1. Do Now
SGQ #6
SGQ #7
SGQ #8
There is controversy over the use of ethanol as a replacement for gasoline, write an argument supporting the use of ethanol and write an argument opposing the use of ethanol as an alternative to gasoline. Barron’s pgs
Wind power is sometimes considered a form of solar energy. Explain why this is true, and list two environmental disadvantages to the use of wind power.
Barron’s pg. 334 and pg. 331
Describe two methods of generating electricity from water, and for both methods, list two environmental disadvantages. Barron’s pg. 324 and pg. 335

2. Energy Efficiency
Objective: I will discuss the significance of energy efficiency and describe ways we can cut energy waste by evaluating the pros and cons of renewable energy sources.

3. Norms Raise your hand before speaking
Do not talk while others are talking
Use our daily focus words during J-TPS
No electronics or food
Be engaged and present in the lesson!

4. Self-Assessment Rubric
Score
Level
Evidence 4
Advanced
I understand the power point notes and can ask additional questions. I can complete the active practice worksheet while helping my peers. I will take the time to read supplemental info within the Barron’s Book and quiz myself after. 3
Proficient
I understand the power point notes. I can complete the active practice worksheet, but I have to ask for help to get started. I use the Barron’s Book to help clarify concepts so that I will feel prepared for the quiz. 2
Basic
I copied the power point notes. I need help to complete the active practice worksheet from my peers and the teacher. I don’t feel ready to be quizzed on the concept. NP
Below Basic
I got lost during the power point notes. I don’t understand the active practice questions. I feel I need to stay after school for tutoring.

5. Energy Efficiency
The measure of how much work we can get from each unit of energy we use.
The second law of thermodynamics:
energy transformation is not 100% efficient
waste heat produced when energy is converted from one form to another

6. Energy Efficiency
Ratio of quantity of work or energy produced to the quantity of work or energy used.
Units of Energy (heat)
BTU (British Thermal Units)
J (joules)
cal (calories)
Units of Power (work)
kWh (kilowatt hours)
W (Watt)

7. Why Is Energy Efficiency an Important Energy Resource?
Improving energy efficiency can save the world at least a third of the energy it uses, and it can save the United States up to 43% of the energy it uses.
Four widely used devices that waste energy:
Incandescent light bulb
Motor vehicle with internal combustion engine
Nuclear power plant
Coal-fired power plant

8. Energy Efficiency
Energy efficiency can be calculated using the following formula:
Efficiency = work/energy produced x 100%
work/energy used
I do: If 500 BTU of electric energy is produced from 5000 BTU of potential energy in fuel, what is the efficiency of the fuel?
500 / 5000 x 100 = 10%

9. Energy Efficiency
We do: A 100 Watt bulb uses 100 J/sec of electrical energy. If it is 20% efficient, how much electrical energy was produced?
x/100 x 100 = 20
x = 20 J/s

10. Energy Efficiency Energy can also be calculated by energy conversions:
Energy Unit conversion factors:
1 cal = J
1 Btu = 252 cal = 1055 J
1 Watt = 1 J/s
1 kWh = 3400 Btu
1 kWh = 8.6 x 105 cal
I do: A city that uses ten billion Btus of energy each month is using how many kilowatt-hours of energy?
10 billion BTU x 1 kwh
3400 Btu = 2,941,176 kWh

11. Energy Efficiency
We do: One barrel of crude oil provides about six million Btus of energy.
Assuming that all of the energy in crude oil could be converted to electricity with 100% efficiency, how many kilowatt-hours of energy will one liter of crude oil produce (1 barrel = 159 liters).
b. With the same assumption, how many calories of energy will one gallon of crude oil provide (1 gal = 3.76 liters)
6,000,000 / 159 = 37,736 Btus per liter
1 kWh = 3400 Btus
37,736 / 3400 = 11 kWh per liter
1 kWh = 8.6 x 105 cal
11 x 8.6 x 105 = 9,460,000 cal per liter
3.76 liters = 1 gal
9,460,000 x 3.76 = 35,569,600 cal per gallon

12. Energy Efficiency
You do: If one barrel of crude oil provides six million Btus of energy and releases 150 pounds of CO2 per million Btus of energy, how much CO2 is produced by each barrel of crude oil?
1 barrel = 6 million Btus
150 lbs CO2 per million Btus
900 lbs of CO2 per barrel of oil

13. How do you think we can reduce energy using these strategies?
Energy Conservation
Strategies that reduce the amount of energy that is being wasted.
Decrease energy for transportation
Decrease energy for heating
Decrease electricity use
J-TPS
How do you think we can reduce energy using these strategies?
How do you think we can reduce energy using these strategies?
Transportation: reduce driving by using mass transit, walking or riding a bike; carpooling; walk up and down stairs instead of using an elevator; by locallly grown food and locally made products; replace gas-guzzling cars with hybrids or electrics
Heating: decrease the thermostat setting when it is cold and wear warming clothing indoors; use less hot water; take cooler shorter showers; increase insulation; improve seals around windows and doors; install active solar energy systems to replace a furnace and hot water heater
Electrcity use: turn off lights; increase the thermostat setting when it is hot of an air conditioner, replace incadescent light bulbs with fluorescent light bulbs, unplug electronics when not in use, install photovoltaic solar panels

14. Energy Conservation
Cogeneration: excess heat by large companies and power plants can be used to produce steam and generate electricity.
Governments can mandate energy standards
Corporate Average Fuel Economy (CAFE)
US Congress enacted in 1975
Require automobile manufacturers to produce cars that meet a minimum fuel efficiency standard
Rose average mileage from 13 mpg in 1973 to 22 in 1985
Standard will raise to 35 mpg by 2020
Regulated by National Highway Traffic Safety Administration (NHTSA)

15. Energy Conservation Hybrid-electric vehicles Efficiency of 40-50 mph
Combine an electric motor with a small gasoline
Reduces use of fossil fuel

16. Miles per gallon (mpg) (converted to U.S. test equivalents)50 45
Europe 40
Japan 35
China
Miles per gallon (mpg) (converted to U.S. test equivalents) 30
Canada 25
United States 20
2002
2004
2006
2008
Year 25
Cars 20
Cars, trucks, and SUVs
Trucks and SUVs 15
Average fuel economy (miles per gallon) 10
1975
1980
1985
1990
1995
2000
2005
Year
Stepped Art
Fig. 16-5, p. 402

17. Alternative Energy Re-Cap
Solar
Hydrogen Fuel Cells
Biofuel
Wind Energy
Ocean/Tidal Energy
Geothermal
JTPS
Using your prior knowledge of these renewable energy sources, how can we improve the energy efficiency of our own school site?

18. Quick Check
Please silently and individually record the letter of your answer to the next 3 questions on your post-it note. You may use your notes. I will be collecting these.

19. Quick Check #1 Which of the following is a unit of power? Joules
Calories
Watts

20. Quick Check #2
Approximately how many Joules would be equal to 100 calories? 4 41
418
4186

21. Quick Check #3
A company is proposing to build a wind-power plant off the coast near a beach resort. Which of these is a negative result that opponents of the plant will most likely state?
The water in the area will become polluted.
The power plant will prevent sea breezes from cooling the beach.
The view from the beach will be less appealing with the many wind turbines.
The supply of winds will be quickly used up, leaving abandoned wind turbines.