sun_screen is a customizable facade solution that combines sustainable energy generation, effective solar protection, and aesthetic design for urban environments. The concept originated from a city walk in Halle, where unutilized "solar gaps" were identified in the urban landscape. While current plug-in solar devices often lack architectural harmony, sun_screen solves this problem by transforming standard PV modules into dynamic, high-quality shading elements. By integrating large-format modules into a rail system, users can move the panels horizontally across the facade. This creates a functional facade element for increased privacy and a visual statement. The visual identity is defined by generative line patterns. This algorithmic approach makes it possible to translate digital data sets into rhythmic, parametric compositions that integrate seamlessly into the existing architecture. To achieve this, a special color coating is applied to the module glass. A laser partially removes this layer, creating high-contrast motifs. This coating technology has only a minimal impact on energy yield, ensuring a harvest of 90-95% compared to uncoated modules. The focus is on achieving a balance between modern abstraction and functional architectural integration. The designs deliberately avoid overly pictorial imagery and instead maintain a refined, technical aesthetic. A curated and constantly expanding catalog offers diverse pattern options to respond flexibly to various architectural contexts. Through the parametric implementation of the image files, specific variables such as line weight, frequency, and horizontal or vertical spacing can be adjusted flexibly. Adjusting the parameters shows the influence of color and line weight on the perception of the module. While the patterns appear strictly graphic and static up close, they transform into fluid, wave-like structures from a distance. The result is a consistent "visual DNA" that remains scalable and adaptable to different module sizes without losing its detailed, high-contrast quality. The horizontal rail system ensures smooth movement of the modules along the window front. The foundation is an aluminum profile mounted above the window, which supports the weight of the large-format units. While roller carriages in the upper profile handle the guidance, an additional guide track at the bottom ensures maximum stability. This secures the module against wind loads and guarantees vibration-free, fluid movement. All components are designed for long-term outdoor durability and easy technical installation. The rail system is designed for retrofitting existing buildings, making it a versatile solution for both new constructions and renovations in urban areas. The system establishes solar technology as an integral component of modern architecture. It goes beyond mere utility and offers a vision in which renewable energy becomes a conscious and aesthetic element of our daily architectural experience, promoting visible participation in the energy transition.