Renewable energyRenewable energy
Alternatives to fossil fuelsAlternatives to fossil fuels
Which countries consume the most energy?
think: How much more energy do Americans use than Chinese?
Alternative energy Alternative energy sourcessources
SolarSolar WindWind GeothermalGeothermal NuclearNuclear TidalTidal HydroelectricHydroelectric BiofuelBiofuel
We are searching for We are searching for other sources of energyother sources of energy
Renewable resourcesRenewable resources will not run outwill not run out
Environmental impacts Environmental impacts could be much lesscould be much less
Solar powerSolar power Turning light energy into Turning light energy into
electricityelectricity Sun produces 10,000 x Sun produces 10,000 x
the amount of energy the amount of energy needed to power the needed to power the worldworld
Adv: Free, non-pollutionAdv: Free, non-pollution Dis: Expensive to build Dis: Expensive to build
and install the panelsand install the panels& don’t work at night/ & don’t work at night/
cloudycloudy
WindWind
Wind is the movement Wind is the movement of air caused by the of air caused by the uneven heating of the uneven heating of the Earth’s atmosphere.Earth’s atmosphere.
Pros: non polluting, Pros: non polluting, renewablerenewable
Cons: unreliable, many Cons: unreliable, many birds have be killed by birds have be killed by turbines, loud turbines, loud
Geothermal Geothermal Heat generated by the Earth’s coreHeat generated by the Earth’s core water is pumped deep into the Earth crust water is pumped deep into the Earth crust
where it turns into steam that turns a turbine where it turns into steam that turns a turbine generating electricitygenerating electricity
Pros: renewable, nonpollutingPros: renewable, nonpolluting Cons: not available everywhere, can use up Cons: not available everywhere, can use up
water reserves (unless reclaimed water is water reserves (unless reclaimed water is used) used)
Nuclear EnergyNuclear Energy Nuclear fission: splitting large atoms Nuclear fission: splitting large atoms
releases energyreleases energy Adv: plenty of fuel, no greenhouse Adv: plenty of fuel, no greenhouse
gasses, existing technologygasses, existing technology Dis: radioactive waste which causes Dis: radioactive waste which causes
cancercancer
Tidal powerTidal power Building a dam in a bay or estuary to use Building a dam in a bay or estuary to use
the tides to turn turbines the tides to turn turbines Adv: non polluting, renewableAdv: non polluting, renewable Dis: only available in limited areas, could Dis: only available in limited areas, could
harm sea life harm sea life
Think: how could tidal power harm sea life?
Hydro-Hydro-electricelectric Moving water Moving water
turns turbines to turns turbines to Most rivers are Most rivers are already dammedalready dammed
Causes problems Causes problems for fish, for fish, downstream downstream habitatshabitats
Biofuel Biofuel
Organic matter: food scrap, manure, corn Organic matter: food scrap, manure, corn ethanol, algae…ethanol, algae…
Pros: can be “carbon neutral” or decrease Pros: can be “carbon neutral” or decrease greenhouse gasses, can be a reuse of greenhouse gasses, can be a reuse of waste products, renewable waste products, renewable
Cons: can increase food prices, may use Cons: can increase food prices, may use up too much land or not generate enough up too much land or not generate enough energy to be cost effectiveenergy to be cost effective
Reducing energy wasteReducing energy waste All forms of energy All forms of energy
generation waste generation waste energyenergy
Power plants are only Power plants are only 35% efficient35% efficient
We need to reduce our We need to reduce our energy use energy use andand energy energy wastewaste
157 mpg car
Think: of 3 ways you can save energy.
Summary Review Summary Review 1.1. How much energy does the US use How much energy does the US use
compared to the world average?compared to the world average?
2.2. Make a chart of the alternative energy Make a chart of the alternative energy sources listed in this lecture of: what sources listed in this lecture of: what they are, how they are ‘harvested’, and they are, how they are ‘harvested’, and the pros and cons of each. the pros and cons of each.