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What if Umbrellas Could Generate Solar Power?

Organic solar cells offer a great opportunity to build inexpensive, portable and flexible solar generating devices

Seema Singh
Published: 11, Feb 2013

Until Dec 31,2013, I was a Senior Editor at Forbes India and I usually wrote about science and technology on this blog. I believe while we may have settled into consuming the nicely packaged final products of science - technology being a hand maiden of science - we are distancing ourselves from all the effort that goes into it. This blog was an attempt to bring occasional peek into those efforts and ideas. I've been a journalist for 17 years and have written for The Asian Age, The Times of India, Mint, Red Herring, IEEE-Spectrum, Cell, New Scientist and others. I'm now available at You will find my future articles on

Imagine an umbrella functioning as solar concentrator, funneling the energy to its stick from where you can charge your cell phone? Or, even power a few other basic electrical devices, or run a tiny fan as the accompanying picture shows.


umbrella made from polymer solar cells

This may sound gimmicky but the scope that organic photovoltaic cells offer for inexpensive, portable and decentralized solar power generation is enormous. The US military has already built tents that generate solar power – where solar cells are integrated with the canvas -- and remain as foldable and flexible as always.

In solar technology parlance, organic cells represent the third generation, after crystalline and thin film solar cells. While organic solar cells are inexpensive to manufacture, the issue that companies and researchers are grappling with today is the low efficiency that these cells today offer. That is, conversion of solar insolation into electricity. It is 8-10% lower than crystalline solar cells.

One of the reasons that hinder large scale manufacturing is the fact that power efficiency, which scales inversely with the active area size, does not make single large area cells amenable to roll-to-roll manufacturing. There are dead zones or unutilized spaces in large surfaces that make commercial manufacturing nonviable.

Now, KS Narayan and his team at Jawaharlal Nehru Center for Advanced Scientific Research in Bangalore show that they have made a dent in both these problems. They propose their new strategy and results in the latest issue of Advanced Materials.

For increasing power efficiency they use low temperature meltable alloys as cathodes which results in reduced resistive electrical loss and additional photo-generated carriers near the metal electrode. Secondly, and more interestingly, they do better light harvesting by using specific flurorescent dyes in the non-active zone of the cells.

Dyes are introduced in the electrode gaps which cause re-direction and re-emission of incident white light. (They absorb the blue light and remit it as red.)

Researchers say this active encapsulation where light wavelength is converted to a more desired wavelength for the device to be redirected effectively is a new concept in the field. Their devices showed 12 percent increase in efficiency upon inclusion of the suitable dyes. They also argue that since there’s a wide selection of dye-molecules and a reasonable large range of melt processible alloys, this fabrication technique can be used for a variety of organic cells.

Brian C O’Regan, who is part of the Solar Network at Imperial College London, works in the related area of dye-sensitized cells (not polymer cells) says he “really likes” Narayan’s work. “I am fairly sure the work is novel, I haven’t heard of this approach before. And it appears to solve a problem that polymer cells face in the issue of upscaling.”

Narayan, who has secured his intellectual property through PCT, is keen to commercialize this technology. He believes there are many small and big uses in India, from canopies in large hotels to small devices running off-grid in rural areas. “Companies which are looking for non-existing applications will find this more appealing,” he says.

India is a melting pot of renewable energy experiments, including  business models. Unlike Europe,Germany in particular,India isn't subsidizing generation, nor is it subsidizing manufacturing like China. With nearly 400 million people without grid power, it’s clear that decentralized non-polluting sources of power will bring relief to millions in this country.

Even with the first two generations of solar technology, industrial commercial users are moving to decentralized power generation because it is more economical, says Tobias Engelmeier, managing director of Bridge to India, an environment consulting company in New Delhi. With new technology, you can expect even more decentralization. “Organic solar cells would accelerate this trend as the cost/kWh comes down further, say from Rs 7 to Rs 5,” he says. “It has almost become a question of commercialization, not one of whether it’s the best technology.”

There has been some fatigue with solar technology breakthroughs because of the initial hype generated, especially in the US, and VCs went along with it. But as we saw, solar made bigger advances through evolution – cost, scale, volume—rather than revolution (in technology).

Incidentally, the pace of R&D and the subsequent breakthroughs have once again brought the shine back on solar technology. TechNavio’s analysts expect the global next-generation organic solar cell market to grow at 66.23 percent over 2012-2016. One of the key factors contributing to this market growth is the increase in attributes. Earlier this year German company Heliatek, one of the leading organic solar cell manufacturers, improved its own previous record by showing  an efficiency of 12%.

“It’s fantastic that an Indian lab has shown this breakthrough as India has traditionally not contributed to solar technology development,” says Engelmeier.

But since it’s now a question of commercialization, will Narayan find equally talented partners to take his lab prototypes to the market?

Rajesh Rai, chief executive of India Innovation Fund which invests in IP-driven start-ups, finds the technology interesting. “Assuming that the technology is differentiated and novel (as it seems to be) the key is how well Prof Narayan may work with a partner - a corporate partner or an individual,” he says.

For Narayan, who is also the dean of R&D at JNCASR, it isn't just about commercializing this particular technology. He has a full portfolio of ready-to-commercialize technologies. More importantly, he also has to set an example. “I will have to take the plunge as this [commercialization] is what we are encouraging among our students.”


  • mert gulgec

    This idea has already been patented amd realised as a whole product in Turkey. Our patented product SolBrella is on the market and booming to be used on Turkish coasts and beaches. We manufacture solar power system for umbrellas and awnings since 2010.

    on Feb 3, 2014
  • Rahul

    Why only umbrella, why not the roof tops of each individual home...whats the harm in generating power like that

    on Mar 22, 2013
  • Rajesh K

    @Seema: What the IIT Madras team is about to do is even bigger: They are working on a solar concentrator prototype which is very much suitable for a hot/cost-conscious country like India. The heat of the sun is much more powerful than the light. When commercialized and utilized in large-scale, concentrated solar power can be very economical and very much suitable for Indian conditions.

    on Feb 21, 2013
  • Sanjiv Rao

    Folks do not forget that India has a basic necessity of power energy for about 400 mil people who has not seen the glimse of light at their home. And we cannot see any light at the end of the tunnel in this direction by the current govt to root out this energy crisis of the people. Under this circumstances any green power energy as long as affordable would be a good attempt and great market in India. So far solar lantern and other economical approach in rural area has done tremendous changes of lives. I would congratulate KSN to do a economical commercial approach to tap this demand. The umbrella approach make sense for the extreme hot condition in India.

    on Feb 16, 2013
  • Kamaljit Singh

    It is a promising endeavor and holds considerable potential for commercialization. Good luck KSN

    on Feb 12, 2013
    • Kreno

      Do not want to discourage you, but it wont see the light in India. EU/Japan/US are 10-12 years ahead in a field 20 years old and are growing much faster. This is good work, but one will soon find companies like Eight19 coming to India at full scale rather than any areal products being developed here.

      on Feb 15, 2013
      • Atul patel

        have a query kreno Can't somebody stay in india , and can't think to make patents/products which are applicable to global world. They can go to developed world to file the patents and get the funding but can stay in india and enjoy their native lifestyle. or can support /pass knowledge which they have received over the period of time to young indian students who in turns goes to this big energy companies research department to create world class solutions on any technological field? to support at global scale. at the end what matters is effective youth to develop the technology ...which is very low at this moments... watching the big problems we are having in future

        on Feb 16, 2013
      • Seema Singh

        Kreno: Thanks for your comment. I wouldn't go that far and say, so early in the day, that it won't see the light in India. What makes you think a solar manufacturer, from any other part of the world, wouldn't want to license this technology? It doesn't necessarily have to be an Indian company. Secondly, it often takes years for such next-gen technologies to come to the market. And these endeavours are not mutually exclusive; are they? US sent a man to the moon in 1969, India sent its own lunar mission nearly 40 years later, in 2008.

        on Feb 15, 2013
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