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Renewable EnergyRenewable Energy
Section 1- Renewable Energy Section 1- Renewable Energy Today Today
Renewable EnergyRenewable Energy
• Energy from Energy from sources sources constantly being constantly being formedformed
• Use needs to be Use needs to be increasedincreased
Solar PowerSolar Power• Sun Sun • Passive Solar Passive Solar
HeatingHeating– Uses heat from Uses heat from
sun directlysun directly– Large windows Large windows
face directly into face directly into sunsun
– N. hemisphere- N. hemisphere- south windowssouth windows
Solar Power Solar Power
• Active Solar Active Solar HeatingHeating– Gathered by Gathered by
collectorscollectors– Usually mounted Usually mounted
on roofon roof– Heats water in Heats water in
collector and collector and transfers transfers throughout home throughout home
Solar Power Solar Power
• Photovoltaic Cells- Photovoltaic Cells- solar cellssolar cells– Use sun energy to Use sun energy to
produce a small produce a small amt. of electricityamt. of electricity
– Can be stored in Can be stored in batteriesbatteries
– Efficient and less Efficient and less expensiveexpensive
– Good for developing Good for developing countriescountries
Wind Power- Cheap and Wind Power- Cheap and AbundantAbundant
• Uneven heating from sun causes windUneven heating from sun causes wind• Wind turbines can convert into Wind turbines can convert into
electricityelectricity• Cheap Cheap • Wind Farms- Large arrays of wind Wind Farms- Large arrays of wind
turbinesturbines• Problem transporting electricity from Problem transporting electricity from
rural to urban areasrural to urban areas
Wind FarmWind Farm
Biomass- Power from Biomass- Power from Living ThingsLiving Things
• Biomass fuel- any Biomass fuel- any organic matter organic matter used for energyused for energy– Ex: Wood, organic Ex: Wood, organic
trash and manuretrash and manure– Burning can release Burning can release
air pollutionair pollution– Methane gas from Methane gas from
decompositiondecomposition
Biomass- Power from Biomass- Power from Living Things Living Things
• Alcohol- Liquid fuel Alcohol- Liquid fuel derived from derived from biomassbiomass– Ethanol- from Ethanol- from
fermenting fruit or fermenting fruit or agricultural waste; agricultural waste; corn is major sourcecorn is major source
– GasoholGasohol- gasoline + - gasoline + ethanolethanol• Less air pollutionLess air pollution
Hydroelectricity- Power Hydroelectricity- Power from Moving Water from Moving Water
• 20% of world’s electricity 20% of world’s electricity • Dams hold water- reservoir Dams hold water- reservoir • Released to turn a turbine Released to turn a turbine • Benefits: Benefits:
– Inexpensive Inexpensive – No air pollutionNo air pollution– Last longer than power plantsLast longer than power plants– Provide: flood control, drinking water, Provide: flood control, drinking water,
agriculture, industry, and recreationagriculture, industry, and recreation
Hydroelectricity- Power Hydroelectricity- Power from Moving Water from Moving Water
• Disadvantages: Disadvantages:
– Disruption of Disruption of ecosystems; Ex: ecosystems; Ex: SalmonSalmon
– Displacement of Displacement of people people
– Farmland below dams Farmland below dams less fertileless fertile
• Future: Future: • Micro-hydropower- Micro-hydropower-
Floating turbine in a Floating turbine in a small streamsmall stream
Geothermal Energy- Power Geothermal Energy- Power from the Earthfrom the Earth
• Energy from heat in the water Energy from heat in the water deposits of the earth’s crustdeposits of the earth’s crust
• Geothermal pumps- heated water Geothermal pumps- heated water to turbine and recycle back for to turbine and recycle back for reheatingreheating– U.S. world’s largest producerU.S. world’s largest producer– Ex: The Geyser’s in CA-1.7 million Ex: The Geyser’s in CA-1.7 million
houseshouses
Geothermal EnergyGeothermal Energy
Geothermal Heat Pumps- Geothermal Heat Pumps- Energy for Homes Energy for Homes • 600,000 homes in U.S.600,000 homes in U.S.• Stable underground temperatures Stable underground temperatures
year-round allows for heating and year-round allows for heating and cooling all yearcooling all year
• Ground cooler in summer and Ground cooler in summer and warmer in winter warmer in winter
Geothermal Heat PumpGeothermal Heat Pump
Chapter 18- Renewable Chapter 18- Renewable EnergyEnergy
Section 2- Alternative Energy Section 2- Alternative Energy and Conservationand Conservation
Alternative Energy Alternative Energy
• Energy sources that do not use Energy sources that do not use fossil fuels and are still in fossil fuels and are still in developmentdevelopment
• Viable if cost effective and Viable if cost effective and environmental effects are environmental effects are acceptableacceptable
• Research with gov’t investmentResearch with gov’t investment
Tidal Power Tidal Power
• Tide- movement of Tide- movement of water caused by water caused by gravitational b/w sun, gravitational b/w sun, moon and Earthmoon and Earth– Twice a day, rise and Twice a day, rise and
fallfall– Used to generate Used to generate
electricity in France, electricity in France, Russia and CanadaRussia and Canada
– France and Britain France and Britain used over 1000 yrs used over 1000 yrs ago ago
• High tides come in, High tides come in, trapped by a damtrapped by a dam
• After low tide, dam After low tide, dam opens to allow water opens to allow water to rush out spinning to rush out spinning a turbine to generate a turbine to generate electricityelectricity
• Cost is high to build Cost is high to build and maintainand maintain
• Few siutable Few siutable locationslocations
Tidal Power Tidal Power
Ocean Thermal Energy Ocean Thermal Energy Conversion Conversion
• Warm surface water boils sea water at Warm surface water boils sea water at low temp. in a vacuum low temp. in a vacuum
• Steam spins a turbine to generate Steam spins a turbine to generate electricityelectricity
• Cold water from deep ocean cool steam Cold water from deep ocean cool steam back into liquid to be used againback into liquid to be used again
• Not cost effective and effects of Not cost effective and effects of pumping large amounts of cold water to pumping large amounts of cold water to surface are unknownsurface are unknown
Ocean Thermal Energy Ocean Thermal Energy ConversionConversion
Hydrogen- A Future Fuel Hydrogen- A Future Fuel Source?Source?
• Most abundant element in universe can Most abundant element in universe can be burned as fuelbe burned as fuel
• No carbon-no pollution!No carbon-no pollution!• When burned combines with oxygen to When burned combines with oxygen to
form water vapor and nitrogen oxideform water vapor and nitrogen oxide• Can split molecules of water or grow Can split molecules of water or grow
plants to produce hydrogen cost plants to produce hydrogen cost effectivelyeffectively
Challenge of Hydrogen Challenge of Hydrogen FuelFuel
• Takes a lot of energy to produceTakes a lot of energy to produce• Use of fossil fuels to split atoms Use of fossil fuels to split atoms
pollutespollutes– Can use solar or wind powerCan use solar or wind power– Can store in tanks and transport in Can store in tanks and transport in
pipespipes– Could use as it is produced in fuel Could use as it is produced in fuel
cellscells
Fuel CellsFuel Cells
• Produces electricity Produces electricity chemically by chemically by combining H with Ocombining H with O
• Can be fueled by Can be fueled by anything w/ large anything w/ large amounts of H, such amounts of H, such as gasoline, natural as gasoline, natural gas and alcoholgas and alcohol
• Could continue to Could continue to use gasoline stationsuse gasoline stations
Energy EfficiencyEnergy Efficiency
• Percentage of energy put into a Percentage of energy put into a system that does useful worksystem that does useful work
• Energy efficiency = Energy efficiency =
Energy OutEnergy Out X 100 X 100 Energy InEnergy In
• First Law of First Law of Thermodynamics- Energy in must Thermodynamics- Energy in must equal energy out; much lost as heatequal energy out; much lost as heat
Energy EfficiencyEnergy Efficiency
• Over 40% of commercial energy is Over 40% of commercial energy is wastedwasted– Fuel-wasting vehicles, furnaces, and Fuel-wasting vehicles, furnaces, and
appliancesappliances– Leaky, poorly insulated buildingsLeaky, poorly insulated buildings
• Could save by:Could save by:– Fuel cells instead of internal combustion Fuel cells instead of internal combustion
enginesengines– Increase public transportationIncrease public transportation– Fluorescent instead of incandescent lightsFluorescent instead of incandescent lights
Hybrid CarsHybrid Cars
• Small, efficient gasoline engines with Small, efficient gasoline engines with also an electric motor for extra poweralso an electric motor for extra power
• Convert braking energy into electricity Convert braking energy into electricity to store in batteryto store in battery
• Shut off gas engine to save fuel when Shut off gas engine to save fuel when sittingsitting
• Aerodynamics make less energy for Aerodynamics make less energy for accelerationacceleration
• Cost a little bit more, but less to refuel Cost a little bit more, but less to refuel and pollute lessand pollute less
HybridsHybrids
CogenerationCogeneration
• Production of two useful forms of Production of two useful forms of energy from same fuel sourceenergy from same fuel source– Ex: Waste heat from an industrial Ex: Waste heat from an industrial
furnace can run a steam turbine for furnace can run a steam turbine for electricityelectricity
– Can supply heat and electricity to Can supply heat and electricity to multiple buildingsmultiple buildings
– Small units now available in U.S.Small units now available in U.S.
Energy Conservation-Energy Conservation-Saving EnergySaving Energy
• Cities and TownsCities and Towns– Plug leaks around Plug leaks around
windows and doorswindows and doors– Replace inefficient Replace inefficient
furnacesfurnaces– Insulate water heatersInsulate water heaters– EX: Osage, Iowa saved EX: Osage, Iowa saved
over $1 million a year; over $1 million a year; boosted economyboosted economy
• Around the HomeAround the Home– $1,200/year per $1,200/year per
home; lost energy home; lost energy through poor through poor insulationinsulation
– Seal doors and Seal doors and windows (replace windows (replace w/high efficiency w/high efficiency windows)windows)
Save Energy Around the Save Energy Around the HomeHome
Conservation in Daily LifeConservation in Daily Life
• Use less of any Use less of any resource to save resource to save energyenergy
• Wash clothes in Wash clothes in cold water for less cold water for less energy usage energy usage (25% of heat (25% of heat usage)usage)
• Conservation Tips:Conservation Tips:– Walk or ride a bike on Walk or ride a bike on
short tripsshort trips– Carpool or use public Carpool or use public
transportationtransportation– Drive a fuel-efficient Drive a fuel-efficient
automobileautomobile– Choose ENERGY STAR* Choose ENERGY STAR*
productsproducts– Recycle and buy Recycle and buy
recycled productsrecycled products– Set computers to sleep Set computers to sleep
mode when not in usemode when not in use