SGIP and Powerwall discharge behavior with Self Powered mode

[highstrunghero]

Hey everyone, I'm trying to understand Powerwall's discharging behavior in Self-Powered mode, as being part of the SGIP program I am obligated to discharge a certain amount back to the grid per year. According to the Tesla website " To meet the annual usage requirement, you will want to make sure Powerwall is set to Self-Powered or Time-Based Control. In either of these modes, Powerwall will cycle, or charge and discharge, daily. "

However, the Powerwall's seemingly never discharge unless they are at 100% despite my reserve being set to a modest 35%. Do other people have luck with their Powerwall's discharging below 100% in Self Powered mode? Due to the size of my solar setup, getting above 100% is a pretty rare occurrence. Is this some hidden setting that my solar or energy provider needs to enable? Or do I really need to be in Time Based Control to get any reliable discharge action below 100%?

 

[jjrandorin]

Yes, mine do (discharge whenever they are above the reserve, and PV doesnt cover the home load). I dont quite understand what you are saying though, because I dont understand the following statement:

Due to the size of my solar setup, getting above 100% is a pretty rare occurrence

I dont understand what "getting above 100%" means as far as powerwalls go and the tesla app.

I would say that you should log in locally to the gateway and see what setting the powerwalls are actually in. Perhaps they are not in self powered mode even though the app says they are.

Self powered mode is pretty simple. It simply:

1. Uses Generated PV to cover home load. If PV > than home load at the time, then
2. Use excess PC from point one above to charge powerwalls, as long as there is excess PV
3. If PV < home load, use powerwall power to supplement, up to powerwall limit of 5k per powerwall, until Powerwall hits reserve or PV > home load.

Thats pretty much it.

 

[highstrunghero]

I dont understand what "getting above 100%" means as far as powerwalls go and the tesla app.

Sorry I am not as well versed in this as most of you, so please bear with me. The only instances that the Powerwalls seemingly discharge to the grid is if they are above their maximum charge capacity, regardless of what I have my reserve set to. This makes hitting my SGIP agreement very challenging.

I will login to the gateway and see if it adds any clarity to my situation.

 

[miimura]

If your system is not minimizing grid draw in Self Powered mode, it's not working correctly. Try changing to another mode for a short time, then changing it back. If that doesn't work, restart the Gateway with the Reset button. If you don't have one, you will have to cut all power to restart the Gateway. That should restore normal operation.

 

[wattsupguys]

Hi, did you figure out your issue? It sounds like you’re describing normal behavior when you’re producing solar during the day. All solar production goes to fill the powerwall to 100% and excess goes to the grid after that.

When I was reading my SGIP agreement about a year and a half ago, my understanding was that I needed to cycle the equivalent of the 14kwh of the powerwall storage at least once per week over the year, meaning that I had to store and later use at least 14kwh from the powerwall during each week on average. If my reserve is set at 35%, and the powerwall charges to 100% and then during peak evening time I use 7kwh from the powerwall instead of 7kwh from the grid, that’s half of my week’s expectation.

So as long as you don’t put the reserve at 100% and leave it in backup only mode (thus not using the battery to reduce peak grid demand), you would be likely to meet the agreement with normal self-powered or even time-based control with a less than 85% reserve (unless your sgip is different from mine).