If you’re mounting solar panels, everybody knows the drill, right? Point them south, angled according to latitude. It’s easy. In a video which demonstrates that [Everyday Dave] is truly out standing in his field, we hear a different story. [Dave] has a year’s worth of data in his Solar Panel Showdown that suggests there are good reasons to mount your panels vertically.

Specifically, [Dave] is using bifacial solar panels– panels that have cells on both sides. In his preferred orientation, one side faces South, while the other faces North. [Dave] is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South.

Since [Dave] is far from the equator, the N/S vertical orientation beats the pants off of East-West facing panels, especially in winter. What’s interesting is how much better the bifacial panels do compared to the “standard” tilted orientation. While peak power in the summer is much better with the tilted bifacial panels (indeed, even the tilted single-sided panels), in winter the vertical N/S panels blow them out of the water. (Especially when snow gets involved. Vertical panels don’t need sweeping!)

Even in the summer, though, there are advantages: the N/S panels may produce less power overall, but they give a trickle earlier and later in the day than the tilted orientation. Still, that extra peak power really shows, and over a six-month period from solstice-to-solstice, the vertical panels only produced 77% what the tilted bifacial panels did (while tilted single-sided panels produced 90%).

Is it worth it? That depends on your use case. If most of the power is going to A/C, you’ll need the extra in the warmer months. In that case, you want to tilt the panels. If you have a steady, predictable load, though, having even production winter/summer might be more to your liking– in that case you can join [Dave] in sticking solar panels straight up and down.

These results probably apply at latitudes similar to [Dave] who is in cloudy and snowy Ohio, which is perhaps not the ideal place for solar experimentation. If you’re not an Ohio-like distance from the equator, you might find an East-West array is the best bang for the buck. Of course if you really want to max out power from each individual cell, you can’t beat sun tracking regardless of where you are.