Issue link: http://read.dmtmag.com/i/89494
VINEYARD lines. Large wind farms in some locations have been linked to bird deaths and injuries from rotating turbine blades, but this is gener- ally not an issue with small wind turbines. Wind turbine manufacturers and wind energy contractors can assist with site evaluation to determine the feasibility for wind power based on weather data and site monitor- ing for the local wind resource, determining the height of the tur- bine tower, and sizing the turbine based on needed capacity in kW. Wind speed is an important fac- tor in site feasibility for wind power and to estimate the total annual kilo- watt-hours (kWh) a turbine can gen- erate. The "cut-in wind speed" is the minimum wind speed at which the turbine will generate usable power. For small wind turbines, this ranges from about 7 mph to 10 mph. The "rated wind speed" is the minimum wind speed, or wind speed range, at which the turbine will generate its rated power capac- ity. This commonly ranges from 20 to 35 mph for small wind turbines. At speeds between cut-in and rated, power generation increases as wind speed increases. Wind speed commonly increases with the height above ground surface, so higher turbine towers can often increase overall power generation. EQUIPMENT CONSIDERATIONS There are two primary types of wind turbine designs. The "Hori- zontal Axis Wind Turbine" is the most common, with a vertical pole or tower structure that has a two- or three-blade, propeller-style rotor at the top that spins when there is sufficient wind speed. The rotor is attached to turbine housing and powers a generator that takes mechanical energy created by the rotor and converts it to electric- ity. A "Vertical Axis Wind Turbine" catches wind using a vertical airfoil to spin and turn a rotor on a vertical axis that rotates around or within the turbine pole or tower. Other equipment and infrastruc- ture for wind turbine installation includes a utility grid-connected inverter to convert direct current to alternating current, a control and monitoring system, and a poured concrete foundation for the turbine tower. Wind turbines are equipped with braking systems to prevent damage in high winds. U.S. vineyards and wineries can qualify for loans and grants for wind turbines under the U.S. Department of Agriculture (USDA) Rural Energy for America Program (REAP), autho- rized through the 2008 Farm Bill, and being negotiated for renewal in the 2012 Farm Bill. Owners of wind WWW.VWM-ONLINE.COM NOV - DEC 2012 VINEYARD & WINERY MANAGEMENT 65