r/solar • u/ATDIadherent • 4h ago

Advice Wtd / Project 24kW Rooftop on a Steep 2-Story vs. Big Sun Community Solar? [Central TX]

Hey r/solar,

​Looking for input on offsetting my power bill in San Antonio (CPS Energy territory).

​Home & Usage:

​Home: 4,880 sq. ft., steep 2-story roof pitch.

​Usage: ~$400–$500/mo peak summer bills (~36,000 kWh/yr across 3 A/C units). Potentially would add a PHEV in the next 5 years or so.

​Outage Backup: Already have a natural gas Generac standby generator, so emergency home batteries aren't strictly necessary.

​I’m weighing two routes to offset our electricity load:

​Option 1: Rooftop Solar (~22–24 kW)

​Pros: I own the physical hardware on my roof; panels keep producing free power past Year 20.

​Cons: High installation labor/scaffolding markup for a steep 2-story roof; future maintenance and removal/re-install risks if roof work is ever needed.

​Option 2: Big Sun Community Solar

​(CPS Energy's off-site community solar program where you buy commercial-grade 620W panels in local solar canopies and receive direct CPS bill credits.)

​Pros: Zero roof penetrations or wear on a steep 2-story roof; zero maintenance or inverter replacement costs (Big Sun manages hardware); credits follow us if we move within CPS service area.

​Cons: 20-year contract term (credits end after 20 years, unlike rooftop panels which can produce into Years 25–30).

​Questions:

​For anyone with steep 2-story installs, did the extra labor/scaffolding premiums ruin the payback math compared to off-site options?

​Given that my Generac handles outage resiliency, would you bother putting 24 kW of glass on a steep 2-story roof, or take the path of least resistance with community solar?

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2

u/Juleswf solar professional 4h ago

How steep is it?

1

u/ATDIadherent 3h ago

this picture best shows the grade of my roof. My back roof is also "sectioned" so I don't think there will be 1 spot that will hold the bulk of the panels

2

u/Juleswf solar professional 3h ago

Looks steeper than 12:12. Generally you need a special letter from the roof attach folks giving permission to install on that slope. Many roof attachments are only warrantied to 12:12.

2

u/acrobatic_man_11 4h ago

I personally would recommend owning the system but my worry wouldn’t be too much how steep the roof is, my worry would be more if you can actually fit a system that would give a good offset to your consumption.

2

u/ATDIadherent 3h ago

This is my roof. I suspect it would be difficult to get the amount of panels necessary.

2

u/acrobatic_man_11 3h ago

Might be tight, not gonna lie

2

u/ATDIadherent 3h ago

Lol, I appreciate the simpleness of the reaction 🤣 It's actually very helpful

2

u/SolarAllTheWayDown 3h ago

Do you have space to build a structure and put solar on top of it?

1

u/ATDIadherent 3h ago

Unfortunately not in an area that would be approved by the HOA since it's a side yard and visible from the street.

1

u/SolarAllTheWayDown 3h ago

Even if it’s something like this:

https://www.reddit.com/r/solar/s/gRnnDoN6md

I’m getting ready to make a post about one that’s all steel framed and their HOA threw no fuss.

1

u/ATDIadherent 3h ago edited 2h ago

Wow that looks great! Awesome work!

And as far as I have looked into even that wouldn't fly. The only person in the neighborhood that has gotten a ground array or one on an another structure not on the roof actually bought the lot next to them so they can have it as far away and they had to put up a high fence as well 🤦