1. Energy Efficiency
APES

2. Some conversion factors
One calorie is the amount of energy needed to heat 1g of water 1°C.
A kilocalorie is 1,000 calories
1 BTU = energy to heat 1 lb of water 1°F
1 watt (W) = Btu/hour
1 horsepower (hp) = 746 W
Watt-hour- used to describe electrical energy used for an item per hour. Usually use kilowatt-hour (kWh) cuz it is larger.

3. Energy Efficiency
Measure of useful energy produced compared to energy consumed.
Also known as the total net energy yield
Ex: nuclear power plants produce a lot of energy from small amount of fuel but the energy put into mining, smelting, etc is greater so it is hard to “break-even”
Light given off from light bulb is useful but heat given off is wasted
Incandescent bulb (regular bulb) is 5% efficient. 95% is lost as heat.
Fluorescent bulb is 22% efficient 78% lost as heat.

4. Energy Efficiency in the Home

5. Compact Fluorescent Light (CFL) Bulbs & Your Home
1CFL is equal to 13 regular bulbs
CFL’s are a little more expensive but you save money on bulbs & electric bill later
1 Sylvania CFL- $6.98
24 Sylvania regulars- $9.98
CFL’s use lower wattage to get same amount of light
13 watt CFL can give off as much light as 60 watt regular bulb using ¼ of electricity
By replacing 25% of your regular with CFL, you can save 50% on energy bill.
Incandescents & Halogens give off more heat than CFL’s
In summer this can cause you to use your air conditioning more.
Same quality of light

6. INCANDESCENT vs. COMPACT FLUORESCENT BULBS
Bulb Type
100W Incandescent
23W Compact Fluorescent
Purchase Price
$0.75
$11.00
Life of the Bulb
750 hours
10,000 hours
Number of Hours Burned per Day
4 hours
Number of Bulbs Needed
About 6 over 3 years
1 over 6.8 years
Total Cost of Bulbs
$4.50
Lumens Produced
1,690
1,500
Total Cost of Electricity (8 cents/kilowatt-hour)
$35.04
$8.06
Your Total Cost over 3 years
$39.54
$19.06
Total Savings over three years with the Compact Fluorescent:
$20.50
Source: U.S. Department of Energy, Energy Information Administration

7. CFLs and the environment
20 watt CFL used instead of 75 watt incandescent bulb saves 550 kWh of electricity
This saves 500 pounds of coal which keeps 1300 pounds of carbon dioxide emissions and 20 pounds of sulfur emissions out of the air.
Cons- contain small amounts of mercury and must be disposed of safely- not just thrown away. (Home Depot will take them)

8. Energy Star Products Joint program of the U.S. EPA and the U.S. DOE
Designed to protect the environment thru energy-efficient products & practices.
In 2005, programs coordinated thru Energy star saved $12 billion in utility bills and avoided greenhouse gas emissions equivalent to 23 million cars.

9. Energy Efficiency & Cars

10. State Energy Program Energy Conservation Act (1975)
Set up Strategic Petroleum Reserve so we can stockpile crude oil (in response to 1970’s Arab oil embargo)
Established programs to foster energy conservation in federal buildings and major U.S. industries
Provide states with funding for renewable energy and energy efficiency projects
Corporate Average Fuel Economy (CAFE) standards set. See next slide about CAFE
Energy Policy Act (1992)
States play crucial role in regulating local energy industries
Expanded states role in policy development & technology deployment
Allowed “revolving” funds for renewable & energy efficient projects
Energy Funding Allocation- how is the money distributed by Department of Energy (DOE)?
1/3 distributed equally
1/3 based on population
1/3 based on energy consumption
20% must be provided by state

11. CAFE standards Corporate Average Fuel Economy
Average fuel economy for a manufacturer’s fleet of cars that have a gross vehicle weight rating (GVWR) of 8,500 lbs or less. Expressed in miles per gallon (mpg). Tested by company or EPA.
Passenger cars standard mpg
Light truck standard mpg
SUV’s, Pickup trucks, and large vans are exempt
Achieved thru better engine design, efficiency & weight reductions
If car/truck does not meet standards, may be penalized.
Charged $5.50 per 1/10th of a mpg that does not meet target rate
Can earn credits during “passing” years that can be used during “non passing” years to help them “pass” and not have to pay so much in penalty
From fuel efficiency increased. Since 1985, fuel efficiency has leveled off.

12. Gas Cars vs. Electric Cars vs. Hybrid cars
1 gallon of gas weighs 6 lbs and when burned releases 20 lbs of CO2!
Electric cars produce no emissions (from the car) but must be recharged between uses (every miles). This slow recharging process draws a lot of electricity so you still have energy generated from coal power plants which still causes pollution.
Hybrid cars- increase mileage of gas (reduce emissions) and do not have to be recharged.
Gas
Electric
Hybrid

13. Hybrid Cars Gasoline-electric engine High efficiency, lowest emissions
An electric motor run by batteries supplements gas engine so uses less gasoline.
Can get miles per gallon in many hybrid cars
Cons- higher initial cost
Pros-
lower operating costs later on
Economic incentive: Can earn tax credits of up to $3,000

14. Types of Hybrids
Parallel- fuel tank that supplies gasoline to engine & set of batteries that supplies power to electric motor; both gas & electric supply power to wheels; shuts down gas at a light & accelerates using electric (Toyota, Lexus, Ford)
Series- gas engine turns generator, which charges the batteries &/or powers an electric motor; gas engine is not used to make car go (General Motors)
Plug-in- added battery; plugged into 120 volt outlet to charge (60 miles per charge); when run out of charge, switches to fuel tank

15. Hydrogen Fuel Cells Works like a battery
Cathode & anode separated by membrane
Oxygen passes over one, hydrogen over the other
Hydrogen reacts with anode & is converted to negatively charged electrons & positively charged hydrogen ions.
Electrons flow out of cell to be used as electrical energy.
Hydrogen ions move thru the electrolyte membrane to the cathode where they combine with oxygen to make water
Only have to refill the hydrogen to keep reaction going.
Fuel Cell Animation

16. How a Hydrogen Fuel Cell Works

17. Hydrogen Fuel Cells Pros Cons Waste is pure water
Ocean or freshwater can be used to obtain hydrogen
Does not destroy wildlife habitats
Causes minimal environmental impact
Energy used to create hydrogen could come from solar power
Hydrogen easily transported thru pipes
Can be stored in compounds to make it safe to handle
Cons
Takes energy to produce hydrogen from either water or methane
Changing from fossil fuels to hydrogen fuel would be very expensive & cost people their jobs
Hydrogen gas is explosive
Currently difficult to store hydrogen gas for cars

18. Biofuels Types: Ethanol, biodiesel, methanol
Ethanol- corn, sugarcane
Biodiesel- oil + alcohol using soybeans, rapeseed, sunflowers, palm plants
Can be used to replace or supplement gasoline or diesel fuel
Biggest producers- Brazil, US, European union, China
Projected 25-50% of US cars will run on this type of fuel by 2030

19. Ethanol vs. Gasohol vs. E85
Ethanol- fermented & distilled sugars from plants (corn, sugarcane, switchgrass)
Gasohol- gasoline mixed with 10-23% ethanol.
E85- 85% ethanol & 15% gas. Used in “flex-fuel” cars. Costs about $150 to convert.

20. E85- the way to go?
If 5% of US vehicles switched over we’d decrease our oil imports by 6%
Problems:
Very few E85 fuel stations
Gets 25% fewer miles per gallon

21. Brazil- A Case Study Leader in biofuel industry
Energy independent- no imports
Create ethanol from bagasse- sugarcane residue
Created 1 million rural jobs
Yields 8.3 times MORE energy when burned than the energy used to produce it.
Cons- destroying biodiverse areas (Cerrado wooded savanna) to make way for agricultural land.

22. United States- A Case Study
2nd largest leader
Produce ethanol from corn
Farmers get subsidies for growing corn for ethanol
Genetic engineering can improve yields
Cons-
only yields 1.5 times more energy than energy used to make it
Labor & chemical intensive to grow corn
Cannot produce enuf to satisfy US citizens. If we processed all corn in US only give enuf ethanol for 55 days of driving. No corn for cattle feed or food.

23. Is Switchgrass the Answer?
Native grass
Attributes:
Grows taller & faster
needs less fertilizer
grown on land unfit for other crops
sucks a lot of CO2 out of air
Yields 4 times more energy than energy used to make it. Not as much as sugarcane (8.3) but much more than corn (1.5)
Cons
Much larger & more powerful lobby for corn by US political powers

24. Biofuel Advantages and Disadvantages
Crops can be grown in many different environments
If harvested sustainably, will absorb as much CO2 when alive as CO2 released when burned
Easy to store, transport
Provide jobs- especially in rural areas
Higher octane- better for car
Reduced CO emissions
Environmental impact of growing crops- pesticide, fertilizer, etc. Monocropping depletes nutrients in soil.
Native areas are destroyed to make way for agricultural land (Brazil destroying wooded savanna)
Competition for land to grow food crops vs. biofuel crops. Causing increase in food costs.
Reduced gas mileage
Hard to start in cold weather

25. Maglev Trains Magnetic Levitation Trains Watch this cool video!!
Science & Technology Movie - Maglev Trains
Maglev Train in Powder Springs!
Other videos to watch on your own:
Science & Technology Movie - The Wind Business
Science & Technology Movie - Making Sparks

26. What can be done to help?

27. Negawatts program Programs sponsored by energy companies
Easier to finance education & conservation projects than build new coal power plants
Encourage “demand avoidance”- don’t use energy at peak times
Conservation projects cost about $350 per kWh saved
Ex: public education, home improvement loans, efficiency labels, reduced taxes on energy saving appliances
New nuclear power plants cost $3000-$8000 per kW of installed capacity
New coal power plants with latest air pollution control equipment is $1000 kW

28. What can you do? Drive less; make fewer trips
Use public transportation, walk or ride bike
Carpool; drive smaller car; reduce speeds
Use stairs instead of elevator
Insulate home or add more insulation. Higher the “R” value on insulation, the better it is
Turn thermostats down in winter & up in spring
Weather strip or caulk around windows & doors
Add plastic sheets to windows
Open blinds during day and close at night trapping heat stored during day
Turn off lights, TVs, computers when not in use; use compact fluorescent lights
Stop faucet leaks- especially hot water
Use low flow shower heads, take shorter, cooler showers
Recycle glass, metals, paper; compost organic matter
Eat locally grown food in season- reduces transportation cost & use of gas
Buy locally made, long-lasting materials

29. Interesting Links