Ok, these “windmills” are a bit big to think of them as gadgets but there cool technology so I am including this. These “wind lens” turbines produce up to 3 times the energy of conventional wind turbines. They plan on running a test generation facility next year.
The breakthrough and research are being done by the Wind Engineering Section at Kyushu University in Japan. Strong vortices are created by the diffuser and the brim of the Wind Lens producing low pressure region behind the turbine. This increased pressure difference that helps the wind to flow more into the Wind Lens. It is amazing, to me, that it has such a huge impact.