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Could a tree be the future of solar energy?

The solar panel of the future may not resemble a panel at all. Dominic Utton spoke to Dr Rebecca Cain on why she believes a tree may be the solution to a solar-powered future.

By Dominic Utton, October 2015


Rebecca CainDr Rebecca Cain is a woman on a mission. The industrial designer heads up Warwick Manufacturing Group’s (WMG) Experiential Engineering team and she believes their latest project has the potential to be genuinely world-changing.

“We’re trying to answer one of the biggest questions we have in society,” she says. “And that is: where’s our power going to come from? We can’t carry on as we are – we’ve got to look to use the sun, wind, tidal, all these renewables.

But the big problem at the moment is that people don’t seem to be engaging with solar power, despite its massive potential.

“I think there are many reasons for that but one of them is definitely that aesthetically solar panels just don’t appeal to people. While they might like the idea in principle, they don’t want it on their own roof. What we’re saying is: if there’s an alternative, would that change your mind?”

To get the general public thinking and engaged about solar power, Dr Cain and her team have created a two-metre tall solar panel tree, using 3D printing, to show the potential for a whole new way of harnessing solar power.

“It’s purely a sculpture at the moment,” she says, “but it will show the potential for the designs. We have got some working solar-powered leaves on the tree which people can use to charge mobile phones and things. We’re posing the question – imagine this as your future power source. What do you think? We want to get people – and especially the next generation – feeling that they can be part of designing these structures.”

The idea behind the solar panel tree has its roots in a very simple problem. While solar power is unquestionably a vital source of energy for the future, the current panels are – not to put too fine a point on it – ugly. Rebecca’s team wanted to find a way to harness the power of the sun in a way that was effective, efficient and aesthetically pleasing.

And, like all the best ideas, it began with a cup of coffee. Explains Dr Cain: “Dr Yorck Ramachers is a physicist at the University and he was looking at ways moving away from the idea of solar panels as flat and making them three-dimensional. So the idea is they’d have a smaller footprint – meaning that per square metre you can potentially generate more power. And through the work that he was doing computationally, which was producing some quite interesting shapes, he thought there was potential for a designer to exploit these new forms. So he invited me over for a coffee, and it took off from there.”

Dr Cain’s own background is as an industrial designer. After completing her PhD at Loughborough University, she joined WMG and eventually worked her way up to lead the experiential engineering team.

By her own admission, she’s motivated by the idea of collaborating with the public to create new kinds of designs. Dr Ramachers’ idea immediately appealed – not only because of the importance of the subject, or the simplicity of the original question – but because by necessity, every solar panel tree created would be its own unique design.

“The way the physics works is that these solar shapes could be anything,” she says, “but we chose a tree structure because trees are a really good example of a structure that harnesses the sun’s energy through photosynthesis – and trees also have quite a small footprint compared to their surface area of the leaves.”

Solar tree

In very basic terms, every living tree uses solar power to create its own energy: the leaves gather energy from the sun, which is used to grow and sustain its own life. For Dr Cain’s team, it made sense to use nature’s example as inspiration.

“On the solar panel tree, effectively every leaf is like a little solar panel. So the way it works is that the photovoltaic cells (that harness the sunlight and convert it into electricity) go on the leaves. But the other thing about these structures is that you can make other parts of the trees reflective – like the branches, or the trunk. So the light can effectively be bounced around the tree and the energy-generating potential increased.”

The team also realised very early on that by necessity, every solar panel tree created will be entirely unique.

Dr Cain explains: “How it works is that we feed in a lot of parameters to the computer – so that’s information about the particular unique environment where that tree would be, what are the buildings around it, is it northern or southern hemisphere, where are the shadows, as well as things like maximum size, what type of leaves would it have… and then the computer creates a design wholly unique to those particular needs. The really exciting and surprising thing is you don’t really know what the design is going to be.”

As well as Dr Ramachers and Dr Cain, the experiential engineering team is made up of 20 people, including designers, engineers, scientists, psychologists, health professionals and an architect, Dr Eliza Dimitrokali.

Dr Dimitrokali has been leading a series of public design workshops around the Solar Panel Tree. Working with the public has been central to the development of the project: the team want to not only develop the potential of solar power, but to also combat the “Not In My Back Yard” effect and create solar power-generating structures that people will see as both practical and beautiful.

“From the beginning we took the approach that this should be about provoking people,” she says. “This was never about trying to design something that could be built tomorrow. It’s about trying to pose the question again about new forms of solar power.

“The forms that this kind of modelling creates are actually very beautiful. And if things look beautiful, people are prepared to make trade-offs. They’re more accepting of things like cost. It immediately takes on an intrinsic value that’s more than just what that product does.

“At the moment the big flat squares are basically the cheapest way of doing it. But I think our trees have the potential to not only be more beautiful but also more efficient.

“So for example, could you have a small solar panel tree on your desk for charging your phone? Or could you have a forest of them that would power a church hall? It’s very exploratory – we’re playing around to see what’s possible.”

It has been less than two years since Dr Cain was first introduced to the idea of solar panel trees over coffee with Dr Ramachers.

“What we’d really like to do is find some genuine use cases – actual communities with whom we can really work on designing solar trees,” she says. “This project has been an adventure for us. The bit that I love is what happens when you show these to the public – getting people really excited about solar energy again.”