Ch. 17 and 18

 The world’s populations rely on energy  Some energy now is being used faster than it can be replenished  Ex.) Coal  Most electricity is made from non-renewable resources

 Non-renewable resources include Fossil Fuels  Fossil Fuels: are formed from plants and other organisms that were buried and altered over millions of years  What are some examples of fossil fuels?  What are they used for? ▪ Transportation, manufacturing, heating, electricity

 Electricity is created by a generator:  Turbine changes mechanical into electrical  Water is heated into steam which spins the turbine

 It is the most abundant fossil fuel in the world

 Coal is a rock that contains at least 50 % plant remains  Coal begins to form when plants die in a swampy area  The dead plants are then covered by plants, water, and sediment ▪ this prevents oxygen from touching the dead plant matter  Takes millions of years to form

 1.) The dead material adds up and builds up over time forming peat (organic layer of sediment)  2.) As peat continues to get buried by sediment it changes to lignite (a soft brown coal)  3.) As the layers are buried deeper, bituminous coal (soft coal) forms  4.) If enough heat and pressure are applied to buried bituminous coal, anthracite coal forms

 Strip Mining: layers of soil and rock are piled to one side to reveal the coal below

 Underground coal mining: tunnels are dug and pillars of rock are left to help support the rocks surrounding the tunnels  Slope mines: an angled opening is made in the side of the mountain or the ground

 Coal is not the only fossil fuel used to make energy  Oil: is a black liquid that is made from buried remains of marine organisms  Natural gas: often forms the same way as gas but instead forms into gaseous state

 Oil and gas are hydrocarbons  Natural gas though is made of lighter hydrocarbons than that of oil  What are some uses?

 This process starts when marine organisms die and fall to the bottom of the ocean floor (plankton dies and falls)  Similar to how coal forms, that sediment builds over it in time  As the depth increases temps increases and the marine life turns into oil

 Often found in layers of rock that are tilted  Usually stopped by a rock layer (shale)  This build of oil or gas under rock is called a reservoir rock

 Oil and natural gas can be pumped from underground  Comes from drilling through reservoir rock

 Reserve: The amount of fossil fuels that can be extracted for a profit using technology  However, a resource is not considered a reserve unless the fuel can be extracted economically

 Most electricity in the US is generated by fossil fuels  Why not Nuclear?  It is an alternative energy source produced by atomic reactions  When the nucleus is split, lighter elements are created and energy is released

 The process of splitting heavy elements to produce energy is called nuclear fission  Nuclear fission is carried out in nuclear power plants

 Fig. 15, Pg. 445  A plant has a nuclear reactor in which uranium fuel rods sit in a pool of water  Neutrons are fired into the fuel rods this causes a chain reaction of energy being released  This energy is used to boil water, which turns turbines

 1.) Very concentrated  2.) No air polluting gases  3.) Release less radioactivity than coal powered fire plants (let me explain)  4.) It works (75% of Frances electricity)

 1.) Nuclear energy from fission is considered non-renewable  It uses Uranium-235 which is limited in amount  2.) Nuclear waste (it can remain radioactive for 1000 yrs)  EPA says it must be stored safely for 10,000 yrs before it can be released into the environment  3.) Dangerous  Chernobyl, Ukraine

 This is how the Sun creates energy  Substance of low massed are fused together to make higher masses  No polluting because Hydrogen fuses into Helium a natural occurring element  However, we do not possess the technology to perform such a task yet

Ch. 18

-When we run out of natural resources depends on us and only us -How we use and conserve natural resources depends solely on how we use them -However, if we attempt to try to conserve and find new ways of energy we will not be in such a predicament

 Inexhaustible resource: resources that are constant and that will never run out  Did you know that any time you feel the wind, feel the sun, or sail in the ocean you are experiencing solar energy  Solar Energy is energy from the sun  The sun’s energy heats the Earth, and causes the Earth’s oceans and atmospheres to circulate

 People can use the energy in two ways:  1.) Passive way: south facing windows can be used for heating a house  2.) Active way: solar cells actively capture the sun’s energy to make electricity  (these have been used everywhere. Can you think of any places solar cells are used?)ds

 Although solar energy is clean and never ending it does have its downfalls  Solar cells do not work as well on a cloudy day  They cannot work at night  They often need batteries to work on cloudy days which in turn leads to one more thing having to be thrown away

 Wind is a source of energy  It was and still is used to move big ships or boats  Windmills have been used to grind wheat and corn  Today windmills are used to generate electricity  When many windmills are placed in one area to generate electricity we call it a wind farm

 It does have its good side and bad side  It does little harm to the environment and produces little to no waste  However, only a few regions have strong enough wind to produce electricity  Also wind is not steady or consistent

 Waterwheels have been next to streams for many years  They were used to grind flour or cut lumber  Today it is used to create electricity (hydroelectric energy)  To retain energy in a river, a large dam must be built  This creates a large reserve of water for use to produce electricity

 It also has its disadvantages  Water essentially is a free resource and costs nothing  However, when dams are built, upstream lakes fill with sediment and downstream erosion increases  Land is flooded and wildlife is put in danger

 Ex.) Volcanoes and Geysers  This type of energy can be used to make electricity  Energy obtained by using magma, or hot, dry rocks is called geothermal energy  This idea of making electricity comes from boiling water to turn a turbine

 These are energy resources that can be replaced in nature or by humans within a relatively short period of time  This short time span is usually considered in a human life span  Ex.) Trees

 A major renewable resource is biomass materials  This is energy derived from burning organic materials  Ex.) wood, alcohol, and garbage

 Ex.) Campfire, Wood stove  When you burn wood you release stored solar energy as heat energy  This biomass is used more worldwide than any other type

 Gases and small particles are released when wood is burnt  These materials can pollute the air  When trees are cut down for firewood natural habitat can be destroyed  However, proper conservation can prevent this from happening

 Some biomass can be burned directly (wood, peat)  However, some can be transformed to be used to produce cleaner, more efficient fuels  Ex.) Distillation, corn is distilled to produce alcohol (Ethanol)  This Ethanol can be used to mix with gas to make a biofuel (Gasohol)

 You use a lot of fossil fuels to make the alcohol  You actually use more energy from fossil fuels to distill and produce the corn than you get from burning biofuels  They are best used locally

 Every day we throw away tremendous amount of burnable garbage  If more humans energy was used by burning garbage we wouldn’t need as many fossil fuels  It is cheap, and reduces the amount of stuff put in landfills

 Compared to other nations the US is lacking in garbage use as an energy source  In Western European nations they use as much as 50% of garbage as an energy source  When garbage is burned it boils water and turns turbines producing electricity  However, burning garbage can produce toxic ash, and air pollution (lead and mercury)