New Powerwall Advanced Options [Toggles for charging from and discharging to grid from powerwalls]

[Electrph]

can anyone report / give updates on the behavior of their system when set to export everything and time based ? have they "learned"

searched forum and keep landing on this thread

I was on export solar only .. just noticed option to export everything tried it yesterday and right at 4pm (i have peak 4-9pm only all other times off peak ) discharged both power walls at their max plus excess solar and went from 100% to 20% reserve by ~ 6pm then had to run off peak grid import till 9pm ..i assume this is the systems 1st "uneducated" attempt to cover peak and export max so wondering what ppl saw/ see what sort of timeline should i expect while learning if any

 

[aesculus]

can anyone report / give updates on the behavior of their system when set to export everything and time based ? have they "learned"

searched forum and keep landing on this thread

I was on export solar only .. just noticed option to export everything tried it yesterday and right at 4pm (i have peak 4-9pm only all other times off peak ) discharged both power walls at their max plus excess solar and went from 100% to 20% reserve by ~ 6pm then had to run off peak grid import till 9pm ..i assume this is the systems 1st "uneducated" attempt to cover peak and export max so wondering what ppl saw/ see what sort of timeline should i expect while learning if any

I tried it a few times and it seemed that it did start to learn on the third event, but I decided I did not like export everything, so it never completed it's learning process for me. From what I saw it looks like the learning curve is about the same as Cost Savings was. Also, I doubt it has two sets of algorithms: Export Solar and Export Everything, so if you are not consistent it may never be effective. Just my WAG.

 

[Electrph]

I tried it a few times and it seemed that it did start to learn on the third event, but I decided I did not like export everything, so it never completed it's learning process for me. From what I saw it looks like the learning curve is about the same as Cost Savings was. Also, I doubt it has two sets of algorithms: Export Solar and Export Everything, so if you are not consistent it may never be effective. Just my WAG.

Thanks for the reply … I may be with you on not liking export everything and stick with export solar only … even on the highest use ac days on export solar only I still have at least 50% left at end of peak .. sitting at 20% from 6pm to 9pm on export everything during often the biggest grid stress time of day while system learns makes me too nervous

 

[cwied]

Thanks for the reply … I may be with you on not liking export everything and stick with export solar only … even on the highest use ac days on export solar only I still have at least 50% left at end of peak .. sitting at 20% from 6pm to 9pm on export everything during often the biggest grid stress time of day while system learns makes me too nervous

I actually don't think there's much learning to export everything. I've been running it since it's been available to me. It seems to be optimized for NEM 1 in the sense that it assumes the price in the rate plan is the only cost to importing energy. If you're on NEM 2 and have non-bypassable charges (NBCs) you can adjust the rate plan and lower your export price by that amount ($.04, or something like that). With the lower export price the Powerwalls will try to avoid importing during peak.
Note that export everything does not adjust for grid stress. It just front-loads all of the exporting. I've experimented with automation to shift the times to peak net demand times, but it requires adjusting settings several times a day.
Note: I'm on NEM1 so I don't worry about the extra imports.

 

[Electrph]

I actually don't think there's much learning to export everything. I've been running it since it's been available to me. It seems to be optimized for NEM 1 in the sense that it assumes the price in the rate plan is the only cost to importing energy. If you're on NEM 2 and have non-bypassable charges (NBCs) you can adjust the rate plan and lower your export price by that amount ($.04, or something like that). With the lower export price the Powerwalls will try to avoid importing during peak.
Note that export everything does not adjust for grid stress. It just front-loads all of the exporting. I've experimented with automation to shift the times to peak net demand times, but it requires adjusting settings several times a day.
Note: I'm on NEM1 so I don't worry about the extra imports.

yea i was thinking my system was just going to continue dumping a bunch of energy at full tilt into grid at start of peak (if thats what you meant by front loading) and the only learning would be throttling back and keeping enough to more or less arrive at end of peak at my reserve . if that were case why not dump at end of peak and leave a larger reserve for a longer time during the peak hours ?
guess not programmed from perspective of "what if grid outage during peak"

 

[swedge]

I may be with you on not liking export everything and stick with export solar only

When set to Export Everything, PW is actually pretty smart. It optimizes your export/import to minimize your true-up bill. This behavior is different from what we were used to, which can be confusing.

Specifically, it adjusts the discharge rate so that it gets down to the reserve setting very near the end of the peak price period. If you have a partial peak period after the peak period ends, this means your house will run off the grid during that partial peak time. This is a bit of a shock, because with Export Solar Only, PW would keep us from using any peak or partial peak power if it could, and typically would have more left over in case of a blackout.

But the new behavior makes the NEM credit higher, by exporting more at the higher peak price, and then re-importing at the lower partial peak price. This nets out to a net benefit, So the net bill is lower than it used to be.

If you are concerned about how low it takes the charge, you may want to increase the reserve setting. The new behavior not only takes you down the the reserve every day, but the low point is reached earlier, 9 pm instead of 12 pm on the EV2-A rate. So it will be three hours more till sunup, and if you want the reserve to be enough to get you through a blackout starting at 9, a higher reserve setting makes sense. I stayed with 20%, because I'm willing to risk a few hours with the fridge in that worst case scenario, in exchange for several extra bucks of credit each month.

SW

 

[Electrph]

so based on what others and you have seen after my system "learns" i should see it arrive at my reserve setting closer to 9pm instead of 2 hours into peak ?
my tou summer is simple now only two rates peak 4pm- 9pm all other times off peak
i think i was more annoyed with system exporting down to reserve so early just to import from grid at peak for next 3 hours to run house

 

[cwied]

so based on what others and you have seen after my system "learns" i should see it arrive at my reserve setting closer to 9pm instead of 2 hours into peak ?
my tou summer is simple now only two rates peak 4pm- 9pm all other times off peak
i think i was more annoyed with system exporting down to reserve so early just to import from grid at peak for next 3 hours to run house

As long as you set the price for export lower than the price for import in the rate plan it will stretch it out so you don't import any peak energy. When I tried it it still started out at the maximum rate rather than starting out slower and maxing out later in the period. That's what I meant by "front-loading."

The fix is not "learning," but a simple configuration change. If you don't change the rate plan, it'll behave as you've observed, no matter how long you let it "learn."

 

[swedge]

so based on what others and you have seen after my system "learns" i should see it arrive at my reserve setting closer to 9pm instead of 2 hours into peak ?

Perhaps. It may also depend on how your buy/sell (export/import) rates are set. If you have the buy price and sell price set the same, PW may be happy to export and then reimport. Mine is set for NEM2 which has about a $0.03 lower export credit, so it minimizes reimporting during. That difference did seem to change the behavior of mine when I experimented with it. I haven't tried the winter rates, so it will be interesting to see what it does when those kick in.

In any case, it did seem to figure out how much I am likely to use toward the end of the peak period, and adjusted the discharge and export accordingly. I expect if I fired up the oven or some other unusual large load late in that period, it would have to reimport to cover it.

my tou summer is simple now only two rates peak 4pm- 9pm all other times off peak

The behavior you are seeing now is quite different from mine. Yours discharges to reserve level much more early than mine.

I do wonder why our PWs do the export early in the peak period. Perhaps, instead they could wait untill max discharge would get it down to reserve at the end of peak time. No "learning" would be needed that way, I think.

i think i was more annoyed with system exporting down to reserve so early just to import from grid at peak for next 3 hours to run house

Me too, until I got my head around what PW was thinking.

One other interesting aspect is combining charging from the grid with export all. In the winter or cloudy weather I sometimes don't get to 100%, so the Export Everything has less to work with. Grid charging does top PW off, so there is still plenty to export even without solar. PG&E does limit export based on an estimate of solar production during each month, so there is a limit on how much export one can get credit for.

SW

 

[Electrph]

i think @cwied and also @swedge nailed my issue .. i had buy and sell set same which in export only solar made no diff .. i set sell price 0.04 lower and i'll try again during today's peak and see what system does

 

[aesculus]

i think @cwied and also @swedge nailed my issue .. i had buy and sell set same which in export only solar made no diff .. i set sell price 0.04 lower and i'll try again during today's peak and see what system does

I did forget to mention that I also tweaked my import/export costs by $0.03. But it still took a few days even after that to stop the big "front loading" drain and get me to a place where I ended the discharge near the end of my peak period (9pm).

And there was at least once where my consumption did not seem to map like it wanted so it stole some solar to put in the PWs during peak to make sure I did not end up using grid power later.

 

[Electrph]

I did forget to mention that I also tweaked my import/export costs by $0.03. But it still took a few days even after that to stop the big "front loading" drain and get me to a place where I ended the discharge near the end of my peak period (9pm).

And there was at least once where my consumption did not seem to map like it wanted so it stole some solar to put in the PWs during peak to make sure I did not end up using grid power later.

I recall somewhere way earlier in this thread or another on my search you or others may have mentioned tweaking export vs import price with export everything but I glossed over it of course

 

[Electrph]

thanks for all the help everyone
when 4pm peak time hit power wall no longer went crazy dumping all it's power into the grid ( like @holeydonut in front of PG&E headquarters with a stolen dump truck of fresh manure )
will be intersting to watch behavior thru the peak time as ac cycles on and off

 

[kgharrison]

I recently tried the new Powerwall grid charging feature. Unfortunately it charges from the grid regardless of the time of day. My rate plan in the app is specified as TOU and has the various rate tiers configured. Is there any way to force grid charging only during off-peak rates?

 

[JJ-Moonstone]

I recently tried the new Powerwall grid charging feature. Unfortunately it charges from the grid regardless of the time of day. My rate plan in the app is specified as TOU and has the various rate tiers configured. Is there any way to force grid charging only during off-peak rates?

Did you ever find a solution for this? We wish our powerwall would fill from the grid as soon as our off peak rates begin, so that they are filled for frequent power outages, especially in winter months when there is not reliable sunshine to fill the powerwall either. Thanks.

 

[crackers8199]

random question: is there a financial downside to just dumping everything to the grid right when peak starts and then drawing a bit at peak rates if necessary for the remainder of the peak period? wouldn't what you draw just effectively cancel out what you sent back to the grid earlier, making it a zero sum game?

 

[aesculus]

random question: is there a financial downside to just dumping everything to the grid right when peak starts and then drawing a bit at peak rates if necessary for the remainder of the peak period? wouldn't what you draw just effectively cancel out what you sent back to the grid earlier, making it a zero sum game?

Not sure what you mean by "dumping everything". Do you mean all solar or all solar plus what is in your PWs? And you have to add in the power loss of going into and out of the PWs as well as NBCs. So its not a zero sum game exactly, or at least it is not linear. It would take a bit of calculation to figure out the most optimal mix.

BTW this is what the VPP did. TBD if it was worth it, even at $2 kWh. I had to buy expensive power for the 3rd hour, even with my AC set back. I wish it would have paced the discharge to keep me from needing grid power at all during peak.

 

[crackers8199]

Not sure what you mean by "dumping everything". Do you mean all solar or all solar plus what is in your PWs? And you have to add in the power loss of going into and out of the PWs as well as NBCs. So its not a zero sum game exactly, or at least it is not linear. It would take a bit of calculation to figure out the most optimal mix.

BTW this is what the VPP did. TBD if it was worth it, even at $2 kWh. I had to buy expensive power for the 3rd hour, even with my AC set back. I wish it would have paced the discharge to keep me from needing grid power at all during peak.

if you don't tweak your sell price and set it to export everything (hence what I meant by "dumping everything,") it'll export almost all of your available powerwalls within the first hour or two (at least that has been my experience).

as for NBCs, if I'm on NEM 1 I don't need to worry about those. the question was more about the in and out loss you mentioned, and how much that will affect things.

 

[swedge]

Did you ever find a solution for this? We wish our powerwall would fill from the grid as soon as our off peak rates begin, so that they are filled for frequent power outages, especially in winter months when there is not reliable sunshine to fill the powerwall either. Thanks.

Mine is set to 20% Backup Reserve, Time Based Control, Export Everything, Grid Charging enabled, and PG&E EV2A rate with $0.03 deduction for sell prices for NEM2 NBC.

It waits to let solar charge, and grid charges at ~3.3kW if needed to get to 100% prior to off peak pricing start.

You might try setting the reserve to 100%, as that may make it start to grid charge, perhaps with a few minutes of delay. This may not be a solution to your issue as It would be a nuisance to need to switch the reserve up and down each day, but it is possible for a script to do that automatically.

SW

 

[wwhitney]

Time Based Control, Export Everything

Can you tell by examining the system behavior whether with that combination of options the system imposes the restriction that Net Export < PV Production? As a running total, not as an instantaneous constraint.

I.e. With the battery charged both from solar and from the grid, that the grid charged portion of the battery is only used for house loads (load time shifting), and any amount that gets exported to the grid comes from the solar charged portion of the battery (production time shifting)?

Cheers, Wayne