Here in San Antonio you will need power for the AC most of the year. Solar would be a good choice for me if it weren't for all the oak trees I have completely shading the whole yard and almost all of the roof which helps considerably with the heat. I opted for a whole house generator after almost two weeks without power a few winters ago. The limitation is if the gas goes out which should last for at least a week maybe more. I don't know of anyone in my subdivision that has a gas powered (natural gas) generator. That is a good thing for using my generator. It could be uncomfortable when all the neighbors show up at my doorstep though. Lucky we have three spar bedrooms and several couches that could be used to sleep on. Another thing to consider is how long the generator can/should function in continuous use. Mine will work for 10 days before they recommend servicing. As far as noise, my generator runs once a week to do a self test. I asked my neighbor on the side the generator is on if it bothered him and his reply was "You have a generator?" I spent a little more for a quiet and reliable cummins generator but I think it is worth it.
If shading is not too important, micro-inverter solutions might work. See here for education on solar panels wiring
Discover all the solar panel wiring basics from terms, to sequence of operations, you'll discover everything you need to know to wire solar panels.
aurorasolar.com
and micro-inverter
An important decision solar contractors face is determining whether to use MLPE. Read more to learn the fundamentals of MLPE for solar.
aurorasolar.com
For me, it is minimal. I calculated the yearly production estimate without shading with SAM and with shading with SAM 3D modeling (I just have a 2-story house and a big tree on the E. side of my 1-story house; the E. Array is shaded the first 30 - 60 mins of sun (confirmed with NetZero PW Watts solar forecast overlay over solar production feature), where I loose 1-2% per year (which is irrelevant).
Whole House Generator vs. Solar panels + battery backup I explained my reasoning on the 1st page.
I don't have Nat Gas, burying a 500G LPG tank + 20kW WHG is expensive. This is my math / ROI in 5 years (if I could benefit from the 30% Federal Tax Credit...)
| 5 YEARS | 24 panels solar + 3 batt | gen 20kw + 500G |
| purchase | 45275 | 24000 |
| elec | 1500 | 6000 |
| maintenance | 0 | 1750 |
| fuel | 0 | 1500 |
| total | 46775 | 33250 |
| tax credit | 13582.5 | |
| total | 33192.5 | 33250 |
+ benefits highlighted above (see Motivations section) which LPG tank + WHG does not provide; it only tackles the hurricane outage.
RE Heat on roof. You are right. In Central Florida, my shingle roof made the attic very hot. Last summer (the year I moved in this new house), I could feel the heat radiating from the attic to my house; like a 'giant baked potato on top of my house' from 7pm to 1-2am.
This year I tackled this issue:
1/ R30 insulation above the attached garage (DIY)
2/ R8 Garage Door insulation (DIY)
3/ R30 insulation above the entry door (DIY)
4/ Radiant barrier aluminum foil installed on the roof rafters (30-hours DIY! 1,600 sf of foil installed!)
5/ Attic smart exhaust fan ($350 installation)
6/ Then AC was added in the attached garage
a/ Now that it is insulated, it makes sense
b/ Last year the shared wall (house / attached garage) was very hot, now it's not
c/ PWs generate heat when charging and discharging.
Insulation + radiant barrier should offer 30% Federal Tax Credit as well.
Now my attic temperature is +15F (measured at close to the ridge line, but not on the wood sheeting as shingle heat radiates through it) above max outside temp. at all times where it should be:
The hotter your attic, the harder it is to cool your living space. Hot temperatures in your attic can also damage your home. Learn more.
energyattic.com
And +5F measured close to the soffit air intakes at all times.
My house is energy efficient.
