philip said:
There are definitely some "ifs" to consider, but generally I think over-sizing is a bad idea, financially.
Yes, this is true with current rates. I sized my system originally to account for about 90% of my overall usage.
But even at 90% overall, you still get stuck with the minimum charge in the months you overproduce, which is about half the year.
If you know for sure you won't be getting any more plug-in vehicles or other large loads - then yeah, size your system accordingly.
ybitz said:
But from elsewhere I've heard, EV-TOU2 won't be as lucrative going forward for solar owners because SDGE is going to change the peak times, right?
Yes, SDG&E is doing two things to make solar less attractive financially. Solar is in many ways becoming a victim of it's own success with net demand from 10am-4pm currently being as low as 12am-5am.
This document has proposed TOU rate periods:
https://www.sdge.com/sites/default/files/documents/2025168264/FINAL_GRC_PhaseII_S1510133.pdf?nid=16476
I don't know if these TOU rate periods will be the same for EV-TOU, but I assume they will be similar.
Instead of Summer/Winter TOU periods, now they will be year round.
On peak rates will be 4pm-9pm instead of 11am-6pm 7 days a week.
Super off-peak will be 12am-6am weekdays and 12am-2pm weekends.
The estimated impact on residential rates will be an increase of over 11%.
You're going to need to produce a lot more energy off-peak to make up for energy used on-peak, or you are going to need storage. Right now at this time of year my PV system only generates 13% of it's energy on-peak.