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Warm up
How do you think renewable
energy is different than
nonrenewable energy?
Renewable Energy
SEV4 Resource allocation and
use
Renewable Energy
●Sources that are constantly being formedoSolar
oWind
oMoving water
oEarth’s heat
Solar Energy
●Already used oWater cycle
oPhotosynthesis
oWind
oSunshine warming a room
oSolar cells
Passive Solar Heating(no moving parts)
●Use sun to heat something directly
●Northern hemisphere homesoLarge, south facing windows absorb heat in
winter
oOverhangs block sunlight in the summer
oInsulation and air flow are important
Active Solar Heating(moving parts)
●Sun’s energy is gathered to heat a building or
water
oSolar water heaters
Water heated on roof
Hot water used to heat water supply
Solar Panels
●Photovoltaic cells
oNo moving parts, no pollution (PRO)
oNeed many cells to produce decent
yields (CON)
Wind Power
●Air is heated unevenly --> wind
●Wind power --> Electrical energy
●Fast growing resource
●3 months to build a windmill
Wind Farms
●280,000 homes in CA powered by wind
●Take up little spaceoFarmers add windmills to farm
oSell power to cities
Currently Underused
●Windiest areas on earth could generate
10x energy used worldwide.
●Transportation of energy is challenging
●Wind farms may make hydrogen from
water in the future. Hydrogen used as fuel.
Biomass
●Plant material, manure, other organic
matter used as fuel
●ChallengesoTrees – renewable, but must be managed
oBurning wood or manure – air pollution
Methane
●Decomposition --> methane (CH4)
●Can be burned for heat or electricityoChina – 6 million homes use methane for
heating/cooking
oEngland – Methane from cow manure as fuel
for electricity
oUSA – electricity from methane generated by
landfills
Alcohol
●Ethanol – fermenting fruit or agricultural
waste
●Gasoholomix of gasoline and ethanol
oProduces less pollution when burned
●Requires more fossil fuel input than it yields
Hydroelectricity
●Produced from moving water
●20% of world’s electricity
●How it worksoReservoir holds water
oWater turns turbines/generator
oGenerator turns movement into electricity
Benefits of Hydroelectricity
●Expensive to build but cheap to operate
●No air pollution
●Last longer
●Flood control
●Water for drinking, agriculture, industry,
and recreation
Disadvantages of Hydroelectricity
●Disrupts river flowoEcosystems flooded behind dam
oRiver flow diminished below dam
●Displaces people
●Farmland downstream less productive
●Decay in reservoir --> greenhouse gases
Modern Hydroelectricity
●No new dams in the USA
●Brazil, India, and China still building large
dams
●Micro-hydropower
Geothermal Energy
●From the heat in earth’s crust
●Use water or steam to turn turbines
●The Geysers in CA powers 1.7 million
homes
●Philippines, Iceland, New Zealand, Japan,
Mexico, and Italy
●Renewable, but must be managed
Geothermal Heat Pumps
●Heat and cool homes
●Temp underground is constant
●Loop of fluid in a pipe underground and
into house
Warm up
●What is the difference between
renewable energy and
alternative energy?
Alternative energy
●Still in development
●Some renewable energy was once
alternative energy.
●Gov’t investments are vital to
development.
Tidal power
●BenefitsoTides happen 2x a day
oGenerates electricity
like hydroelectric dams
●DrawbacksoExpensive
oFew suitable locations
Ocean Thermal Energy Conversion
(OTEC)●Benefits
oCold and warm ocean
water are available at
different depths
oCold water boils at low
temp in vacuum
chamber
oSteam can turn a
turbine
●DrawbacksoNot cost effective
oUses 1/3 of the energy
it produces
oEnvironmental effects
unknown
Hydrogen
●BenefitsoAbundant
oNo air pollutants when
burned
o(plants may produce it)
●DrawbacksoGenerating it uses
energy, money, and
makes pollution
oExplosive and
dangerous
Fuel Cells
●Produce electricity chemically
●Combine H2 and O2 and electricity is
produced.
●Water is only byproduct
Energy Efficiency
●What you get out vs. what you put in
●%Energy efficiency =
●Much energy is wasted
Useful energy out
Energy
in
x 100
Efficient Transportation
●Public transportation
●Hybrid carsoEfficient gasoline engine
oElectric engine
oAerodynamic
Cogeneration
●Production of 2 useful forms of energy
from 1 fuel source
●Use waste heat from a furnace to turn a
turbine
Energy Conservation
●Saving energyoUse energy efficient devices
oWasting less energy
Energy Conservation Poster
Create a poster that includes…an energy conservation method around the homea slogan to convey that messagea picture that supports your messagean explanation of why this method saves energy
This will count as a formative grade
Cities and Towns
●Osage, IAo3,600 people saved $1 million/year
Sealed doors and windows
New efficient furnaces
Insulated water heaters
oBusinesses moved to the area
oUnemployment is down
Around the Home
●Spend $1,500/year on energy costs
●Much is wastedoInsulation
oEfficient windows
oWeather stripping
oWash clothes in cold water