nwdiver
Well-Known Member
Last I checked it's more 'free' than FREE. Don't they still charge transmission and distribution? ~$0.03/kWh? If you're making as much as you're using you won't pay anything anyway under NEM.
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Clean your solar panels!
- Thread starter Electricfan
- Start date
Last I checked it's more 'free' than FREE. Don't they still charge transmission and distribution? ~$0.03/kWh? If you're making as much as you're using you won't pay anything anyway under NEM.
Just an update - my system switched to grid power at 9pm, hallelujah! If it keeps working like this I can't ask for more. Now whether the whole thing is some kind of glitch I just don't know, because tech support and everybody with experience told me that it doesn't charge the powerwall during peak time. So I'm still confused. But I'm happy. I can live like this.
You're absolutely right. I've never understood this "Centerpoint TDU delivery charge". It was $56.16 on my last bill, and the total bill was $80.50 But I don't think I can avoid that charge no matter what plan I choose. Am I wrong? There might be a better plan for me, but if the damn delivery charge is on all of them, then as best I can tell this free nights is good for me. I'm very curious what its going to be with the powerwalls, if I can succeed in avoiding any import of power (or next to none).
I didn't get the powerwalls to save money. I just wanted to keep my solar and use it myself, and also have the backup in case of an outage. Outages aren't common here, but I had one a couple weeks ago in the middle of the night, and all the battery backups went off and started screaming. I won't miss that. They're all unplugged and awaiting disposition now. I fully expect in 5 yrs or so that whole house battery backups will be much cheaper, and much more common. I sure hope so anyway. Solar plus battery is awesome.
Today, my third day with time based control, it started discharging from the powerwall at 4:30am, just like yesterday. Not sure why it would do this. Have you tried any settings changes to fix it? I think I'm going to leave it alone for a while and see if its consistent. If it stays the same a week or so, I might change the 6am number in my peak time, up to 7am, to see if that has any impact. What hour does your peak time start?
My part-peak starts at 9 am M-F and my peak period is from 2 pm until 6 pm M-F. Mine continues to switch over around 4:30 am as well and then drains about 50%, down to the reserve. This is new behavior as of 1.37.1.
The Powerwalls are more predictable before peak now. While my peak starts at 2 pm, the batteries used to charge up just as high as they predicted they needed to be so that they could discharge until my part-peak ended at night. Usually, it was pretty accurate and they would only charge to 80% or so and still be able to power the house until my scheduled off-peak start time. Once they reached the predicted charge level, they would immediate start discharging, sometimes as early as 10 am. Now, they are charged up to 100% and don't discharge until peak actually starts at 2 pm.
I haven't tried changed any of my settings yet.
Shygar
Member
It will now discharge in off-peak if you are set to 'Balanced' mode. If you switch it to 'Cost Saving', then it will not discharge in off-peak. This is with 1.37+ as far as I can tell
Did you call powerwall tech support? Losing charge down to your reserve level during non-peak time sure sucks. They've been extremely helpful when I've called them. I only lose a little bit of power, and I reprogrammed my water heater not to come on past 4:30am, so it won't drain the battery now. But still I hope I can get the settings right, and it will just use powerwall power between 6am and 9pm. It sure seems like that should be easy to do. But not if you're trying to make one App work for the entire world, maybe.
But I'm already in "cost saving", and its discharging off-peak.
No, but I will after a week on this schedule. I want to see if it holds. Everybody, tech support and forum members all said it would not charge the powerwall during peak hours. But mine is. So, I'm badly confused about what is going on. And since its so so close to what I want, I'm reluctant to mess with it right away.
I think it knows that by your schedule it must charge during Peak in order to take on any energy at all. I'm assuming your schedule is same weekdays and weekends. In the past, my system has behaved differently on different days of the week because I have Off-Peak generation on weekends instead of just Part-Peak and Peak.
Well, I can't explain what the powerwalls are doing. They charge all day, use solar for the house first, then if the powerwalls are at 100% I end up exporting power - that's all perfect. But what I can't understand is why it still discharges from the powerwall during non-peak hours, when I want it to use the grid exclusively. But, so far it doesn't seem to matter that much. I am not importing power from the grid during peak hours, so the only thing I'm losing is that the powerwall could be at a higher state of charge all night (non peak), so if there were an outage I'd have more battery backup available. I'm wondering if they don't want the powerwall to sit there at 100 percent? I always thought that was bad for Tesla's batteries, so maybe its good that it doesn't hold 100 percent at night. It seems to go down to 80 percent and then keep that until morning. Whatever, I'm very happy with them.
Shygar
Member
Maybe it's trying to keep its SoC lower for a happier battery lifetime. Maybe it thinks you won't be needing it otherwise so it doesn't hurt to discharge.
This would work just as well if they allowed a upper-charge limit such as 90% max for any mode (such as with Sony phones and former laptops, etc). Noting 100% is actually about 94% (@13.2 kWh) of full-capacity.
I'm in time-based control, cost saving option. I posted pictures above somewhere of my settings in the app if anyone is interested. My "peak" is from 6am to 9pm. When I talked to the powerwall tech support I was told "that's not a peak time", so I'm guessing they are expecting a smaller window, like 4pm to 8pm, as a "peak". But my electricity is 16cents/kwh from 6am to 9pm, and free outside those hours, so I want the powerwall to discharge only when my electricity is costing me money, not when its free. Tesla doesn't seem to see it that way, however! I'm ok with whatever they're doing, as long as I don't use grid power when it costs money. And so far that's almost exactly what its doing. But as I'm typing this, it is 10:30pm in Houston, which is 1.5 hours into my "free" time frame, but the powerwall is discharging, for some reason. I just wish I knew why.
Yes, I wonder why they don't let you set the upper charge limit. But maybe they take care of that automatically. I hope that's what they're doing. But lots of people use their powerwall in backup-only mode, so it sits there fully charged waiting for a blackout. Doesn't this hurt the battery? I guess not, or they wouldn't allow it.
I still don't understand why my powerwalls discharge during non-peak hours. But they do. Not always. It varies. I am happy about one thing, they store excess solar in the powerwall during peak time, and discharge it during peak time when needed, to avoid using the grid. So far I've had almost zero grid usage since setting up time based control with peak from 6am to 9pm, with cost savings mode. I wish it would save charge during non-peak time, in case of an outage. Why Tesla can't give us a simpler method to control the powerwall, I do not understand. Just let us set the time it will discharge, and the time it won't. Its almost like Tesla thinks they have a right to control the powerwall to achieve social/environmental goals that trumps the owners right to dictate how the powerwall works. It makes no sense. I paid for the powerwall. I should own it, and dictate how it works. Not Tesla. At the least they should give a clear explanation of how the modes work. The powerwall customer service person I spoke with told me it would NOT CHARGE at all during peak periods, the way I have it set up, and she was dead wrong. How can the tech support not understand how the product works?
eml2
Member
Are you saying that in Cost Saving mode, it will not export ALL solar to grid during peak anymore? This is different than before. What is your firmware version?
The thing to know is that @Electricfan has his peak set to 6am-9pm since his plan is a "free nights" plan. I suspect the Powerwall detects this as a special case since all solar falls within the peak period and is therefore compromising and doing self-consumption during that period.
Exactly. My "peak" is not a real "peak" according to one powerwall person I talked to. Whatever. I'm thrilled with them so far. The idea of exporting all solar to grid during peak makes no sense. I'm guessing in CA maybe you make a lot of money for exported power during peak time?
