Changing panel pitch on roof

[texasranger556]

Last month I finished installing my 13.3 kW roof mount system. I might post about it in the show and tell when I get some time. I originally designed the system around a pair of EG4 6500 inverters, but after installing everything had an issue with them that led to returning them for warranty/credit and switched to a Sol-Ark 15k. The Sol-Ark has been working great. Last few weeks the system has been producing 50-55 kWh per day, sometimes 10-20 if cloudy/raining. 50 kWh mostly covers our summer time usage per day, depending mostly on how many loads of laundry. Our usage in winter is 50-100% higher and obviously PV production will be half what it is now, at best.

Now I have a fair bit of credit at Signature Solar and more MPPT capacity than I planned on, so I am planning to buy some more panels.

I used Iron Ridge Flash Vue and XR100 rails which I am very happy with. However, the remaining southern facing roof I have is over a screened in porch and a shallower pitch. Eventually I plan to re-build the porch with a gable roof and enclose it, but that project is several years away. Until then, looking at options to install some panels.

The existing 30 panels are on 6:12 pitch roof. The porch roof is around 2:12 pitch. I'm looking at options to raise panels on the porch roof to 6:12 pitch to match the rest. I have space for 6 portrait panels across the top of the porch roof, close to the vinyl siding. I started looking around but most products I find are aimed at "flat" roof installs, which isn't quite what I have. Anyone done something like this? How did you do it? Anything to look out for?

Thanks!
Ryan

 

[SamDeleted]

I'm not sure it's to code.... ? ... and I maybe couldve done with 2x6 beams rather than 2x4


The roof is east northeast facing , the panels are now west southwest

 

[zanydroid]

There are risers in some racking systems but in my town and likely others you lose exemption from needing engineering stamps for a permitted installation of the panels are not parallel to the roof. IOW if parallel you don’t need a stamp, if raised to different angle, have fun finding an engineer

I am watching this thread to see if IronRidge et al would be willing to provide stamped plans for these pitch changes, and how much it costs.

 

[Oldtimmer69]

I have 54 panels at 30° and 16 panels laying flat.. Theres not enough difference to mater IMO. I only make a few less watts on this string than i do on any of the rest.

 

[texasranger556]

I have 54 panels at 30° and 16 panels laying flat.. Theres not enough difference to mater IMO. I only make a few less watts on this string than i do on any of the rest.

I looked at the difference in PVwatts for 6:12 versus 2:12 for a 2.7 kW string of 6 panels. In the worst month, December, the prediction is 142 kWh for 2:12 and 185 kWh for 6:12 pitch. 30% difference for that string in December/January when we use the most electricity. In the context of the entire system, that equates to a 4% difference for December/January. 1% difference over the entire year. So I guess it depends how you look at it whether it's worth the effort.

Still interested in ideas

 

[zanydroid]

Since I am risk averse both for personal and financial exposure management reasons, everything that deviates from the happy path of structural goodness has so far landed deep in the “not worth it” column. Vertical panels and changing angle on roof for one or two panels are the things I looked at and bailed on after some research.

 

[texasranger556]

After considering my options, I re-measured and decided I can fit two rows of panels so while it will cost a bit more extra panels, rails, and Tigo modules, it will remain a standard install and perform better than any orientation I could have put 6 panels in. There might be some shading on the bottom row but I just bought a new bar for my chainsaw...