Chapter 18 Chapter 18 Renewable Energy Renewable Energy

SourcesSources

Cleaner Cars, Cleaner FuelsCleaner Cars, Cleaner Fuels

Cars release a lot of pollutionCars release a lot of pollution 20052005

Bush administrationBush administration 7% improvement in 7% improvement in

mileagemileage 22.2 mpg22.2 mpg 2020 30.5 mpg2020 30.5 mpg

Diesel engines need workDiesel engines need work

Cleaner Cars, Cleaner FuelsCleaner Cars, Cleaner Fuels

Energy Policy Act of 2005Energy Policy Act of 2005 Tax creditsTax credits Energy-efficient autosEnergy-efficient autos

Liquid hydrogen as a Liquid hydrogen as a fuelfuel

What does the future What does the future hold?hold?

Electrical Generation CostsElectrical Generation Costs

Direct Solar EnergyDirect Solar Energy

Energy directly from the sunEnergy directly from the sun Tremendous amountTremendous amount Always availableAlways available Must be collectedMust be collected

Active Solar HeatingActive Solar Heating

Collectors absorb solar energyCollectors absorb solar energy Pumps or fans distribute heatPumps or fans distribute heat Primarily for heating waterPrimarily for heating water

Passive Solar HeatingPassive Solar Heating

No mechanical devices to distribute heatNo mechanical devices to distribute heat New home designNew home design Room temperature is Room temperature is

steadysteady ConvectionConvection Save on heating!Save on heating!

A Passive Solar HomeA Passive Solar Home

Photovoltaic (PV) Solar CellsPhotovoltaic (PV) Solar Cells

Convert sunlight into electricityConvert sunlight into electricity Thin wafers or filmsThin wafers or films No pollutionNo pollution Minimal maintenanceMinimal maintenance

Photovoltaic (PV) Solar CellsPhotovoltaic (PV) Solar Cells

Can be used in remote areasCan be used in remote areas Good choice for developing Good choice for developing

countries: why?countries: why? School, home useSchool, home use

Photovoltaic (PV) Solar CellsPhotovoltaic (PV) Solar Cells

Can look like conventional roofingCan look like conventional roofing Prices are coming downPrices are coming down Future progress is criticalFuture progress is critical

Solar Thermal Electric Solar Thermal Electric GenerationGeneration

Sun’s energy concentrated by Sun’s energy concentrated by mirrors, lensesmirrors, lenses

Heat a working fluidHeat a working fluid Fluid is circulated to Fluid is circulated to

boil waterboil water Steam generates Steam generates

electricityelectricity

Solar Thermal Electric Solar Thermal Electric GenerationGeneration

Backup system neededBackup system needed Very efficientVery efficient No pollution No pollution

producedproduced Must be cost- Must be cost-

competitivecompetitive

Hydrogen As A Fuel SourceHydrogen As A Fuel Source

Could be the fuel of the futureCould be the fuel of the future Where does the hydrogen come from?Where does the hydrogen come from? ElectrolysisElectrolysis Must use renewable fuel source to Must use renewable fuel source to

obtain the hydrogen!obtain the hydrogen! Few pollutants produced when burnedFew pollutants produced when burned Can be used for transportationCan be used for transportation

Solar-Generated HydrogenSolar-Generated Hydrogen

Use PV cells for electrolysis of waterUse PV cells for electrolysis of water Currently not very efficientCurrently not very efficient Still expensiveStill expensive Would need new distribution system Would need new distribution system

for transportationfor transportation Future development is criticalFuture development is critical

Solar-Generated HydrogenSolar-Generated Hydrogen Fuel cellsFuel cells

Electrochemical cellElectrochemical cell Like a batteryLike a battery Major carmakers working on itMajor carmakers working on it

Indirect Solar EnergyIndirect Solar Energy Indirect use of sun’s energyIndirect use of sun’s energy Biomass, wind power, hydroelectricityBiomass, wind power, hydroelectricity

Biomass EnergyBiomass Energy

Wood, plants, animal Wood, plants, animal wasteswastes

Potentially renewable: Potentially renewable: why?why?

Burned to release energyBurned to release energy Half of human population Half of human population

relies on relies on Cooking, heatingCooking, heating

BiogasBiogas Mixture of gasesMixture of gases Similar to natural gasSimilar to natural gas Animal wastesAnimal wastes Biogas digestersBiogas digesters

Decompose wastesDecompose wastes Use gas for cooking, lightingUse gas for cooking, lighting Solid remains are fertilizerSolid remains are fertilizer

Can also be used to power fuel cellsCan also be used to power fuel cells

Biogas DigesterBiogas Digester

Biomass As A Liquid FuelBiomass As A Liquid Fuel

Methanol, ethanolMethanol, ethanol Gasohol: mix gasoline and ethanolGasohol: mix gasoline and ethanol BiodieselBiodiesel

Plant, animal oilsPlant, animal oils Becoming more popularBecoming more popular Burns cleaner than regular dieselBurns cleaner than regular diesel

EthanolEthanol

Sugarcane, corn, wood, agricultural Sugarcane, corn, wood, agricultural and municipal wastesand municipal wastes

Government subsidizesGovernment subsidizes Good outlet for some wastesGood outlet for some wastes ProblemsProblems

Land and water useLand and water use Soil erosionSoil erosion Decreased food productionDecreased food production

Wind EnergyWind Energy Fastest growing energy sourceFastest growing energy source No waste, emissionsNo waste, emissions ElectricityElectricity Costs are decliningCosts are declining Denmark is a world Denmark is a world

leaderleader Need steady windsNeed steady winds Great Plains of U.S.Great Plains of U.S.

Wind Power Is On The Rise!Wind Power Is On The Rise!

Wind Energy ProblemsWind Energy Problems

Birds and bats killed by turbinesBirds and bats killed by turbines Avoid migration routesAvoid migration routes Operate only at certain timesOperate only at certain times Monitor the projectMonitor the project

Visual pollutionVisual pollution Maple Ridge, NYMaple Ridge, NY Massachusetts coastMassachusetts coast

HydropowerHydropower

Flowing or falling Flowing or falling water spins turbineswater spins turbines

Most efficient way to Most efficient way to produce produce electricityelectricity

19% world’s 19% world’s electricityelectricity

2200 U.S. plants2200 U.S. plants

Hydropower ProblemsHydropower Problems Damages ecosystem, speciesDamages ecosystem, species Displaces people: Three Gorges DamDisplaces people: Three Gorges Dam High construction costHigh construction cost Reduces downstream flowReduces downstream flow Reservoirs eventually fill inReservoirs eventually fill in Danger of collapseDanger of collapse Degrades riverDegrades river Increase in waterborne disease: Increase in waterborne disease:

schistosomiasisschistosomiasis

Geothermal EnergyGeothermal Energy

Use energy from Earth’s interiorUse energy from Earth’s interior Big potential sourceBig potential source ElectricityElectricity

Hydrothermal reservoir: hot fluidHydrothermal reservoir: hot fluid Bring fluid to surface to generate Bring fluid to surface to generate

electricityelectricity

Geothermal EnergyGeothermal Energy

Geothermal EnergyGeothermal Energy

Emits very few pollutantsEmits very few pollutants Is it truly renewable?Is it truly renewable? Land may subsideLand may subside

Geothermal Heat PumpsGeothermal Heat Pumps

Used for heating and coolingUsed for heating and cooling Ground temperature relatively constantGround temperature relatively constant Underground pipes carry waterUnderground pipes carry water Fluids circulateFluids circulate Expensive to installExpensive to install Use is on the increase: why?Use is on the increase: why? Very efficient!Very efficient!

Tidal EnergyTidal Energy

Use power of the tides to generate Use power of the tides to generate electricityelectricity

France, Russia, China, CanadaFrance, Russia, China, Canada Very few ideal locationsVery few ideal locations May be damaging to ecosystemsMay be damaging to ecosystems

Conservation & EfficiencyConservation & Efficiency Energy conservationEnergy conservation

Using less energyUsing less energy Reduce use, wasteReduce use, waste CarpoolingCarpooling

Energy efficiencyEnergy efficiency Using less energy for a taskUsing less energy for a task More fuel-efficient carsMore fuel-efficient cars

Both very important!Both very important!

Energy Consumption TrendsEnergy Consumption Trends Use is on the increaseUse is on the increase Greatest increase in developing Greatest increase in developing

countries: why?countries: why?

Energy-Efficient Energy-Efficient TechnologiesTechnologies

Appliances, automobiles, light bulbs, Appliances, automobiles, light bulbs, furnaces, etc…furnaces, etc…

““Superinsulated” buildingsSuperinsulated” buildings May cost more, but will save money!May cost more, but will save money!

Energy-Efficient Energy-Efficient TechnologiesTechnologies

National Appliance Energy National Appliance Energy Conservation ActConservation Act Sets national standardsSets national standards Much greater efficiency todayMuch greater efficiency today

Invest in energy improvements now Invest in energy improvements now to save money in the long runto save money in the long run

Automobile EfficiencyAutomobile Efficiency

Has improved since 1970s: why?Has improved since 1970s: why? Increased use of minivans, trucks, SUVsIncreased use of minivans, trucks, SUVs Efficiency must continue to improveEfficiency must continue to improve

CogenerationCogeneration Combined heat and power (CHP)Combined heat and power (CHP) Recycling “waste” heatRecycling “waste” heat Generate electricity, use steam before Generate electricity, use steam before

cooling it back downcooling it back down

Electric Companies & Electric Companies & Energy EfficiencyEnergy Efficiency

Make more money, generate less Make more money, generate less electricityelectricity

Incentives for conservationIncentives for conservation Help consumers save electricityHelp consumers save electricity

Light bulbs, furnacesLight bulbs, furnaces Company doesn’t have to invest in Company doesn’t have to invest in

new power generationnew power generation

Electric Companies & Electric Companies & Energy EfficiencyEnergy Efficiency

Use cogeneration to save energyUse cogeneration to save energy Improve electricity gridsImprove electricity grids

Some energy lost in transmissionSome energy lost in transmission Plan for future usePlan for future use

Energy Conservation At Energy Conservation At HomeHome

Average household: $1500/year on Average household: $1500/year on utilitiesutilities

Use energy-efficient technologiesUse energy-efficient technologies Better insulation, windowsBetter insulation, windows Seal cracksSeal cracks Replace inefficient appliancesReplace inefficient appliances

Energy Conservation At Energy Conservation At HomeHome