Chapter

Without it we could not –Play video games –Eat –Drink –Live There would be no animals, plants, toys... Our planet could not exist

Importance We can not live without ENERGY –Our Existence –Heat –Food –Travel –Daily Activities

Types Of Energy Fossil Fuels Nuclear Energy Wind Solar Geothermal Hydroelectricity Biomass

Fossil Fuels Nonrenewable resources formed by the decay of plant and animal matter in the earth’s crust Coal Examples –Coal –Petroleum –Natural Gas

Coal Formed in the absence of oxygen from swamp plants, which were buried for a long period of time under heavy layers of rock. Stages (removal of impurities & moisture) –Peat –Lignite –Bituminous –Anthracite

Peat 50 – 60% carbon Dark, brown, spongy substance that looks like rotted wood Is cut, stacked, dried and is an important fuel source in Ireland and Russia

Lignite 70% Carbon Has lost most of its moisture, oxygen and nitrogen Burns with a smoky flame and produces relatively little heat

Bituminous 80% Carbon More compact and efficient than lignite Burns with a smoky flame

Anthracite 90% Carbon Burns hotter and longer with a blue flame, nearly smokeless flame The largest known anthracite coal deposits are found in Pennsylvania

Pros and Cons of Using Coal Advantages –Plentiful supply –Burns with great heat Disadvantages –Produces physical and chemical pollution (carbon dioxide and smog) –Mining can destroy the surface of the land

Petroleum Means “oil from rock” A thick, black liquid A flammable hydrocarbon formed from the decay of marine organisms that collect on the ocean floor Pumped from wells drilled into oil fields Can be separated into various compounds –propane, butane, ethane, gasoline, jet fuels, lubricants, waxes, asphalt

Pros and Cons of Petroleum Advantages –Easy to transport –Cleaner burning than coal –Produces more heat than coal Disadvantages –Limited supply –More expensive than coal –Major chemical pollutant from oil spills

Natural Gas – Methane CH 4 Methane is formed from the decay of marine organisms in the same manner as petroleum Clean burning Cheaper than coal or oil Produces great heat Easily transported But the supply is limited

Nuclear Energy Fission –Splitting of atomic nuclei resulting in the release of large amounts of energy Fusion –Union of nuclei to form heavier nuclei resulting in release of large amounts of energy

Fission Uranium-235 –Chain reaction- neutron hits uranium nucleus, resulting in the release of a great amount of energy, Barium-140, Krypton-94 and three neutrons, which can in turn bombard other uranium-235 nuclei –Energy produced is in the form of heat that turns water to steam, which will turn the turbines that run generators that produce electricity. The water is cooled and recycled

Pros and Cons of Nuclear Energy Advantages –Huge amounts of heat –Small amounts of material Disadvantages –Safety hazard due to radioactivity –Problem of waste storage, for every 100g used 99g of waste is produced (needs years until it is not harmful) –Thermal Pollution –Most Uranium-235 will be used up in years

Fusion 4 hydrogen nuclei join to form helium; reaction much the same as on the sun Unlimited supply of hydrogen from the ocean Does not pollute the air Requires extremely high temperatures to initiate the reaction More research is needed to find safe practical ways to achieve fusion

Wind Energy Used directly to pump water or to run generators to produce electricity

Wind Energy Advantages –Power source is free –Does not pollute Disadvantages –Wind must be constant –No practical way of storing energy during periods of calm

Solar Energy Types of Solar Power –Solar Cell –Solar Collector (solar panels) –Power Tower –Passive Solar Power

Solar Cell Made from silicon and small amounts of arsenic and boron Produces an electric current as sunlight strikes electrons loose from top layers

Solar Collector (solar panels) Sunlight heats water as it passes through black tubes located inside a box which has a clear plastic or glass on top Hot water can be collected in a tank

Power Tower Many mirrors are used to reflect sunlight to the top of a structure, where concentrated sunlight heats water to produce steam that generates electricity

Passive Solar Power Through a greenhouse-type structure on the side of a building Sunlight strikes a storage mass of concrete, brick or stone, which will absorb radiant energy during the day This causes convection currents to carry warm air to the rest of the house

Pros and Cons of Solar Energy Advantages –Free supply of power –Does not pollute Disadvantages –Direct and constant use not available in some places –Some collection methods are expensive to build –Storage problems during cloudy periods

Geothermal Energy contained in intense heat that continually flows outward from deep within the earth. This heat comes mostly from the core Some heat is generated in the crust by the decay of radioactive elements in the earth’s crust

Geothermal continued… Flash Steam Plants – most popular- hot water from wells is piped into the plant where released from the high pressure turns to steam Dry Steam Plants – steam is used Binary Power Plants – uses another liquid (usually isobutane) to get heated by the water and to run the turbine generator

Pros and Cons Advantages –Free –Clean Disadvantages –Limited availability –Thermal pollution

Hydroelectricity Water stored behind a dam falls through large pipes in the dam to a powerhouse where it moves turbines to run electrical generators

Pros and Cons Advantages –Power source is generally free –Self-renewing resource (keeps on flowing) Disadvantages –Dams are expensive –Limited location –Environmental concerns; lakes behind dams cover farmland, marshes, deposits of minerals, and alters ecosystems

Biomass Parts of plants or other organic material that can be used for energy –Burned directly for heat energy –Can be converted into fuels Rotted in a closed container w/o air produces methane Containing sugar or starch with the addition of yeast, produces alcohol for burning

Pros and Cons Advantages –Mostly inexpensive –Renewable Disadvantages –Could never be a sole source of energy –Practical aspects need to be researched

Study Chapter 11 Have a fun field trip! Have a safe and fun Ascension Day and Memorial Day vacation!