The D400 is extremely efficient by design, making it the most powerful and productive wind generator of its rotor size currently available.
The D400 has been developed specifically to operate in close proximity to people. The noise and vibration usually associated with small wind turbines has been designed out of the D400. This has been achieved by making the turbine run relatively slowly for a given electrical output. In a given wind speed and a given electrical output, the D400 rotates at less than one quarter the speed of some competitor units. Combined with its rugged engineering and advanced computer-designed air blades, this makes the D400 the most reliable and benign turbine of its class currently available.