SolFilm is a “lightweight photonic film consisting of high-efficiency, gallium arsenide PV nanowires that converts high energy sunlight directly into power and is transparent for infra-red light.  The infra-red light can be converted into power…enabling a far greater power conversion efficiency than found in current leading-edge conventional modules.  Solvoltaics.com photo.

SolFilm can be easily adopted by solar panel manufacturers

Republished from the full article that first appeared in Solar Tribune, a solar news, education, and advocacy website where Matt Chester contributes as a featured writer. 

Solar power is arguably the most visible clean and renewable energy technology, thanks to the increasingly prominent solar installation projects on rooftops, as well as the simplicity in idea of harvesting energy from solar rays constantly striking the Earth.

Despite these advantages, actual solar generation remains behind most other energy sources– including the renewable technologies of hydropower, wind, and biomass.

Despite widespread desire to buck that trend and allow solar energy to blossom, many constraints still surround solar power, whether they be political, economic, or institutional.

A non-controversial way to make progress outside of these roadblocks is to advance the technology. While such technological progress often takes immense investment and resources, they face few opponents once they emerge from R&D and can be embraced across the world without much debate.

Sol Voltaics, a Sweden-based company, is demonstrating that universal truth, particularly with their nanotechnology called SolFilm. This company is driven to use their innovations to advance the efficiency of solar panels across the world, both newly produced panels as well as those already installed.

By adding their lightweight nanowire SolFilm technology, Sol Voltaics boasts that this cost-effective and easy-to-install material can improve panel efficiency by a mind-blowing 50 per cent (safe to say that would represent the largest ever single jump in the efficiency of mainstream solar power).

sol voltaics solfilm solar power panel technology innovation
Source: Sol Voltaics

What exactly is SolFilm? According to the company, it is a “lightweight photonic film consisting of high-efficiency, gallium arsenide PV nanowires [that] converts high energy sunlight directly into power and is transparent for infra-red light. The infra-red light can be converted into power…enabling a far greater power conversion efficiency than found in current leading-edge conventional modules.”

That’s quite a mouthful, and the more technical among us can read more from their recently published scientific paper, but essentially SolFilm enables existing solar panels to produce significantly more energy from the same amount of sunlight.

Best of all, Sol Voltaics will ensure solar panel manufacturers can integrate their product without much additional cost or effort– SolFilm can be used alone as a replacement for thin film/silicon cells in the manufacture of solar panels, or even better they can be stacked on top of the conventional PV module (during the latter stages of manufacturing) to create an even more high-efficiency product.

I recently had an opportunity to ask a few questions to Erik Smith, CEO of Sol Voltaics, about this technology that will inevitably be a true disruptor of the solar power industry.

Sol Voltaics

Matt Chester: Erik, I wanted to first thank you for making yourself available to answer my questions about Sol Voltaics, the exciting SolFilm development, and the solar market in general. I’ve read a decent amount about SolFilm on your website, in Forbes, and other publications, and the future appears bright. But before getting into the future, I wanted to get a sense of the past. Can you provide a quick overview about how Sol Voltaics got here?

Erik Smith: Sol Voltaics was founded in 2011. Our roots are firmly embedded in Lund, Sweden, and Lund University. The University’s NanoLund organization is one of the international pioneers of nanoscience and nanotechnology.

World-renowned nanotechnologist Lars Samuelson is a scientific founder of the company and the vice director of NanoLund. Sol Voltaics’ intellectual property is based on a combination of Professor Samuelson’s 25 years of Silicon (Si) and III-V nanowire research and Sol Voltaics-generated IP.

I have spent over 20 years in technology development and leadership in solar, semiconductor equipment, and materials and global contract manufacturing. Our wider team is a nexus of science and industry.

It is important that the managers understand not only their scientific fields, but also the requirements of being in a company with the ultimate objective of providing a product. The company consists of 55 people representing 15 different nationalities.

The impetus for the founding of Sol Voltaics was the invention of Aerotaxy by Dr. Samuelson. Aerotaxy is a continuous flow manufacturing process that enables Sol Voltaics to produce gallium arsenide (GaAs) solar cell nanowires at a very low cost.

The ability to bring GaAs, the best solar material in the world, to market at a low cost was the idea that attracted the investors. Since being founded, Sol Voltaics has raised $64 million of total investment, with 20 per cent coming from non-dilutive sources.

Chester: Continuing with that thread, how does SolFilm factor into the whole story of Sol Voltaics? Was the SolFilm technology the reason behind Sol Voltaics being formed, or is it one in a line of multiple products? Are there other innovations into which you’re looking to branch out? 

Smith: Sol Voltaics was formed to realize the vast solar energy potential of GaAs through nanotechnology. GaAs has tremendous solar energy-generating properties and holds the single-junction conversion efficiency record. It is also an extremely robust and reliable material. It has been used for many years in concentrated solar PV systems and in space applications.

However, until now, the high cost of GaAs has prevented it from being manufactured into a scalable, economically acceptable product for the mass solar power market. Through our patented Aerotaxy process and the nanophotonic effects of the nanowires, we are able to produce a highly-efficient, low-cost GaAs PV cell called SolFilm.

SolFilm will be the first commercial product produced by Sol Voltaics. But given the ability of Aerotaxy to produce numerous kinds of sophisticated nanowires and our ability to align and organize these nanowires, we see vast potential to apply these two core technologies to other applications.

sol voltaics solfilm aerotaxy gaas solar power PV technology innovation
Source: Sol Voltaics

Chester: What are the biggest hurdles facing Sol Voltaics today? Do they come from the technology side, the economics or market side, any sort of political obstacles, or something else?

Smith: As with many start-ups, obtaining funding is always an obstacle to bring product to market. However, we’re in a good position because we have demonstrated all the key technological aspects of SolFilm.

The next round of funding will be used for process optimization to produce prototype samples. This is the final stage before we can commercially manufacture SolFilm.

The SolFilm Technology

Chester: I found that your marketing materials give a great ‘elevator pitch’ summary of the SolFilm technology. Generally, do you find people get on board and understand what you’re trying to do quickly, or do they get a bit lost in the weeds of understanding the tech?

Smith: For those within the solar market, particularly cell and module manufacturers, they understand our value proposition and the benefits of SolFilm very quickly. The solar industry has an urgent need to innovate and bring to market technologies that can enable greater module efficiencies.

The industry has seen only incremental increases in efficiencies over the past 10 years. SolFilm’s great success has been the ability to reduce costs to the point where, in many regions, it is competitive with traditional energy sources.

To ensure the world complies with COP21 targets, innovation is paramount at acceptable costs. SolFilm represents a technology that will help meet those targets and catapult mainstream solar module efficiencies towards 30 per cent.

Chester: A few companies have come in recent years promising thin film technology that could provide a breakthrough in the solar space, but little progress has been made and investors were resistant to bet on the technology. What makes SolFilm different? How will the story play out this time?

Smith: One key difference for Sol Voltaics is our patented Aerotaxy process. Aerotaxy provides a low-cost path to bringing the well-accepted, sought-after GaAs material to the marketplace. Aerotaxy generates GaAs PV nanowires within seconds, at yields comparable with semiconductor industry standards, and can produce them on a continuous basis.

A second key to our low cost is the nanophotonic properties of nanowires. Acting like waveguides, one only needs to cover the module with 20 per cent nanowires. This is the optimum light gathering density.

These two critical aspects of SolFilm enable us to bring efficiencies in the upper 20 per cent range at a comparable cost per Watt peak (Wp) to standard low-cost silicon modules.

Finally, it is important to note that many of the locations where solar is and will continue to be deployed are in high temperature regions. The temperature coefficient of GaAs as a material is significantly better than silicon.

In a region like the Middle East, this can translate to 15-20 per cent more power output with the same efficiency module because GaAs degrades significantly less than silicon in high heat.

Another important point of difference is our association and continued collaboration with the University of Lund and NanoLund. The depth of nanowire understanding at NanoLund in conjunction with its ability to supply a flow of excellent scientists to Sol Voltaics makes it a very valuable partner.

Nanolund, sweden university solar power solfilm sol voltaics PV
Source: Nanolund

Chester: A main application for SolFilms is to integrate directly into existing PV module lines. Have you had any pushback from the PV cell manufacturers about your product and its integration strategy?

Smith: We have numerous letters of intent from the PV industry to integrate our SolFilm into modules. The integration is an extremely simple process that requires virtually no alternation of the manufacturing process. To execute these LOIs, our job is to produce full-size samples.

Chester: Because the technology applies right to the cell, it seems like SolFilm is equally applicable to utility-scale solar, residential rooftop solar, and any other solar installation. This is obviously valuable for your market to be so wide, but are there any specific applications where SolFilm is especially suitable and the gains are even more impressive?

Smith: We see vast potential for SolFilm in utility-, commercial-, and residential-scale solar. We believe residential and commercial solar are particularly well-suited for SolFilm because of the significantly increased power the cells can generate per square meter of rooftop, thus reducing the overall cost per watt of the system. Its excellent all-black aesthetic and heat resiliency are also key benefits.

Market Appetite for SolFilm

Chester: The technology seems like a game changer, but better tech can’t do much unless it’s successfully implemented in the market. With that in mind, what’s the current market of SolFilm? Is the technology still in the development phase or are there any modules in commercial operation today?

Smith: Our technology is still in the optimization phase, so there are no commercial projects featuring SolFilm. We have LOIs and NDAs with all the major solar module manufacturers, all of whom are interested in adopting SolFilm. We are working toward shipping samples to our partners by the end of 2019.

Chester: The solar industry is notorious for being slow to change and adopt new technology. What sort of feedback have you gotten from the solar community– skepticism and doubt or excitement at the potential to disrupt the market?

Smith: Given the urgent need for innovation at the cell and module level, the vast majority of module manufacturers are interested in and excited about the prospect of SolFilm.

The solar industry has been aware of the properties and potential of GaAs in PV for many years since it has been successfully deployed on concentrator PV projects and in outer space. We are on the path to becoming the first company manufacturing mainstream GaAs solar technology at low cost, which has generated significant anticipation of SolFilm in the industry.

The boost that a GaAs material in tandem conjunction with Si/CIGS is also well known. The record is 33 per cent efficiency in this combination. It is our job to demonstrate the product.

We have shown that the process of SolFilm works, and we have demonstrated with a world-record nanowire cell that nanowires can make good solar cells. We now need the funds to optimize and scale the form factor. It’s more a matter of when it will happen than if it will happen.

solar power panel residential solfilm sol voltaics comparison
Source: Sol Voltaics

Chester: I’ve seen you talk about how strong the solar market, both commercial and residential, is and how that shows the high, high ceiling of Sol Voltaics’ market potential. Are you seeing a future where SolFilm is in most of the world’s solar panels? What sort of rollout strategy would get you to that point?

Smith: There are a number of rollout strategies we can take. The good news is that the terrestrial solar panel market is already $40 billion a year. So, there is plenty of room for growth!

For more information on Sol Voltaics’ continued developments, visit their website for regular updates and follow them on LinkedIn.

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To see other posts about the world of solar energy, see this article on a company who sent solar equipment and expertise to Puerto Rico in the wake of Hurricane Maria, this interview with the Director of Solar Head of State, and this article profiling the California wineries most utilizing solar power

About the author: Matt Chester is an energy analyst in Washington DC, studied engineering and science & technology policy at the University of Virginia, and operates this blog and website to share news, insights, and advice in the fields of energy policy, energy technology, and more. For more quick hits in addition to posts on this blog, follow him on Twitter @ChesterEnergy.