[geoffmunn]

People (usually installers) also get hung up on having the correct angle for stationary panels. In winter the solar gain difference on 'correctly' angled panels vs just having them flat on the roof is basically zero, and in summer you should have excess solar gain anyway so again it doesn't matter.

And even if you're losing a small amount due to an inefficient angle, just get more panels!

[Retric]

On a roof it's not worth it, you can even install panels facing the wrong way and get useful power out of em compared to retail electricity rates.

However, at grid scale a few percent difference in cost or output can have dramatic impact on profitability so there's a lot of seemingly trivial optimizations going on. Some instills go so far as to aim some non tracking panels slightly to the east or west because slightly more valuable kwh beats slightly more kwh.

[llm_trw]

At grid scale it doesn't matter either because most installation are saturated anyway. The periods where they care about are the ramp up to noon and the ramp down till sunset, if you can keep the installation producing at it's stated capacity for as long as possible you make a killing, middle of the day power often costs nothing or has a negative price.

People think renewables are efficient in some way. They aren't. It's literally the most wasteful way to produce power because it doesn't get here when we need it and grid scale storage is orders of magnitude more expensive than production.

[fragmede]

Vertical seems to be gaining some traction.

https://undecidedmf.com/have-we-been-doing-solar-wrong-all-a...

[stephen_g]

You'll still get more output for the same amount of panels when they're tilted in most places.

This guy did some interesting real-world testing in a bunch of different circumstances - https://www.youtube.com/watch?v=5AVO1IyfA9M

[happytiger]

Works really well in snow.

[hagbard_c]

The "correct" tilt in the more northern and southern regions as well in higher places is "enough so the snow slides off the panels". I built a barn with a roof at the "correct" 36° angle specifically so that the panels - 36x400W - both produce the maximum amount during the summer months as well as shed snow without the need for manual intervention.

[gonesilent]

So that's about a 8/12 roof pitch ish.

[potatochup]

Do flat panels need regular cleaning though? I'm in a rainy location and was told to always have at least some tilt so that you don't have to clean them as frequently

[londons_explore]

My flat panels lose about half their electrical output if I don't clean them for a year.

They end up covered in moss and mud.

[sunshinesnacks]

You are correct. It’s especially true with a raised frame on the edge of the panels.

[myself248]

Having them flat on the wall is even better. You lose production in the summer when you'd usually have excess power anyway, and you gain snow-shedding in the winter, which can be tremendously important.

[jvanderbot]

The exterior of the house you mean?

[sidewndr46]

How would you have "excess gain" ?

[geoffmunn]

If you are generating more power than your batteries can store, or you can use, then this is excess gain.

If you're selling it back to the power company then this might not be a problem unless you also have resell limits.