Invisible Adhesive Elegance: Enhancing Solar Roof Aesthetics and Performance

At the crossroads of architectural ingenuity and environmental responsibility lies Building Integrated Photovoltaics (BIPV). This concept gained widespread attention in 2016 when Tesla partnered with SolarCity to introduce more stylish solar tiles. Yet, the origins of roof-integrated solar panels can be traced to 2005 and a patent from NASA. The whole idea is to echo conventional roofing materials while offering a more refined, aesthetically pleasing alternative to the standard array of aluminum frames, rectangular mounts, and traditional Building Attached Photovoltaics (BAPV).

While roof-integrated solar panels are a relatively new innovation, Sika has been a trusted partner to the solar industry for decades. This collaboration involves everything from extensive R&D expertise in bonding sealants and automation to simplifying the application process for diverse photovoltaic (PV) products. A recent client provided a compelling testimony, emphasizing that their choice of Sika went beyond a specific adhesive; it encompassed the company’s ability to support all project phases comprehensively. From initial design to prototyping, validation, and full-scale production, Sika’s contributions extended to automation solutions, machinery selection, and achieving full certification through local subsidiaries in multiple markets.

In another compelling case, a Dutch customer wanted to manufacture glass-glass roof-integrated solar panels to meet a wide range of tough requirements. These panels had to prevent moisture ingress, minimize the risk of micro-cracks, and have non-combustible properties.

Moreover, they were engineered with a matte finish to seamlessly integrate into the roof structure while maintaining the invisibility of the mounting system.

These high-performance roof-integrated solar panels had a dual mission. Firstly, they needed to effortlessly merge into the architectural design, becoming an integral part of the aesthetics while delivering electricity performance on par with standard solar panels. Their application extended across a diverse range of newly constructed homes in central Europe.

Beyond their visual integration, they were expected to resist dirt, water, and even hailstones (up to 9 cm in size), all while enduring the long-term effects of UV light. Equally crucial, they had to offer easy removal when the need arose.

This case was especially challenging as it meant finding a delicate balance between aesthetics, optimal energy conversion, and the overall building functionality.

To meet this challenge, Sika engineers recommended Sikasil® AS-785, a high-speed, two-component industrial structural silicone adhesive and sealant with an impressive proven track record of more than 20 years. This adhesive is specially designed for rapid and automated bonding, offering exceptional longevity and adhesion properties on a variety of substrates. These include aluminum, ceramic materials, glass, metals, and plastic.

One noteworthy advantage of the two-component system lies in its curing speed. Unlike one-component systems that require a significantly longer time (many hours) for curing before the joined parts are moved to further processing steps, Sikasil® AS-785 cures in minutes. This accelerates the over- all production process and enhances efficiency, ultimately contributing to increased productivity and faster turnaround times.

Moreover, Sikasil® AS-785 consistently maintains its bonding performance across a wide temperature range, enduring conditions as low as -40°C and as high as 150 °C. It comes with a proven track record of providing outstanding durability, even in the harshest of environmental conditions.

Sikasil® AS-785 sets a benchmark for structural performance by meeting the demanding requirements for structural glazing adhesives as defined in EOTA ETAG No. 002. Furthermore, it with stands the rigorous testing and evaluation procedures mandated by IEC 61646 and IEC 61215. This commitment ensures the utmost quality, safety, and performance of roof-integrated solar panels, guaranteeing their ability to endure real-world conditions and consistently meet or exceed expected performance levels throughout their operational life.

Sika’s Technical Competence Centers work in strategic collaboration with customers to help reduce production costs, enhance product reliability, improve aesthetic appeal, and ensure fast turnaround times. Simultaneously, our dedicated Sika Technical Service teams operate in close proximity to our customers, facilitating prompt and reliable testing and support throughout the technical application development process.

To sum up, roof-integrated solar panels represent the epitome of harnessing solar energy in a stylish, unobtrusive, and architecturally appealing manner. In this context, Sika emerges as a facilitator of streamlined, effective bonding that maintains its integrity for 30 years or longer – a driving catalyst propelling advancements in the solar industry.