Commercial and industrial rooftops have become fertile ground for installing photovoltaic s due to their large available areas, flat surfaces and high demand for electricity in the commercial and industrial sectors.
However, applying photovoltaic products to C&I roofs is not an easy task.
Considering the various construction characteristics, as well as the need for production, property and personnel safety, photovoltaic equipment aimed at this type of application is undergoing a change in concept.
Traditional photovoltaic modules are giving way to ultralight modules, due to their harmonious integration with buildings without compromising the load ability of the building structure.
At the beginning of the solar PV market, homeowners and even installers were concerned about the energy generation and short-term economic benefits of applying solar energy products to their rooftops for the first time, coupled with the limited choice of PV solutions. available on the market. In this way, traditional modules naturally became the first purchase option.
However, the PV energy industry is constantly evolving, and rooftops installed with conventional photovoltaic systems have faced numerous problems over time.
Insufficient roof load ability, need for lighter PV solutions
Commercial and industrial roofs with single layers of metal or concrete coating offer savings in building construction costs, but have the disadvantage of not having high load .
Conventional PV systems, when applied to the roof or covering, add an extra load to the building due to the use of PV modules with wide aluminum frames and the application of metal structures to and fix the s.
After years of exposure to the sun and climatic conditions, problems such as cracks and rust in the substrate increase the load on the building structure.
Aiming to solve the problem of extra load on roofs, most manufacturers have developed flexible modules.
Although flexible products have the characteristics of being light, thin and flexible, in practice, due to the lack of stability of the flexible surface, over time, there is a high probability of deformation in the areas that are suspended between the recesses of metal tiles, resulting in microcracks in the cells and hot spots.
In a hot spot risk test carried out with a flexible photovoltaic module fixed to a galvanized steel tile, the results showed that the back of the product could reach a maximum temperature of 140°C, resulting in unwanted bulging and showing that the Hot spots are an inevitable problem for flexible products.
Carrying out the same hot spot test on light but rigid photovoltaic modules, it was possible to confirm that the 1.6mm thick thin glass surface guarantees the rigidity and stability necessary to avoid bulging and consequent hot spots.
The tests are applied following the test criteria of the IEC61215-2:2016 MQT 09 standard. Three cells with the highest leakage current and one cell with the lowest leakage current were selected, the most critical shading area was identified, and the Cells were exposed to steady-state conditions to monitor the temperature under test.
The results show that the appearance, insulation resistance and moisture resistance of the rigid lightweight samples after external testing are in compliance with the IEC 61215-2:2016 standard, contrary to what is observed in flexible samples.
According to the standard, the power degradation should be ≤ 5%, and the power degradation of light rigid samples after hot spot testing was ≤ 0,53%. No abnormalities were observed during the test for the light sample, therefore, the test was approved.
Water infiltration is also a serious and difficult problem to solve on building roofs, and waterproofing when integrating PV solutions is crucial
Leaks represent another fatal problem for commercial and industrial roofs, especially when structures for fixing PV modules are installed on concrete roofs, which can easily compromise the coverage and allow water and humidity to through.
Furthermore, the impact of cracks in the base makes identifying the leak point difficult, and maintenance costs are high as the leak problem occurs frequently.
The aging of the paint and/or surface coating of metal roofs also leads to corrosion of the steel of the tile substrate and water infiltration, while the costs for maintenance, even renovation or replacement of the metal roof are high.
For these reasons, when installing PV solutions on concrete roofs or metal roofs, the waterproofing capacity of the surface must also be taken into consideration.
Generally, the designed service life of a concrete structure is 50 years, while that of a steel structure is 25 years. However, industrial roof waterproofing generally only lasts 8 to 10 years before repair is needed.
If roof waterproofing is not considered when installing PV modules, a large number of them may require reinstallation or even be discarded due to leakage problems.
Currently, the most suitable commercial and industrial waterproofing measures include the use of polymeric waterproofing membranes such as TPO, PVC, etc. Therefore, the integration of PV energy products and waterproofing membranes has become a key point.
Extreme weather is frequent in some regions, and PV solutions need to be able to withstand hail, rain and snow
In Brazil, windstorms and hailstorms are very common, especially in the south of the country. When installing solar energy products in these areas, it is critical to consider wind and hail resistance in addition to the common issues discussed previously.
Flexible photovoltaic modules are especially unsatisfactory in this regard, as they lack a reinforcing layer and have insufficient load withstand, with a resistance of only 2400Pa on the front side.
In thicker snow conditions, this can easily cause the cells to break down, resulting in efficiency losses or complete failure.
The images below show the results of the electroluminescence test on a flexible module before and after the hail test, indicating that the cells of the flexible module were damaged by the hail impact (the black areas represent the damaged parts).
Electroluminescence before hail impact
Electroluminescence after hail impact
The ultralight rigid modules, in turn, ed load ability tests, following the TGM1220590110014 standard, with a power attenuation of just 0,4% after applying a pressure of 5400 Pa to the front side of the product.
In the hail impact resistance test, they were subjected to hail with a diameter of 25 mm, weight of 7-8g at a speed of 22m/s. The test results are shown below in before and after electroluminescence images, no damage to cells was observed.
Before hail impact
After impact
This demonstrates that rigid ultralight modules have superior impact resistance, better performance in extreme weather conditions and a longer service life than flexible products.
Traditional and flexible photovoltaic modules present inevitable limitations in the face of the various challenges of integrating photovoltaic energy into commercial and industrial rooftops.
Faced with the growing demand for photovoltaic systems on new or renovated roofs, there is an urgency for a lightweight product that meets this market demand without compromising the building structure and the impermeability of the covering or roof.
GoodWe's line of ultralight Galaxy modules was developed in response to this market demand. With a weight of just 6 kg/m2 and integration with the roof's waterproofing material, it is suitable for roofs with insufficient load bearing and need for waterproofing.
Adding a layer of 1,6mm tempered glass to the product makes it rigid and easily resistant to hail and heavy rain.
Features of the Galaxy GoodWe Line
Driven by the global goal of achieving “carbon neutrality,” energy sources around the world are undergoing an unprecedented transformation. A new energy grid, founded on power electronics and clean energy technology, is gradually emerging.
Product Definitions
The Galaxy line's ultralight products are a new type of construction material that integrates energy generation technology into the structure of roofs and buildings.
It is a product based on BIPV technology (Building Integrated PV Solutions), taking into both aesthetics and functionality, generally prioritizing construction and architectural needs first and energy generation demands second.
Structure Design
The Galaxy module is ultra-light, weighing just 6 kg/m2, being up to 65% lighter than conventional modules and significantly reducing the extra additional weight of the building structure, often avoiding the need for structural reinforcement to install the PV solution on the roof or roof.
The Galaxy line has rigid, lightweight and corrosion-resistant modules, integrated and encapsulated with TPO, a polymeric waterproofing membrane.
In addition to effectively reducing the load pressure on the roof, it also prevents potential aging and leakage problems, precisely solving the fundamental problems of high leakage rate, insufficient load and difficulties in the operation and maintenance of industrial and commercial building roofs.
Hail Resistance
In addition to the advantages of lightness, GoodWe creatively incorporated a reinforcement layer into the Galaxy to increase the product's resistance and flatness, avoiding bulging and hot spots.
The Galaxy line successfully ed the hailstorm impact test with a diameter of 25 mm, showing no hidden cracks or microcracks in the cells. Even in the event of a hail storm, it is capable of maintaining stable power generation.
Electrical Performance
The Galaxy line is designed without metal frames, thus eliminating the need for lightning protection and grounding.
The modules are adapted for RSD (Quick Shutdown) and AFCI (protection against direct current electric arcs).
The design of the electrical circuit takes into ease of maintenance, with discreet treatment of cabling, electrical components and connection devices.
Easy Installation Method
The Galaxy range offers a variety of installation methods that eliminate the need for mounting rails, making the installation process quick and simplified, resulting in significant labor and material cost savings.
Its fixation can be done through hot air welding of a TPO membrane, gluing with extreme fixation industrial glues such as PU adhesives or clamps with direct fixation on metal roofs.
The ultra-lightweight modules allow for quick installation without damaging the roof's structural layer, saving labor, materials and time.
Although the installation method is simple, after installation, Galaxy has excellent wind resistance and can withstand wind pressures of up to 5400 Pa, ensuring the safety of the roof.
The ventilation and thermal grille on the back of the product dissipates heat, ensuring efficient power generation while protecting the roof and interior of the building from overheating.
The grid is attached with structural adhesive to aid in the installation of Galaxy products, preventing wind vibration and further improving roof safety.
Integrated Solutions for Zero Carbon Production
The fundamental requirement for zero-carbon power generation is to meet the requirements for efficient capacity, safe operation and long-term performance.
Offering integrated solutions throughout the production lifecycle, the Galaxy range is suitable for a wide variety of applications such as PV systems on single-ply metal roofs and concrete coverings.
Even on roofs that do not require waterproofing and where TPO waterproofing membranes are not available, Galaxy modules can also be installed by gluing or mechanical fixing, adapting to all roof situations.
The integration of PV solutions into buildings is one of the most significant areas for future applications of this technology. These solutions must meet the specific needs of waterproofing, resistance to weather conditions and preservation of the building structure.
GoodWe aims to develop intelligent solutions so that each building can generate its own energy in a harmonious and economical way, moving towards a sustainable future!
Find out more about the Galaxy line and other BIPV solutions by visiting the website br.goodwe.com/galaxy-series and the free e-book 'All about BIPV solutions' now: https://news.goodwe.com/tudo-sobre-solucoes-bipv
The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of the author. Canal Solar.
