Make-Energy.net

I DID NOT BUILD THIS OR MAKE THE VIDEO, just posting it bcz I encourage everyone to invest in their own. This is a test run of the guys newly made wind turbine.

Output depends entirely on wind speed, windy days will yeild more power.

smaller units 5′-10′ average 50-500 watts
larger units 11′-20′ produce on average between 500 watts-up
(professionally 21′ and larger up to 7.5 Kw and up)

Power is defined as the rate at which work is done or energy is consumed. The formula for average power is acquired by dividing work by the time needed to perform work: P = W/t. Power has units of newton-meters per second or joules per second or watts

A kilowatt-hour is the electrical energy consumed in one hour at the constant rate of one kilowatt. The average household in the United States uses about 8, 900 kilowatt-hours of electricity each year.

Here are some math formulas to consider…(source: http://www.awea.org/faq/windpower.html)

Because air has mass and it moves to form wind, it has kinetic energy. You may remember from science class that:

kinetic energy (joules) = 0.5 x m x V2

where:
m = mass (kg) (1 kg = 2.2 pounds)
V = velocity (meters/second) (meter = 3.281 feet = 39.37 inches)

Usually, we’re more interested in power (which changes moment to moment) than energy. Since energy = power x time and density is a more convenient way to express the mass of flowing air, the kinetic energy equation can be converted into a flow equation:

Power in the area swept by the wind turbine rotor:

P = 0.5 x rho x A x V3

where:
P = power in watts (746 watts = 1 hp) (1, 000 watts = 1 kilowatt)
rho = air density (about 1.225 kg/m3 at sea level, less higher up)
A = rotor swept area, exposed to the wind (m2)
V = wind speed in meters/sec (20 mph = 9 m/s) (mph/2.24 = m/s)

This yields the power in a free flowing stream of wind. Of course, it is impossible to extract all the power from the wind because some flow must be maintained through the rotor (otherwise a brick wall would be a 100% efficient wind power extractor). So, we need to include some additional terms to get a practical equation for a wind turbine.

Wind Turbine Power:

P = 0.5 x rho x A x Cp x V3 x Ng x Nb

where:
P = power in watts (746 watts = 1 hp) (1, 000 watts = 1 kilowatt)
rho = air density (about 1.225 kg/m3 at sea level, less higher up)
A = rotor swept area, exposed to the wind (m2)
Cp = Coefficient of performance (.59 {Betz limit} is the maximum thoretically possible, .35 for a good design)
V = wind speed in meters/sec (20 mph = 9 m/s)
Ng = generator efficiency (50% for car alternator, 80% or possibly more for a permanent magnet generator or grid-connected induction generator)
Nb = gearbox/bearings efficiency (depends, could be as high as 95% if good)

If there is any single equation that the beginning wind enthusiast should memorize, this is it.

Here Are some links…

www.blueenergy.org
www.homemade-wind-turbines.co.uk
www.otherpower.com/otherpowerfront.shtml

Other Energy resource websites..

http://peswiki.com/energy/Main_Page

http://www.absak.com/