Sunflare’s Lightweight Solar Lets Solar Go Where It Couldn’t Go Before #SPI2018
October 21st, 2018 by Kyle Field
One of the most exciting companies we found at the 2018 Solar Power International show in Anaheim this year was Sunflare and its line of flexible CIGS solar panels.
CleanTechnica sat down with Sunflare’s Chief Marketing Officer, Elizabeth Sanderson, and its Vice President of Commercial Business Development, Joshua Held, to chat about their world debut at SPI. “This is our launch to the world, at this show,” Joshua said.
Sunflare may have made its world debut at SPI this year, but is is by no means new to solar. The company has been working on the design of its cells and products for 9 years now and only started actually producing the cells at meaningful volumes last year.
The panels start with Sunflare’s CIGS (copper indium gallium selenide) solar cells, created with a proprietary technology that actually prints the cells onto a stainless steel backing. The sheet of stainless that they’re printed on is durable and flexible, and opens up new options for how and where solar panels can be turned into products.
Sunflare’s team took their new solar cells and turned them into standard 6 by 10 panels of flexible solar modules, which has been appropriately named the Flex 60. They come out just about the same size as a traditional solar module and on the surface, you probably wouldn’t be able to tell the difference. But Sunflare’s panels are different and transformational because they are much lighter than traditional solar panels and because they are flexible.
New And Improved CIGS
CIGS solar cells have historically been inefficient and costly, which have made them uncompetitive with traditional silicon solar. Joshua Held shared that Sunflare has developed a unique cell-to-cell manufacturing process that provides a number of advantages of the more traditional roll-to-roll manufacturing process for CIGS cells.
Elizabeth shared that the company’s proprietary process lets it optimize the output of each cell in a panel. “We have a bypass diode per cell, so shading is not an issue,” she said. This optimizes the output for each cell versus normal panels that lose panel efficiency when any part of it is shaded. Adding a diode for each cell does add cost vs a more traditional wiring scheme and is one of the factors the Sunflare team is weighing
The downside of CIGS is the efficiency. Silicon solar cells and modules have had decades of work for companies around the world to optimize cell design, efficiency, cost and ultimately, overall output. “We need to continue doing exactly what silicon has been doing for years,” Josh said. Because of its lower efficiency, “the biggest constraint is energy density per square foot,” he said.
Sunflare is currently at 14-16% efficiency at the cell and 11% efficient at the module level. With traditional panels up around 20% efficiency, depending on the manufacturer, there is clearly some work to do. Having said that, the Kyocera panels REC Solar put on the roof of our home back in 2011 were 15.6% efficiency, so even silicon cells have made progress just over the last few years. Check out the comparison of their CIGS-based modules and traditional silicon modules here (PDF).
Even with the lower efficiencies, Sunflare’s system costs are competitive as the installation is a much more straightforward process and requires no racking. This also lowers the carbon footprint of the systems, making Sunflare’s systems some of the more climate friendly panels out there. They expect that to continue to improve as they scale up operations over the next few years. The full specs for Sunflare’s modules can be found on their product data sheet. (PDF)
Like most traditional solar modules, Sunflare’s panels sport a 25-year warranty with a production guarantee of 90% of stated capacity for the first 10 years and at least 80% of the nameplate output for years 11-25. These claims and warranties are based on accelerated life testing that mandates solar products endure at least 1,000 hours for UL certification. Sunflare lasted 6,000 hours, which provides confidence in the product.
Sunflare’s modules are made with a 3M top sheet, giving name brand credibility to the only thing standing behind the cells and the sun. Backing them up, the cells are actually printed directly onto high quality stainless steel which is sealed in with a composite Polytetrafluoroethylene (PTFE) back sheet.
Sunflare Goes Where Traditional Solar Couldn’t Go Before
The lightweight design means installers can put these 5 kilogram | 11 pound modules in places where the traditional ~19 kilogram | ~40 pound solar modules were not able to be installed. Taking that to the market, Sunflare has focused its efforts on lightweight shade structures and membrane commercial roofing systems.
Lightweight shade structures are the structures like carports and patio covers that were built to provide shade or protection from the elements, but lack the physical integrity needed to be used for a traditional solar system. Because Sunflare’s modules are nearly 30 pounds lighter than traditional panels, they are ideal for these types of installations and truly open up many existing structures to solar installations.
Membrane commercial roofing systems similarly lack the structural integrity required to support larger solar installations, but that’s not a problem for Sunflare. The company currently uses a butyl adhesive to hold the panels to the roof, but are focused on developing a mechanical system to secure their panels to a roof.
Having said that, even with the current technology, Sunflare’s panels do not require roof penetrations to be installed, which is sure to bring peace of mind to all those facility managers out there dreading the prospect of extra weight on their roof with a serving of new holes on the side.
Development of the mechanical system is still very much in development, but theoretically will allow the modules to be strung over rooftops very quickly, with very little incremental effort required. It also has the potential to open up exciting new installation applications like stringing them over difficult terrain, rooftops, rapid deployment setups for emergency relief, and shading.
Solar Roof Tiles
Looking to the future, Sunflare has already identified solar roof tiles as a lucrative application for lightweight, durable solar products. These aren’t going to be laminated between two sheets of glass, but rather, developed much like Sunflare’s larger panels that bring their flexibility, durability and lightweight form factor to the building integrated photovoltaic (BIPV) party.
The current design has the panels snapping together with two connectors that almost look like the snap buttons commonly found on clothing. Sunflare’s snaps also provide a means for current to flow. To secure them to the roof, roofers can use normal composite roofing nails that won’t interrupt the flow of power. Rounding out the installation, a strip of adhesive tacks the bottom of the roof tile to the tile or surface below it.
Each tile will generate about 2 watts each and they are linked together in strings that run across the roof. In total, they expect to be able to put a 4kW system on the roof of an average single family home. For reference, we had a 4.4kW system comprised of 17 panels on the roof of our house and it took up about half of the roof. On the other hand, our installation was beastly heavy and required numerous holes into our roof to install, not to mention the extra weight on the roof.
Sunflare’s solar roof tiles are still 18-24 months from moving into production, but the prototypes the company had at Solar Power International this year looked extremely promising. The team shared that they are still working to finalize the design, to ensure the tiles are as easy to install as possible.
Sunflare’s R&D and proprietary printing process comes from Sweden, but the manufacturing is based in Nanjing, China. The company currently has 8 MW of production capacity online and is working to establish a further 40 MW of production capacity by the end of next year.
The team has big plans for the technology, the only question is whether or not they can continue to improve the efficiencies, cost, and scale of the production process to support larger volumes. To grow beyond the early markets it has identified, Sunflare is going to have to put in some serious work.
On top of the technological challenges, Sunflare has hit the headwinds shared by the majority of the solar industry in the form of Trump’s Tariffs. These went into effect at the end of August and are having a very real impact on not just the higher price of the modules themselves, but also on the company’s bottom line. While Sunflare did take pricing to offset some of the hurt, the margins are also cutting into its margins.
It is absurd to think how much time and energy in the solar industry alone are being dedicated to finding solutions to the self-made problem that tariffs represent. Looking a few years ahead, the instability and uncertainty that the current administration have introduced to the solar industry and beyond makes the problem that much more difficult to solve, if that’s even a thing.