11.3 A Sustainable Energy Future Unit 11: Energy May 26, 2009 Unit 11: Energy

Energy Conservation The average American uses twice as much energy as the average European. Ways to counteract consumption Conservation: Use less energy Modify systems: Increase energy efficiency Cars Buildings May 19, 2019 Unit 11: Energy

Energy for the Future As fossil fuels dwindle, we need alternative energy resources. Buoy at left harness ocean waves. May 19, 2019 Unit 11: Energy

Solar Energy The energy from the sun is known as solar energy. Harnessing the sun’s energy is known as solar energy. May 19, 2019 Unit 11: Energy

Passive Solar In a passive solar house, double paned windows facing south let in the winter sun but prevent heat from escaping. Overhangs on the house prevent summer sun from coming in. May 19, 2019 Unit 11: Energy

Active Solar Heating Water heated from the sun is carried away from the solar box by use of a pump. Heated water can go to a boiler or house heating. May 19, 2019 Unit 11: Energy

Solar Cells Solar cells are devices that collect energy in photovoltaic cells. Converts sun’s energy directly into electricity. Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity. May 19, 2019 Unit 11: Energy

Wind Energy Wind energy harnesses energy of the wind. The energy is captured by windmills. Mechanical energy transferred to electricity. May 19, 2019 Unit 11: Energy

Hydroelectricity Water is used to push heavy turbines and generators. Hydroelectricity is Clean Renewable No waste Niagara Falls is a natural waterfall that provides electricity to the greater Buffalo area. May 19, 2019 Unit 11: Energy

Hydroelectric: Damming Advantages: Offers recreational activities. Provides drinking water Controls flooding Disadvantages: Disrupts the river’s ecosystem. Dam construction cost. Limited to areas with rivers and streams. May 19, 2019 Unit 11: Energy

Geothermal Energy Heat energy from inside the earth drives electric generators. Geothermal is a clean energy. Disadvantages of this energy is that it is a limited place. May 19, 2019 Unit 11: Energy

Biomass May 19, 2019 Unit 11: Energy

Hydrogen Hydrogen is a clean fuel. Hydrogen is very voluminous. To use as a fuel would require a large tank. Expensive to condense. May 19, 2019 Unit 11: Energy

Summary There are alternatives to fossil fuels. Most applications work only is certain areas. Our energy needs continue to grow. A sustainable energy future will require the efficient use of all forms of energy. May 19, 2019 Unit 11: Energy