Since their popularization, one of the biggest drawbacks to solar panels has been finding somewhere suitable on your property to place them in order to soak up as much sun as possible. For those without south facing roofs this has been an uphill struggle, but new technology from the University of Wisconsin Madison inspired by the simple sunflower could be about to change that.
Although there are solar power systems on the market which use GPS in order to attempt to reposition the panel throughout the day and catch the most sunlight, this method is not as efficient as it could be, as it requires motors to power the panels. The lack of a dynamic reaction to the sun’s position also means that the panels won’t necessarily be catching as much sunlight as they could.
In response to this problem, researchers at the University have developed a new solar power system that is inspired by the reaction of sunflowers towards sunlight: the heliotropism adaptation found in sunflowers means that they will track the sun throughout the day by rotating in order to position each leaf to grab the most sun. The researchers sought to replicate this behavior in their new solar panel design which utilizes a new material called liquid crystalline elastomer (LCE).
The LCE is paired up with carbon nanotubes that can absorb a wide range of light wavelengths. This drives the system naturally in a similar manner to sunflowers. The University explains: “When sunlight hits a mirror underneath the solar panel it is focused onto one of multiple actuators made up of LCE infused with carbon nanotubes. The temperature of the carbon nanotubes increases as they absorb light, creating a heat differential between the environment and inside the actuator which causes the LCE to shrink. The result is that the entire assembly bends towards the strongest source of sunlight.
As the sun travels across the sky, the actuators will cool and re-expand, and new ones will shrink and the panel will track over the 180 degrees of sky that the sun occupies over the course of the day.”
Tests carried out by the University have so far proven an increase in efficiency of 10 per cent while using this method. This increase is colossal considering that to date other panel improvements have only netted increases of a few percent at best. The other obvious benefit to this system is that because it is driven by a passive, natural response there are no motors and thus no additional energy required to power it.
The system is still in the proof of concept stage for the time being, but the team at the University is currently developing larger panels that utilize the technology in order to take it to the next step.
It’s not just the University of Wisconsin Madison that has been inspired by sunflowers: researchers at Massachusetts Institute of Technology have been working with RWTH Aachen University in Germany have been working on a project in a bit to increase sunlight exposure to panels using mirrors that was inspired by the spirals on the face of the flower. Clearly scientists are realizing there is a lot we can learn about protecting the environment from the environment itself and hopefully this will lead to more innovations inspired by our planet.
Jessica is a renewable energy enthusiast. She currently writes about recent developments in solar power technology for Solar Contact.