1. Chapter 18
Lesson 2

2. Renewable Energy Resources
Renewable resources come from natural processes that’ve happened for billions of yrs and will continue.

3. Solar Energy
Solar energy = energy from Sun
Solar cells in calculators capture light energy and transform it to electrical energy, while solar power plants generate electricity by transforming energy in sunlight to turn turbines connected to generators.

4. Solar Energy
Technology, such as solar panels, that gathers and stores solar energy that heats water and homes = active solar energy.
Passive solar energy uses design elements that capture energy in sunlight.

5. A group of wind turbines that produce electricity = wind farm.
Wind Energy
Wind energy = renewable resource that has been used since ancient times to sail boats and to turn windmills.
A group of wind turbines that produce electricity = wind farm.
Wind turbines produce lots of electricity

6. How is wind a renewable energy resource?
Wind energy is capable of being replaced faster than it is used.

7. Hydroelectric power = electricity produced by flowing water
Water Energy
Hydroelectric power = electricity produced by flowing water

8. How is water in the reservoir used to produce electricity?
Water released into tunnels. The stored energy of water changes into kinetic energy causing turbines to turn and it makes a generator spin to produce electricity.

9. Hydroelectric Energy
To produce hydroelectric power, we build a dam across a powerful river.

10. Tidal Power
Coastal areas that have big differences bw high/low tides can be a source of tidal power.
Tidal power uses water that flows across turbines as the tide comes in and as it goes out

11. Geothermal Energy
Thermal energy from Earth’s interior = geothermal energy
Geothermal energy - used to heat homes & generate electricity in power plants.
Geothermal energy from hot rocks / magma heats water, makes steam, then turns turbines connected to generators & make electricity.

12. Biomass Energy
Energy produced by burning organic matter such as wood, food scraps, and alcohol = biomass energy.
Most used = wood
Ethanol and biodiesel are 2 vehicle fuels that can be made from biomass.

13. Biomass Energy
Ethanol - made from sugars in corn
Biodiesel - made from vegetable oils and fats

14. Advantages and Disadvantages of Renewable Resources
The main advantage = they will be available for millions of years to come.
Renewable energy resources produce less pollution than fossil fuels.
Two disadvantages of using renewable resources are that some are costly or limited to certain areas.

15. Managing Renewable Energy Resources
Renewable energy currently meets only 7 percent of U.S. energy needs.
The renewable energy resource used most in the United States is biomass energy.

16. Managing Renewable Energy Resources
Some states require power companies to produce a percentage of electricity using renewable resources, and U.S. government has programs to encourage use of renewable resources.
You can encourage the use of renewable energy resources by educating others and buying products made using these resources.

17. How does a hydroelectric power plant produce electricity
How does a hydroelectric power plant produce electricity? Compare hydroelectric power with tidal power.
Water from behind a dam flows downhill through tunnels. As it flows, the stored energy in the water changes into kinetic energy. The energy of the flowing water turns a turbine connected to a generator. The generator spins, producing electricity. Tidal power is similar, except that water flows across turbines as the tide comes in at high tides and as it goes out at low tides. The flowing water turns turbines connected to generators that produce electricity.