A solar film thin and light enough to stick to surfaces where conventional panels could never go: not just rooftops, but walls, highway barriers, curved factory roofs, even rice paddies. Sekisui Chemical has now launched SOLAFIL, Japan's first commercially produced perovskite solar cell.

What Is SOLAFIL? Japan's First Commercial Perovskite Solar Cell

On March 27, 2026, Sekisui Chemical Industries and its subsidiary Sekisui Solar Film (SSF) officially announced the commercial launch of "SOLAFIL," a film-type perovskite solar cell. This marks the first time a Japanese manufacturer has brought a perovskite solar product to market.

The product measures 1 meter wide by 1.5 meters long, achieves approximately 15% power conversion efficiency depending on installation conditions, and has a rated durability of 10 years. Because it is film-based, SOLAFIL is lightweight and flexible, making it suitable for structures like factory roofs and school gymnasiums that cannot bear the weight of conventional silicon panels. Pricing has not been disclosed.

One detail matters here: the launch runs on Sekisui's existing equipment, not the new plant. Sekisui and SSF had targeted commercialization in fiscal 2025, and the Sakai line does not come online until 2027. That means output starts at roughly 10 MW a year, and installations are limited to metal roofs for now.

The brand name "SOLAFIL" is a contraction of "Solar Film," designed to immediately convey what the product is. The "Fil" also alludes to "Fill," expressing the company's vision of filling people's lives with clean solar energy.

Perovskite vs. Silicon: Why This Technology Matters

To understand the significance of SOLAFIL, it helps to know how perovskite solar cells differ from the silicon panels that dominate the market today.

Manufacturing: Silicon solar cells require growing crystal ingots at extremely high temperatures, an energy-intensive, time-consuming process. Perovskite cells are made by coating a liquid material onto a film substrate, similar to a printing process. Sekisui uses a "roll-to-roll" (R2R) manufacturing method that enables continuous production, potentially slashing costs dramatically at scale.

Form factor: A standard residential silicon panel weighs 15–20 kg (33–44 lbs) and is rigid. Film-type perovskite cells are paper-thin, light, and bendable. This opens up entirely new installation locations: building facades, highway sound barriers, wind turbine towers, and even above rice paddies. Sekisui has conducted pilot installations at all of these locations.

Raw materials: Roughly 95% of the world's polysilicon, the key raw material for silicon panels, is produced in China. Perovskite solar cells, by contrast, rely on iodine as a primary ingredient, and Japan is the world's second-largest iodine producer. This makes perovskite technology strategically important for energy security, especially as geopolitical tensions reshape global supply chains.

The Road to Commercialization: $600 Million and a Government Bet

Perovskite's path from lab to market has been anything but smooth. Despite impressive lab results, perovskite cells were notoriously fragile in real-world conditions, degrading quickly when exposed to moisture, UV light, and even during the manufacturing process itself. Sekisui leveraged its decades of experience in encapsulant films and glass interlayer materials (used in liquid crystal displays) to tackle these durability challenges head-on.

The decisive moment came on December 25, 2024, when Japan's Ministry of Economy, Trade and Industry (METI) selected Sekisui's perovskite mass-production effort for its GX Supply Chain Development Support Program. Eligible costs total ¥314.5 billion (about $2.1 billion) at a one-half subsidy rate, which puts the subsidy itself at ¥157.25 billion (about $1.0 billion). The program runs from November 2024 to the end of February 2029 and is aimed at gigawatt-scale capacity. Large corporations are usually capped nearer one-third, so the rate is unusually generous.

Armed with this backing, Sekisui took over the buildings, power equipment and cooling systems at Sharp's former headquarters factory in Sakai, Osaka, and committed a total investment of roughly ¥90 billion (about $600 million), subsidy included, to build a 100 MW production line targeting operation in 2027. The longer-term goal is gigawatt-scale production by 2030.

Sekisui Solar Film was established in January 2025 with ¥100 million in capital. Ownership is split between Sekisui Chemical (86%) and the Development Bank of Japan (14%).

First Customers: Cities and Public Infrastructure

While 2026 production volumes will be limited, SOLAFIL's initial customers are already lined up. The first recipients include municipalities and organizations selected under a Ministry of the Environment program promoting perovskite deployment: Saitama City, Shiga Prefecture, West Nippon Expressway Company, Fukuoka Prefecture, and Fukuoka City. Tokyo Metropolitan Government's pilot program for solar installations on public buildings is also on the list.

The initial focus is on metal-roofed public facilities, including gymnasiums that serve as emergency evacuation shelters during natural disasters, a practical application that resonates deeply in earthquake-prone Japan.

The Global Perovskite Race: A Three-Way Contest

Sekisui's move takes place against a backdrop of intensifying global competition in perovskite technology.

China is moving fastest. Multiple startups, GCL Perovskite, UtmoLight, Renshine Solar, and Wonder Solar, are already shipping megawatts of perovskite panels, accounting for the majority of global commercial output. GCL is building a gigawatt-scale factory, and LONGi holds the world efficiency record for perovskite-silicon tandem cells at 34.85%.

Europe is led by Oxford PV, a University of Oxford spinoff. In 2024, the company completed the world's first commercial shipment of perovskite-silicon tandem modules to a U.S. solar farm, achieving 26.9% efficiency. Oxford PV is now licensing its patent portfolio globally, to Trinasolar for China and First Solar for the U.S., targeting mass production by 2027.

Japan also has other players in the field. Panasonic Holdings began pilot testing glass-type perovskite cells in early 2026. EneCoat Technologies, a Kyoto University spinoff backed by Toyota, aims to start mass production by 2027.

Sekisui's differentiation lies in its "film-only" approach. While most competitors focus on "tandem" designs that layer perovskite on top of silicon to boost efficiency, Sekisui is betting on standalone film-type cells that unlock markets silicon simply cannot serve, walls, curved surfaces, and lightweight structures. It is not trying to replace silicon; it is creating an entirely new category.

Japan's National Energy Strategy and Perovskite

Perovskite solar technology occupies a critical position in Japan's national energy planning. The revised Basic Energy Plan adopted in December 2024 sets a target of deploying approximately 20 gigawatts of next-generation solar cells, primarily perovskite, by 2040. This would cover roughly 10% of household electricity consumption.

The strategic importance extends beyond green energy. Japan's second-place ranking in global iodine production means perovskite offers a pathway to a domestically sourced energy technology, a rare advantage for a nation that imports nearly all of its fossil fuels. Combined with rising geopolitical tensions related to Russia's war in Ukraine and increased military activity in the Asia-Pacific region, energy security has become a driving force behind Japan's aggressive perovskite push.

Challenges That Remain

SOLAFIL's commercial launch is a milestone, but significant hurdles remain.

Durability is the biggest concern. At 10 years, SOLAFIL's lifespan is far shorter than the 25–30 years expected from conventional silicon panels. Sekisui is working toward 20-year durability, but until that is achieved, total cost of ownership comparisons will favor silicon.

Efficiency also lags behind. SOLAFIL's approximately 15% conversion rate compares unfavorably with silicon's 20–24%. However, this is partially offset by the fact that film-type cells can be installed in locations where silicon panels cannot go at all, the relevant comparison is "15% power from a wall versus 0%."

Lead content remains a concern as well. Most perovskite formulations contain small amounts of lead, raising questions about environmental impact during disposal. Developing proper recycling and waste management systems will be essential as deployment scales up.

Not Competing With Silicon, Going Where Silicon Can't

On the numbers alone, SOLAFIL beats silicon at nothing. Efficiency is 15% against 20 to 24%. Lifespan is 10 years against 25 to 30. In a head-on comparison it loses.

So it does not compete head-on. It targets the surfaces that were never even considered, because silicon's weight and rigidity ruled them out before anyone did the math: factory roofs that cannot take the load, building walls, noise barriers, curves. There is no incumbent there. Efficiency and lifespan mean plenty when the alternative is nothing at all.

New technology does not always replace the old. Sometimes it just makes the market bigger. That is the bet SOLAFIL is making.

In Japan, perovskite solar is seen as both a green energy breakthrough and a national security asset. How is next-generation solar technology viewed in your country? Does your nation have a similar strategy for energy independence? We'd love to hear about your country's approach.

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