Engineering news
By recreating the v-shaped posture adopted by Cabbage White butterflies to heat up their flight muscles before take-off, the amount of power produced by solar panels can increase by almost 50%
Scientists examining new techniques for generating photovoltaic (PV) energy have discovered that mimicking the design of butterfly wings can make solar energy cheaper and more efficient.
A team of experts from the University of Exeter found that by recreating the v-shaped posture adopted by Cabbage White butterflies to heat up their flight muscles before take-off, the amount of power produced by solar panels can increase by almost 50%.
Crucially, by replicating this 'wing-like' structure, the power-to-weight ratio of the overall solar energy structure is increased 17-fold, making it much more efficient.
Professor Tapas Mallick, lead author of the research from the Environment and Sustainability Institute (ESI) and the Centre for Ecology and Conservation at the University of Exeter, said: "Biomimicry in engineering is not new. However, this truly multidisciplinary research shows pathways to develop low cost solar power that have not been done before."
The Cabbage White butterflies are known to take flight before other butterflies on cloudy days, which limit how quickly the insects can use the energy from the sun to heat their flight muscles.
This ability is thought to be due to the v-shaped posturing, known as reflectance basking, they adopt on such days to maximise the concentration of solar energy onto their thorax, which allows for flight.
Furthermore, specific sub-structures of the butterflies' wings allow the light from the sun to be reflected most efficiently, ensuring that the flight muscles are warmed to an optimal temperature as quickly as possible.
The team of scientists investigated how to replicate the wings to develop a new, lightweight reflective material that could be used in solar energy production. They found that the optimal angle by which the butterfly should hold its wings to increase temperature to its body was around 17 degrees, which increased the temperature by 7.3 degrees centigrade compared to when held flat.
They also showed that by replicating the simple mono-layer of scale cells found in the butterfly wings in solar energy producers, they could “vastly improve” the power-to-weight rations of future solar concentrators, making them significantly lighter and so more efficient.
Professor Richard Ffrench-Constant, who conducts research into butterfly mimicry at the University of Exeter, said: "This proves that the lowly Cabbage White is not just a pest of your cabbages but actually an insect that is an expert at harvesting solar energy."
The paper, White butterflies as solar photovoltaic concentrators, by Katie Shanks, Dr Senthilarasu Sundaram, Professor Richard Ffrench-Constant and Professor Tapas Mallick from the University of Exeter, is available online.