15.3 energy resources - …leilehuaphysicalscience.weebly.com/.../15.3_energy_resources.pdf ·...
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15.3 Energy Resources
Pg 462-‐466 Notebook page 117
Nonrenewable Energy Resources
• Exist in limited in quanDDes and once used cannot be replaced except over the course of millions of years
• Nonrenewable resources include oil, natural gas, coal and uranium
Fossil fuels
• Fossil fuels -‐ formed underground from the remains of once-‐living organisms.
• A hydrocarbon deposit, such as petroleum (oil), coal, or natural gas – formed by the decomposiDon of prehistoric organisms
• Are the majority of the world’s energy source
• Are NOT found everywhere
http://www.wrongtees.com/product.php/11/fossil_fuels
Fossil Fuels • The US provides:
– 2 % of the world’s oil supply – 25% of the world’s coal supply
• Good things – RelaDvely inexpensive – Usually readily available
• Bad things – Their use creates polluDon – We don’t have much in the US
Renewable Energy Resources
• Resources that can be replaced in a relaDvely short period of Dme
• MOST originate directly or indirectly from the sun. • Renewable energy resources include hydroelectric, solar, geothermal, wind, biomass, and possibly in the future nuclear fusion.
Renewable Energy Resources
• Include: – Hydroelectric – Solar – Geothermal – Wind – Biomass – Nuclear Fusion (possibly in the future)
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Hydroelectric Energy • Energy obtained from flowing water • As water flows downhill, its GPE is converted into KE.
• The KE is used to turn turbines connected to electric generators
• Good things – Low cost to produce and lack of polluDon
• Some bad things – Use dams which blocks the flow of water and cause a variety of environmental problems
• Hamper the run of fish upriver for spawning
Hydroelectric power plants
• Some used as water flows naturally down hill
• Some use dams to build and hold back the water to create energy
Solar Energy • Sunlight converted into usable energy
• Passive Solar: like light going through the window
AcDve Solar:
• Sun heats flat collecDon plates through which water flows, this water used for your water heater
• Sun converted into electrical energy through solar cells
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Geothermal Energy
• Thermal energy found under the earth’s surface
• Pump water underground to create steam which in turn moves the generators to produce electricity
• Does not pollute but not found everywhere
• Biomass Energy: Energy stored in living things
– Use wood, corn stalks (the stuff thrown away), and convert into thermal energy
– Use to create bio fuel -‐ a high-‐ energy alcohol fuel
Hydrogen fuel cell:
• generates energy by reacDng hydrogen with oxygen – Waste product would be water so it’s nonpolluDng
Nuclear Fusion:
• sDll being worked on today but would probably produce li`le polluDon or radioacDve waste
Wind turbines: • converts the kineDc energy of wind into rotaDonal energy of the turbines which is then converted into electrical energy by an electric generator. – Clean and wind is everywhere but takes up a lot of space
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Conserving Energy Resources
• Energy resources can be conserved by reducing energy needs and increasing efficiency of energy use
• Finding ways to use less energy or to use energy more efficiently is known as energy conservaDon
• Energy Saving Decisions for us all: turn off lights, carpool, change the light bulbs, bike to work or school, etc.