You are of course correct. However, I can look at the performance of each of my panels historically or in real time. I can also compare today’s with yesterday’s and tomorrow’ s output. . Most days where I live are cloud free in the summer.
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Clean your solar panels!
- Thread starter Electricfan
- Start date
Just a quick update, got the time based control this morning and set it. Waiting to see if the control works. So far it used the powerwall power almost exclusively today during peak time, 6am to 9pm. Its not 9pm yet so looking to see if it switches to grid properly. Long term it will be interesting to see how often the battery drains because of no sun. I never really kept up with it with just solar panels, but the battery will make it starkly apparent when they haven't been producing enough. I hope one day we can charge off the grid in the USA like they do in other countries.
You're going to have a problem if your peak is 6am to 9pm because outside that time, when charging occurs, you won't have much solar generation, if any. Is your rate really a 15 hour peak period?
Naturally, today, the first full day I have time-based control available to me, the sun almost never shined. Almost complete and total cloud cover, rained all day. (yesterday when I had time based control only after 6am when it showed up on my App it seemed to work perfectly - it charged up the battery whenever solar exceeded my house draw, had lots of sun in Houston yesterday, the battery hit 100% charged in early afternoon)
But, when I checked it this morning at 4:30am I noticed my powerwall was discharging (4:30am is non-peak, so I wanted to use grid power only). Later once tech support opened, I called them and got the bad news - basically what you said - it doesn't charge the powerwall during the "peak" period. This is NOT what I observed yesterday, which she could not explain unless the powerwall never got the setting until very late in the evening, even though I set it that morning at about 6am. My powerwall is connected with an ethernet cable to my router, no drop-out from wi-fi is possible.
So, I'm badly confused. And to make it worse, the tech support person had no explanation for why it was discharging outside my peak with about 40% charge in the battery at 4:30am today.
And worse still, when the sun came out today at all (as I type this I am getting 0.4kw) the system is doing this - all 0.4kw is going to the house, plus another .3kw from the powerwall, for a total of .7kw feeding the house. This contradicts what tech support said (I think, I certainly could be wrong) which was that all solar would go out to the grid during peak. Meaning if my house was drawing 0.7kw, and the sun was producing 0.4kw, then the powerwall would provide 0.7kw to the house and the solar 0.4kw would be exported. Nope, did not happen that way.
At any rate, I have zero understanding of what time of use means or does, after listening to tech support explain it and reading the Tesla website.
The solution she gave me was to try a couple of things - 1) I can turn off the powerwalls at 9pm. This will prevent them from discharging at night, but of course they won't be there in an unplanned outage, 2) put them in backup mode at 8pm, so by 9pm they'll register it and stop discharging at night. Of course this would mean changing the mode back in the morning if I want to store solar energy and use it when my rates are high. 3) she thought self-powered mode might work best for me. But this mode would allow the powerwall to discharge at night if there was any battery left at the end of the day. In turn that would mean a flat battery in the morning, and I'm buying expensive kwh until the sun comes up.
So, I'm disappointed with the modes of operation - none serve my needs. She said they are busy updating all the time, and it may be that they'll have a mode I can use someday. Till then, its going to be a very manual operation getting the most out of my powerwall. I define most as storing my expensive (I had to pay through the nose getting the solar panels installed, they are not cheap in TX where few subsidies exist) solar energy in the battery and not exporting ANY to the grid, and using it during the time of day from 6am to 9pm when I pay for electricity. Outside those hours my rate is zero cents per kwh.
If anybody can post a clear, sensible explanation of what Tesla's time of use, cost saving mode does that is in any way good for the consumer, please try. Because I have no idea.
Are you on a TOU rate plan? If so, what are the rate periods? With that we can help you set it up.
If you are not on a TOU rate plan, then self-consumption would be a better option for you.
If you are not on a TOU rate plan, then self-consumption would be a better option for you.
@Electricfan, with a 6am to 9pm peak period, I'm not sure the Powerwalls can do anything to help you unless grid charging were available. All your solar production is during peak, so you don't have any solar available to charge the Powerwalls. It makes more sense just to use the solar you have right away and export the rest. What the Powerwalls effectively do in time-based control mode is shift solar energy from one time to another to take advantage of the difference in rates.
You might check if your utility has different rate plans available that are more advantageous for the Powerwall. What you're looking for is a plan which has part of the day in off-peak and the other part as peak. You can then charge from solar during off-peak and use that energy during peak. This is presuming that you have net energy metering (NEM), of course.
You might check if your utility has different rate plans available that are more advantageous for the Powerwall. What you're looking for is a plan which has part of the day in off-peak and the other part as peak. You can then charge from solar during off-peak and use that energy during peak. This is presuming that you have net energy metering (NEM), of course.
He is in Houston where they offer a "Free Nights" rate plan. Night time is literally $0.00/kWh. Daytime is some flat rate. What he really needs is a special mode I will call "Scheduled Self-Powered". Basically, it is Self-Powered during the day and discharge is prevented at night. As far as I know, there is no sure way to accomplish this with the currently available Time Based Control modes.
What firmware are you on? We started seeing our Powerwalls discharge at 4:30 am once we got the 1.37.1 firmware. Before that, ours never discharged in off-peak.
Shygar
Member
I'm also on 1.37.1
This morning it did not discharge from the powerwall during non-peak hours.
Well the mystery deepens folks. Below are pictures of the settings my PW2s have had for a couple days now. Today it has done exactly what I wanted - stored power during the day and used power from the battery only when solar wasn't enough. At 9pm I'm hoping it switches to grid power. If it does, game over! There was one mystery discharge of power to the grid today for a few minutes, and it amounted to 0.7kwh of power. I have zero idea why it did that.
Everyone seems to agree, it will not charge the battery during peak times. But this is not what I'm seeing. Maybe Tesla did something special for Texas? For Houston? For me? Or my system is broke? If its broke, please don't fix it! Assuming it switches to the grid at 9pm.
Everyone seems to agree, it will not charge the battery during peak times. But this is not what I'm seeing. Maybe Tesla did something special for Texas? For Houston? For me? Or my system is broke? If its broke, please don't fix it! Assuming it switches to the grid at 9pm.
This is my current plan - free nights. 16cents/kwh from 6am to 9pm. Its always worked pretty well because solar cuts my daytime consumption a lot. But now with the powerwalls it should cut it to near zero. Today the time-based mode worked as desired. I have no idea what's going on, since everybody agrees its not supposed to charge the powerwall during peak hours. I have no idea what it IS supposed to do during peak hours though. I guess export all solar?? Makes no sense to me though.
Nothing would make up for losing the free car charging at night. I charge my car about 30kwh each night, from a 70 mile round trip commute.
What do your daytime rates look like? Are you paid full price for electricity exported? Or part price? Or nothing? Different electric plans price that differently, and it makes all the difference in how you set things up.
If you're paid full price for exports, there's nothing for the Powerwall to do. The most valuable use of that peak-time solar is to export it to the grid.
If you're paid a lower price (or nothing) for exports, then the ideal thing for the Powerwall to do is zero out your daytime grid use and charge/discharge to keep from importing or exporting anything. I think people have had luck with setting the 6am-9pm time as part-peak and not having any peak. I'm not sure though, as I'm on a full-price exports plan.
If you're paid full price for exports, there's nothing for the Powerwall to do. The most valuable use of that peak-time solar is to export it to the grid.
If you're paid a lower price (or nothing) for exports, then the ideal thing for the Powerwall to do is zero out your daytime grid use and charge/discharge to keep from importing or exporting anything. I think people have had luck with setting the 6am-9pm time as part-peak and not having any peak. I'm not sure though, as I'm on a full-price exports plan.
I am paid zero for exported power. Daytime cost for imported power is 16cents/kwh. I am not sure what you mean by "part-peak". I don't have that in my App. Or, haven't seen it - maybe its in a spot I haven't tried to set up for yet. I don't have it in my time-based cost-savings set up. I agree, I am trying to get it to zero out my daytime grid use and not export or import anything grid wise.
Read his post again. He cleaned one panel and looked at the output power of the adjacent panels that were not cleaned in real time. He clearly showed it was significant. ~20%
When you go to "Edit Price Schedule" where you currently have orange peak time defined for the whole day, I think you want that to be grey for part-peak. When you adjust the times, you get different results when you drag the handle just above the orange area vs the handle just below the orange. Try playing with part-peak and possibly setting "Balanced" vs "Cost Saving". Unfortunately, Tesla isn't very clear about what the different modes do, so it can take a bit of experimentation. Also, changes between "Balanced" and "Cost Saving" can take a day or so to switch over, so you have to be patient in your experiments.
nwdiver
Well-Known Member
Who is your utility? You guys don't have choice in Houston? In West Texas there are several RSPs to choose from. Some net meter... some don't.
No, he has a mop on the second panel.
No you don’t need to clean them if they are covered in pollen, if rain is going to do the job shortly for you. Mine are bad right now but the next storm will clean them up. If I did clean them they would be dirty again in a couple days. If rain didn’t routinely come I’d wait until pollen season is over.
TXU. We have a choice. But I can't see how I can do better than zero cost per kwh at night. This lets me charge my car, 30kwh, every night for free.
