Webeevdrivers
Active Member
I might be wrong, but my understanding is that the solar + couple of powerwalls solution is still grid-tied and provides solution for normal daily shift of production - usage differences (where you produce more energy during the sunny day-light time than used, but need to use some energy during the dark hours). However, it does not give you the ability to operate off-grid for 2 main reasons:
1. Your system would not be able to power the house in case of a several day generation outage due to bad weather (stormy, cloudy for several days in a row). You would need much bigger battery packs for true off-grid worst case scenario (upto a week or two usage amount would need to be stored).
2. You need different inverters for off-grid use than grid-tied use. Inverter models that are designed for grid-tie application are synced to the grid to generate the same sinus wave of AC power and they simply SHUT DOWN, when the grid is down -- at least that is the case for my grid-tied roof-top solar system I have been using for 8 year snow.
Because of these points, I believe a 2 powerwall system will not save you in case of a several day outage. You maybe able to ride-out a short outage of a few hours, but not anything prolonged.
Hmmm. I don’t know. Under “emergency operations procedures” we can live off of 3 KWH per day including refrigerator operation, basic lights, router, etc. How big is a power wall?
Is there not a big ass cutoff switch which allows isolation from the grid for safety purposes?