An opportunity to simultaneously harness solar and wind energy resources is being pursued by University of Manchester, U.K., researchers. An energy-harvesting device based on the inverted flag concept is envisioned forEnergy-harvesting flags generate electricity using wind and solar power. Source: Manchester University use in powering small-scale portable electronics deployed for environmental sensing.

The system combines flexible piezoelectric strips with flexible photovoltaic cells to exploit both wind and solar energy. Piezoelectric strips comprising the body of the flags capture energy as the device flaps around in the wind, enabling power generation from the deformation of piezoelectric materials, as the flexible photovoltaic cells capture solar energy. The piezoelectric strips were observed to increase the damping of the flags while the solar panels served as an added mass.

Three inverted flags constructed with off-the-shelf components were tested under controlled wind and illumination conditions, demonstrating an output of 3 to 4 milliwatts under wind speeds of 0 to 26 m/s and 1.8 kilolux constant lighting exposure.

The team plans to increase the power output for more demanding applications such as charging stations for mobile devices.