Solar panels that track the sun currently involve the use of motors and electronic control systems to move them and convert the power to energy. But a team of engineering students at MIT, inspired by heliotropic plants that move in the direction of the sun all day (like a sunflower), have developed a new method of motivation for the photovoltaic cells to move. Their invention won first place in MIT's Making and Designing Materials Engineering Contest (MADMEC).
Solar cells that track the sun can be 38 percent more efficient in generating power than fixed solar cells, but the systems required are very expensive. Instead of using an electronic tracking system, Forrest Liau, Vyom Sharma, and George Whitfield, who made up the "Heliotrope" team, decided to use the difference in temperature between shaded and sunny areas to change the properties of the material supporting solor photovoltaic cells.
After experimenting with different materials and configurations, the Heliotrope team came up with a system whereby solar panels would be placed on top of a curved arch made of a pair of metals, such as aluminum and steel. The concept was demonstrated by shining a spotlight on one side of a bridge containing a solar panel. The heat from the light causes the bridge to arch, tilting the panel towards the light.