Solar panels are typically designed and installed to capture sunlight when placed at an optimal tilt and orientation, such as on rooftops or ground-mounted structures. While it is technically possible to install solar panels on a vertical wall, it is not a common practice. Installing solar panels on a vertical wall would not be as efficient as installing them on a tilted surface facing the sun. The vertical position would limit the panels' exposure to direct sunlight and reduce their overall energy production.

Moreover, mounting solar panels on a vertical surface presents additional challenges. The panel's angle and alignment would need to be carefully adjusted to maximize sunlight absorption, and structural considerations would need to be taken into account to ensure the panels are securely fastened to the wall. Additionally, maintaining proper ventilation for the panels could be more challenging when they are mounted vertically.

In most cases, it is more practical and efficient to install solar panels on rooftops, angled structures, or ground-mounted systems for optimal energy production.