Time of Use Power Shifting for Powerwall 2

[Frankman60]

If I am able to log in as an Installer, does it immediately go through the set up wizard or do I have to start it? Is it obvious what to do if I am trying to change the TBC setting to Self Powered mode? Are there any other things to be careful of when doing this?

Installer. Try your gateway serial number with "S" in front of it (if not already there) as the password. I believe if they changed the password you should be able to go through the password recovery procedure to log in.

 

[NuShrike]

If I am able to log in as an Installer, does it immediately go through the set up wizard or do I have to start it? Is it obvious what to do if I am trying to change the TBC setting to Self Powered mode? Are there any other things to be careful of when doing this?

Everything is pretty self-explanatory. Don't mess with the CT settings if you don't understand it.

The PWs will refuse to start (grey background = success instead of white background), if it thinks it's misconfigured. It's pretty hard to misconfigure it, and there isn't any real configuration except for the CTs. It only matters to set some some inverter if it thinks you need it.

 

[cwied]

@Frankman60 - one other note - the wizard will not let you change the operating parameters if you are in TBC mode. It will only let you change the mode and backup reserve if you're either in backup or self-consumption mode. For instance you could switch to backup mode before the OhmHour and then switch to self-consumption with reserve of 10% when the OhmHour starts.

 

[Artimis]

OK - so I am trying to resend to an ohm hour and wanted to start the powerwall powering the home. Switched to self-powered at 7:40 pm to force the battery to be used instead of the grid. 8:35 pm and the change has not taken affect. Is there a was to force a new setting to be used?

Another way to do this besides logging into the gateway's web interface (if you are technically inclined) is to utilize the API (documentation is floating around these boards).

Personally, I have an Android phone and use Tasker + RESTask plugin to make the necessary calls for the this. That allows me to change the mode instantly with a push of a button (or voice command).


BTW, I envy you that you still get Ohm Hours. I haven't gotten one in like 10months. Ever since the found out I was a solar user with battery storage, it's like they flagged my account or something.

 

[Frankman60]

@Artimis and @cwied thanks for those tips. Getting back to the reason for doing this, Ohm Hours, I am trying to understand how this works. My PWs are set for TBC Cost Savings and every day during Peak from 4 to 9 PM they supply all of the power for my home. Therefore, my baseline usage for this 5 hour window is zero. If I understand this correctly, I would not want to schedule Ohm Hour availability during this window because I can’t use less electricity than my baseline during the Ohm Hour. I set my Ohm Hour availability from 10 to 3 PM because I figured I could switch from TBC to Self Powered if I received an Ohm Hour notification during that time period. But during the last two weeks I have not received any Ohm Hour notifications for that time period. I know that the past few days because of the heat there has been a high electricity demand here in California but still no Ohm Hour notification. Am I understanding Ohm Hours correctly. Suggestions appreciated.

 

[Artimis]

@Artimis and @cwied thanks for those tips. Getting back to the reason for doing this, Ohm Hours, I am trying to understand how this works. My PWs are set for TBC Cost Savings and every day during Peak from 4 to 9 PM they supply all of the power for my home. Therefore, my baseline usage for this 5 hour window is zero. If I understand this correctly, I would not want to schedule Ohm Hour availability during this window because I can’t use less electricity than my baseline during the Ohm Hour. I set my Ohm Hour availability from 10 to 3 PM because I figured I could switch from TBC to Self Powered if I received an Ohm Hour notification during that time period. But during the last two weeks I have not received any Ohm Hour notifications for that time period. I know that the past few days because of the heat there has been a high electricity demand here in California but still no Ohm Hour notification. Am I understanding Ohm Hours correctly. Suggestions appreciated.

Yes, you understand Ohm Hours correctly and I've faced the same issues with it myself for that same reason. My strategy has been a little different......I typically run in self-consumption mode (reserve set to 70%) most of the time. I try to target hours where the sun is transitioning (e.g. 5-6pm) whenever possible so I can use the Cost Savings mode to divert all my solar production to the grid while running off battery.

Example: Let's say that around 5pm on a typical day, my system is still producing 3kW at this hour and my house is consuming 1.5kW. That means my average baseline around this time would be -1.5kW. If there is an Ohm Hour scheduled for this time, I'll setup Time-based control in Cost Savings mode with Peak schedule for the Ohm Hour time. This will force the gateway to run my house on the battery while diverting all 3kW that the solar is producing to the grid. So I'll get credit for double what my baseline would be (-3kW for that hour).

The problem I have been having is I'm just not getting Ohm Hours for those times anymore (even when I had voting enabled and people voted for those times). Seems all the Ohm Hours in my area are well after the sun goes down which does me no good since my baseline is already at 0 for those times.....and with no sun, it's impossible to get lower than that.

 

[cwied]

Because of the "duck curve," I believe OhmHours now tend to happen 6pm-9pm. I'm on the P&E E-6 rate, so my peak ends at 7pm. I set everything after 7pm to off-peak. This means that if I get OhmHours in that period, it reduces my marginal cost for electricity usage during those hours (since any usage adds to my baseline). Note that since it's set to off-peak after 7pm, the residual solar production goes to charge the Powerwall so it doesn't lower my baseline.

I got OhmHours 7-8 pm last Wednesday, 8-9 pm this Monday and 7-9 pm yesterday. The latter had only 15 minutes notice.

I've actually automated my Powerwall settings using OhmConnect's IFTTT triggers. When the OhmHour starts, the Powerwall is switched to self-consumption with 15% reserve. When the OhmHour ends, it is switched to 100% reserve. I then manually change it back to TBC because the "API" doesn't support TBC. When you go directly to the API, it doesn't have the limitation that you can't switch modes away from TBC.

The bottom line is that you have to make a choice for each time period whether you're going to use the Powerwall to offset peak rates or if you're going to use OhmConnect to offset the cost instead. During the summer, it's probably advantageous to use OhmConnect. I'm not as sure it's worth it in the winter given the lower frequency of OhmHours and the lower payouts. It may be worth it in San Diego since the grid is in worse shape - I would ask on the OhmConnect forums.

 

[NuShrike]

Because of the "duck curve," I believe OhmHours now tend to happen 6pm-9pm. I'm on the P&E E-6 rate, so my peak ends at 7pm. I set everything after 7pm to off-peak. This means that if I get OhmHours in that period, it reduces my marginal cost for electricity usage during those hours (since any usage adds to my baseline). Note that since it's set to off-peak after 7pm, the residual solar production goes to charge the Powerwall so it doesn't lower my baseline.

I got OhmHours 7-8 pm last Wednesday, 8-9 pm this Monday and 7-9 pm yesterday. The latter had only 15 minutes notice.

I've actually automated my Powerwall settings using OhmConnect's IFTTT triggers. When the OhmHour starts, the Powerwall is switched to self-consumption with 15% reserve. When the OhmHour ends, it is switched to 100% reserve. I then manually change it back to TBC because the "API" doesn't support TBC. When you go directly to the API, it doesn't have the limitation that you can't switch modes away from TBC.

The bottom line is that you have to make a choice for each time period whether you're going to use the Powerwall to offset peak rates or if you're going to use OhmConnect to offset the cost instead. During the summer, it's probably advantageous to use OhmConnect. I'm not as sure it's worth it in the winter given the lower frequency of OhmHours and the lower payouts. It may be worth it in San Diego since the grid is in worse shape - I would ask on the OhmConnect forums.

My TBC app, I can schedule an OhmHour period same way as yours. Just had one yesterday, and worked like a TpLink scheduled event. I need to put a GUI on it though.

As said, because of solar and duck-curve one will probably never ever get an OhmHour during solar hours (such as 10am to 3pm). The only really viable OhmHours are 7pm to 11pm. My allowed OhmHours are from 8pm to next morning.

I don't use Tesla's stone-age TBC. I configure 4 shoulder-peak periods (via self-powered and reserve-level), and I don't run the PowerWalls past 8pm, so that works with OhmHours. I'm never zero past 8pm unless OhmHour.

If I can generate enough load, such as charge the batteries from 7pm on (during peak), I would allow OhmHours then also.

 

[Frankman60]

Thanks @NuShrike and @cwied. I now understand that I likely won’t see any Ohm Hours outside of the Peak period (4 - 9 PM), because they will likely be during the Peak period. That makes sense.

 

[markwong]

Can anyone help me explain what is the difference when you adjust the Tesla app of PW where it shows grey bar? I think I understand that yellow is peak, blue is off peak. What happen if I adjust to get some grey in it. I have TOU in Arizona and in Nov 1st, the peak will be 5am-9am; 5pm-9pm. Not sure how to adjust to make it work.

 

[MorrisonHiker]

Blue = Off-peak
Gray = Shoulder/part-peak
Orange = Peak

Depending on which TBC setting you use, the Powerwalls will attempt to first cover peak usage. They can then continue to cover shoulder/part-peak usage. Later, they will even discharge during off-peak if they have sufficient charge and it is getting close to when they will start charging again via solar.

Do you have all three rate periods (off-peak, shoulder/part-peak and peak) in Arizona?

 

[markwong]

I don't have shoulder. I only have 3 rates. Peak, off peak, super off peak being a EV owner. My electric company is SRP. All year round for EV owner they give me super off peak from 11pm-5am. Other times are such below.

May 1-Oct 31 peak from 2pm-8pm

Nov 1-Apr 30 peak from 5am-9am; 5pm-9pm.

So for the period of May 1-Oct 31, it's easy for me to set up PW to charge during super off peak then discharge during other period to cover the peak period.

Now Nov 1 is getting closer, not sure how to set it to cover the 2 peak period.

 

[nil0lab]

It's a few months later, but I'll add my 2c for posterity. As I read the SGIP regs, when applying for SGIP with solar, you agree that you won't charge the powerwall from grid. And also the federal tax incentive has similar restrictions. Tesla "Customize, Advanced, Cost Saving" setting results in my solar going straight to grid during peak hours for maximum dollar-basis credit and my solar going into my powerwall off peak to run my home during those same peak hours and avoid consumption at peak rate. So not actually shifting power from grid cheap-time to grid expensive time, but getting some of that effect. General behavior is my powerwalls charge up during summer weekends, draw down during summer weekdays, and stay pretty full during the winter.

 

[nil0lab]

You definitely cannot claim the ITC without renewable energy charging at least 70% of the energy going into the batteries.

With app set to Customize, Advanced, Cost Saving, my weekend and morning solar goes into the batteries, peak time solar goes to grid, so it's easily 70%.

 

[AEdennis]

It's a few months later, but I'll add my 2c for posterity. As I read the SGIP regs, when applying for SGIP with solar, you agree that you won't charge the powerwall from grid. And also the federal tax incentive has similar restrictions. Tesla "Customize, Advanced, Cost Saving" setting results in my solar going straight to grid during peak hours for maximum dollar-basis credit and my solar going into my powerwall off peak to run my home during those same peak hours and avoid consumption at peak rate. So not actually shifting power from grid cheap-time to grid expensive time, but getting some of that effect. General behavior is my powerwalls charge up during summer weekends, draw down during summer weekdays, and stay pretty full during the winter.

Don't you need to draw down the equivalent of your PW2 capacity every week for California SGIP?

My configuration in California (SCE) is to run off the PW2 during the week-day peaks, then charges at off-peak and super-offpeak... However, in the weekend, I still discharge even though it is an off-peak time as I want to make sure that I hit the full PW2 capacity cycle.

 

[miimura]

With app set to Customize, Advanced, Cost Saving, my weekend and morning solar goes into the batteries, peak time solar goes to grid, so it's easily 70%.

They don't care how much of your solar goes into the grid versus the batteries. They only care what goes into the batteries. For Residential ITC, the IRS says 100% of the battery energy must come from on-site renewable generation. I'm not sure why the Storm Watch grid charging is allowed. In any case, I have Storm Watch turned off because I don't want it to charge from expensive Peak power without my knowledge.

 

[MorrisonHiker]

They don't care how much of your solar goes into the grid versus the batteries. They only care what goes into the batteries. For Residential ITC, the IRS says 100% of the battery energy must come from on-site renewable generation. I'm not sure why the Storm Watch grid charging is allowed. In any case, I have Storm Watch turned off because I don't want it to charge from expensive Peak power without my knowledge.

We usually leave Storm Watch enabled but keep an eye on it. It does send a notification to the app when it is activated so you can disable it temporarily if you want to avoid peak charging.

 

[jboy210]

They don't care how much of your solar goes into the grid versus the batteries. They only care what goes into the batteries. For Residential ITC, the IRS says 100% of the battery energy must come from on-site renewable generation. I'm not sure why the Storm Watch grid charging is allowed. In any case, I have Storm Watch turned off because I don't want it to charge from expensive Peak power without my knowledge.

I plan on leaving Storm Watch disabled also for the same reason. I figure the apps makes it easy to adjust the PW levels based on conditions. Also, the biggest reason we are getting PWs is because of power shutoffs from PG&E. And they send out alerts at least 24 hours ahead of time.

 

[Ed Hart]

You guys have me worried about whether I am in compliance. I have two PWs, and the directive I got was this:

"Over the next five years the system needs to meet SGIP’s minimum requirement to support the grid infrastructure. For each Powerwall installed, this means discharging 687 kWh of each Powerwall's capacity to meet your home's energy needs every 12 months."

I translated that to mean my "From Powerwall" figure must be at least 1.374 mW each year. Last year, that number was 7 mW for me. All the PW juice comes from solar. I have had the reserve set at the recommended 20%.

The PW then typically runs our home until 10:00 PM at which time our rate drops from summer peak of $0.53 to $0.13/kWh. We charge the first car starting at 10:00, then the second car at 2:00 AM. It all seems to work, and our electric bill is the minimum charges.

So....do I understand the rules correctly?

 

[bob_p]

Storm Watch could be an exception to the "charge PowerWalls only from solar" rule, allowing the PowerWalls to be temporarily charged from the grid prior to a potential power outage, without impacting Tesla's PowerWall warranty (which is different when charged from the grid) or the IRS tax credit.