There are several benefits to mounting solar panels horizontally instead of vertically. First, fewer rails are required to mount a solar panel horizontally, making it easier and cheaper to install. Additionally, horizontal solar panels can self-clean more effectively than vertical panels, as they are exposed to more sunlight throughout. Yes, there are some disadvantages to mounting solar panels horizontally. One disadvantage is that they can get dirtier over time, and dirt can. When mounting solar panels horizontally, it is important to consider a few factors in order to ensure the best possible results. First, fewer rails will be required for horizontal mounting, which can save on installation costs. Second,. There are a few things to consider when deciding whether or not to mount your solar panels horizontally. The first is the amount of sun exposure your panels will get. If you live in an area. Yes, there are a few things to keep in mind when mounting solar panels horizontally. First and foremost, solar panels installed horizontally will not produce as much energy as if they were.