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Tiny wires could be a breakthrough for cheap solar panels

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Chinese solar panel giants are in a bind — they’re churning out too many rock-bottom, commodity solar panels, and losing millions every day. In fact, most solar panel makers are currently laser focused on trying to boost the efficiency of their panels so that they can sell them at higher prices and actually make some money. A Swedish startup called Sol Voltaics says it can help out.

WireArraySol Voltaics, which is discussing its product and funding for the first time this week, said it has developed a low cost way to make tiny nanowires out of the semiconductor gallium arsenide. The company turns these nanowires into an ink, which can be layered onto basic solar panels and boost the efficiency of a standard panel by 25 percent.

The idea is that solar panel makers would want to buy this technology because they can sell the more efficient panels at a higher price, and raise their margins. In addition, the overall installed cost of the more efficient solar panels (they produce more power) could be lower by 15 percent to 20 percent.

Swedish solar innovation

Founded in 2008, Sol Voltaics won’t be producing its nanowire ink — called SolInk — at pilot scale until 2015, and commercial scale in 2016. But it’s already started to prove that its technology works, and has had its nanowire cells certified by research firm Fraunhofer for an efficiency of 13.8 percent. This year the company is focused on demoing how its ink boosts efficiency on a larger scale, and in 2014 they’ll work on perfecting the equipment that its customers will use to cover panels with the ink.

With just 20 employees, Sol Voltaics has been operating in a relatively lean mode for a solar manufacturing company. To date the startup has raised just $11 million in funding from private and public funders and family offices, including Industrifonden, Foundation Asset Management, Scatec, Nano Future Invest AS, Nordic Innovation and Vinnova. The company hopes to raise another $10 million to $20 million this year, and plans to cap all of its funding at $50 million by 2016.


Sol Voltaics has some well-known names in the solar and venture capital sectors. The company was founded by Lund University Professor Lars Samuelson, who is an expert on the type of semiconductor that Sol Voltaics uses to make its nanowires. The company is led by Dave Epstein, who is a serial entrepreneur and former partner with Crosslink Capital, and Magnus Ryde, who was the former CEO of TSMC America, is Sol Voltaics Chairman.

How does it work?

Sol Voltaic’s innovation is that it’s figured out how to make tiny wires using the normally expensive but highly efficient semiconductor¬†gallium arsenide. Solar scientists have spent years using gallium arsenide in various ways to make ultra-efficient solar cells, but the only way the material can be cheap enough to actually be used on a commercial scale is if it’s used in very small amounts — hence the nanotech wire part. But, again, in previous years the production of nanowires has also been relatively expensive.

Sol Voltaics nanowire

The breakthrough came when Samuelson figured out a way to make the gallium arsenide nanowires in a gas phase instead of in a solid phase. Sol Voltaics calls this their aerotaxy process. Under the right conditions, in an air reactor, the company can grow these nanowires in seconds and store them in a liquid, producing a sort of ink.

Sol Voltaics wants to take this ink and sell it to solar panel makers, alongside production equipment that they can use to layer the ink — inkjet style — onto their own solar panels. The nanowires in the ink act as guides for the light and concentrate it. The company says the capital expensive of the ink and machines add 1 to 2 cents per Watt for the panels.

Apple Solar Farm

Sol Voltaics is targeting Chinese and other global silicon solar makers that are struggling and producing many of their panels at a loss right now. Proving that the technology can help them out — and is worth the investment — will take quite a few key partners and demonstrations. The good thing, though, is that if one customer starts using it as a competitive advantage and it works, others will want to use it to keep up.

Some of these huge solar maker players will have to survive, and could adopt and invest in new technologies to do that. The ones that do survive, will see the continued solar panel market explode over the coming years. There was a record-breaking 3.3 gigawatts worth of solar panels — or 16 million individual solar panels — installed in the U.S. in 2012, making solar power the fastest-growing energy source domestically.

11 Responses to “Tiny wires could be a breakthrough for cheap solar panels”

  1. Maria Arrilu A. Quinto

    We are inviting you guys to come into my country,Philippines.We are badly needed alternatives on Energy.We are so tired of paying high cost of electricity for decades and there is corruption on reading our electricity consumption. There is a monopoly on Electricity business here in the Philippines the people has no voice coz there is only 1 company who is operating.If they told you you consume more kilowat than you expected we can’t do nothing, but to follow.Where we can buy? So we can’t complain.Please introduce this Technology ion the Philippines.

  2. Nervlak Mighjj

    What needs to be concidered regarding toxicsity during production of the ink materials, their storage and handling at all phases of production, application, use in the world, and end of life?

    Mike V.

  3. The role of the nanowires in the cell is, at least, unclear. Concentration of the sunlight is unnecessary for flat solar cell, and is likely to reduce overall conversion efficiency.

    The nanowire are likely to be profitable if they are able to convert high energy blue and green light into red and infrared photons, is that what they do?

    They have confirmed 13.8% efficiency – says nothing. What was the initial conversion efficiency of the cell prior to addition of nanowire ink layer?

    • (Dave Epstein, CEO, Sol Voltaics) Thanks for the comments, Rotem. The article is great, but of course there is limited space to put all of the details in.

      You are correct, that a flat panel of a planar layer needs no concentration. We, however, only cover a small portion (10-20%) of that panel with nanowires, but we still trap a majority of the whole area’s light! That infers that there is concentration taking place. That is what we refer to as WCPV – a quantum effect of wave concentration without optics or mechanical means.

      The nanowires are made of Galium Arsenide which is a high conversion efficiency material. It absorbs light over a wide spectrum and that can be converted into a current. Each wire is an independent solar cell.

      And as far as the last comment, the 13.8% efficiency was achieved with no cell below it — that is, just the GaAs nanowires themselves. When we layer this on top of a silicon cell, it becomes additive, but of course with some degradation, thus “only” a 25% increase over the original cell itself.