Scientists at the University of Manchester in the UK have created a combination of a wind turbine and a solar panel, giving it the shape of ... an ordinary flag. The device is interesting, first of all, from an engineering point of view, its performance is still almost symbolic. However, the generated energy is sufficient to connect several sensors - for example, light and wind speed.
Instead of the classic fabric flag, it uses a design of alternating strips of piezoelectric cells and solar panels. Both are flexible enough to sway in the wind, with the former converting these movements into energy. The latter, on the other hand, do not just catch the light of the sun - wide batteries play the role of a sail and a destabilizing mass in order to start oscillatory processes under the influence of the wind.
Such an energy flag can only oscillate along one trajectory, with a significant limitation in tempo and amplitude; it is unsuitable for operation in a strong changeable wind. During the tests, scientists deliberately waited for almost complete calm in order to check the operation of the system. With uniform illumination or wind blowing, the energy flag generates 3-4 mW. These are symbolic amounts of energy, but it is completely free and suitable for powering many micro-devices.
The most interesting thing about such an energy flag is its versatility, since it is designed to work in mutually compensating conditions. With a strong wind, clouds come in and the sun does not shine, and when the element dies down, the flag stops waving and continues to generate energy from the sunlight. It is simple and convenient, and therefore one can hope to see the development of the concept to devices that will be massively used in everyday life and urban infrastructure.