Solar energy: Butterfly wing design helps increase power collection by 50%

Scientists have borrowed a leaf from nature in copying the cabbage white butterfly's design to improve solar panel efficiency and decrease costs.

A team of experts from the University of Exeter mimicked the v-shaped posture adopted by the butterflies to heat up their flight muscles before take-off. In doing this, they were able to increase harvested solar power in panels by almost 50%.

The power-to-weight ratio of the overall solar energy structure was also increased 17-fold in the process, making it much more efficient.

Professor Tapas Mallick, lead author of the research 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."

Being the early birds among butterflies on cloudy days, the Cabbage White butterflies that take off early have limited access to solar energy. The V-shaped posturing used on such days helps them maximise the amount of solar energy onto their thorax and fly.

Sub-structures on their wings reflect light efficiently, ensuring that the flight muscles are warmed to an optimal temperature as quickly as possible. The optimal angle of 17 degrees between the wings increases temperature by around 7 degree C as compared when held flat.

The Exeter team set out to replicate the wing structure and develop a new, lightweight reflective material for solar panels.

Besides the angle, a single layer of scale cells as found in the butterfly wings helped improve power-to-weight ratios of solar concentrators, making them significantly lighter and more efficient.

The research by the team from the Environment and Sustainability Institute (ESI) and the Centre for Ecology and Conservation, based at the University of Exeter's Penryn Campus in Cornwall, is published in the leading scientific journal, Scientific Reports.

Solar energy is predicted to become the cheapest source of electricity across much of the globe in the next 10 years.

It is fast approaching grid parity with fossil fuel power, and in some cases falling even lower as wafers go thinner and more efficient. Solar photovoltaic prices have fallen by 80% since 2008.

The global installed capacity of solar electricity has increased by six times to 135GW in 2013 from 23GW in 2010.

Electricity production from fossil fuels accounts for more than 40% of man-made CO2 emissions.