In the sunlight, the sparkling wings of the morpho butterflies of the Amazon rainforest shimmer in turquoise, blue and silver.

The bright, metallic hues are stunning to the naked eye. But when Professor Ken Durose viewed them down his microscope at Durham University, he saw something even more spectacular.

"I couldn't believe my eyes. It was like turning a lightbulb on," said Durose, one of the UK's leading experts in solar- cell technology.

A few hundred miles down the road, in Southampton, his colleague Dr Darren Bagnall was experiencing the same revelation. "Looking down the microscope, we see a whole other level of beauty - these incredible nanoscale patterns. I'm kind of dazzled by them, really," says Bagnall.

They were gazing upon one of evolution's most beguiling creations - the tiny reflective wing-scales that create the kaleidoscopic array of colours a butterfly uses to attract its mates.

Under the microscope, in grainy black-and-white, the complex landscape of grooves and folds, each hundreds of times thinner than a layer of paint, might not look so pretty to you and I. You certainly wouldn't hang pictures of them on your wall.

But take a closer look, and you may find they may have another quality that will make them indispensable in your future home. According to Bagnall and Durose, these patterns may be the key to designing an entirely new generation of solar cells, so cheap and efficient that all of us will have panels on our roofs.

By mimicking the butterfly's tricks, and those of other insects such as moths and beetles, they hope to design powerful new solar cells capable of trapping the elusive British sunlight from dawn till dusk, and generating electricity even on dull winter days.

"There are so many people who would love to buy solar panels," says Bagnall. "Some of us want to be environmental, others just want to look good. It's potentially a massive industry.

"But at the moment, in terms of energy efficiency, it just doesn't make fiscal sense. You'd probably be better off using a wood-burning stove."

Gordon Brown has famously paid £15,000 to install solar panels on his roof - a mating call for voters. But the contraption only generates up to £200 worth of energy a year. "At that price, it's not going to pay itself off in your own lifetime," says Bagnall. But the problem is not down to a lack of rays in Britain. "Even the sunniest places on Earth - Ethiopia and Australia - have only two to three times more sunlight than the UK," says Durose. "Any light is good light."

No, the difficulty is designing a solar cell which is cheap to build and buy, yet still efficient.

Today's solar cells use expensive thick silicon wafers as semiconductors. "Half the cost of a solar cell is the wafer itself," says Bagnall.

Some labs, including Durose's, are working on replacing silicon with cheaper alternative compound semiconductors. But Bagnall has a different aim - thin-layer silicon.

"My ambitions are quite modest," says Bagnall. "I would like to make a 10% efficient device - which is quite standard. But I would like to do it for a tenth or a hundredth of the cost.

"The trouble with thinning the silicon layers is that they won't absorb as much light," says Bagnall. "The way you get round that is by light-trapping - surrounding the wafers with mirrors which pull the light in between the layers."

To do this well, you need broadband mirrors, which trap light no matter the wavelength or which direction the sun is shining from. The solution lies in nature.

"If we look at the butterfly, we see all of the things that we would like to do in a solar cell," says Bagnall. "On their wings we see examples of mirrors, blacks, whites and transparencies, and all the different colours - all things you can imagine wanting to recreate in a photovoltaic cell. It's a perfect system."

"And the great thing," says Durose, "is that it does this on an incredibly small scale. At less than a micron thickness, it will make mirrors which are broadband and effective over the whole spectral range and all the angles of incidence. That's the trick.

And that is very hard for us to do in technology."

Of course, they are not suggesting we farm butterflies to build power stations out of them. The aim is to mimic the unique reflective structures of the wing scales with a synthetic substitute.

Looking down the microscope, the secret lies in the complexity and irregularity of the scale patterns - optimised over millions of years of evolution.

"The magical thing is that we see patterns in nature that we could not have dreamed of," says Bagnall. "They are inspirational. We couldn't just sit down and calculate them."

Mimicking these structures will be no mean feat. But Bagnall has already shown that it can be done, in this case with moth eyes.

"The moth's eye is anti-reflective to the moonlight to avoid detection by predators. So by coating the silicon wafers with this black structure, we reduced reflection by about 10%. That's how we got started," he says.

"But, for me, it's not about gaining 10%. What excites me - the thing that gets me out of bed in the morning - is that if we can trap light by mimicking nature, we can begin to think about wholly different types of solar-cell designs.

"We could, for instance, take a piece of glass and use a biomimetic structure to trap the light within it. Glass is much cheaper than silicon, and within the glass you could embed tiny nanoscale solar cells. With that type of structure, you can reduce the amount of semiconductor you need by maybe a hundredth."

Of course, he admits to achieve this cost-effectively will require some major feats of engineering.

"The features on the butterfly scales are so small that we have to use electron beam lithography to stamp the structures on to a thin polymer layer. It's very expensive at the moment, but if we can scale up the techniques, it will become cost-effective."

Time is running out to discover a cure for the world's oil addiction, and nowhere more so than the Amazon, where governments are selling vast tracts of rainforest for oil exploration. What a beautiful irony it would be, then, if the solution lay not with the black sludge under the ground, but in the rich tapestry of creatures above.