1. What is the difference between active and solar power?
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What is the difference between active and solar power?
What is one advantage and one disadvantage of wind power?

2. Hydroelectric Power

3. Hydroelectric Power
The kinetic energy of moving water is used to turn turbines and generate electricity

4. Hydroelectric Power

5. Advantages
Disadvantages
High efficiency (80%)
High environmental impact
Low-cost electricity
High construction costst
Provides flood control
Floods area behind dams
Long life span
Danger of collapse
No CO2 emissions from operation
Decreases fish harvest below dam
Provides water for irrigation and recreation
Decreases silt flow below dam (fertilizes soil)

6. Tidal Dams
In coastal bays and estuaries, water levels can rise and fall by 20 feet between high and low tides
The water flow can be used to spin turbines

7. Tidal Dams
This is not a large-scale viable option because of a lack of suitable locations and high costs of construction

9. Geothermal Energy

10. Geothermal Energy
Geothermal energy is a renewable source of energy that is generated from deep within Earth
The radioactive decay of elements within the Earth creates heat that rises to the surface through magma
This energy can heat groundwater and creates geysers

11. Geothermal Reservoirs

12. Geothermal Energy
Geothermal power plants use the energy of naturally heated water to generate power
The water and steam are harnessed to turn turbines and create electricity

14. Geothermal Energy in your home
The hot water can be used directly to heat homes
Iceland uses geothermal heat for 86% of its homes and buildings

15. Benefits of Geothermal Energy
Greatly reduces emissions relative to fossil fuel combustion
Does emit gases that are trapped in the water, but in very small quantities
1 MW of geothermal power prevents the emission of 7.8 million lbs of carbon dioxide and 1900 lbs of other emissions per year

16. Negatives to Geothermal Energy
The geothermal sources may not be sustainable
Water from hot springs has minerals in it that may corrode machinery
Geothermal electricity plants are limited to areas where the energy can be tapped