Alternative Energy Sources
How Electricity is generated… • A force is needed to push the blades of a turbine • Turbine keeps a generator turning • Electromagnet produces electrical current
Combustion of Fossil Fuels Hydrocarbon + O2 CO2 + H2O
Benzene – C6H6(liquid) Examples: • Methane (CH4) – small – Gas at room temp. • Benzene (C6H6) – medium - Liquid • Paraffin (CxHx) – large - Solid
Uranium Uranium Pellets NUCLEAR ENERGY Fuel Rod Assemblies
Nuclear Fission • Energy within the nucleus of an atom is more than 1 million times stronger than the chemical bonds between atoms. • FUEL = URANIUM (nonrenewable metal) • Uranium atoms are bombarded with neutrons that cause the nucleus to split open and energy is released.
Advantages • Energy is very concentrated in the Uranium (one pellet = 1780 lbs of coal = 149 gallons of oil!) • Non-polluting – only steam, not smoke Disadvantages • Disposal of hazardous waste • Can be dangerous – meltdown or weapons Nuclear Energy
Low-Level Radioactive waste High-Level Radioactive waste
Storage Options - Temporary/On-Site Temporary storage includes above-ground storage casks Storing Spent Fuel in wet and dry storage
Solar Energy Passive Solar Heating – uses Sun’s solar energy to heat something directly
Active Solar Heating – Energy from the Sun is gathered by collectors and used to heat water or heat a building.
Photovoltaic Cells – Energy from the Sun is gathered by collectors and used to heat water or heat a building.
Solar Power Tower – Heliostats (mirrors) focus sun’s light on a central receiving tower. • A liquid is heated inside of a pipe. • Hot pipe comes in contact with water & makes steam
Solar Energy Disadvantages • Expensive to install/build • Need battery back up for night & cloudy days • Land-intensive Advantages • “Fuel” is free (the sun) • Provides endless heat & light • It’s non-polluting
Wind Farm – large array of wind turbines that collectively generate electricity - Sun & convection produce wind
Wind Energy Disadvantages • Land-intensive • Large & Noisy • Hazardous to birds (flyways) • Consistent wind is on shoreline & mountainsides Advantages • “Fuel” is free (sun wind) • Meet 10-15% of U.S. energy needs • It’s non-polluting
Hydroelectric Energy Disadvantages • Sediments build up behind the dams • Reservoir floods land • Disrupts fish migration • Too much development to build new dams Advantages • “Fuel” is free (sun water cycle) • Water storage • High energy storage • Non-polluting
Geothermal Energy – Groundwater that has been heated by energy within Earth’s crust Geothermal Heat-pump
Advantages • “Fuel” is free (hot water) • There is an abundance of hot water underground • Non-polluting Geothermal Energy Disadvantages • Steam in one location only lasts 10-15 years • Will not produce a high percentage of power • Overuse & reinjection may deplete hot water
Advantages • “Fuel” is free (moon tides) • The tides are a steady source of energy • It’s non-polluting Tidal Energy Disadvantages • Limited use (area must have > 8 ft tidal range) • Block boat traffic • Hazardous to marine organisms • Corrosion in salt water