Code compliant flat roof mounting options

[aeiro]

Hi all,

I have a flat MB roof in Long Beach, CA. In my preliminary research, the simplified solar permitting process from the city requires that panels are flush mounted with the roof. I know that's suboptimal on a flat roof but I'm struggling to understand alternative options. As far as I can tell I don't think I can DIY angled roof mounts and still remain code compliant (it requires engineering analysis and plan review), so I'm looking hiring out the design and permitting of the mounts (and I think I can DIY everything else up until I pursue grid tie). I've done some research and contacted a few local companies, but nobody, as far as I can tell, does angled mounts on flat roofs. Are there any regional or national companies that I could hire out at least the design/permitting of the roof mounts to? Is there something that I'm not thinking about?

 

[sunshine_eggo]

At this moment the ideal tilt of panels in your location is about 10°... that's pretty close to flat. Here's what a 1kW array will produce on average flat on your roof:



If you tilt them on a flat roof, you will have to stagger them so the front panels don't cast a shadow on the panels behind them. Given that panels are pretty cheap, a whole flat roof of flat panels may be only marginally more costly and perform as well or better than tilted panels that can only occupy 50% of the roof.

 

[aeiro]

Ah ok, it sounds like it's a lot of extra expense for minimal gain. I was planning on getting bifacial panels which seem to benefit from being tilted, but does that change the calculus at all?

 

[45North]

I would not install bifacials flat on a flat roof because there's no light under them.

 

[WorldwideDave]

In Manhattan beach neighbor. Also flat roof. What did you go with?