The Air X s/n ABeta004 was installed for noise testing in December 2003. It ran unattended until the fall of 2007 when it failed. It lasted four years and kept the batteries charged against their internal draw. After the turbine failed, the batteries subsequently failed and had to be replaced. Like Southwest Windpower’s H40 tested previously at the Wulf field, both units ran fine in unattended operation for four years.
The Air X s/n ABeta004, a preproduction version, was installed at the request of Southwest Windpower. This version of the Air X series met the manufacturer’s power curve up to about 24 mph where the controller begins to regulate the turbine. Peak power (1-minute averages) of nearly 225 W was reached at 25 mph.
The Air X s/n ABeta004 will deliver in the low range of the annual energy output projected by the manufacturer, but will fall well below the upper range. At an average wind speed of 12 mph, this version will produce about 360 kWh/yr, only two-thirds as much as the manufacturer’s advertised high range.
While there was no exterior damage visible, the rotor shaft would bind slightly when turned by hand. The controller likely failed and the turbine failed in the fail-safe mode.
