Ten years ago, Perry Carroll was sailing in the Atlantic when he looked up to see his sail glowing in the moonlight. "It should be solar," he thought, in a stroke of brilliance. Ever since, he has been chasing the idea of making a flexible solar panel.
Carroll, a 25-year veteran in the tech startup world, founded the Solar Cloth Company in 2012. This year, the outfit built the world's first parking lot covered with a fabric that contains photovoltaics just microns thick at the Cambridge Research Park in England. The 1,600-square-foot canopy, above 12 parking spaces, generates 15 kilowatts an hour—enough to power ten houses each day, according to Carroll. And, the company is poised to make a significant impact, with billions of square feet of non-load bearing roofs and parking lots, prime for this technology, in the United Kingdom alone. Carroll shares his story with Smithsonian.com.
Let's start with the problem. What problem are you trying to fix?
Renewables are becoming an ever more crucial part of the energy mix as concerns deepen over the security and availability of fossil fuels. Solar derived energy has a big part to play in the solution. However, deployment of traditional solar farms can compete with food production or threaten valuable green belt. The question is to how to create spaces for solar energy on existing commercial property that can be both efficient and attractive. This is the massive step forward enabled by the Solar Cloth Company.
So, what exactly is a solar cloth? How is it constructed, and how does it work, exactly?
Obviously our company didn’t invent solar panels or cloth—our unique innovation is to develop products that integrate the two. We use thin-film photovoltaics just a few microns thick—less than the width of a human hair—and integrate them into flexible and lightweight structures, known as building-integrated photovoltaics. We use copper indium gallium diselenide [CIGS] as a base technology, [as it is] known for its higher light-to-electricity conversion rate and lightweight flexible properties. Our technology is 100 times thinner than the conventional silicon glass-backed solar panels that most people picture.
How efficient is the photovoltaic fabric? How much power can it generate?
Our solar fabric generates around 100 Watt-peak per square meter. Importantly, the power yield over the course of a year is higher than traditional solar as CIGS works better in the winter and low light levels during dusk and dawn. So how much can it generate? Take your area covered in meters by our solar cloth and multiply it by 100 Watt-peak. This means that a car port can power a house, and a football stadium roof covered in solar cloth could power a small town.
What are the best use cases for it?
At the moment, there is a lot of interest in car ports and commercial roofing. Most commercial roofing cannot support the weight of heavy glass solar panels, so our lightweight solar cloth is ideal in these situations. We estimate there is almost 9 billion square feet of commercial roof space and more than 3.5 billion square feet of car parking space in the UK alone, which, if covered with solar panels, could produce enough power to feed the UK’s national grid three times over.
Everyday we come up with new applications for the product or have people coming to talk to us about ideas we'd never envisaged. We're working on some wearable solar technology solutions and bespoke projects, but really the only limit is our imagination.
Where have you installed the solar cloth, so far?
Earlier this year we unveiled the world's first solar fabric tensile structure car park in Cambridge, UK. We are currently closing in on deals involving 27,000 car park spaces with leading UK retailers and 15 local authorities. We have built a growing sales pipeline worth £4.2 million [about $6.5 million] for 2015, including park and ride projects, airport parking operators and retail park owners. Further, we are trialing new-to-market flexible, lightweight building-integrated solar installations with one of the UK's biggest retailers in January 2015. We are also very excited to be in discussion with two well known London museums who have set us the challenge of solarising their buildings in ways that complement their period design.
And what about the product's potential impact on how we source our energy?
Solar power can generate electricity at the point of use: above buildings and above electric vehicle carports. We need ways of integrating solar into every building that we build, so that throughout the lifetime of a building it generates more energy than we use to build it. When we reach that level of building-integrated solar power, we will have truly green cities.
How do you plan to scale your company? What's next?
We are currently crowdfunding. This investment will enable us to scale up the human resources of the company in terms of sales and marketing and administration. This will mean we can fulfill our growing pipeline of orders quicker and deal with the growing global interest in our products. Crowdfunding is an exciting option for growing cleantech firms. The crowd not only wants to invest in companies that make a profit, but they also want to invest in companies that perform a social good. We see crowdfunding as a great way for the public to support environmental issues in a game changing way.
How else can people help?
I just encourage people to think outside the box about what is possible with solar fabric and to talk to us about their ideas.