1. Green Resources

2. Solar Panels History 1883 – first solar cell made
1892 – first solar energy company founded
1950 – discovery that silicon works well as a semiconductor
1970’s - energy crisis forced energy research

3. Photovoltaic Cells
These are what you see on calculators and satellites
Light strikes the cells and absorbs light and is transferred to the semiconductor. An electrons field forces electrons in a certain direction. This current creates energy

4. What is a solar panel? A large panel made up of photovoltaic cells
Consists of two thin layers of silicon wafers 1 mm thick. One + and one -.
Electron activity is generated, captured on the panel and emerges as a direct current.
Wafers are then covered with 3mm thick glass strong enough to withstand hail and extreme temperatures. Aluminum then lines the back of the panel to reflect the light.

6. Solar farms
Everyday more solar energy falls to the Earth than the total amount of energy the planet would use in 27 years.
Two kinds – Photovoltaic Cells and Solar thermal plants
Solar power currently makes up less than one percent of U.S. energy.

8. Pros Clean, renewable and has vast potential
If you built a solar power system 100 mile by 100 mile square, in the Southwest U.S. would generate enough energy to meet the entire countries demand.

9. Cons
The sun is not always out. Lack of energy during cloudy days or at night
High cost, but is declining
Land to be used is federally owned
Jurisdiction problems and “ not in my backyard”
Not situated near the population that needs it.

10. Wind power
What is it?????
Wind power is actually converted solar power
It’s the result of hot air rising, reducing air pressure on earths surface, and cool air is drawn in to replace it. The result is wind
Wind contains kinetic energy and can be converted into electricity

11. Wind Turbines Two basic shapes: Egg Beater or vertical-axis
Propeller style or horizontal-axis
Horizontal make up nearly all of the turbines used in the global market

13. How Big??????
1981 – 30 ft
1985 – 51 ft
1990 – 81 ft
1996 – 120 ft
1999 – 150 ft
2000 – 213 ft
Today – 442 ft but that’s on the large side

14. Wind Farms Groups of large windmills in one area Paw Paw, IL
Consists of 63 windmills that stand 214 ft tall an d has 85 ft long blades
Each cost about 1 million dollars
Generates revenue for the city, state, and school district

16. Pros Cleanest of all renewable energy
Build on farms and can use the land to farm Only lose the land that the bases are built on

17. Cons Noise pollution When the wind does not blow, no energy High cost
Built in sparsely populated areas so getting it to people increases the cost