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