Internal combustion engine Fig. 18-3 p. 381

Energy Efficiencies (Fig. 18-5 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.

Comparing Efficiency of 2 Types of Space Heating

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)

Average Fuel Economy of New Vehicles Sold In U.S.

Price of Gas in 1993 Dollars

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

Toyota Prius

Ford Escape Hybrid

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

Fuel Cells

GM’s prototype future 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.

Using Solar Energy to Provide Heat Active Solar: absorbs heat energy from sun by pumping heat absorbent fluid through collectors. Great for hot water heaters in warmer climates

Using Solar Energy for Electricity Solar energy can be converted directly into electricity using PHOTOVOLTAIC CELLS (PV) or “Solar Cells” Sunlight energizes electron to flow in a semi conductor producing an electrical current

Using Solar Energy for Electricity Solar Cells can be incorporated into roofing and windows. High costs are expected to fall Currently only supply 0.05% of world electricity

Using Solar Energy for Electricity Great for rural locations BP in 2004 began to mass produce cells With increased R&D and government help --- 25% by 2040???

Using Solar Energy for Electricity Solar Thermal Systems: large solar arrays in sunny areas can produce high-temperature heat for: Electricity Hot water Heating Wash Machines

Using Solar Energy for Electricity Solar thermal systems Photovoltaic (PV) cells

Producing Electricity From the Water Cycle: Section 4 Key Concepts How can we produce electricity from flowing water? What are advantages and disadvantages of hydropower? What is tidal and wave power?

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

Renewable Hydropower Water flowing in rivers and streams can be trapped in reservoirs behind a dam and released to spin turbines to produce electricity. In 2002, hyrdro accounted for 20% of world electricity (Norway 99%, U.S. 7% -- 50% in west)

Renewable Hydropower According to UN only 13% of potential hydropower has been developed Large Scale Hydro Power has been curtailed recently by environmental concerns

Large-scale Hydroelectric Power: Trade-offs

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

Hoover Dam

Tidal Power Using the twice daily natural rise and fall of tidal waters to produce power. Newer concept Lot of potential in certain tidal regions. Problems???

Tidal Power

Wave Power Using the constant wave action along shorelines to produce power. Another form of wind power. Problems???

Producing Electricity from Wind Section 5 Key Concepts

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

Altamont Pass California

Atlantic City

http://www. eere. energy http://www.eere.energy.gov/windandhydro/windpoweringamerica/where_is_wind_new_jersey.asp

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

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

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

The Hydrogen Revolution Fig. 18-31 p. 403

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

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