I'm in same boat. I had NEM credit last true-up, but I was not a net producer. I've reduced my PW arbitrage so that I will end up ~zero true-upAfter a year of studying my NEM2-PS bill, it didn't quite work the way you said (at least, I don't experience it that way under NEM 2.0).
For example, in the previous annual true up cycle, my house took from PG&E 5,440 kWh. But I only exported 5,189 kWh. At first blush, I would have a NEM deficit and a true up bill right? Since my exports were less than imports?
However, I actually ended the year with a total combined generation + distribution NEM credit of about $150 (which PG&E just deletes when the NEM cycle resets). This is because for the annual kWh exported that is less than the annual kWh imported, they give me credit for the spot rate (peak, shoulder, off).
So when I export at noon, I get the off-peak rate. But if I export from 3pm to 4pm under EV2A, my NEM bank got the credit at the higher/shoulder rate. And for the rare peak 4pm to whenever exports, I got the peak EV2A rate.
So my understanding is that if I bank some solar in a Powerwall during off-peak, then export during peak... I get the higher rate (and even more credits) without actually generating more solar power. Basically I push my power out there when it's more valuable. I'll need to do this to charge my EVs without becoming a net NEM importer.
However, keep in mind these these credits vanish at the end of the NEM cycle. PG&E doesn't pay them out. If I export 5,000 kWh all at peak, and use 6,000 kWh from off-peak, I'd have like a $1,000 credit that gets reset with no cash payment or bill credit.
The $0.02-3 you speak of is the value of the kWh exported in excess of imports. This is actually paid out as cash or a bill credit.
At least, that's my understanding. Because PG&E blocked me from adding enough solar panels to be truly break-even on a NEM basis, I'll never know what it feels like to be h2ofun with lots of solar.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
New Powerwall Advanced Options [Toggles for charging from and discharging to grid from powerwalls]
- Thread starter dailo
- Start date
I'm in same boat. I had NEM credit last true-up, but I was not a net producer. I've reduced my PW arbitrage so that I will end up ~zero true-up
I have to admit, it is great to never have to think about this stuff. I just set it and leave it. Now, I did pay up front for this, so was not free.
I believe you're correct in that your credits are balanced based on $$ first, then if there is extra, is paid out at $0.02-$0.03 (no matter when it was banked). This makes exporting during peak better like you say since you build up a $$ credit faster (export 1 hour of peak is worth maybe 2-3 hours of off-peak).
My wonder/debate is whether the increased cycling of the battery is worth forcing your PWs to export when it's night time at all. I've been debating mentally whether I should raise my reserve so I start drawing power from the grid after peak periods (4pm-9pm) rather than use the battery overnight at all to minimize cycling the batteries even more. Does having a reserve of 80% allow the battery to last much longer vs. say, 20% or 40%?
I'm not sure how much degradation really appears from normal use. I assume with 10 year warranties, that's about full drains daily for 10 years. If it was 50% of that, maybe that's 20 years before it gets to the possible usual 70% degradation.
I pretty much stuck as many panels as I could and with more sun in So Cal, should end up net exporting anyways, but still not sure if it's worth it vs. using the battery more. I'll probably wait for my tru-up to see how the year went, but since we're already passed the winter months, assume it'll be more net exported for the rest of the year.
It goes like this:
If you have a $ deficit, you pay the $ deficit.
If you have a $ surplus, but a kWh deficit, you pay nothing and get nothing.
If you have a $ surplus and a kWh surplus, you get reimbursed for the kWh surplus at the $0.02-$0.03/kWh rate.
So "Export Everything" is only useful if you are otherwise in the first category. And once you hit the second category, there's no benefit in further "Export Everything." But of course if you are close to the threshold between the first two categories, it's hard to know exactly which side of the line you'll end up on.
Cheers, Wayne
I was in first category (but not a lot) before I got PWs. Now with PWs, I am in second category. Went too aggressive in the first year with the PWs and fairly large deficit. Now I am managing more carefully and expect to be about Zero true up. Oddly enough, I have the Grid Charge feature, but not the Export Everything
Thank you for the nice summary. I will leave it on TBC and Grid Charge On to see how well it goes.
I've been following this thread off and on, but since I don't have Powerwall's, things are a bit abstract. I've been trying to justify the economic arguments for ordering a Powerwall, which with Tesla also requires adding more solar to my existing 4 kw system. I know it's pretty hard to ever make an ROI argument for Powerwalls, but I keep coming up that aside from current load-shifting, if I can just export another 1-2kwh per day in summer where I'm producing surplus, it would at least bring the payback period on the Powerwall portion from 20 years down to a somewhat more reasonable 15 years or so.
So my understanding is that the new setting allows "Charging from Grid" generally during off-peak times, it is not allowing "Discharging to Grid" at peak times, or anytime for that matter. The only thing you can export during peak is "excess solar" net of what you self-consume or send to the Powerwall?
So if you have say ample late afternoon production, you could use "Charging from Grid" to fill up the Powerwall's on the "cheap gas" in the off-peak, so by say 4pm peak start, your Powerwalls are full. And if you're not consuming too much at that time, more solar could thus be exported at peak than before?
But if you have very little afternoon production (in my case due to shading), it won't help much? I do get about 2 kwh of production from 4-6 pm in the summer months, but I'm also consuming about the 2 kwh during that time. There's no way to configure "ok, let me consume the 2 kwh from the Powerwall during this time, while the 2 kwh of solar gets pushed to the grid" - as that not truly excess solar?
So my understanding is that the new setting allows "Charging from Grid" generally during off-peak times, it is not allowing "Discharging to Grid" at peak times, or anytime for that matter. The only thing you can export during peak is "excess solar" net of what you self-consume or send to the Powerwall?
So if you have say ample late afternoon production, you could use "Charging from Grid" to fill up the Powerwall's on the "cheap gas" in the off-peak, so by say 4pm peak start, your Powerwalls are full. And if you're not consuming too much at that time, more solar could thus be exported at peak than before?
But if you have very little afternoon production (in my case due to shading), it won't help much? I do get about 2 kwh of production from 4-6 pm in the summer months, but I'm also consuming about the 2 kwh during that time. There's no way to configure "ok, let me consume the 2 kwh from the Powerwall during this time, while the 2 kwh of solar gets pushed to the grid" - as that not truly excess solar?
If you are with PG&E for generation then you get paid at the 12 month average Net Surplus Compensation Rate which is currently $0.03936. The rate changes monthly and has been steadily going up and for May 2022 it is $0.04723/kWh.
If you are with a CCA for generation then your compensation for net kWh exports might be different. Silicon Valley Clean Energy, SVCE, was paying at the retail TOU rates and just switched to 200% of the NSC rates starting 4/1/2022. Since there isn't a TOU differential discharging during peak doesn't make financial sense any longer as a net producer due to the 10% loss on the recharge.
I believe one can only get credit to the max of the estimated PV generation. If one goes over, which I have, I got no credit for it. Not sure why folks are not looking at this first.
In my limited experience with time based mode it will do exactly that. During peak it powers the house from the powerwall and it exports all solar to the grid.
aesculus
Still Trying to Figure This All Out
Can you explain what you mean by "a fairly large deficit" and what you are doing to correct it?
I doubt that I will ever be a net producer and probably not get a $ surplus since I have an EV and heat pumps, but I need to know my options.
If you consume a lot more kWh than you generate, you will ultimately owe PGE more. I definitely use more than I generate but because of NEM and being able to shift my power, I can offset those costs and export more power during peak hours. With PW I only use the grid when rates are the lowest and export at the highest, so I end up banking credits. Without PWs I always had to pay quite a bit for NBC and usage during true up, but doing some balancing I expect to pay only NBC for my true up and hopefully the climate credits will offset that. With the export everything option I am able to export around 25+ kWh during peak daily, which has helped wipe out my winter usage pretty quickly.
I was using a Reserve of ~30% which allowed me to send a lot more solar to the grid during Peak. This pushed my NEM true up to -$800 which as described just goes poof. I was still a net user, so I did not have excess kWh. Now I set my reserve to 75% and I changed my Peak start time to 5pm (my actual Peak is 2pm to 9pm as I'm still on EV1-A). I should be on track for ~zero NEM at true up.
aesculus
Still Trying to Figure This All Out
Interesting. And this was last year with all the wildfire smoke limiting production. But based on this it does not look like you need to worry about not having the Export feature.
I am still on EV1-A too but am a pretty big consumer during the winter months with heat pumps. I will need to monitor my white bills pretty strongly I guess over the next few months as my true up is in July. Might have to take some local road trips to eat up credits if I have a $ surplus coming.
yup - Export Feature would not help me at all. I have 2 Heaters: One is Heat pump and one is NG furnace. I replaced an old NG Furnace with Heat Pump 3 years ago. So I do use a good bit of electricity in the winter, but probably not as much as you. Turned in my leased EV last year. Haven't replaced it yet
If PG&E has proper records for your solar equipment and you don't grid charge, even using the Export Everything should never put you in the situation where you have disallowed credits. The reason is that if all the battery energy came from your solar in the first place, exporting everything could not exceed your solar production. However, this is dependent on PG&E doing accurate estimates in the NEM-PS billing if you don't have a NGOM.
Yeah, people with electric heating under EV rate plans get hosed unless they can use their Powerwalls to grid-export some solar during peak to balance things out over their annual NEM.
Assuming winter means limited solar production, you'll likely be heating your home with the peak time energy rates from 4pm to 11pm. That's insanely expensive and could easily make you have a credit deficit even if your NEM kWh exports and imports are 100% offset.
Sorry I meant the shoulder times. I didn't mean peak. The EV2A plan I'm on is peak 4pm to 9pm. Shoulder starts at 3pm and ends at 11pm.
But this is still kind of crazy with so many folks having EVs (but no solar or powerwalls) on this rate plan. They get absolutely KILLED by this, especially in the summertime when they run ACs.
I had a neighbor tell me that after getting an EV and switching to EV2A, her monthly expenses went up ~$100 compared to what they were paying before under E-1 and paying for gasoline. She was like "I don't understand why people get EVs, gasoline was way cheaper". I told her she should just switch back to E-1 or go to E-TOU-C, since her home energy use (excluding car charging) was so focused during partial/peak time that it didn't make economic sense for her. But all this started go confuse her.
She insisted PG&E told her the EV2A rate plan was best for EVs as long as she charged her car at night, so going to those other plans would be worse. She wasn't going to take my advice. I guess the other reason her utility bill shot up was simply the cost of electricity/gas went up like 33%... so maybe the $100 had nothing to do with the EV and everything to do with energy costs.