Tesla still has to make the firmware enforce your interconnect rules. If you have a non-export interconnect agreement, then they have to make sure that no combination of user settings will allow it to discharge into the grid. When I originally calculated arbitrage potential, I did not consider such things.
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Time of Use Power Shifting for Powerwall 2
- Thread starter zanary
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- Powerwall Tesla Energy
I'm not too sure why applying for SGIP or the 30% Federal Tax Credit would limit functionality for ToU once the PowerwallOS update is available? ToU is something that the Powerwall will provide once Tesla get the buy in from the electric grid operators. In any event, even if they don't introduce the software you can still do it manually. It's a PITA, but it works.
I've been doing it manually since Sept 13, 2017. No PV here, just Quantity 2 Powerwall so I can do ToU because purchasing electricity from PG&E at $0.125/kw (non-peak) is much cheaper than $0.43/kw (peak)
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I just contacted Tesla Energy. The Dec 31st date was pushed to 1st week of February 2018. Hope it comes out that week.
Frankman60
Member
Yes, this is what I would like to do to neutralize SDG&E’s recent redefinition of Peak hours. I have been using a TOU rate plan for the past 8 years with Peak period defined as 12:00 PM to 6 PM. A solar PV system in my location with this Peak period window allowed me to sell most of the excess solar energy to the utility at Peak rates (up to 50 cents per kWh). To stop that from happening, SDG&E changed the Peak window to 4 PM to 9 PM last month. So now, the utility is buying my excess solar production in the middle of the day at a low rate, and charging me the highest rate when I am home using appliances and not producing solar energy (i.e. 4 to 9 pm). With a few Powerwalls, I want to do what Wayne says in his post. That is, store the excess solar energy in the Powerwalls up to 4 PM, and then use the Powerwall energy during Peak, and what I don’t use before 9 PM push it onto the grid to get a premium price for it. Will this be possible with Powerwall II?
Yes, from Tesla’s Powerwall 2 homepage under “Supported Applications”:
“Time-of-use load shifting (coming soon)”.
This is the only reference I can find on their web site (FAQs):
How does Load-Shifting Time of Use work?
This feature will be available in early 2018.
Powerwall will be able to store grid and solar energy when rates are lower, and discharge that energy to offset your usage when rates are higher. Using the Tesla mobile app, you will be able to customize a charge/discharge schedule based on your utility's Time-of-Use rate plan.
So my guess is that it may - but I've never seen any specifications on how it is supposed to work for any feature.
How does Load-Shifting Time of Use work?
This feature will be available in early 2018.
Powerwall will be able to store grid and solar energy when rates are lower, and discharge that energy to offset your usage when rates are higher. Using the Tesla mobile app, you will be able to customize a charge/discharge schedule based on your utility's Time-of-Use rate plan.
So my guess is that it may - but I've never seen any specifications on how it is supposed to work for any feature.
I think "offset your usage" mean using the energy, not putting it back into the grid. I imagine the utilities really don't want to buy stored energy if they can avoid it. I don't think they want to buy solar energy, either, but they are forced to in California.
In Australia they will pay the same Feed In Tariff (FIT) at the same rate at any time during the day (of course I've heard discussions that this may change). There are also no restrictions on when that can be feed back into the grid. Until Tesla does something similar to Reposit Power and will let you send power to the grid when it is most beneficial to you and the grid provider (which will take a lot of development and marketing agreements) then it will only be TOU if you want to charge your PW2 at off-peak rates and only use the PW2 during Peak or as we say here in AUS is not so peak (shoulder rates).
I have no idea what Tesla is going to offer in their TOU upgrade to their application - I've never seen a specification on their features or functionality so no one has a clue to what the future will bring.
I have no idea what Tesla is going to offer in their TOU upgrade to their application - I've never seen a specification on their features or functionality so no one has a clue to what the future will bring.
WannabeOwner
Well-Known Member
No Feed-in-Tariff export meter here (well ... not in my home, maybe in some homes in UK), so Utility assumed that 50% is exported, and pays accordingly. Haven't looked at whether using a Battery voids that ... probably does. Not installed Powerwall as not quite ticking all the boxes I need yet ...
... we have max solar panels (forgotten the actual output, but its 16 panels) for single-phase. To be able to "export more" I would have to upgrade to 3-Phase, which in UK because of monopoly is an arm-and-leg to install, even if everything they need is at the nearest pole ... (it is possible to ask the Utility if my property would be allowed to export more - presumably if the local area infrastructure would support that then they would be happy, but I haven't asked)
My plan is to install more solar and feed that into Powerwall, so only my legacy 16-panels exports to grid (and gets the FiT subsidy payment). I'd like to reduce my usage (car mostly charged at work) but we have a lot of work-based computer/server stuff running here
hence I would like to install more self-generation
Also considering if I could install Wind instead/in-addition. Its basically open farmland towards the prevailing wind, but we have some trees around which, last time I enquired, would cause too much wind turbulence to be much good for generation. I have a tower and logging anemometer, which has been lying on the deck for ... Ahem! ... "some years" ... which I really need to get mounted to start logging how good my wind is
basically I need to get off my backside and get on with it ...
... but I wonder if you folks States-side who have restriction on Federal + Local subsidies could have two powerwalls, and only charge one of them for ToU in order not to fall foul of the rules-and-regulations? Some cost involved of course ...
... we have max solar panels (forgotten the actual output, but its 16 panels) for single-phase. To be able to "export more" I would have to upgrade to 3-Phase, which in UK because of monopoly is an arm-and-leg to install, even if everything they need is at the nearest pole ... (it is possible to ask the Utility if my property would be allowed to export more - presumably if the local area infrastructure would support that then they would be happy, but I haven't asked)
My plan is to install more solar and feed that into Powerwall, so only my legacy 16-panels exports to grid (and gets the FiT subsidy payment). I'd like to reduce my usage (car mostly charged at work) but we have a lot of work-based computer/server stuff running here
hence I would like to install more self-generationAlso considering if I could install Wind instead/in-addition. Its basically open farmland towards the prevailing wind, but we have some trees around which, last time I enquired, would cause too much wind turbulence to be much good for generation. I have a tower and logging anemometer, which has been lying on the deck for ... Ahem! ... "some years" ... which I really need to get mounted to start logging how good my wind is
basically I need to get off my backside and get on with it ...
... but I wonder if you folks States-side who have restriction on Federal + Local subsidies could have two powerwalls, and only charge one of them for ToU in order not to fall foul of the rules-and-regulations? Some cost involved of course ...
Frankman60
Member
I presently have a 7.6 kW AC ground mounted 44 panels and 2 SMA inverters. I saw two numbers in the Tesla website about the maximum kW rating of each Powerwall. I saw 7 kW and 7.6 kW. If 7.6 kW is the maximum amount of power that the Powerwall can handle, I should be able to use just one Powerwall with my PV system right? This would provide a 13.5 kWh backup or eventually the ability to time shift up to 13.5 kWhs of energy with a TOU rate plan.
My understanding is that the Powerwall 2s have built in inverters. But if that is right, why does the Tesla FAQ say that the Powerwalls are compatible with SMA and other manufacturer’s inverters?
For those of you in California, could you point me to an explanation of how the California rebates work? I looked at the SDG&E SGIP webpage but I don’t understand the 5 “step”s shown and how the funding for this program works. How much of a rebate can I count on from California, and would I be able to know how much before I committed to an installation?
Please let me know if I am not correct about anything that I stated above. Thanks!
My understanding is that the Powerwall 2s have built in inverters. But if that is right, why does the Tesla FAQ say that the Powerwalls are compatible with SMA and other manufacturer’s inverters?
For those of you in California, could you point me to an explanation of how the California rebates work? I looked at the SDG&E SGIP webpage but I don’t understand the 5 “step”s shown and how the funding for this program works. How much of a rebate can I count on from California, and would I be able to know how much before I committed to an installation?
Please let me know if I am not correct about anything that I stated above. Thanks!
The only time a rating of a draw of around 7kWs is the initial load. The normal maximum draw and recharge rate is 5kWs, and I think that is reduced when you have more than one. Or at least that is what I've seen posted, I only have one PW myself and the max I've seen is 5kWs draw and recharge.
eml2
Member
7kw is the maximum discharge rate. Charge rate is max out at 5 kW. If you have solar and the Powerwall/Backup Gateway is setup properly, each Powerwall will be charged up to 5 kW. i.e., if you have 2 Powerwalls, the charge rate is up to 10 kW.
My grid-charging of 4 Powerwalls is limited to 6.7kW. Maybe the Grid-Charging is limited by the AC-->DC conversion?
Nope. Solar charging PowerWall(s) 2.0 goes through the same conversion. If anything, they're intentionally being gentle on the grid load while soaking up the solar fast is also minimizing grid impact.
When I talked to support last night they indicated that they are hoping that it will make it out this month (Jan 2018)
arnold
I think you misspelled "next year".OK, so it will be out next month...
Parzival
Member
FWIW, my retail electric provider (MP2 Energy) is working on incentive plans for EV charging as well as Powerwalls for later in 2018. They would not tell me exactly what the plans are, but since I have both, I signed up to get the details later. I would not mind selling energy to the grid from the Powerwalls if there's enough in it for me. I assume the EV plan will involve some kind of device that can interrupt charging at times of peak load, but maybe I am overthinking it and they will just want to switch me to a TOU plan from the fixed $/kWh plan I am on now.
