Energy Efficiency & Renewable Energy

Ch.16

Why is energy efficiency an important energy resource?

Improving energy efficiency can save the world at least a 1/3rd of the energy it uses, and it can save the U.S. up to 43% of the energy it uses.

How do we get our power?

CURRENT MEANS: via centralized power system and existing grid

FUTURE MEANS: via decentralized power systems and grid revision - need gov’t aid in upstarting - Advantages - Low emissions - Use local available renewable energy sources - Reliable

How do we get our power?

Doing more with lessEnergy Efficiency – Percentage of total energy input into an energy conversion device or system that

1)Does useful work and 2)Is not converted into low-quality

heat

Fig. 16-2, p. 399

Energy Inputs System Outputs

9%

7%

41%85%

U. S. economy

43%8%4%

Nonrenewable fossil fuels Useful energy

Hydropower, geothermal, wind, solar Unnecessary energy

waste

3%

PetrochemicalsUnavoidable energy waste

Nonrenewable nuclear

Biomass

Importance of Improving Energy Efficiency

84% of energy in US is wasted!

43% unnecessarily wasted

Four widely used devices that waste energy

1. Incandescent light bulb2. Motor vehicle with internal

combustion engine3. Nuclear power plant4. Coal-fired power plant

Also: houses & cars

Energy use of various types of transportation

www.bio.miami.edu/beck/esc101/Chapter14&15.ppt

The Importance of Improving Energy Efficiency

• Lower Life Cycle Costs– Initial cost plus lifetime operating cost

• Net Energy Efficiency– Total amount of useful energy available

minus the amount of energy used/wasted• Used (1st Law of Thermodynamics)• Automatically Wasted (2nd Law of

Thermodynamics• Unnecessarily wasted (this is what needs to be

conserved)

Efficiencies (fig. 16-4 p. 382)

Uranium100%

Electricity from Nuclear Power Plant

14%

Resistanceheating(100%)

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%)

Energy

Efficiency

Could we save energy by recycling energy?

NO! - 2nd Law of Thermodynamics

How Can We Reduce Energy Waste?

In Our Homes• Insulation• Eliminate Air Leaks• Clean Air-to-Air

Heat Exchangers

Industry• Cogeneration• Efficient Electric

Motors• Recycling Materials• High Efficiency

Lighting (LEDs)• Increased Fuel

Economy

How Can We Reduce Energy Waste?

Utility Companies: Switch from promote use to promote energy efficiency - spurred by state utility commissions

How Can We Reduce Energy Waste?

Smarter Electrical Grid• Ultra-high-voltage• Super-efficient transmission lines• Controlled digitally• Responds to local changes in demand/supply• Two-way flow of energy & info• Smart meters show consumers how much

energy each appliance uses

• U.S cost -- $200-$800 billion; save $100 billion/year

Proposed U.S. Smart Grid

Figure 20, Supplement 8

How Can We Reduce Energy Waste?

Saving energy in existing buildings

About one-third of the heated air in typical U.S. homes and buildings escapes through closed windows and holes and cracks.

A Green Roof in Chicago

Fig. 16-8, p. 405

Outside Plant deciduous trees to blocksummer sun and let in wintersunlight.

Other rooms • Use compact fluorescent lightbulbs or LEDs and avoid using incandescent bulbs wherever possible.• Turn off lights, computers, TV, and other electronic devices when they are not in use.• Use high efficiency windows; use insulating window covers and close them at night and on sunny, hot days.• Set thermostat as low as you can in winter and as high as you can in summer.• Weather-strip and caulk doors, windows, light fixtures, and wall sockets.• Keep heating and cooling vents free of obstructions.• Keep fireplace damper closed when not in use.• Use fans instead of, or along with, air conditioning.

Bathroom• Install water-saving toilets, faucets, and shower heads.• Repair water leaks promptly.

Stepped Art

Attic• Hang reflective foil near roof to reflect heat.• Use house fan.• Be sure attic insulation is at least 30 centimeters (12 inches).

Kitchen• Use microwave rather than stove or oven as much as possible.• Run only full loads in dishwasher and use low- or no-heat drying.• Clean refrigerator coils regularly.

Basement or utility room • Use front-loading clothes washer. If possible run only full loads with warm or cold water.

• Hang clothes on racks for drying.• Run only full loads in clothes dryer and use lower heat setting.• Set water heater at 140° if dishwasher is used and 120° or lower if no dishwasher is used.

• Use water heater thermal blanket.• Insulate exposed hot water pipes.• Regularly clean or replace furnace filters.

Fig. 16-10, p. 407

How Can We Reduce Energy Waste?

Transportation – 28% energy consumptionCAFE (corporate average fuel economy) standards

How Can We Reduce Energy Waste?

Give consumers tax breaks & economic incentives for more fuel efficient vehicles

Example: Feebate

How Can We Reduce Energy Waste?

Types of More Energy-Efficient Vehicles• Superefficient & ultra light cars• Gasoline-electric hybrid car• Plug-in hybrid electric vehicle• Energy-efficient diesel car• Electric vehicle with a fuel cell

Fig. 16-6, p. 403

Conventional hybrid Fuel tank

Battery

Internal combustion engine

Transmission Electric motor

Fig. 16-6, p. 403

Plug-in hybrid Fuel tank

Battery

Internal combustion engine

Transmission Electric motor

Light-Weight Carbon Composite Concept Car

Fig. 16-7, p. 405

How Can We Reduce Energy Waste?

Transportation• Usable & Convenient Mass

Transit• Electric Rail Systems• Biking

Why are we still wasting so much energy & money? *

• Energy remains artificially cheap– Government subsidies– Tax breaks– Prices don’t include

true cost

Why are we still wasting so much energy & money?

• Few large and long-lasting incentives– Tax breaks– Rebates– Low-interest loans

We Can Use Renewable Energy to Provide Heat and Electricity

• Renewable energy– Solar energy: direct or indirect– Geothermal energy

• Benefits of shifting toward renewable energy

• Renewable energy cheaper if we eliminate– Inequitable subsidies– Inaccurate prices– Artificially low pricing of nonrenewable

energy

What Are the Advantages & Disadvantages of Different

Renewable Energy Options?

That’s for you to tell us!

Shifting to Alternative Energies

1. Decreases reliance on foreign oil

2. Increases autonomy3. Relies on economic and political

shift

Strategies to Assist the Shift

1. Competition in free market without government interference

2. Keeping prices artificailly LOW to encourage use of slected energy resources

3. Keeping prices artifically HIGH to discourabe use of selected energy resources.