Ch. 18.1 Renewable Energy Today

1
Ch. 18.1 Renewable Energy Today
2
A. Renewable Energy

• Energy from sources that are constantly being
  formed.
• Life on Earth has always been powered by
  renewable energy the sun!

3
A. Renewable Energy

• Other forms of renewable energy wind, biomass,
  moving water, Earths heat.

4
B. Solar Energy

• Passive solar heating uses the suns energy to
  heat something directly (i.e. sunlight coming
  through windows).

5
B. Solar Energy

• How? Homes positioned according to the yearly
  movement of the sun benefit most from passive
  solar energy.

6
B. Solar Energy

• Active solar energy Suns energy is gathered by
  collectors and used to heat water or to heat a
  building.

7
B. Solar Energy

• Photovoltaic Cells solar cells, often placed on
  roofs, that convert the suns energy into
  electricity. Also used in calculators and to
  power the space station.

8
C. Wind Energy

• Wind farms large arrays of wind turbines, such
  as in California. Turbines spin, and this
  mechanical energy is converted into electrical
  energy.

9
C. Wind Energy

• The windiest spots on Earth could generate more
  than 10x the energy used worldwide.

10
C. Wind Energy

• Some farmers place 1 or 2 windmills on their land
  and then sell the electricity it produces to the
  power company!

11
D. Biomass

• Power from organic (living) things, such as plant
  material and manure.
• Methane gas produced from decomposing organic
  wastes. Can be burned to generate heat.

12
D. Biomass

• Alcohol liquid fuels derived from biomass.
• Ex. Ethanol produced from corn and currently
  used as an alternative to gasoline in the Midwest.

13
E. Hydroelectricity

• Hydroelectric Dams accounts for 20 of the
  worlds energy, making power affordable and
  renewable.

14
E. Hydroelectricity

• Benefits
• Inexpensive to operate
• No air pollution

15
E. Hydroelectricity

• Disadvantages
• Creates a reservoir, flooding the land, and
  possibly displacing people from their homes
• Can disturb ecosystems downstream

16
E. Hydroelectricity

• Micro-hydropower
• Used in developing countries
• Floating turbines used in small streams

17
F. Geothermal Energy

• Power from the Earths heat used to heat water
  and form steam, which turns a turbine, thereby
  producing electricity.