Energy Coal-remains of plants that have undergone carbonization Occurs when partially decomposed plant material is buried in swamp mud and becomes peat Types of Coal-peat, lignite, bituminous, anthracite Advantages – Enormous reserves, cheap to mine, use as electricity Disadvantages – Recovery can be dangerous and hazardous-types of mining – Air pollution – Cannot be used for transport purposes – Non-renewable

Interesting Facts – Accounts for 28% of nation’s energy needs – Powered industrial revolution – Coal is crushed into powder form and burnt

Oil and Natural Gas Provides 40% of our nation’s energy use Found in similar environments and typically occur together Formation of petroleum and natural gas – Microorganisms and plant remains in shallow pre-historic Advantages – Mobile (migrates toward surface), relatively low cost, plentiful for now, easily transported, electricity is proven reliable Disadvantages – Urban air pollution, acid rain, global warming, global tensions, oil spills

Nuclear Energy Energy released by reactions w/in atomic nuclei Nuclear fission-nucleus of heavy atoms splits into 2 or more fragments-process releases neutrons and energy Nuclear fusion-nuclei of small atoms combine to form new, massive nuclei-releases energy Advantages – Burn no fossil fuels, no air pollution, radioactive materials have long half live, cheap source, vast amount of energy in one atom Disadvantages – Separating the uranium isotopes is difficult, uranium is rare, cost of building facility is pricey, radiation, accidents

Interesting facts – Accounts for about 11% of the worlds energy demands – Energy that reaches Earth from sun-nuclear fusion – Fuel rods last several yrs

Geothermal Energy produced by heat w/in the Earth Magma heats water-wells are drilled to reach hot water Used as source of heat or sources of power to drive turbines-generate electricity Problems – Need large potent source of heat (magma) deep enough to apply enough pressure and slow cooling – Steam and hot water lasts hrs – Not expected to provide high % of worlds growing energy needs

Hydroelectric and Tidal Power Electrical energy produced by flow of water, tides Dams hold back water, control the flow, water spins turbines which turn generators that produce electricity Contributes to 5% of country’s demands Many occur in SE and Pacific NW of U.S. Problems – Dams have finite lifetimes, rivers deposit sediment – Availability of sites

Wind Wind is movement of air, results from air pressure differences caused by sun’s uneven heating of Earth’s surface Use movement of air to convert wind energy into mechanical energy-generates electricity Advantages – Almost free, non polluting Disadvantages – Costs of large tracts of land in populated areas – No wind, no energy – Need better means of storage – Noise pollution