The power ratings usually given by the manufacturers for wind generators are nearly useless, in that they are determined at wind speeds much higher that you will normally see. A good rough formula to keep in mind in evaluating different wind turbines is:
Annual Output (KWH/year) = 0.01328 (D^2) (V^3) source...
Where D^2 is the blade diameter in feet squared, and V^3 is the wind velocity cubed in mph -- this is the year around average wind speed. Another way to show it is (0.01328 x D x D x V x V x V).
So, a 10 ft diameter wind turbine in 12 mph average winds might produce about (0.01328)(10^2)(12^3) = 2300 KWH/year. With a 15 foot diameter it calculates as (0.1328)(15^2)(12^3) = 5150 KWH/year. Notice that a 50% increase in blade diameter equates to a 120% increase in power. Another way to look at it is that a 15 foot diameter blade in 9 MPH winds will produce almost the same energy as the 10 ft blade in 12 MPH winds.
Pay very close attention to that formula when you are designing you system. The power output is the square of the blade diameter and the cube of wind speed. Locating your wind generators where you get every last MPH out of the wind is vital. But since most people don't have control over their wind speed, the diameter of the blade makes the biggest difference. Even a modest increase from a 10 foot to 12 foot diameter increases the output by 44% in 12 MPH winds.
For More Information
Women Owned Business Grants
Espresso Machine
Buy unique Handmade Gifts
online marketing
beat maker software
Thursday, February 25, 2010
Subscribe to:
Post Comments (Atom)
Posts
’)
No comments:
Post a Comment