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Powerwall settings
- Thread starter Merrill
- Start date
No, just like you, just part peak. The cost differential is trivial. Your approach is fine from a minimizing cost approach. I initially answered from a mobile device so I didn't write a longer response.
I'm running "balanced" for a couple of reasons. One reason is to be as "helpful" as I can be. I'm hoping that the part peak self consumption that happens is offsetting fossil fuels somewhere. The second reason is PG&E has the wrong PV size for me. They think I have a much smaller PV system than actually have (basically a Tesla error I didn't catch during the Powerwall add). This means that the amount of energy I can sell is limited to the predicted production of a much smaller system that I can exceed easily (and have). So, to avoid giving power away, I'm better off doing some amount of self consumption.
Before I discovered the PV sizing error I was running "cost saving" even during the winter. I simply raised my reserve percentage to get "backup only" like behavior.
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Thanks for the explanation, so if I use cost savings I would set the timed base controls to just indicate my off peak and partial peak times.
You just set the off peak hours and no peak. What is left is considered "shoulder" or "part peak". Not the most intuitive thing. First year I tried to set it caused some head scratching. Part of the confusing was dealing with the wrapping the time around, it took me a moment to figure out how to express it.
Here is screenshot of how it looks like for weekdays for me:
edit replaced link with a uploaded photo
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Hmm, tried editing the post and replacing with a inline photo, that seems to have failed as well. Trying a response here:
Another question, if I use self powered the Powerwalls will power the house when solar production stops, how long do they stay in that mode. Do they power the house until the solar starts the next day, I’m unclear on that.
In self powered mode, the powerwalls will continue to power the house until they reach the threshhold you have set for the reserve, (in which case they go into standby mode and you start pulling from the grid). If your threshhold is zero, they will power the home until they reach that threshhold (keeping in mind that zero in the app isnt really "zero".
They will continue to discharge to the home while they have power, then when the sun comes back up, solar will go toward powering your home. If not enough solar is being generated to power your home, the powerwalls will still discharge to make up the difference.
If more solar is being generated than your home requires to run itself, the excess goes to re charge the powerwalls.
Self powered attempts to keep you from pulling from the electrical grid as much as possible, up to the reserve set in the app. It doesnt have fancy algorithms that try to guess when you might or might not need power, and doesnt have any TOU settings etc. I use this mode only, but thats because I am grandfathered in on a tiered rate and holding onto it for dear life.
Thanks for the info, what do you set your reserve at when in self powered. I have been using back up since I went on line with my Powerwalls, but still wondering since it is winter and there is no peak what is the best setting.
I change my reserve fairly often, manually, to whatever I think would leave me enough power to get from sundown back to sun up again. This is going to be a pretty personal thing (related to your own usage and managing your own risk tolerance, etc).
To answer your question, right now I have my reserve set to 65%. Starting in March, however, it will be as low as 20% (because there is enough solar generation at that point to run my home during the day, and still fill my powerwalls from 20% to full before the sun goes down). At that level, I can run on my powerwalls all through the evening, and make it to the morning sun again before I hit the reserve.
I change the reserve if its going to rain, etc. A lot more "micro managery" than most want to be, but I still enjoy looking at the tesla app, watching the power flow into the powerwalls, etc. I find it strangely comforting, and as I have said before, gives me an incredible sense of "connection" to my home that I did not have before. I feel very safe here.. and because of covid, and mostly working from home now, I am here a LOT.
In your case, based on previous posts you have made, it appears to me that you have a very high concern about not having enough power in your powerwalls for a power outage, because we cant charge from the grid, so I would recommend you leave it in backup only unless your risk tolerance for that scenario has changed.
The trip into and out of the powerwall for power also has some losses (I think roughly 10%) so the "most efficient" thing is to not suffer that 10% penalty unless you are getting benefit from it (like not pulling power during peak TOU rates).
I dont have "peak TOU rates" as I am on a tiered plan as I said. I believe that in california, some form of the advanced setting is best for most users unless they are in my specific situation, or, alternatively, want to pull as little as possible from the electrical grid for personal reasons, if not financial ones.
Thanks for helping it is appreciated, when summer rates come I probably will look at ways to use the Powerwalls during peak rates to save some money. Pacific Graft and Extortion just raised their rates January 1st to help pay for their ineptitude.
i have been thinking about what it would take to automate the setting of the reserve value. it seems like all you need to know is what your production would be like for a given clear day of the year, and some derating factor depending on what openweathermap.com says about the weather/cloud cover for the next day. of course for me in the summer there is frequently a lot of fog every morning and its not clear that will be taken into account by openweathermap.com since it is a hyperlocal phenomenon.
i think you can set the reserve via the local API? if not is there a remote API?
