Switched on my system today!

[woferry]

Yes, the Solar Edge output should purely be the inverter output, regardless of where that power is going (though as noted it might actually be the inverter input, which would overreport by the power lost in the inverters themselves). I don't see any reason why the Gateway's solar reading would be any different, however (except for definitely being inverter output), unless there's something wrong with the CTs / configuration of the Gateway. The solar reported in my Tesla app matches what my inverters say they output at any given time (both instantaneous and day-so-far).

 

[NuShrike]

I suspect (but don't actually know) that Solar Edge does not see the Powerwalls except as part of the house, so counts power into the PWs as power consumed by the house, and doesn't see power coming out of the PWs at all.

Unless the SE has CTs on the battery, it will not be accurate when the batteries discharge to offset any load.

You can definitely trust your SE as the ground-truth for solar production, but you need something else for consumption. Tesla's meter/aggregate numbers should be good for that.

For me, my locale supports smart-meters so I can use a RainForest Eagle-200 which reads the meter directly for revenue-grade consumption accuracy. It's actually more accurate than my utility, Sense, and alternate Neurio, unless RFA's cloud system goes down.

I wonder if your locale system supports something like the Eagle.

 

[daniel]

Unless the SE has CTs on the battery, it will not be accurate when the batteries discharge to offset any load.

You can definitely trust your SE as the ground-truth for solar production, but you need something else for consumption. Tesla's meter/aggregate numbers should be good for that.

For me, my locale supports smart-meters so I can use a RainForest Eagle-200 which reads the meter directly for revenue-grade consumption accuracy. It's actually more accurate than my utility, Sense, and alternate Neurio, unless RFA's cloud system goes down.

I wonder if your locale system supports something like the Eagle.

Tesla's numbers are complete wackadoodle, other than (I presume) the present-time power flow. I believe SE's consumption numbers are correct because they match the production numbers (corrected by the minuscule grid power). And they match what I expect based on last months utility bill. This, of course, is as long as I regard power as "consumed" when it goes into the Powerwalls.

I don't need to know exactly how much power the house or cottage used separate from the powerwalls. I just want to know that the PWs are sufficient so that I'm not consuming grid power for lack of sufficient storage. And I can see that from the very low input from the grid and by checking the SoC of the PWs in the early morning just before the sun comes up. And Solar Edge shows me on the graph if there's enough power coming from the grid to make a difference.

My regular, old-fashioned digital electric meters (one each for house and cottage) are good enough to confirm that I'm using no significant amount of grid power.

 

[Hugh-SG]

You are lucky, they won't touch my cedar roof

Ouch!!! You may have cedar shingles instead of cedar shakes.

My contractor had no problem installing 18 LG 325w on my cedar shake roof. Shakes are a lot thicker and stronger then shingles.

 

[daniel]

Yesterday (or the day before? not sure) the panels for the house stopped producing power. The system for the cottage is separate and had no issues. I texted my solar contractor and he did a remote re-set and it came back on. I asked him if there was a way for me to do a reset and he told me where the switch is. Later, it stopped again, and I did a reset and it came back on again. But yesterday afternoon it stopped again and a reset did nothing. The sun was going down, so this morning I again tried a reset to no avail, so my solar guy came over and looked at it through the app on his phone, and said it had not logged any errors and the firmware is up to date. He changed one setting (the "export limit"? maybe) from 30 watts to 50 watts, and now it's working and pumping out almost 9 kW (10 is its limit) and he's going to keep an eye on it and open a case with Solar Edge if it happens again.

Knock on wood! <Raps head with knuckles>

I've used less than one kWh from the grid since I wrote down my meter reading a week ago. The cottage has used one and a half in five days, probably because with just one PW it gets usage spikes that the PW cannot supply more often. (For some reason, I didn't write down both meter readings the same day.)

 

[Unofficial]

That is very interesting that your installer has the site limit set above 0.00kw which is what the utility requires for zero export systems. Having it set at 30-50watts is a hack to get the Pv to produce when the grid goes down. This could be ok but if you export more kwh per month than the size of your system allows then you will be getting letters from the utility company to fix this. It sounds like your cottage is going to go over and you’ll start getting letters in a couple months.
Ask your installer to apply for smart export even though he doesn’t want to or put up with letters from meco telling you are out of compliance.

 

[daniel]

That is very interesting that your installer has the site limit set above 0.00kw which is what the utility requires for zero export systems. Having it set at 30-50watts is a hack to get the Pv to produce when the grid goes down. This could be ok but if you export more kwh per month than the size of your system allows then you will be getting letters from the utility company to fix this. It sounds like your cottage is going to go over and you’ll start getting letters in a couple months.
Ask your installer to apply for smart export even though he doesn’t want to or put up with letters from meco telling you are out of compliance.

I have mentioned what you said to my solar guy. He disagrees with you. Since I know nothing about this kind of stuff, I'm going to trust my solar guy, who's been working here for a very long time. FWIW, for the month, the house and cottage have each exported 3 kWh. (They have separate meters and are on separate systems.) My solar guy says that MECO knows there will be a small amount of export and they don't care. And the meter doesn't show export, so I'm not sure they'll even know. However, if I do get such a letter, I promise I will post a "You were right" note in this thread.

As I write this the sun is just starting to peek over the mountain and my solar is producing half a kWh, so I'm hopeful that the problem is solved and it will produce normally now.

 

[daniel]

Yesterday my house system fed 1/5 of a kWh back to the grid and purchased 1/10 of a kWh. The cottage fed back 1/3 of a kWh and purchased 1 kWh. Overall, the house used 31 1/2 kWh and the cottage used 21 1/2 kWh.

 

[mikfis57]

You mean like this?
Snaggy - easy screenshots

That requires a LibreNMS server though which may be overkill for what you're after.

Hi there,

I just finished a successful installation of LibreNMS to monitor my home network. This post really intrigued me since I also have Tesla Solar and a Powerwall 2. I would be very interested in learning how you connected LibreNMS to monitor your solar production. Thanks in advance.

 

[Vostok]

I have an obsessive, and probably unhealthy, need to understand what's going on.

Join the club!

The daily totals shown on the Tesla app and the Solar Edge web site are vastly different. For example, as of 4:30 p.m. today, Solar Edge says that I have produced and consumed about 30 kWh. The Tesla app says that I've produced 15 kWh and consumed 14.2 kWh.

Something is seriously wrong there. I download my PW2 stats every day from the Tesla app and store them in a spreadsheet. The totals always add up, give or take 0.1 kW due to rounding errors of individual data points (I really wish the Tesla data was saved to 2 decimal places rather than one).

I have not found any significant discrepancy between what the Tesla data has recorded over time and what my utility bill says I have consumed and exported in a given period. So if your problem still exists, something is quite wrong somewhere.

 

[daniel]

The daily totals shown on the Tesla app and the Solar Edge web site are vastly different. For example, as of 4:30 p.m. today, Solar Edge says that I have produced and consumed about 30 kWh. The Tesla app says that I've produced 15 kWh and consumed 14.2 kWh.

Something is seriously wrong there. I download my PW2 stats every day from the Tesla app and store them in a spreadsheet. The totals always add up, give or take 0.1 kW due to rounding errors of individual data points (I really wish the Tesla data was saved to 2 decimal places rather than one).

My post quoted above is from about nine months ago. After a while I quit looking obsessively at the Tesla and Solar Edge apps. I couldn't even tell you if the same discrepancy is still there, and I no longer care. When I do want to check, I use the Tesla app for real-time power flow, and the Solar Edge app for daily, weekly, and monthly totals.

My system supplies all the power I need for my house including A/C and charging the car. My most recent utility bill says I used 17 kWh for the month, which is just over 1/4 of the way to going over the minimum fee. MECO charges a minimum fee of $26.25 for anything under around 40 kWh. So if the apps are giving me bad information, my system is still functioning as it should. (I'd like to be using zero power from the grid, but apparently the system needs some for load balancing.)

I am over-the-moon happy with my system. With free electricity I can run the oven just to bake a potato if I feel like it, AND run the A/C to cool the house from the oven heat, and my carbon footprint for all of it is zero and it costs nothing. Well, just the cost of the potato.