ALTERNATIVE ENERGY SOURCES Nonrenewable energy sources take a

ALTERNATIVE ENERGY SOURCES § Nonrenewable energy sources take a toll on our natural resources and pollute the environment. § Alternative energy sources do not impact our environment as badly.

SOLAR ENERGY § 1. Uses the Sun’s radiation to produce energy. Solar panels collect solar energy & photovoltaic cells convert the sun’s energy into electricity. 2. Advantages – non-polluting, makes lots of energy

SOLAR ENERGY CONTINUED… § 3. Disadvantages – photovoltaic cells produce a very small electrical current = need many to meet needs, takes up lots of space, expensive to install, not always sunny § 4. Where - areas with lots of sunlight & open space (desert)

WATER ENERGY (Hydroelectric) § 1. Hydroelectric power - water falls on turbine which causes them to turn, producing energy. § 2. Advantages – non polluting, recreational opportunities, drinking water, water for irrigation

WATER ENERGY CONTINUED… § 3. Disadvantages – floods behind dam, destroys wildlife habitat, interrupts migrating fish, changes natural pattern of water flow § 4. Where – Must have flowing water source (river)

WIND ENERGY § 1. Wind turns propeller that then generates energy. § 2. Advantages – unlimited, built quickly, expandable, non polluting, land under wind farms can be used for cattle, least expensive alternative energy source

WIND ENERGY CONTINUED… § 3. Disadvantages – need steady winds, interfere with birds, noisy, difficult to transport produced energy to far away locations. § 4. Where – coastal areas, areas with constant winds and open ground, or high elevations

GEOTHERMAL ENERGY § 1. Uses Earth’s internal heat to produce energy § 2. Advantages – abundant, reliable, steam doesn’t pollute

GEOTHERMAL ENERGY CONTINUED… § 3. Disadvantages – water needed, minerals clog pipes, steam impacts birds § 4. Where – near plate boundaries or hot spots (Iceland, Yellowstone)

BIOMASS FUELS § Biomass fuels are obtained from organic materials. 1. Wood, dried crops (hay), dried fecal material from animals (manure) § 2. Methane – produced when bacteria decompose organic wastes (decomposition of trash, fermenting manure – both can be used to produce gas and fuel power 3. Alcohol – ethanol can be made by fermenting agricultural waste (corn) § Can be used in vehicles (gasohol) – produces less air pollution

Biomass Advantages § ~ Environmentally friendly (limited air pollution) § ~ Reduces the amount of wastes entering a landfill or polluting the earth

Biomass Disadvantages § ~ It takes many resources to grow crops for biomass § ~ Burning of biomass does release greenhouse gases into the air § ~ Ethanol (from corn) is less efficient than fossil fuel

NUCLEAR ENERGY § 1. Nuclear fission of radioactive uranium creates energy § 2. Advantages – no release of greenhouse gases, very efficient

NUCLEAR ENERGY CONTINUED… § 3. Disadvantages – high cost of operation, safety with radioactive materials, nonrenewable § 4. Where – near a water source for cooling the reactor

Other Alternatives… Tidal Power § 1. As ocean tides rise, water flows behind a dam; when tides fall, the water is trapped behind the dam. The trapped water is released to turn a turbine. § 2. Advantages – nonpolluting, renewable

Tidal Power Continued § Disadvantages – expensive to build and maintain, not many suitable locations. § Where? – coastlines (France, Russia, Canada)

Other Alternatives… § Hydrogen – an abundant element found in all living things and water. § Advantages – abundant, produces harmless water vapor when burned § Disadvantages – producing hydrogen right now is expensive and causes pollution. Needs to be compressed to be as effective as gasoline = explosive.

Other Alternatives… § Ocean Thermal Energy Conversion (OTEC) – warm surface ocean water (in the tropics) is brought to boil in a vacuum chamber, turns to steam, & turns a turbine. § Disadvantage - expensive, possible environmental impacts of pumping deep ocean water to the surface

THINK ABOUT IT… § If you were a politician and it was up to you to decide how the US should produce energy, which type of energy would you choose and why?