Perhaps others can benefit from my PV experience, and even give me some suggestions on adding EV support:
I had a meter wired directly to a 150 amp "main" breaker in the immediately adjacent (connected) 150-amp rated breaker panel.
I was told that SDG&E requires trenching, conduit (24" deep), and new feed wires (to replace the 32-year old "buried" service feed wires) if ANY service panel "upgrade" is done.
I was adding 7050 watts (SunnyBoy 7000 inverter, max just over 29 amps of AC) of Solar Generation required adding a 40-amp dual breaker for the PV "feed-in".
I was told (apparently incorrectly) that I would have to reduce the size of the main feed breaker by 40 amps to avoid the theoretical possibility of over-driving the 150-amp buss. So, we replaced the 150-amp main breaker with a 110-amp breaker, and added the 40-amp "PV" braker, thereby avoiding the expensive panel upgrade and trenching.
Apparently the "correct" buss loading calculation for PV feeds is: one is allowed to "over-rate" a panel by 20% when adding a PV feed-in. So, my 150 amp panel should have been treated like a 180-amp panel. Then, adding the 40-amp breaker would have only required reducing the main breaker from 150 to 140 amps. But, a 140-amp breaker seems very difficult to find. I suppose that a case could be made that the PV "feed" could never exceed 30 amps, and using the original 150-amp breaker should be OK, but I doubt that an inspector would go for that argumenr, because of the 40-amp PV breaker.
Now, faced with an almost full breaker panel, and wanting to add a dual 40-amp breaker (or two, the second for a future 2nd PHEV) for EV charging (and possibly one or two dedicated 20-amp breakers for Level 1 EV charging).
Since it is a GE panel that already uses "narrow" breakers, I cannot gain space by replacing pairs of 15 (or pairs of 20) amp breakers with the 2-in-1 type breakers, to free up a few slots. I will have to open it up to see if any of the remaining (two single and one double) knockouts will take breakers. I think the PV electrician said that some contact "tabs" were either missing or broken, and the associated spaces could not be used.
So, I might need to add a subpanel on the inside of the garage wall (right in back of the main panel that is IN the wall, facing outwards).
Perhaps I could then move some of the existing loads to the sub-panel and have the new EV-charging breakers conveniently located (within line-of-sight of the future EVSE) in the interior sub-panel.
When one has PV generation, a two-meter solution does not allow running both meters "backward". So, it would seem that some one-meter solution (Tariff) would be "best", even "required" to offset both the house consumption and the EV charging.
Further complication: If one has EV-TOU metering, the generation will all be in the daytime, in the high-rate or mid-rate time slots. There, I over-generate at least 9 months of the year, and A/C usage spikes usage in at least August and September so that there is perhaps 300 to 600 kWh net usage in those months. But, for the year, there is net generation. The night-charging time slot will never get any generation, so it would always show net usage (EV charging), perhaps of 200 to 600 kWh a month. Within one month's billing, does the over-geberation in the daytime time slots offset the net usage in the night slot? If it does, is it kWh for hWh, or datyime power rate offsetting nightime total (power plus distribution) billing?
Thanks for any help.
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle