I've designed a solar system for my house and would love any feedback. I have a few specific questions at the end as well - region is outside Tampa, Florida.
I don't have a ton of roof space, so the system isn't large. Goal is to be cheap (5k to 10k USD for everything), easy to install and grid tie, and to offset 1 to 2 hundred dollars from my (currently atrocious) power bill each month. Would like to maximize ROI. I want to do minimal upgrades - so sticking with a 7600w inverter and about the same in panels so I don't have to do any crazy panel upgrades, or extra permitting right now.
I might be able to upgrade and add panels in the future, but budget doesn't allow right now. Also planning some separate energy efficiency upgrades to get power bill lower.
Recent hurricanes have opened up my canopy by a good amount I think Solar will now work well for me and ROI in just a couple years with this plan.
This system is inspired significantly by this user's post here
Starting off with my electricity usage (TECO is my power company) for 2024 and some estimates for what a ~7600w system might do just to see if this is realistic:
Now the house I'm working with:
So I modeled my roof in Fusion360 to start trying out panels and came to this design as what I think will work best:
*also yes I know there are tools to plan the racking / mounting that I intend to use for final selections of those parts.
I only want panels on the very topmost roof areas - house is 2 story but I think panels will only work well on what i've modeled as follows.
The best I came up with is 8x 550W panels on the south side and 6 550w panels on the north side.
Now I drew up an electrical diagram trying to minimize cost and ease of install. I really don't want to work with actual metal conduit in my attic - thus the flexible MC cable.
My MSP is in my Garage with the Utility meter just on the outside wall of the garage. I'd like the inverter to live right next to it. Pic of unmodified current situation:
Now here's a rough pic of the plan for mounting things:
This is how I intend to run the DC wiring in the attic (red lines are inside ofcourse)
Bill of materials - not entirely complete as I haven't detailed out the racking yet:
I think I have most things covered, but there are still some unknowns / questions I have:
1. Quantity and Location of all the safety switches.
3. I'm a bit unclear about the fire setback rules on my specific roof. From the pics above - anyone see issues there or what I may have to adjust? I'm still planning to have a local company generate plans formally, but I'd like to know sooner or later if this deisgn will work or not.
4. Still need to do some research on grounding for this setup. Can grounding occur only through the green ground wire of the MC cable from Array to the breaker box? or do I need to sink a separate ground rod and run a larger copper wire to the arrays?
4 .Anything else I'm missing - or other recomendations or thoughts?
Thanks for the help!
I don't have a ton of roof space, so the system isn't large. Goal is to be cheap (5k to 10k USD for everything), easy to install and grid tie, and to offset 1 to 2 hundred dollars from my (currently atrocious) power bill each month. Would like to maximize ROI. I want to do minimal upgrades - so sticking with a 7600w inverter and about the same in panels so I don't have to do any crazy panel upgrades, or extra permitting right now.
I might be able to upgrade and add panels in the future, but budget doesn't allow right now. Also planning some separate energy efficiency upgrades to get power bill lower.
Recent hurricanes have opened up my canopy by a good amount I think Solar will now work well for me and ROI in just a couple years with this plan.
This system is inspired significantly by this user's post here
Starting off with my electricity usage (TECO is my power company) for 2024 and some estimates for what a ~7600w system might do just to see if this is realistic:
Now the house I'm working with:
So I modeled my roof in Fusion360 to start trying out panels and came to this design as what I think will work best:
*also yes I know there are tools to plan the racking / mounting that I intend to use for final selections of those parts.
I only want panels on the very topmost roof areas - house is 2 story but I think panels will only work well on what i've modeled as follows.
The best I came up with is 8x 550W panels on the south side and 6 550w panels on the north side.
Now I drew up an electrical diagram trying to minimize cost and ease of install. I really don't want to work with actual metal conduit in my attic - thus the flexible MC cable.
My MSP is in my Garage with the Utility meter just on the outside wall of the garage. I'd like the inverter to live right next to it. Pic of unmodified current situation:
Now here's a rough pic of the plan for mounting things:
This is how I intend to run the DC wiring in the attic (red lines are inside ofcourse)
Bill of materials - not entirely complete as I haven't detailed out the racking yet:I think I have most things covered, but there are still some unknowns / questions I have:
1. Quantity and Location of all the safety switches.
- Do I need a DC power disconnect if I have the TIGO RSS system?
- Does the DC power disconnect need to be accessible outside by firemen or can i put it in garage next to the inverter?
- Does the RSS E-STOP button need to be accessible outside by firemen or can i put it in garage next to the inverter?
- From my reading, it seems the AC disconnect DOES need to be outside by Utility Meter. If I have this one, do I need the others?
- In general - 3 SEPARATE disconnect devices by the Power Meter (plus multiple standard breakers in breakerbox) seems absolutely absurd - which subset do I really need?
- I am planning grid-tie with TECO, so I believe there are 2 inspections? One by the county, and then one by TECO before they sign the interconnect agreement.
3. I'm a bit unclear about the fire setback rules on my specific roof. From the pics above - anyone see issues there or what I may have to adjust? I'm still planning to have a local company generate plans formally, but I'd like to know sooner or later if this deisgn will work or not.
4. Still need to do some research on grounding for this setup. Can grounding occur only through the green ground wire of the MC cable from Array to the breaker box? or do I need to sink a separate ground rod and run a larger copper wire to the arrays?
4 .Anything else I'm missing - or other recomendations or thoughts?
Thanks for the help!
