Small scale windmill

In this letter the authors report experimental results on an optimized small scale piezoelectric windmill, which can solve the problems associated with autonomous sensor networks in outdoor, remote or inaccessible locations. The whole structure of the windmill is made of plastic, and it utilizes 18 piezoelectric bimorphs which makes this design extremely cost effective. The windmill was tested at average wind speed of 10 miles/h and it provided 5 mW continuous power. The threshold wind speed for the windmill was found to be of the order of 5.4 miles/h. Further, the authors present analysis on two other windmill structures which illustrate the design parameters required for small scale windmill.