Mine is planned to be 10.2 kW the 11.3 kW was referring to destructure00. I have looked at my peak usage over 1 hr from this summer from SRPs data logger and my 1 hour peaks are ~ 12.5 kWH/hr and this is likely with 2x ACs running full 100% with maybe a dishwasher/clostheswasher/pool pump during my current pre-cool period for the EZ-3 TOU from 3-6. I think 4 is probably not needed and 3 will fully cover the peaks... it certainly can with the 15 kW capacity and I think 3 would be enough to 0 out my demand.
Even with Tesla low prices the payback on these should will be many years :/ I guess this is for the environment too...
As far as PW physical placement. I know they have cooling units, but does it make sense to install them inside my garage instead of outside on a non-direct sunlight wall? I am mostly thinking about longevity of these things. Does Tesla have any reliability/life cycle data on these batteries? Charge/Discharge %s vs life? I would think if you were draining 2 batteries 100% every day they would die sooner than using 4 batteries to 50%. Any idea how much energy do the battery cooling units use or what technology they use on them?
The more you are able to keep the Powerwalls inside of their recommended operating temperatures of 0°C to 30°C (32°F to 86°F) the better. https://www.tesla.com/sites/default.../Powerwall 2_AC_Datasheet_en_northamerica.pdf
Tesla warranties Powerwalls to retain 70% of their capacity after 10 years. https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall_2_AC_Warranty_USA_1-1.pdf
Anecdotal historical capacity reports from members of this board are here Total Pack Power vs. Ownership Lifetime.