Self Powered vs Time-Based control

[SolarBob]

Not sure if this has been discussed but I don't understand the differences and what is best to use to insure you do not have a large true-up bill at the end of the year.

I am on the PG&E plan that charges a premium for usage between 4pm and 9pm.

Last year I used self powered and with the drought I had in my true-up bill a $1,000 credit to me at the end of the year.

However, PG&E actually on gave me a $130 credit to use so I really did not get much for the excess power I returned to the grid.

I have 48 panels, and 2 PW that I keep a reserve between 40 and 50 percent, so during the day i charge as much as possible to the PW's and use that energy to power the house between 4pm and 9pm.

I am not sure what is best. This year so far a lot less sun with all the rain. Can someone help me understand the differences and best way to use to insure lowest possible bill.

Thanks

 

[getakey]

Do you review your B&W bills?
You obviously over produce by a lot and using the PWs to arbitrage the rates just makes it worse (if worse is really the right word to use). I would raise the reserve on the PWs especially during times when there could be PSPS events. You have a lot of room before you would incur a positive NEM true-up

I had similar experience with my first year of PWs which I added to my existing solar. Without PWs, my true-up was about $200. I was aggressive using the PWs for arbitrage for the first year and I got a large negative NEM at true-up. This year I scaled back, meaning set my reserves higher aiming for a zero NEM

 

[taphil]

I overproduce too, and up to a point getting fractional credit at true up is pointless. So I turned down the AC temp in summer and use TBC to reduce wear and tear on the batteries. TBC stops battery drainage at 9pm, whereas self-powered keeps the battery draining til sunrise. My power bill has been negative dollars since March 2022.