The new Mono S4 Halfcut BC Full Black module from Solar-Fabrik uses back-contact technology and double-glass construction for increased durability and efficiency.

September 23, 2025, Frankfurt, Germany The Mono S4 Halfcut BC Full Black, the first back-contact (BC) solar module from German solar manufacturer Solar-Fabrik, is intended for use in both residential and commercial & industrial (C&I) settings. With the growing demand for high-end solar solutions worldwide, the company’s strategic entry into the high-efficiency segment of the photovoltaic market is reflected in the new product.

The 480 W panel uses leading-edge back-contact technology that moves all the electrical contacts to the back of the cell, which results in a cleaner front surface and demonstrates a highest efficiency of 23.52%. This competitively positions the Solar-Fabrik offering within the premium solar module market; a market that is rapidly shifting to N-type technology and back-contact designs.

Technical Specifications and Design Features

The Mono S4 Halfcut BC Full Black module is designed with 108 half-cells based on n-type monocrystalline silicon wafers, has dimensions measuring 1,800 × 1,134 mm, and an approximate weight of 25 kg. The module has a 30 mm black anodized aluminum frame to create a sleek look that is valuable for residential installations where aesthetics are more frequently appreciated.

Another aspect of the design is that the product is constructed double-glass with 2 mm glass on each side, which makes the module more durable and resistant to micro-cracks. This construction approach is seen as a market trend amongst manufacturers, alongside the trend for longer-lasting solar products, as manufacturers also start offering extended warranties to show industry confidence in durability.

The module is equipped with Stäubli’s MC4 EVO 2 connectors and a system voltage of up to 1,500 V, fitting various system configurations. The electric characteristics of the module are an MPPT voltage of 33.4 V, MPPT current of 14.2 A, open-circuit voltage of 40.4 V, and a short-circuit current of 14.9 A.

The abilities of the panel and its performance is exceptional, with an operating temperature range of -40 °C to +85 °C and a temperature coefficient of -0.260%/°C. These details ensure that the panel operates to its performance levels regardless of the weather conditions experienced, which is a huge factor for residential customers and commercial installations/systems, as the financial back-end return can be affected by the reliability of the panel.

Enhanced Performance and Durability Features

Solar-Fabrik has developed what it calls an “anti-shading design”, with flexible current paths that ensure that when partially shaded, the entire cell strings do not turn off. This is a common issue in urban residential/commercial situations where shading affects the total performance of the system.

The other important characteristic of the module is that it has structural integrity with hail ratings of category 4 and a snow load of 5400 Pa. For durability characteristics this is particularly important in European markets, with increased extreme weather events associated with climate change.

The company backs its latest product with a 30-year product warranty and a 30-year linear performance warranty that guarantees 88.5% of rated output at the end of warranty term. This warranty package outperforms most industry 25-year warranties and is comparable to top manufacturers like Canadian Solar and Jinko Solar who offer 25-30 years of coverage.

Industry Context and BC Technology Growth

Solar-Fabrik’s entry into the back-contact module sector is coming about as large manufacturers are increasingly moving away from traditional PERC technology and beginning to utilize more advanced architectures. The solar industry has generally transitioned from polycrystalline to monocrystalline technology. N-type cell designs (with back contact) are now employed for the premium segment.

The back-contact approach is one of several methods being pursued in order to achieve higher efficiency. Recently there have been developments in this segment. For example, Longi has recently released HIBC (Hybrid Interdigitated Back-Contact) technology, which is capable of attaining component efficiencies approaching 26%. Additionally, Taiwanese manufacturer WINAICO recently entered the back contact module marketplace with their modules also achieving 23.5% efficiency.

More recently in this competitive space, a major development took place when leading manufacturers JinkoSolar and Longi settled their global patent dispute with a cross-licensing agreement, which may facilitate wider adoption of advanced cell technologies across the solar industry as a result of a resolution to their legal issues.

Market Positioning and Target Applications

Solar-Fabrik’s strategic choice to pursue both residential and commercial & industrial segmentation through a single product is symptomatic of the changing nature of solar market segmentation. While it used to be the case that manufacturers typically created two distinct products around residential and C&I segments, current practice is increasingly creating versatile products distinguishable by their applications.

In the case of residential applications, the full-black appearance and high efficiency of a back-contact solar module satisfy important considerations of a possible home buyer. The back-contact solar module has the back electrodes located on the back side of the cell thus providing an attractive design to satisfy homeowner’s concerns related to the integration of solar into their existing architecture.

In the case of commercial & industrial applications, the high power output and durable characteristics of a back-contact solar module make it an attractive option for large installation C&I projects considering reliability and levelized cost of electricity metrics. Additionally, the back-contact design offers shading tolerance specifically valuable in commercial applications where multiple sources of shading may exist.

Broader Industry Trends

The introduction of Solar-Fabrik’s back-contact module is part of a number of general trends across the solar industry. The decision by major manufacturers to stop manufacturing and selling any polycrystalline technology starting in 2023-2024 has established monocrystalline technology as the new baseline, and efficiency standards are now between 21-22% for standard products.

Leading the efficiency race are companies like Aiko Solar, whose Neostar 2P panel has an efficiency of 24.3%, and Jinko Solar, at 23.8% efficiency. Solar-Fabrik’s 23.52% efficiency does not currently out-perform that of its competitors, but it certainly places the company as a premium member in the sector.

As with other discussions in the industry, companies are making a transition to N-type cell technology (i.e. HJT, TOPcon, and back-contact versions), and the advancements in this technology are yielding substantial gains ranging from 19-24.3% efficiency versus 17.5-21% from previous P-type legacy cells. The advancement in cell technologies has yielded better efficiency, improvements in degradation, and superior temperature coefficients.

European Solar Manufacturing Context

The Solar-Fabrik product launch occurs in an increasingly competitive landscape for European manufacturers against their Asian peers. Solar-Fabrik manufacturers in Germany which may afford them some potential benefit to customers wishing to prefer “Made in Europe” in particular, taking into account some changes in concentration of supply chains and demands for sustainability.

The European solar market has seen significant growth in recent years from energy security, to climate targets, to cost effectiveness for solar generation. As a result of this growth, manufacturers have an opportunity to create differentiation of the product in the market through technology, quality, or local manufacture.

Back contact solar technology has begun to gain traction in European markets, illustrated through Longi’s launching of their HIBC-based EcoLife series of solar products in Europe first, in the high-end residential specific market. Solar-Fabrik is now timing their launch with the increased interest in premium solar manufacturers and products throughout European markets.

Future Outlook

Solar-Fabrik’s expansion into the back contact module market is indicative of broader strategy among solar manufacturers to continue diversifying their product offerings, as they attempt to develop differentiation in a competitive global marketplace. The company’s dual focus on both residential and commercial and industrial (C&i) applications with a single product suggests production efficiency and flexibility in the market were key strategic philosophies.

The continued rapid evolution of technology in the solar industry remains in momentum, with manufacturers pursuing different pathways to higher efficiency and reliability. Back-contact technology represents one of a number of competing technologies—there are also TOPcon and HJT architectures, each with some advantages and challenges.

As the solar market continues to grow in the coming years, being able to differentiate products by technology or warranty terms and durability of features is likely to become increasingly important. The comprehensive warranty package of Solar-Fabrik new back-contact module, located 30-years, indicate an emerging emphasis in the industry to provide longer term value to customers.

The company has not yet provided specific details regarding production volumes or expansion for the new product line. Relation to Solar-Fabrik’s technology roadmap and future product development priorities will most likely depend on market response, in terms of sales and product performance, to the Mono S4 Halfcut BC Full Black module within the competitive context of solar manufacturing as an industry.