Energy Efficiency and Renewable Energy. Chapter Overview Questions How can we improve energy efficiency…

Energy Efficiency and Energy Efficiency and Renewable EnergyRenewable Energy

Chapter Overview QuestionsChapter Overview Questions

How can we improve energy efficiency and How can we improve energy efficiency and what are the advantages of doing so?what are the advantages of doing so?

What are the advantages and disadvantages What are the advantages and disadvantages of using solar energy to heat buildings and of using solar energy to heat buildings and water and to produce electricity?water and to produce electricity?

What are the advantages and disadvantages What are the advantages and disadvantages of using flowing water to produce electricity?of using flowing water to produce electricity?

What are the advantages and disadvantages What are the advantages and disadvantages of using wind to produce electricity?of using wind to produce electricity?

Chapter Overview Questions (cont’d)Chapter Overview Questions (cont’d)

What are the advantages and disadvantages What are the advantages and disadvantages of burning plant material (biomass) to heat of burning plant material (biomass) to heat buildings and water, produce electricity, and buildings and water, produce electricity, and propel vehicles?propel vehicles?

What are the advantages and disadvantages What are the advantages and disadvantages of extracting heat from the earth’s interior of extracting heat from the earth’s interior (geothermal energy) and using it to heat (geothermal energy) and using it to heat buildings and water, and produce electricity?buildings and water, and produce electricity?

Chapter Overview Questions (cont’d)Chapter Overview Questions (cont’d)

What are the advantages and disadvantages What are the advantages and disadvantages of producing hydrogen gas and using it in fuel of producing hydrogen gas and using it in fuel cells to produce electricity, heat buildings and cells to produce electricity, heat buildings and water, and propel vehicles?water, and propel vehicles?

How can we make a transition to a more How can we make a transition to a more sustainable energy future?sustainable energy future?

Core Case Study: The Coming Core Case Study: The Coming Energy-Efficiency and Renewable-Energy-Efficiency and Renewable-

Energy RevolutionEnergy Revolution It is possible to get electricity from solar cells It is possible to get electricity from solar cells

that convert sunlight into electricity.that convert sunlight into electricity. Can be attached like shingles on a roof.Can be attached like shingles on a roof. Can be applied to window glass as a coating.Can be applied to window glass as a coating. Can be mounted on racks almost anywhere.Can be mounted on racks almost anywhere.

Core Case Study: The Coming Core Case Study: The Coming Energy-Efficiency and Renewable-Energy-Efficiency and Renewable-

Energy RevolutionEnergy Revolution

The heating bill for this energy-efficient The heating bill for this energy-efficient passive solar radiation office in Colorado is passive solar radiation office in Colorado is $50 a year.$50 a year.

Figure 17-1Figure 17-1

REDUCING ENERGY WASTE AND REDUCING ENERGY WASTE AND IMPROVING ENERGY EFFICIENCYIMPROVING ENERGY EFFICIENCY

Flow of commercial Flow of commercial energy through the energy through the U.S. economy.U.S. economy.

84% of all 84% of all commercial energy commercial energy used in the U.S. is used in the U.S. is wasted wasted

41% wasted due to 41% wasted due to 22ndnd law of law of thermodynamics.thermodynamics.


Fig. 17-2, p. 385

Energy Inputs System Outputs

9%7%

41%85% U.S.

economy and

lifestyles

8%

43%

4%

Nonrenewable nuclear PetrochemicalsNonrenewable fossil fuels Useful energy

Hydropower, geothermal, wind, solar

Unavoidable energy waste

Unnecessary energy wasteBiomass

3%

REDUCING ENERGY WASTE AND REDUCING ENERGY WASTE AND IMPROVING ENERGY EFFICIENCYIMPROVING ENERGY EFFICIENCY

Four widely used devices waste large Four widely used devices waste large amounts of energy:amounts of energy: Incandescent light bulbIncandescent light bulb: 95% is lost as heat.: 95% is lost as heat. Internal combustion engineInternal combustion engine: 94% of the energy : 94% of the energy

in its fuel is wasted.in its fuel is wasted. Nuclear power plantNuclear power plant: 92% of energy is wasted : 92% of energy is wasted

through nuclear fuel and energy needed for through nuclear fuel and energy needed for waste management.waste management.

Coal-burning power plantCoal-burning power plant: 66% of the energy : 66% of the energy released by burning coal is lost.released by burning coal is lost.

Fig. 17-3, p. 386

Solutions

Reducing Energy Waste

Prolongs fossil fuel supplies

Reduces oil imports

Very high net energy

Low cost

Reduces pollution and environmental degradation

Buys time to phase in renewable energy

Less need for military protection of Middle East oil resources

Creates local jobs

Net Energy Efficiency: Net Energy Efficiency: Honest AccountingHonest Accounting

Comparison of net Comparison of net energy efficiency for energy efficiency for two types of space two types of space heating.heating.


Fig. 17-4, p. 387

Uranium mining (95%)

Uranium processing and transportation

(57%)

Power plant (31%)

Transmission of electricity (85%)

Resistance heating

(100%)

Uranium

100%95% 54% 17% 14% 14%

Waste heat

Waste heat

Waste heat

Waste heat

Electricity from Nuclear Power PlantWindow

transmission

(90%)Sunlight

100%

90%

Waste heat

Passive Solar

WAYS TO IMPROVE ENERGY WAYS TO IMPROVE ENERGY EFFICIENCYEFFICIENCY

Industry can save energy and money by Industry can save energy and money by producing both heat and electricity from one producing both heat and electricity from one energy source and by using more energy-energy source and by using more energy-efficient electric motors and lighting.efficient electric motors and lighting. Industry accounts for about 42% of U.S. energy Industry accounts for about 42% of U.S. energy

consumption.consumption. We can save energy in transportation by We can save energy in transportation by

increasing fuel efficiency and making increasing fuel efficiency and making vehicles from lighter and stronger materials.vehicles from lighter and stronger materials.


Average fuel Average fuel economy of new economy of new vehicles sold in vehicles sold in the U.S. between the U.S. between 1975-2006.1975-2006.

The governmentThe government Corporate Corporate Average Fuel Average Fuel EconomyEconomy (CAFE) (CAFE) has not increased has not increased after 1985.after 1985.


Fig. 17-5, p. 388

Cars

Both

Ave

rage

fuel

eco

nom

y (m

iles

per g

allo

n, o

r mpg

)

Model year

Pickups, vans, and sport utility vehicles


Inflation adjusted Inflation adjusted price of gasoline price of gasoline (in 2006 dollars) (in 2006 dollars) in the U.S.in the U.S.

Motor vehicles in Motor vehicles in the U.S. use 40% the U.S. use 40% of the world’s of the world’s gasoline.gasoline.


Fig. 17-6, p. 388

Dol

lars

per

gal

lon

(in 2

006

dolla

rs)

Year


General features of a General features of a car powered by a car powered by a hybrid-electric engine.hybrid-electric engine.

““Gas sipping” cars Gas sipping” cars account for less than account for less than 1% of all new car 1% of all new car sales in the U.S.sales in the U.S.


Fig. 17-7, p. 389

Regulator: Controls flow of power between electric motor and battery bank.

Fuel tank: Liquid fuel such as gasoline, diesel, or ethanol runs small combustion engine.Transmission:

Efficient 5-speed automatic transmission.

Battery: High-density battery powers electric motor for increased power.

Combustion engine: Small, efficient internal combustion engine powers vehicle with low emmissions; shuts off at low speeds and stops.

Electric motor: Traction drive provides additional power for passing and acceleration; excess energy recovered during braking is used to help power motor.

Fuel Electricity

Hybrid Vehicles, Sustainable Wind Hybrid Vehicles, Sustainable Wind Power, and Oil importsPower, and Oil imports

Hybrid gasoline-electric engines with an extra Hybrid gasoline-electric engines with an extra plug-in battery could be powered mostly by plug-in battery could be powered mostly by electricity produced by wind and get twice the electricity produced by wind and get twice the mileage of current hybrid cars.mileage of current hybrid cars. Currently plug-in batteries would by generated by Currently plug-in batteries would by generated by

coal and nuclear power plants.coal and nuclear power plants. According to U.S. Department of Energy, a According to U.S. Department of Energy, a

network of wind farms in just four states could network of wind farms in just four states could meet all U.S. electricity means.meet all U.S. electricity means.

Fuel-Cell VehiclesFuel-Cell Vehicles

Fuel-efficient vehicles powered by a fuel cell Fuel-efficient vehicles powered by a fuel cell that runs on hydrogen gas are being that runs on hydrogen gas are being developed.developed.

Combines hydrogen gas (HCombines hydrogen gas (H22) and oxygen gas ) and oxygen gas (O(O22) fuel to produce electricity and water ) fuel to produce electricity and water vapor (2Hvapor (2H22+O+O22 2H 2H22O).O).

Emits no air pollution or COEmits no air pollution or CO2 2 if the hydrogen if the hydrogen is produced from renewable-energy sources.is produced from renewable-energy sources.

Fig. 17-8, p. 390

Body attachments Body attachments Mechanical locks that secure the Mechanical locks that secure the body to the chassisbody to the chassis

Air system management

Universal docking connection Connects the chassis with the

drive-by-wire system in the bodyFuel-cell stack Converts hydrogen fuel into electricity

Rear crush zone Absorbs crash energy

Drive-by-wire system controls

Cabin heating unit

Side-mounted radiators Release heat generated by the fuel cell, vehicle electronics, and wheel motors

Hydrogen fuel tanks

Front crush zone Absorbs crash energy

Electric wheel motors Provide four-wheel drive; have built-in brakes


We can save energy in building by getting We can save energy in building by getting heat from the sun, superinsulating them, and heat from the sun, superinsulating them, and using plant covered green roofs.using plant covered green roofs.

We can save energy in existing buildings by We can save energy in existing buildings by insulating them, plugging leaks, and using insulating them, plugging leaks, and using energy-efficient heating and cooling systems, energy-efficient heating and cooling systems, appliances, and lighting.appliances, and lighting.

Strawbale HouseStrawbale House

Strawbale is a superinsulator that is made Strawbale is a superinsulator that is made from bales of low-cost straw covered with from bales of low-cost straw covered with plaster or adobe. Depending on the thickness plaster or adobe. Depending on the thickness of the bales, its strength exceeds standard of the bales, its strength exceeds standard construction.construction.


Living RoofsLiving Roofs

Roofs covered with Roofs covered with plants have been plants have been used for decades in used for decades in Europe and Iceland.Europe and Iceland.

These roofs are built These roofs are built from a blend of light-from a blend of light-weight compost, weight compost, mulch and sponge-mulch and sponge-like materials that like materials that hold water.hold water.


Saving Energy in Existing BuildingsSaving Energy in Existing Buildings

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


Why Are We Still Wasting So Much Why Are We Still Wasting So Much Energy?Energy?

Low-priced fossil fuels and few government Low-priced fossil fuels and few government tax breaks or other financial incentives for tax breaks or other financial incentives for saving energy promote energy waste.saving energy promote energy waste.

How Would You Vote?How Would You Vote?To conduct an instant in-class survey using a classroom response To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. menu for Living in the Environment.

Should the United States (or the country Should the United States (or the country where you live) greatly increase its emphasis where you live) greatly increase its emphasis on improving energy efficiency?on improving energy efficiency? a. No. The free market already encourages a. No. The free market already encourages

investments in energy efficiency.investments in energy efficiency. b. Yes. Without government participation, there is b. Yes. Without government participation, there is

little incentive to improve energy efficiency until a little incentive to improve energy efficiency until a crisis occurs. crisis occurs.

USING RENEWABLE SOLAR USING RENEWABLE SOLAR ENERGY TO PROVIDE HEAT AND ENERGY TO PROVIDE HEAT AND

ELECTRICITYELECTRICITY A variety of renewable-energy resources are A variety of renewable-energy resources are

available but their use has been hindered by available but their use has been hindered by a lack of government support compared to a lack of government support compared to nonrenewable fossil fuels and nuclear power.nonrenewable fossil fuels and nuclear power. Direct solar Direct solar Moving water Moving water Wind Wind GeothermalGeothermal


ELECTRICITYELECTRICITY The European Union aims to get 22% of its The European Union aims to get 22% of its

electricity from renewable energy by 2010.electricity from renewable energy by 2010. Costa Rica gets 92% of its energy from Costa Rica gets 92% of its energy from

renewable resources.renewable resources. China aims to get 10% of its total energy China aims to get 10% of its total energy

from renewable resources by 2020.from renewable resources by 2020. In 2004, California got about 12% of its In 2004, California got about 12% of its

electricity from wind and plans to increase electricity from wind and plans to increase this to 50% by 2030.this to 50% by 2030.


ELECTRICITYELECTRICITY Denmark now gets 20% of its electricity from Denmark now gets 20% of its electricity from

wind and plans to increase this to 50% by wind and plans to increase this to 50% by 2030.2030.

Brazil gets 20% of its gasoline from Brazil gets 20% of its gasoline from sugarcane residue.sugarcane residue.

In 2004, the world’s renewable-energy In 2004, the world’s renewable-energy industries provided 1.7 million jobs.industries provided 1.7 million jobs.

Heating Buildings and Water with Heating Buildings and Water with Solar EnergySolar Energy

We can heat buildings by orienting them We can heat buildings by orienting them toward the sun or by pumping a liquid such toward the sun or by pumping a liquid such as water through rooftop collectors.as water through rooftop collectors.


Fig. 17-12, p. 395

Summer sun

Heat to house (radiators or

forced air duct)

PumpHeavy

insulationSuperwindow

Hot water tank

Winter sun

Super windowSuperwindow

Heat exchanger

Stone floor and wall for heat storage

PASSIVE ACTIVE

Passive Solar Passive Solar HeatingHeating

Passive solar heating Passive solar heating system absorbs and system absorbs and stores heat from the stores heat from the sun directly within a sun directly within a structure without the structure without the need for pumps to need for pumps to distribute the heat.distribute the heat.


Fig. 17-13, p. 396

Direct Gain

Summer sunHot air

Warm air

Super-insulated windows

Winter sun

Cool air

Earth tubes

Ceiling and north wall heavily insulated

Fig. 17-13, p. 396

Greenhouse, Sunspace, or Attached Solarium

Summer cooling vent

Warm air

Insulated windows

Cool air

Fig. 17-13, p. 396

Earth Sheltered

Reinforced concrete, carefully waterproofed walls and roof

Triple-paned or superwindowsEarth

Flagstone floor for heat storage

Fig. 17-14, p. 396

Trade-Offs

Passive or Active Solar Heating

Advantages Disadvantages

Energy is free Need access to sun 60% of time

Net energy is moderate (active) to high (passive)

Sun blocked by other structures

Need heat storage system

Quick installation

No CO2 emissions

Very low air and water pollution High cost (active)

Very low land disturbance (built into roof or window)

Active system needs maintenance and repair

Moderate cost (passive)

Active collectors unattractive

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Energy Efficiency and Renewable Energy. Chapter Overview Questions How can we improve energy efficiency…