In 2001, the Wind Harvest Company installed a single Model 530G turbine and ran it for a year. In 2002, two additional turbines were installed on either side of the first turbine such that the blades of neighboring turbines passed within twenty inches of each other.
The close spacing of the turbines produces a "vortex/wall"
effect that increases output of the interior turbines by 75%
in 16mph wind with diminishing improvement such that the effect disappears in winds above 42mph. The empircal data gained about the vortex effect led to the US Patent office granting Wind Harvest a new patent in 2004 (number 6,784,566).
The Model 530G has 530 square feet of rotor swept area, the same as its predecessor turbine, the Model 530. The main difference is that the 530G was set up without an external superstructure and used guy wires to save on materials and installation costs. After years of testing, the problems with guyed turbines and bearing wear became apparent. Future Model turbines will have an extermal superstructure as had all previous models. A great deal of additional valuable information came from the research and design work on the 530G array that benefits the efficiency, energy output and costs for the Model 1500 and 3000 turbines.