WIND SYSTEMS
Wind powered battery charging systems can be cost effective is the average wind speed is nine miles per hour (mph) or more at the location of the wind generator. If you are using wind in combination with photovoltaic power, it may be cost effective if good wind is available only during part of the year. The power available from the wind is proportional to the cube of the wind speed. When the wind speed doubles, the power delivered is eight mines as great. Most wind generators are designed to delver maximum power at a wind speed of 30 mph. At 15 mph, they will deliver about 1/8th their rated power. A wind generator should be mounted at least 30' above any obstruction within 500 feet to avoid turbulence. You can expect the power generator to decrease roughly 3% for every 1000 feet of elevation. That means that you'll get 70% of the power at 10,000 feet elevation.

MEASURING WIND SPEED

If you measure wind speed at ground level, you can expect about 1.5 times the wind speed 30 feet up, which equates to about three times the power. At 120 feet above the ground, wind speed will be twice what is measured at ground level and power output will be more that twice the output at 30 feet.

TOWERS

We do not recommend mounting wind generators on roofs. Though it is possible with a wind generator of 500 watts or less output, it will be noisy. Larger wind generators could cause severe damage to the building. Freestanding towers, guyed towers or guyed poles may be used with wind generators.
Wind generators can be mounted on freestanding towers designed for antennas. They require a large engineered concrete base for support, but since they do not require guy wires, they can be installed in the smallest space. Guyed steel truss towers, also designed for antenna mounting, are less costly, and require a large area for guy wire placement. A tilt up pole tower is the most economical and the easiest to install. Wiring and mounting of the wind generator are done before the tower is erected. No climbing is necessary.

Contact your local renewable energy contractor for more detailed information and help in designing a system for your home or business.