Time of Use Power Shifting for Powerwall 2

[nil0lab]

> 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. ...

7 > 1.374, so that sounds like compliance to me.

The chart represents your electric bill? Doesn't seem relevant. The amount going to/from powerwall is the important value.

 

[jfabula]

I've been hearing conflicting pieces of information. I have Quantity 2 Powerwall getting installed on Wednesday next week. I live in a townhouse complex, so no Solar right now (maybe in the future). I wanted the Powerwall 2 because I currently am on EV-A because of my Model S.

What I want to do is to charge the two Powerwall 2 between 11pm and 6am @ $0.125 and use it throughout the day. My average daily usage is around 14kw, so that's why I went with two Powerwall.

I'm hearing that even with the latest firmware for the Powerwall, that Tesla does not yet support Time of Use Power Shifting, and right now all your an do is do whole home backup.

Is this true? All of the online documentation and the events they held at the factory in Fremont, indicated that we could do Time of Use Power Shifting.

I've tried searching in this group, but I'm seeing old posting that say the same thing, that it is supported by the hardware, but I can't find anyone WITHOUT solar who is doing this.

Can any exiting Powerwall user confirm this?

Note: When I run through my calculations based on PG&E web site for daily usage, I'm saving over 50% of my bill because during daytime hours we're paying upwards of $0.40/kwh, and with the Time of Use Power Shifting, I'll be consume stored energy at $0.125/kwh.

Note: We have AC, but we barely used it. The few days we do use it, we use around 20kwh per day, so two Powerwall will handle that.

Note: All the numbers above exclude the Model S because my Powerwall will be off grid, and NOT connected to the power walls (or that's my plan)

Im with SDGE and I have Solar (Solar City) now that I am on EVTOU2, all my power produced and send to the grid during the off peak hours (where most of the sun is up)the utility pays me zero, nada, none.....Im kind of contemplating of going to power wall but awaiting on how Tesla can do the automatic calculations of charging the power for that power being send to the grid...TESLA, IM WAITING....its gonna be a long wait I know....hahaha

 

[Ampster]

but awaiting on how Tesla can do the automatic calculations of charging the power for that power being send to the grid...

Yes it will be a long wait not because of Tesla but because I don't think there is anybody out there that can do the calculation that you are asking for. Maybe I misunderstood what your expectation is, but a PowerWall can save you money but only by load shifting. SDGE is trying to get some fixed charges approved that will make even that less productive.

 

[jason1466]

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%.

Does anyone have an idea why my system does not act like this even though I want it to?

I have tesla solar and 3 powerwall2s installed 2 years ago, TOU in Maryland for 1 year, we have only peak and off-peak periods. App is set to Cost Saving and 80% reserve. During peak time the solar goes to home first, then batteries second, then grid last, even with batteries charged 80-90%. Is there perhaps an installer setting to prioritize solar to grid during peak times?

Tesla service has been quite useless telling me to wait for the next firmware update when I called twice in the last 6 months.

 

[cwied]

Does anyone have an idea why my system does not act like this even though I want it to?

I have tesla solar and 3 powerwall2s installed 2 years ago, TOU in Maryland for 1 year, we have only peak and off-peak periods. App is set to Cost Saving and 80% reserve. During peak time the solar goes to home first, then batteries second, then grid last, even with batteries charged 80-90%. Is there perhaps an installer setting to prioritize solar to grid during peak times?

Tesla service has been quite useless telling me to wait for the next firmware update when I called twice in the last 6 months.

What is your peak time period? If there are solar hours that are off-peak, the Powerwalls should charge during those and then discharge during the peak period until they hit the reserve. On the other hand, if there are no off-peak solar hours, you would get the behavior you're describing because the Powerwalls can only charge from solar. The last time I looked at the installer wizard, I did not see any settings that would override the TOU algorithms.

 

[jason1466]

What is your peak time period?

6-9am October-May, 2-7pm June-Sept

The sun is good enough most days to power the house and still send extra to the PW by 7:45am, worst case was 8:30am in December. There is always enough sun in both periods except obviously on very cloudy days to charge the battery for these 6-9am peak needs. I also notice the powerwall discharges early, about 5am when reserve is set to 90%, and all night long if reserve is set to 20%. But why would it deplete itself in off-peak, and on occasional cloudy days it even runs itself out during peak time.

 

[cwied]

That does sound strange. It doesn't sound like it's in Cost Savings mode. You might try to reset all your settings and schedules. Set the weekday and weekend schedules separately just to be safe. What firmware revision are your Powerwalls running?

 

[Dave EV]

Im with SDGE and I have Solar (Solar City) now that I am on EVTOU2, all my power produced and send to the grid during the off peak hours (where most of the sun is up)the utility pays me zero, nada, none.....Im kind of contemplating of going to power wall but awaiting on how Tesla can do the automatic calculations of charging the power for that power being send to the grid...TESLA, IM WAITING....its gonna be a long wait I know....hahaha

Huh? On SDGE EV-TOU2 the Super Off-Peak rate is $0.20 / kWh, so if you're exporting during that time (12AM-6AM weekdays, 12AM-2PM weekends/holidays, and 10AM-2PM everyday March/April), you're getting credits of $0.20/kWh. Most of the time you're exporting electricity during Off-Peak times, at $0.30 or 0.35 / kWh in winter/summer months. And you might be able to export a bit at peak rates ($0.31/0.59 / kWh) from 4-9 PM.

But most houses will be net-importers during peak rates, so yeah, you might have to export 2-3x as much solar to make up for it. A single Powerwall should be enough for most houses to keep from drawing from the grid during peak hours - I've been meaning to write some software to calculate just what the ROI looks like for a Powerwall under this rate structure.

PS - if you're a net importer of electricity, look at EV-TOU5 - the Super Off-Peak rate is only $0.09 / kWh so it makes charging your EV super-cheap, but to make up for the flat $16/month bill on this rate, you have to net import at least appx 160 kWh / month during Super Off-Peak times - generally easy to do with at least one EV.

 

[jfabula]

Huh? On SDGE EV-TOU2 the Super Off-Peak rate is $0.20 / kWh, so if you're exporting during that time (12AM-6AM weekdays, 12AM-2PM weekends/holidays, and 10AM-2PM everyday March/April), you're getting credits of $0.20/kWh. Most of the time you're exporting electricity during Off-Peak times, at $0.30 or 0.35 / kWh in winter/summer months. And you might be able to export a bit at peak rates ($0.31/0.59 / kWh) from 4-9 PM.

But most houses will be net-importers during peak rates, so yeah, you might have to export 2-3x as much solar to make up for it. A single Powerwall should be enough for most houses to keep from drawing from the grid during peak hours - I've been meaning to write some software to calculate just what the ROI looks like for a Powerwall under this rate structure.

PS - if you're a net importer of electricity, look at EV-TOU5 - the Super Off-Peak rate is only $0.09 / kWh so it makes charging your EV super-cheap, but to make up for the flat $16/month bill on this rate, you have to net import at least appx 160 kWh / month during Super Off-Peak times - generally easy to do with at least one EV.

I am currently on EVTOU-2, will see how my annual billings looks like and probably will try the EVTOU-5 next year....my PV used to get me by without paying over $100 per year, but a lot of changes in the utility this year specially with my Tesla. No more free lunch, hahaha