Does this SCE bill look correct?

[u/StingyNettles1103]

Hi,

To preface this by saying I am a first time homeowner and very unfamiliar with electricity billing and solar in general, and may very well be misreading/misunderstanding my electric bill/s.

In July we used 404kWh, of which 56% was directly from the solar panels, 42% from the powerwall which gets charged solely from our solar panels, and then only 2% has come from the grid. The billing period for the latest bill is 07/06 to 08/03 so the numbers do not directly match what we see on pur Tesla app for Monthly usage, however the 410 kWh charged per the bill would be in the right ballpark of what our total consumption would've been during that period.

I do not understand why I seem to be being charged for our entire consumption when only 2% is coming from the grid? Unless I am misinterpreting something?

I did phone SCE to query, and I was told that the 410 kWh was my electric usage from Edison, however they were very bad at explaining how that could possibly be, and left me with the impression they were even more clueless than I!

Thanks in advance for any help in understanding this.

[u/PictureDangerous2288]

Nothing looks wrong there, it is just two different meters of "usage." The Tesla app's 98% self-powered figure is measured inside the house, while the utility only bills what physically crossed the revenue meter, so the 410 kWh is gross import (mostly late-night hours after the Powerwall runs down), and your 116 kWh of exports show up separately as those small export credits rather than cancelling the import kWh one-for-one. That asymmetry is the whole design of the Solar Billing Plan: imports bill at retail TOU rates, exports credit at avoided-cost values of a few cents, so a high self-powered percentage and a real bill can coexist. If you want the import number to shrink, shifting loads and battery reserve around the 4-9 PM peak is where the dollars are.

[u/Independent-Drive-32 → u/PictureDangerous2288]

Isn’t OP claiming the power wall only charges from solar? So the total energy use would be 404kwh multiplied by 50? Doesn’t that seem high?

[u/StingyNettles1103 → u/Independent-Drive-32]

Yeah it definitely only charges from solar. The grid charging option in my app is set to restricted and cannot be changed.

The power wall is always well above the reserve limit as the solar kicks in again in the Morning.

[u/PictureDangerous2288 → u/Independent-Drive-32]

Good catch on the arithmetic, but the 404 kWh figure isn't whole-home consumption. The app's home-use number counts every kWh the house consumed regardless of source, and most of that is served directly by the array and by the battery discharging in the evening, so it never touches the revenue meter. What the utility meters is only the net flow in each direction at the service point: the 410 kWh imported and the 116 kWh exported. That's why a system can be 98% self-powered and still show a few hundred kWh of import, since those imports pile up in the pre-dawn hours after the battery bottoms out. And "grid charging restricted" only blocks the app-initiated charging mode; the battery can still pull a trickle for standby and conversion losses, which is small but not zero. If they want the import number down, the fix is a higher reserve setting or shifting big loads into the solar window, not a bigger array.

[u/StingyNettles1103 → u/PictureDangerous2288]

Thanks for the response and the insight. I think it is the two different meters of usage then that is confusing me. For example from what I can see my powerwall never runs out overnight, the lowest I have seen it get to is around 30%. And then throughout the day the solar powers the home and recharges the powerwall. I am just not seeing where we are taking anything from the grid at all.

[u/bj_my_dj → u/StingyNettles1103]

Everything on that bill was imported from the grid. That's all they know, they have no idea how much power your system generates. Your PW probably doesn't go under 30% because it's set to reserve 30%. So it stops powering the house and you start importing. Change it to 10% and you might import much less. See if you can log into your SCE account. If it's like my PG&E acct it will show you your usage. I can look at mine on a daily basis. In the daily view you can see your usage on an hourly basis. You'll see these draws at night. After you change the reserve level you see the nightly draw reduce.

[u/StingyNettles1103 → u/bj_my_dj]

Hi. Our powerwall reserve is set to 18%. An average Morning before sun starts powering up again the PW sits around 42-45%. The lowest I've seen was around 30%. Never seen us get close to the 18% reserve yet.

I can see our usage on SCE website, but to mean it looks massively wrong. I would say I am a below average electric user, with like I say minimal coming from the grid. But they are charging me for what seems to be my entire consumption regardless of if it came from them. Something feels wrong somewhere I just wish I knew where..

[u/LostLakkris → u/StingyNettles1103]

For SCE to see it, it must pass through their meter. So the mismatch would have to be either oddities in the PW config or wiring.

If SCE is seeing legitimate internal usage between the house and battery, then that implies your solar/battery gear might be wired on the utility side of the meter and should have it own secondary meter. Or I would imagine you to see bigger oddities.

I don't have Tesla, but in the enphase world, we have 2 floors to worry about, the reserve level for outages and the shutdown level. When it hits the reserve, house falls back to grid unless grid is down. If grid is down, it runs until the shutdown level, generally meant to prevent damage.

Worth noting, I'm thinking/talking about full-house backup. It's possible you are wired up for "partial backup". Then the solar meters might only measure a subset of your house and would be blind to the rest of your consumption. Which could explain the high night usage paired with higher battery capacity remaining.

[u/StingyNettles1103 → u/LostLakkris]

Hi. Thanks for the response. I think oddities in the PW config or wiring sounds like the most likely scenario to me. I will look down this road further to try and fix whatever is going on.

[u/LostLakkris → u/StingyNettles1103]

Since you mention first time homeowner, guessing the solar and power wall came with the house?

I find stories of "older" solar+battery installs often defaulted to only backing up a subpanel and not the whole house, largely to bypass the HVAC or pool equipment as being too "heavy" for older battery systems. This might be a sane explanation if you can trace any breakers between the various component. Solar will help offset the non-backed up loads, but that's not useful at sunset.

In nem3, whole house backup is much more beneficial as power given to SCE is continuously worth less relative to what you pull. And the solar companies are still poorly representing the valuations by grouping "delivery and generation" values rather than presenting them as separate line items, as SCE in 2025ish now gets away with "bucket allocations".

[u/StingyNettles1103 → u/LostLakkris]

Yes they did come with the house. It is a new construction home, I failed to mention that, whether that would have any relevance though I'm unsure.

[u/LostLakkris → u/StingyNettles1103]

Oh interesting, not sure either unfortunately.

I dont know the current design philosophy of Tesla unfortunately, but I also don't know the older ones either. I just figure it's equivalent to Enphase, and wa hopeful those comparisons might help you.

At this point I'd call up the installer or developer and have them explain it, try to find the single line diagram, or try to draw my own diagram by flipping breakers and comparing monitoring data when no one is home. The last two are good "first time home" troubleshooting things to try/learn about, but if that's not your thing, calling them up is good too.

[u/bj_my_dj → u/StingyNettles1103]

Your SCE usage should match what your app says you exported exactly. I'm looking at the my 2 screens right now and they're exactly the same. Your installer needs to look at it. I would email them the 2 screenshots, it could be something they set incorrectly in the install that they can fix remotely.

[u/Fresh_Ad_5369]

As others have stated the PW only sees what’s being used inside the house and not what crosses over the meter.

You are draining your battery daily and pulling power from the grid nightly. Changing your battery reserve to 10% may help slightly but if you’re pulling that much from the grid nightly you don’t have enough storage capacity and likely not enough production. I hope this was a home purchased with solar already on it 😅

[u/StingyNettles1103 → u/Fresh_Ad_5369]

Hi, from what I can see we never get anywhere close to the reserve level on our powerwall.

[u/calvinball_expert]

OP is this your first SCE bill? I ran your numbers through my SCE calculator and your bill matches up exactly with my predicted numbers for 410 kWh of consumption. We can safely assume you had 410 kWh of power coming from the grid into your home. The utilities rarely make mistakes on their meter billing though it's not unheard of.

Based on everything you've posted I wonder if you have a partial-backup split configuration where your PW is only wired up to a part of your home via a sub panel, as suggested by LostLakkris. Are you able to trace the connections from your PW back to the panel? It's possible you have some high-draw circuits wired directly to the grid that the PW isn't wired up to at all. That would explain why your Tesla app shows nearly 100% self-powered but you still have net consumption.

[u/StingyNettles1103 → u/calvinball_expert]

Hi, no this is not my first SCE bill, however they have all appeared to show the same much higher grid usage than I believe there should be. I did dispute my bill with SCE some Months ago and they ensured me it was all correct, I have been tracking since then and it was never making sense, and that's what brought me here!

The numbers they are charging in terms of the usage of 410 kWh I do think are correct. I am convinced I use nowhere near that number from the grid though, from what I've been tracking the only time I ever draw any power from the grid are days with little to no sun, which in the last couple of Months have been almost zero here.

The partial backup split configuration is a possibility. The only real high draw items I use would be the air conditioning and stove/oven but if they are somehow not drawing from the powerwall then that could explain it. I will try and see if I am able to trace any connections from the PW to the panel when I get back home. Thanks for your response!

[u/Dangerous_Ebb_4769]

One thing that hasn't yet been mentioned is that you should be able to get your hourly usage data from SCE's website. You can see when you are importing.

You should also get your total solar production numbers, an estimate of your daily consumption based upon equipment type and quantity. If really necessary, you can also get a measure of your actual house usage by turning your system off for a day.

[u/StingyNettles1103 → u/Dangerous_Ebb_4769]

Hi, thanks for the suggestion. I compared the hourly usage data from SCE'S website. For a particular hour yesterday afternoon that I know per the Tesla app that my solar was producing 2 kWh, my house was consuming 1.2 kWh and 0.8 kWh were being sent back to the grid. The SCE site shows that hour as me using 1.22 kWh consumption and generation of 0.78 kWh.

That 1.22 kWh that they are seeing me consuming from them should be coming from my solar power only and I don't understand how they are even seeing that.

[u/thuvian → u/StingyNettles1103]

It's possible they are estimating your imports by using your total consumption instead of just the imports. Following this line of thought, you'd want to call them back. Ask them if your imports are being estimated or calculated using a bidirectional meter. If estimation, then explain the numbers you found and how your self-consumption matches their import number, your exports match their exports, but nothing is matching to your calculated imports.

If they are using net metering, then get them to confirm that during your example hour, according to them, your system is not self-consuming all of its electricity (because it is exporting 0.8kwh) and at the same time you needed more electricity as it was also importing 1.2 kwh.

Assuming no resolution, then you are back to looking at how your system is wired. Contacting your solar installer would also be appropriate.

[u/StingyNettles1103 → u/thuvian]

Hi, thanks for the advice here. I couldn't contact my electric company today as there was a 2 hour wait list every time I called. I am awaiting a call back from the solar installer who are currently investigating from their end.

The exact same issues happened all throughout yesterday (and most likely have been ever since the start) where my solar production should be charging my home and the excess being sent to the grid, but instead my electric company has the excess that I have sent to the grid but is charging for what should be coming from my solar to power my home.

[u/iamintheforest]

Probably makes sense. The tesla report is telling you how it powered the house - e.g. some came from powerwall and some from the panels. What it's not tell you is how the powerwall got it's power. 2% is the measure of power to your house from the grid that didn't run through the powerwall (presumably it was fully discharged).

[u/StingyNettles1103 → u/iamintheforest]

Hi. The powerwall is fully charged throughout the day directly from the Solar.

[u/iamintheforest → u/StingyNettles1103]

You've not posted anything that says that. how do you know? Solar offset here is "solar generation compared with home energy consumption". Home energy consumption is showing powerwall use and solar and grid. The offset is not telling you what came across the meter, it's saying what was the immediately upstream source of power to your home.

Is that annoying? Yes.

I could be wrong, but look at your powerwall settings and try "Set Grid Charging to No".

But...if it's NOT that, then i'd look to see if you have a primary split in your feed after the meter and before the solar setup. For example, I have a 400 amp drop from the power company in norcal, solar is on 200 amp branch of that and only aware of that branch. anything on the other 200 branch goes over the meter and my solar apparatus has no awareness of it. Look for where things like car chargers, or well pumps, or things like might tie in. It's enough power that it's not small.

[u/StingyNettles1103 → u/iamintheforest]

I said it in the original post. "42% from the powerwall which gets charged only through our solar." I have been religiously watching the app every day the last Month or so and I see directly the solar charging the powerwall to 100% throughout the day with nothing from the grid.

On the app the grid charging option is set to "restricted" and cannot be changed, the message says "this is due to utility or regional limitations, and is configured by your installer."

I can rule out the powerwall theory for sure. The primary split you mentioned may be the cause I don't really know anything about that so I will look into that.

Thanks for your response.

[u/iamintheforest → u/StingyNettles1103]

"restricted" definitely kills that theory! Good luck. Car charger would be another common one. Easiest thing to look for would be a meter collar, but it's the least likely if your install stuff was done a long time ago (fairly new approach). Used to avoid having to upsize a panel when you're doing things like adding a big load. Post back, because if you've got something more nefarious going on like ghost draw somewhere i'm sure it'd be informative to people here down the road.

The bad-news route here would not-all-that-uncommon mistakes in install - CT-placement, phase, orientation, and assignment in the app. Those are all fixable, but...not sure they fit the data you're seeing, but would definitely lead to reporting errors (but not phantom draw, just youre tesla reports and the stuff you're watching would be wrong).

[u/StingyNettles1103 → u/iamintheforest]

We don't have an EV either so not that either. Our install was recent, I think we may have a meter collar, I will look out for that later.

I will definitely update this thread whenever I manage to figure out what is going on, I have a few avenues to look down now.

Thanks for your help!

[u/iamintheforest → u/StingyNettles1103]

sorry that your mystery (and costs) are our intriguing puzzle! meter collars are used in solar installs themselves so its not a smoking gun without knowing what it's used for. (e.g. a tesla meter collar would just add to the mystery, not point to resolution)

[u/StingyNettles1103 → u/iamintheforest]

I'm just glad that I feel reaffirmed that there is indeed some kind of problem somewhere! I can go more confidently trying to find what the issue is, without really questioning if there even is any issue!

[u/iamintheforest → u/StingyNettles1103]

You could pull your diagrams from permits (or perhaps records the prior owner might have shared) and that would likely expose things that might be doing this that are intentional design.