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Wind Energy Mr. Huebsch

Behavioral Objectives Students will gain an understanding on the following How wind happens Wind energy stats Vertical turbines Horizontal turbines Pros and Cons of wind energy

What‘s wind? The uneven heating of the earth’s surface and atmosphere from the sun Difference in air pressure within our atmosphere Air under high pressure moves toward areas of low pressure. The greater the difference in pressure, the faster the air flows.

Facts… Wind energy is sometimes called solar energy 2% of solar energy that hits the earth is converted into wind energy Wind energy generating capacity for U.S. in 2007 = 16,818 mw Wind energy generating capacity worldwide = 94,112 mw Just over 1% of U.S. electricity supply = to 4.5 million households

Facts… U.S. wind energy potential = twice the electricity generated in U.S. today. 10,777 billion kWh One megawatt serves 250-300 homes Wind energy has grown 29% a year for five years Denmark, Spain, and some regions of Germany now generate 10% to 25% of their electricity with wind power A typical hot water solar energy system initially costs 3,000 dollars. If yearly savings amount to 500 dollars, then the payback time will be six years. After the six years is up the customer begins to save 500 dollars a year Factors that effect the length of time of payback include the cost of fossil fuels and the amount of solar energy used.

Top 5 state in capacity Texas = 4,356 MW California = 2,439 MW Minnesota = 1,299 MW Iowa = 1,273 MW Washington = 1,163 MW

Largest wind farms in US Horse Hollow, Texas = 736 MW Sweetwater, Texas = 585 MW Peetz Table, Colorado = 401 MW Capricorn Ridge, Texas = 364 MW Buffalo Gap, Texas = 351 MW

Turbines Horizontal Propeller type blades connect to horizontal shaft Accepts wind from any direction Preferred turbine for commercial applications Creates DC and AC electricity

Turbines Vertical Blade connect to a vertical shaft Accepts wind from any direction Very few used in commercial applications Creates DC and AC electricity

Efficiency Highest energy payback ratio Energy Payback Ratios (EPR) compare the amount of energy produced by a power plant to the amount of energy it takes to build, run, and eventually decommission that plant. The more efficient the technology, the higher the EPR. Turbines run 60% - 80% of the time Full rated power only 10% of time On an average day, it generates 30% to 35% of what it would generate if it ran at full power all the time.

Tip Speed Ratio Speed of the blade tips in relation to the wind speed Ratios are between 1 and 7 Tip ratio of 5 means tip speed is 5x faster than wind speed

Pros No pollution Pays for itself Renewable Quiet Minimal maintenance Free fuel Takes less than 5% of the ground area

Cons Higher cost Lower usable % Need wind Dangerous Site specific Longer payback

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