About 6 months ago I installed a solar power system with 2 Tesla Powerwalls for backup. Today, we got to test out the system with a power outage from an ice storm in the southeast. (We are still on battery power as I write this.)
My kids came downstairs to tell me that it was time for bed (9PM), but when I looked at my phone, it was only 8:17PM. They were reading the time off the microwave. I checked the alarm clock in my room and it also read 9PM
I know that the way power is "pushed" around between solar, utility, and the Powerwall is by modifying the frequency of the ac signal. I also know that many digital clocks keep time via utility frequency.
So, my question is this: if our power went out at roughly 10AM, and by 9PM our digital clocks were off by almost 45 minutes, what frequency is the powerwall delivering backup power at? That large of a shift in time seems excessive (purely speculative).