jgleigh
Member
Storm Watch definitely charges from the grid so anyone should be allowed. You just normally don't want to do it since it's not cost efficient.
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New Powerwall Advanced Options [Toggles for charging from and discharging to grid from powerwalls]
- Thread starter dailo
- Start date
Storm Watch definitely charges from the grid so anyone should be allowed. You just normally don't want to do it since it's not cost efficient.
jgleigh
Member
I just saw it today. Probably some combination of app version and Gateway/Powerwall version and/or a push from Tesla.
I'm pre-PTO and I have both options available. If this means I can enable myself after I get PTO from the power company, that is a big improvement. I don't have TOU plans to take advantage of the Charge From Gird but it could be handy if Stormwatch is not enabled. These are good improvements.
I have PW+'s. Maybe that is why these options are available?
I have PW+'s. Maybe that is why these options are available?
According to the support page, yes, the Permission to Export setting is available for Powerwall+. Because of the integrated solar inverter, Powerwall+ has more direct control over how much solar is exported to the grid, where it can't with other solar inverters. (So, one would not expect to see this on a system without Powerwall+)
Somewhat paraphrasing from the support page: In the US, the grid charging setting set to 'No' is intended to comply with the Investment Tax Credit (ITC) guidance from the Internal Revenue Service of charging your Powerwall 100% from solar. When set to ‘Yes,’ Powerwall will charge from the grid[...]. Consider your energy goals and consult your tax advisor regarding any tax-related impacts before enabling Grid Charging.
In reality I am sure the IRS will probably never audit anyone for just the ITC, but wonder how it would work since if you ever have a storm watch event you could not claim that you charged the PW 100% with solar which means you can't claim 100% of the ITC.
What are the implications of grid charging if you've used the tax credit? Will the power company send me a letter? Will the IRS find out? Is it supposed to be the honor system?
My solar export rate is $0.1045/kWh, but I buy power at $0.051/kWh, so it's advantageous for me to charge from the grid, but obviously "against the rules".
My solar export rate is $0.1045/kWh, but I buy power at $0.051/kWh, so it's advantageous for me to charge from the grid, but obviously "against the rules".
In PG&E land, it is cost efficient. I could charge PWs at $.13/kWh and export solar at $.59/kWh
I’m with you … no grid charge option under the Powerwall settings. My screen says operation mode where I select time based control and set a utility rate plan. Nothing else appears there…
Gateway 2 running 22.9.1, iOS app 4.7.3
aesculus
Still Trying to Figure This All Out
Not attacking your post just stating Tesla's logic makes no sense to me. All inverters for the last several years must have the ability to be able to be driven from the utility in terms of limiting solar production. I have yet to see examples of when it has been applied but it's there.
So this seems to be more about your PTO state than anything. And truthfully it should apply to all PWs, with solar or not. All PWs have inverters and have to comply with the utilities signals for exporting power, from the battery or from solar in real-time.
I don't think either the power company or the IRS has a way of finding out that you're grid charging. All the power company can see is that you're using energy, not what it's being used for. Tesla would have to be the one to notify them of the grid charging. I'm not sure why Tesla would do this unless somehow obligated to.
For businesses, Investment Tax Credits have a five year recapture period during which the credit may be recaptured if you no longer qualify. I suspect that at worst, the same would apply to individuals. This would imply that it might be ok to turn on grid charging five years after you get your Powerwalls, but I'm not a tax expert so I recommend that you do your own due dilligence.
Not quite—the utility has smart inverter control over solar inverters (including the Powerwall+ solar inverter) while on-grid, not the Powerwall. Powerwall uses similar controls (e.g., microgrid frequency changes) while off-grid, but it cannot and will not mess with the grid to control other inverters while on-grid.
Right, but that signal from the utility is just the AC frequency, there's no out-of-band communications.
So while on-grid, the utility is controlling the AC frequency, and the ESS (storage, i.e. PW) and PV inverters are in grid-following mode. To tell one of those inverters to export less than the maximum, you'd need an out-of-band communications channel. Which the PW/Gateway has, so it can decide how much to export. And in PW+, the PV inverter is integrated, so it can control the PV inverter that way. But with some other PV inverter, there's no way for the PW/Gateway to control how much that other PV inverter is exporting while on grid.
Cheers, Wayne
Not at the bottom of Powerwall | Advanced Settings? It is showing for my GW2 and ipad running app version 4.7.3
I am so glad I have enough solar I just set and ignore. No need to play with stuff to try and save a few bucks.
But if it ever gets enabled, having the option in the dead of winter with no storm watch on, but batterys dead, nice safety feature
Yippie! I've been pushing for grid charging and finally Tesla has enabled it.
So, Thank You Tesla!
Also thanks to h20fun who emailed me about this new app version.
I am in California PG&E territory, on EV rate with high peak pricing. During summer my solar produces enough to let me use only off-peak grid power. But on cloudy and short winter days I don't have enough production, so the option to charge from the grid will save me a few bucks.
Staying completely off the grid during peak periods also puts the lie to recent statements by PG&E and the CPUC that our rooftop solar is being subsidized by poor people who can not afford solar. They are campaigning to renege on NEM, so this is big deal.
So, Thank You Tesla!
Also thanks to h20fun who emailed me about this new app version.
I am in California PG&E territory, on EV rate with high peak pricing. During summer my solar produces enough to let me use only off-peak grid power. But on cloudy and short winter days I don't have enough production, so the option to charge from the grid will save me a few bucks.
Staying completely off the grid during peak periods also puts the lie to recent statements by PG&E and the CPUC that our rooftop solar is being subsidized by poor people who can not afford solar. They are campaigning to renege on NEM, so this is big deal.
h20,
I'm in PG&E, last night updated iPhone app to V4.7.3. (Shown on the App top page, no PW or car page.). PW setting page has been re-organized, with sub-pages for PW, car charging, storm watch, etc. On the Settings PowerWall sub-page is Advanced Options, Grid Charging.
On the Settings / My Home Info page, it says my Gateway software version is 22.9.1 . I haven't paid attention to the GW software updates, but if they use the same nomenclature as in the car software, this was released in the 9th week of this year, i.e. early Feb.
Per the documentation, denying export means throttling the solar production to match house consumption after PW is full. My older Enphase micro-inverters can not do that, but apparently Tesla's modern inverters can.
I have a hunch about this export option. A friend has a tiny grid tied solar charged backup battery system (not Tesla) which claims not to need utility permission, because it is configured to never exports solar to the grid. Perhaps Tesla's no-export option would allow solar installations without any utility permission. What happens behind the meter stays behind the meter. That would mean no NEM, and importantly no proposed NEM3 solar panel tax. But that is probably a discussion for the NEM3 thread. Anyway, just a hunch on my part.
Last night, in off-peak time, mine grid charged at 3.3kW. Reserve was still set at my usual summertime setting of 20%.
I've turned on grid charging a couple time today, and it appears to prefer to charge from solar when that is available. More time will tell.
I also plan to grid charge mostly during winter. Even cloudy summer days recharge us completely after our peak period discharge.