The renewables sector continues to innovate to compete with conventional energy. Cost of solar equipment has dropped significantly as technology has adapted and improved. In a continuation of this theme researchers at the University of Michigan have demonstrated that a simple method of increasing the amount of energy produced by solar panels can boost a panel’s energy generation by 40 per cent, significantly reducing its overall cost.
The majority of solar panels worldwide are fixed on rooftops at a set angle. This means they miss out on capturing solar energy during parts of every day because they do not tilt to follow the sun.
The engineering researchers found that by cutting solar cells into particular designs using kirigami, a type of origami involving cutting as well as folding, the cells are capable of tracking the sun’s angle – without having to be fitted on a tilting panel.
The process requires the making of a specific kirigami cut to create strips in a solar cell. When the two ends are pulled in opposite directions, the strips then tilt and assume the desired angle.
A key detail is that the structure thus created morphs in such a way as to prevent an individual strip from casting shadows on its neighbours. Further, the “waviness” of the new form does not impair its performance.
The researchers, led by Max Shtein and Stephen Forrest, both professors of materials science and engineering, calculate that solar panels which have tracking mechanisms can generate 20 to 40 per cent more energy a year than fixed panels.
However, tracking panels are can be costly and cumbersome and cannot be used on the majority of pitched roof buildings, which represent around 80 per cent of solar power installations.
The new kirigami panels can generate more electricity using the same amount of semiconducting material. They do this to nearly the same degree that conventional tracking systems do, said Shtein.
He commented: ““It doesn’t take much force at all. And although the technique is best suited for thin, flexible materials, in principle it could work with almost any kind of solar cell.”
However, the newly demonstrated system, which has flexible solar cells made of gallium arsenide, is so far only a proof-of-principle. Bringing the technology to the point of commercial application still appears some years off.