Energy ConservationHome, School, and

Transportation

CPES2009-10

Quiz – Energy Conservation• Energy use in U.S. – graphs• Energy use in average home – graph and discussion• Efficiency

– Definition– Light bulbs

• System efficiency – worksheet • Energy Conservation in the home

– Home energy activity• Energy use and conservation in transportation

– Alternative Fuels– Hybrids– Other ways to reduce energy use in transportation

Where is energy used in the U.S.?

Energy Conservation• Efficiency – system efficiency, appliances• Payback period – calculations – Lutron

– Calculate costs: Compare the incandescent and CF bulbs• Insulation

– Energy Transfer: conduction, convection, radiation– Thermos demonstration

• Home and school energy efficiency• Lighting system – classroom and school

• How does energy use and efficiency relate to other environmental issues?– Energy and global climate change.

Inefficiency of Energy Use

• Efficiency: Energy input that is converted to useful “work” (intended purpose)– What happens to the remainder

• System efficiency vs. efficiency of individual unit (appliance, light bulb, etc.)

• Overall efficiency - U.S. energy use is about 16%• Explain the following:

– About 1/2 second law of energy – About 1/2 wasted unnecessarily

Energy Inputs System Outputs

U.S.economy

andlifestyles

84%

8%

4%4%

9%

7%

41%

43%

Nonrenewable fossil fuels

Nonrenewable nuclear

Hydropower, geothermal,wind, solarBiomass

Useful energy

Petrochemicals

Unavoidable energy wasteUnnecessary energy waste

Figure 16-2Page 381

(gasoline) 10%

Internal combustionengine

Figure 16-4 (5)Page 382

22%Fluorescent light

Figure 16-4 (4)Page 382

5%Incandescent light

Figure 16-4 (5)Page 382

Uranium100%

Electricity from Nuclear Power Plant

14%

Resistanceheating(100%)

SYSTEM EFFICIENCY FOR

ELECTRICITY PRODUCTION

90%

Wasteheat

Passive Solar

Sunlight100%

Wasteheat

14%

Transmissionof electricity

(85%)

17%

Wasteheat

Power plant(31%)

54%

Wasteheat

Uranium processingand transportation

(57%)

95%

Wasteheat

Uraniummining(95%)

Goals of Our Discussion: Home Energy Use and Conservations

• Energy uses in your home – what are they?– How do they rank in amount of energy used?

• School – what are energy conservation measures?– How can energy use be reduced in the school?– Lutron lighting system in classroom

• How does insulation work? – Relate to thermos bottle demonstration and three types of

energy transfer– Contrast types and R-values– Short video- natural insulation

• What is your home’s energy profile?

Transfer of Heat Energy

Fig. 3-11 p. 553

Convection Conduction Radiation

Heat from a stove burner causes atoms or molecules in the pan’sbottom to vibrate faster. The vibrating atoms or molecules then collide withnearby atoms or molecules, causingthem to vibrate faster. Eventually, molecules or atoms in the pan’shandle are vibrating so fast itbecomes too hot to touch.

As the water boils, heat from the hot stove burner and pan radiate into thesurrounding air, even though airconducts very little heat.

Heating water in the bottom of a pancauses some of the water to vaporizeinto bubbles. Because they are lighter than the surrounding water, they rise. Water then sinks from the top to replace the rising bubbles.This up and down movement (convection) eventually heats all of the water.

School Energy – Lighting and Evaluation

• List all of the components of the Lutron System installed in the classroom.

Is our Transportation Sustainable?

35

30

25

20

15

14.9

12.8

10.7

8.5

6.41980 1985 1990 1995 2000 2005

Year

Ave

rage

fuel

eco

nom

y(m

iles

per g

allo

n, o

r mpg

) Average fuel efficiency

(kilometers per liter, or kpl)

Passenger cars

Total fleet

Pickups, vans, andsport utility vehicles

What are ways that the U.S. auto fleet can be increased?

Energy Used for Transportation

What are “walk away ideas” for each graph

Sustainable Transportation

• How can we move toward sustainable transportation?

• Look for: clean-emission cars powered by electricity and

fuel cells; reduction of fuel consumption on airplanes,

transport trucks, and increased use of trains integrated, efficient inter-city buses and trains-

mass transit a key

Electric Cars, Fuel Cells, Hybrids, and Hydrogen Fueled

Are these Your future?

What about electric cars?

• Problem is batteries– cost– storage capacity– weight

Batteries the big problem Heavy (lead-acid battery pack 1,000

pounds or more). Bulky (up to 50 lead-acid batteries, each

measuring roughly 6" x 8" by 6"). Limited storage capacity (range of only 50

miles). They are slow to charge - up to 10 hours Short life (three to four years) They are expensive (perhaps $2,000)

Solving the battery bottleneck

Replace lead-acid batteries with NiMH batteries or other kinds The range of the car will double Will last 10 years But, the cost of the batteries today is 10 to 15

times greater than lead-acid. NiMH battery pack will cost $20,000 to

$30,000 (today) instead of $2,000.

Solar powered cars- Are these commercially feasible

• Hybrids?

• Or, Fuel Cells• Or. …………………….??

What are some options?

ElectricityFuel

Combustion engineA

Fuel tankB

Electric motorC

Battery bankD

RegulatorE

TransmissionF

A

B

C

D

E F

Hybrid Car

Engines and motors•Braking recharges the batteries

•Motor, not engine, runs at lower speeds

•Engine shuts off completely when at lower speeds and when stopped

•So, what are the disadvantages?