Comment by rcxdude
8 hours ago
I get the impression they are getting less viable because the extra cost and maintenance outweighs just putting more panels down. There are some calculations that suggest even mounting them on angled frames might not be worth the cost, depending on how dirty they get when you just lie them flat on the ground.
(This assumes that you have enough space, but for grid-scale solar this is not the limiting factor. The costs are roughly in order from most to least: the cost of the inverters and grid connection, the cost of installing the panels, the cost of the panels themselves, then the cost of the land to put them on)
I can speak to this somewhat. My panels are on adjustable frames. Typically I switch from flat (summer) to tilted (winter).
As always ymmv and depends somewhat on your location. I'm around 30 degrees from the equator.
During summer, lying flat gets a lot more power. And more importantly the start and end of the generating period is longer. Ie the panels get more sun in the morning and evening thankfully they were tilted.
In winter the sun is more "from one direction" and obviously is lower on the horizon.