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Is there anyway to prioritize solar for home and PWs before grid?

sorka

Well-Known Member
Feb 28, 2015
7,867
5,780
Merced, CA
Right now, solar wants to charge powerwalls while house takes power from grid during off peak. If I change the schedule to say it's peak when it isn't, then solar will go to grid and powerwall will goto house.

Since I don't yet have PTO, I have to kill solar early because powerwall charges all the way up from solar while house is taking from grid. I'd rather just not take anything from the grid and power house from solar while I have it during the day and use the leftover to goto the powerwalls.

I can achieve this by disconnecting from the grid but that's pretty drastic plus my PW frequency output since 1.50.2 hits 60.4 HZ as early as 80%.

Are there any combination of settings that can do this without disconnecting from the grid?
 

bmah

Moderator, Model S/X, California Forums
Mar 17, 2015
3,904
7,013
Lafayette, CA, USA
Part of me wants to be snarky and say "well you shouldn't be running the system before PTO".

The other part of me wonders if self-consumption mode will do what you want. Is that available as an operational mode in your app?

Bruce.
 

wjgjr

Active Member
May 11, 2020
1,165
903
Silver Spring, MD
Part of me wants to be snarky and say "well you shouldn't be running the system before PTO".

The other part of me wonders if self-consumption mode will do what you want. Is that available as an operational mode in your app?

Bruce.
The first part is really the correct answer, and to ensure nothing is sent to the grid, disconnecting is the only sure method. It is inconvenient (especially with the apparent change to when the frequency starts to rise,) but it is reliable, and it also potentially (depending on your agreements) more in line with what is allowed before PTO.

Self-powered is probably the best option if your solar production is less than your daily consumption. However, even then, if the gateway estimates or off or your usage patterns work out that way, you still might end up with a full PW in the middle of the day and export will occur. If production exceeds consumption, there is no avoiding exports occurring if the grid is connected.

Unfortunately, Tesla does not seem to have any direct method of controlling the system behavior, instead requiring the selection of modes that behave in certain ways that don't always match up perfectly to what a given user wants.
 

sorka

Well-Known Member
Feb 28, 2015
7,867
5,780
Merced, CA
From my experience, bmah is correct, self-powered mode will prioritize solar to house and any excess to the powerwalls until the powerwalls are full. Then it will split between house and sending energy to the grid.

I tried it for the last 45 minutes and it made no difference. 100% of solar still went to the PWs and the house continued to draw from the grid.

As for PTO, my final inspection was complete on 10/23. Tesla had me sign the interconnection agreement form on 11/11. It was the wrong form and I told them so on the 11th. On the 12th, they submitted the incorrect form. On the 13th, PGE rejected it and sent Tesla and email asking them to resubmit. Tesla says they're still sorting out title 21 issues and they say it will be at least 6 more weeks before they submit the correct form. PG&E says it will take 4 to 6 weeks after (because it's a 3 PW system) before PTO is granted, so I'm looking at over 4 months from the date the county inspection passed to getting PTO *IF* everything goes according to what they say it will.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
8,147
9,003
Riverside Co. CA
I use self powered almost exclusively, and under that mode, solar powers the home + fills the powerwalls, as long as solar power doesnt exceed what the home + powerwalls can take. Its also true that once powerwalls get full or close to full, solar then powers the home and then exports to grid.

So, Self powered will do what op wants at least until powerwalls get full, then solar would be exported when the batteries get full. There isnt any "peak vs off peak" with self powered mode so there isnt any thought by the system to try to "ride through peak" or anything. Self powered is fairly simple.

Solar powers home + fills powerwalls till they get full, then exports to grid when batteries are full.
Once powerwalls are full, they sit on standby, until home load > than solar production. Once this occurs (homeload > solar production) batteries start discharging to cover the gap. This continues until you hit your set reserve, whenever that is.
 

jedmo

Member
Sep 9, 2020
115
49
Northern California
I tried it for the last 45 minutes and it made no difference. 100% of solar still went to the PWs and the house continued to draw from the grid.

As for PTO, my final inspection was complete on 10/23. Tesla had me sign the interconnection agreement form on 11/11. It was the wrong form and I told them so on the 11th. On the 12th, they submitted the incorrect form. On the 13th, PGE rejected it and sent Tesla and email asking them to resubmit. Tesla says they're still sorting out title 21 issues and they say it will be at least 6 more weeks before they submit the correct form. PG&E says it will take 4 to 6 weeks after (because it's a 3 PW system) before PTO is granted, so I'm looking at over 4 months from the date the county inspection passed to getting PTO *IF* everything goes according to what they say it will.

Something may not be wired right. When I switch on Solar, it goes to the house, any excess to the powerwalls, until the powerwalls are full.

From Tesla:

Self-Powered mode stores any solar energy not used during the day to power your home at night. Powerwall will charge when excess solar power is produced. This stored energy will then be used when your home needs more power than solar can provide.

When you have enough solar energy to offset all consumption and your Powerwall is fully charged, the excess energy will be exported to the grid. Similarly, if you are consuming more than is available from your solar and Powerwall, you will import energy from the grid.

This mode approximately doubles the amount of solar energy that powers your home and is the best way to reduce your carbon footprint and be more energy independent.
 

sorka

Well-Known Member
Feb 28, 2015
7,867
5,780
Merced, CA
Screenshot_20201203-132859_Tesla.jpg

Screenshot_20201203-132835_Tesla.jpg

Screenshot_20201203-132830_Tesla.jpg
 

MorrisonHiker

S 100D 2021.4.15
Mar 8, 2015
9,567
8,751
Colorado
Typically you shouldn't see the Powerwalls being charged from the grid but sometimes you'll see 100 W or so appearing to go the wrong direction.

It could be that your CTs aren't configured correctly. They fixed mine remotely a couple days after things were activated in the app. However, they probably won't do much until you have PTO. Once you get PTO, you'll eventually get the Time based options. Then you should be able to configure when it draws from the grid (or doesn't). We have ours configured so that we really only draw from the grid for about 3 hours at night.
 

sorka

Well-Known Member
Feb 28, 2015
7,867
5,780
Merced, CA
Typically you shouldn't see the Powerwalls being charged from the grid but sometimes you'll see 100 W or so appearing to go the wrong direction.

It could be that your CTs aren't configured correctly. They fixed mine remotely a couple days after things were activated in the app. However, they probably won't do much until you have PTO. Once you get PTO, you'll eventually get the Time based options. Then you should be able to configure when it draws from the grid (or doesn't). We have ours configured so that we really only draw from the grid for about 3 hours at night.

The CTs are configured correctly and I've had the time based option for over 5 weeks which is what I've been on. I only switched to self powered mode at the suggestion in this thread.

There's NO way to do what I want with the time based option.
 
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Reactions: MorrisonHiker

AxlxA

Member
Jun 23, 2020
478
327
Bay Area
Disconnect main and just ride on powerwalls for the rest of the day. Switch it back on when sun is down.

Your earlier attempts was trying to fill the powerwall as quick as possible to full as soon as possible. So grid energy was used.

Do you have 1 or 2 powerwalls? What's the max charge rate of the PW? 5-7kw?
 

sorka

Well-Known Member
Feb 28, 2015
7,867
5,780
Merced, CA
Disconnect main and just ride on powerwalls for the rest of the day. Switch it back on when sun is down.

Your earlier attempts was trying to fill the powerwall as quick as possible to full as soon as possible. So grid energy was used.

Do you have 1 or 2 powerwalls? What's the max charge rate of the PW? 5-7kw?

Was doing that for a little while until my TEG updated to 1.50.2 which ruined that because the PWs now switch frequency past 60.4 HZ starting around 80% causing the inverter to cycle for the rest of the day.

There was no real grid energy used to charge the powerwalls. Occasionally shows a hundred watts or so but my point of that picture above was to show all the solar production was going to the PWs and not first to the house with the leftover going to the PWs.

BTW, if I had PTO, the current time based behavior is exactly what I want. I want to charge the powerwalls from solar and use cheap off peak power for the house so that I can put as much as possible during peak from solar to the grid.....despite the NBCs.
 

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