Without question, solar is one of the fastest-growing energy technologies in the world today. Its rapid growth, fueled by substantial investments and greater market penetration, has led to major advancements on the hardware and installation fronts. Adhesives have played a big role in the development of both; they are literally the glue that holds it all together.
Although their primary purpose is to bond the glass, aluminum, silicon and plastic components together in a single package, adhesives are valuable to solar equipment manufacturers in many other ways. They reduce stress points, leaks and corrosion; offer enhanced electrical insulating properties; and provide resistance to extreme environmental conditions.
To get a better sense of the role adhesives play in the advancement of solar technology, let’s walk through how they are addressing some of the industry’s most pressing issues: fierce competition, installation challenges, manufacturing hurdles, and the need to find the right solar partners.
A crowded playing field
Solar is a fiercely competitive industry that has been undergoing serious growth and evolution. Although technology advancements and lower costs are great for consumers, they present both challenges and opportunities for developers. The rugged competition means new technologies have to be ever-more efficient, reliable and cost-competitive to gain traction. Adding to that pressure, offerings must get to market as quickly as possible to stake a claim in the space, extend product life in the evolving landscape and maximize profit margins before competition turns an innovation into a commodity.
Solar draws on many fields for innovation, but bringing multiple components together in a finished product depends increasingly on sealants and adhesives. System developers are recognizing that the cost of solar installations doesn’t end with the purchase of panels; it also includes the price of maintenance and installation, which must be amortized over the life of the unit. To help reduce these costs, adhesive suppliers can customize a package that integrates with an installer’s procedure. This method allows the sealing process to be integrated into the overall procedure, streamlining installation and reducing labor hours, thus lowering installation costs.
Not only must module manufacturers outdo competitors within the solar industry itself, but they also must compete against the overall energy sector. For example, fossil fuels have meant solar panels have always been challenged to increase efficiency. That means the industry must work to remain cost-competitive and create new materials, which should address growing trends, such as dual-glass or back-contact modules. With that, the pressure is on adhesives to ensure modules are tough enough to withstand shipping, the rigors of installation and years of exposure.
There’s no getting around the physical challenges facing solar installations. By definition, they take place outdoors and in areas where they will face maximum heat and radiation. But weather issues don’t end there. In most habitats, the system will face rain and moisture, as well as seasonal changes in temperature. With solar modules having to withstand these extremes for decades in order to amortize their final costs, it’s even more critical for equipment manufacturers to choose an adhesive that can make projects last. Some solutions include the following:
Butyl solutions: These versatile sealants are compatible with a wide range of roofing materials and used in architectural, household and industrial markets.
Silicones: These are ideal for projects with metal-to-metal systems and with glass-to-substrate systems.
MS polymers: Silyl-modified polymers are used in roof materials like asphalt and are better suited for projects with low surface energy materials, such as asphalt shingles.
Understanding how to match the ideal sealant with the best racking system can open doors to more creative and efficient installations. This is critical because companies are constantly challenged to reduce installation times. Faster installations can support revenue growth or cost savings. Incorporating the proper sealants into the installation process will allow system owners to enjoy the benefits of solar energy sooner.
The solar sector, like other industries, has gone through a series of design changes aimed at making products better. Solar modules need to generate more power, last longer, and be less expensive to purchase and install. In addition, in a competitive environment, module makers need to create that product with the secret sauce that differentiates them from the rest. Improvements in today’s solar panels are different from those of just a few years ago. The list of changes and advancements is extensive, including the following:
• Within panels, individual cells are being connected with adhesives and encapsulated with adhesive films for protection from the elements;
• Module architecture is changing with the use of back-contact cells;
• Double glass is being used to help produce robust modules and reduce degradation due to time and exposure to the elements;
• Modules are becoming lighter through the use of thinner glass and lighter frame components;
• In some cases, frames are being eliminated entirely through innovations in glass and sealing technology;
• Manufacturing is being streamlined by replacing solder with conductive adhesives; and
• Structural adhesives are increasingly being used to simplify and speed up on-site installation of completed panels.
More changes are coming. For one, module manufacturers will continue to explore improvements that boost and extend the life of their products, requiring metals, glass and solar cells to come together in a package that safely generates electricity. For this to happen, adhesive and sealant technology must keep pace with the changes, as these materials have to hold the package together.
Second, design changes are inevitable. University labs and start-ups are creating the next generation of cells and modules at this very moment. Still, even with some exotic design changes, adhesive’s role will be to protect and hold all of the materials together.
Finding the right adhesives partner
Taking advantage of adhesive technology can help throughout the solar value chain, from component development, to module production, to installation. But it isn’t as simple as just replacing one technology with another.
First, production methods have to change. This may actually help control costs, as adhesive and sealant technologies will, in many cases, reduce labor requirements and extend product life. To evaluate the change and to implement it, companies need expertise, as well as the material.
Second, there are many adhesive and sealant technologies to choose from and many variations within each. Partnering with an experienced provider will help identify and fine-tune the right “tool” for each aspect of the design and production process. With potentially dozens of options for any single application, choosing the best option means balancing compatibility with materials to be joined, all aspects of processing, the cost to find each application’s ideal material, and more. The following are a number of top considerations for determining partners and materials:
• In choosing partners, look for providers with a broad range of offerings. This will help ensure “technology agnostic” advice based on your needs rather than on the provider’s possibly limited capabilities.
• Consider all aspects of any recommended solution, from material cost to process changes. Look at issues such as shelf life, storage and mixing requirements.
• Consider the material’s field-proven capabilities. New can be good, but companies need a tested solution that lasts. After all, it must work for a 25-year product lifecycle.
• Check the provider’s experience. The best material is only as good as the provider’s ability to match your needs and support the necessary processes before, during and after implementation.
• Finally, having reliable delivery and support is a must. Material in a warehouse half a world away is useless, and a production line that is shut down waiting for support produces no revenue.
A bright future
Solar’s rapid development has disrupted the entire energy market. Although there are many challenges, there are also plenty of opportunities for growth. Companies looking to capitalize on the latter must think about solar holistically, including the role of adhesives. By being strategic and deliberate about the use of adhesives, businesses can differentiate themselves in a crowded playing field, ensure long-lasting modules and improve their bottom lines.
David McDougall is the senior business development manager for the photovoltaics group of H.B. Fuller, which provides adhesives, sealants and specialty chemicals for various industries.