Scientists from the University of Manchester (UK) have developed a flag that collects solar and wind energy for domestic use.
According to the developers, the energy collected by the flag is not enough to power a home or even a gadget, such as a smartphone, but the devices can be used to supply energy to environmental sensors that control things like air pollution, sound levels and temperature.
The inverted flags are made using piezoelectric strips that collect energy when the device flutters in the wind, and flexible photovoltaic cells that capture solar energy.
Under the influence of the wind, flags flutter from side to side with repetitive motions, also known as “limit cycle oscillations”. With the deformation of the piezoelectric materials and the production of electricity.
When testing in calm weather with weak wind speeds and with constant light exposure, it was found that such operating conditions resulted in power output of up to 3-4 milliwatts. But this, scientists believe, is far from the limit.
