Alternative Energy Resources Renewable Resources

Solar Energy from the Sun How It Works Photovoltaic or photoelectric cells are used to convert sunlight directly into electricity. Uses Heat water, cook food, power lights, used on satellites Renewable Yes, as long as the Sun remains burning Advantages  Free  Does not need fuel  Produces no waste or pollution  Safe Disadvantages  Large power cells are expensive.  Needs mostly sunny climate  Energy has to be stored.

Photovoltaic or Photoelectric Cells

Wind Energy from Moving Air How It Works Wind is converted into electrical or mechanical energy. Uses Produce electricity, used on satellites Renewable Yes, as long as the Sun heats the air and causes winds Advantages  Free  Does not need fuel  Produces no pollution Disadvantages  Doesn’t work without wind  Can be noisy  May kill birds

Waves Energy from the Ocean How It Works Wind is converted into electrical or mechanical energy. Uses Produce electricity Renewable Yes, as long as wind blows across water Advantages  Free  Does not need fuel  Produces no waste  Can produce a great deal of energy Disadvantages  Needs strong and consistent waves  Can be noisy  Equipment must be able to withstand very rough weather.

Geothermal Energy from Below the Crust How It Works Steam is collected and used to drive a turbine. Uses Produce electricity, heat homes Renewable Yes, as long the rocks remain heated by magma Advantages  Needs little or no fuel  Minimal physical impact on the environment Disadvantages  Dangerous gases can come up from underground.  Power plants can only be built in specific locations.

Hydroelectric Energy from Falling Water How It Works The kinetic energy of falling water is converted to electrical energy. Uses Produce electricity Heat/cool homes Renewable Yes, as long as the water cycle continues Advantages  Very reliable  Water can be stored in dams for future use. Disadvantages  Expensive to build dams  Causes upstream flooding

Biofuel Energy from Organic Material How It Works Biofuel energy works by using fuels derived from living or dead biological organisms. Uses Replaces gasoline or diesel for vehicles Renewable Yes, as long as there is organic material/waste being produced. Advantages  Reduces waste materials  Fuel tends to be cheap. Disadvantages  When burned, it creates greenhouse gases.

Energy from Other Sources Tidal Uses the tides to generate energy Nuclear Splits the atom to produce energy Waste Burns garbage to produce energy Hydrogen Cells Converts hydrogen gas and oxygen to electricity All forms of energy have advantages and disadvantages.