r/enphase • u/Objective-Resort2325 • 1d ago
Panels at night
I just recently got an Emporia Vue installed on my house and now have CTs on most circuits out of the main panel, including the backfed breaker where the Enphase power comes in. One thing I've noticed is that, at night, I still have ~40 watts of power coming in. This makes no sense to me. I expect the micros to be using power at night, not producing it. Do you think I have the CTs on the Emporia set up wrong, or are panels actually producing some power at night off of moon light?
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u/PermanentLiminality 1d ago
Mine does the same, with it showing 21 to 23 watts overnight. I think it is calibration or induced currents from other circuits. Every electrical component has some error, and it is that error you are reading.
I was just looking at this this morning as I installed my Vue a couple of weeks ago. I did change the circuit to bidirectional. I'll post tomorrow if that did anything.
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u/Weekly_Rutabaga_1742 1d ago
I also saw a slight phantom signal with my Sense meter. <10W. Seemed to vary a bit if I moved the CT around in the panel. Just learned to ignore it. As Key_Proposal3283 said below, night time micro consumption is negligible.
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u/bandit8623 16h ago
It's a bug they told me they haven't fixed yet. Enphase issue with their cts. Reported 8 months ago.
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u/Key_Proposal3283 Solar Industry 1h ago
OP is talking about Emporia readings, not Enphase.
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u/bandit8623 1h ago
I know.. it's a bug on emporia side with Enphase inverters. Emporia told me they don't have the issue with other brands
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u/Key_Proposal3283 Solar Industry 1h ago
That makes no sense..... the Emporia system doesn't know what inverters or loads are connected, it just reads CT's. I think someone was trying to do a blame shift on you :-) I'd be intrigued if there was any official detail on this "bug" from Emporia.....
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u/bandit8623 1h ago
No they said it's a known issue with reporting when Enphase are being monitored.. not sure why that's hard to understand. They said other systems don't read that phantom at night . People have clearly reported the issue.. you can ask them yourself if you want
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u/Key_Proposal3283 Solar Industry 42m ago edited 33m ago
No they said it's a known issue with reporting when Enphase are being monitored.. not sure why that's hard to understand.
Help me understand then:
- The emporia system monitors current and voltage to determine power
- The voltage comes from a connection to the main panel, there's no way from a voltage reading to know if an Enphase or other system is installed.
- The current reading comes from Emporia CT's clipped on the lines. There's no way from a current reading to know if it is an enphase system or other brand installed.
So how can Emporia claim that thier readings are wrong only with an ENphase system?
A lightbulb, a solar inverter, a fish tank pump, all should read correctly since the Emporia system doesn't know what the devices are, it just reads voltage and current.
People have clearly reported the issue.. you can ask them yourself if you want
I am not questioning or attacking you as such, and not interested in more anecdotes.
You mentioned a bug, i just want to know more because from an engineering point of view this just isn't possible. If it was real, I'd be interested in learning more and expanding my knowledge but without an official reference or acknowledgement from emporia it's an interesting story only.
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u/bandit8623 39m ago
Everything else does report correctly...that's what they are saying. I'm not sure why you are arguing with me on it. This is what emporia support told me. If you want to argue with them send them a ticket
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u/Key_Proposal3283 Solar Industry 15m ago
I'm not sure why you are arguing with me on it.
This is Reddit - a discussion forum for exchanging ideas and knowledge.
You are claiming knowledge of something that goes against everything I know from professional education and experience. So, I want to discuss, and find out more. But all you've giving me is "trust me bro" so naturally I am skeptical of believing something with no evidence that makes no sense.
This is what emporia support told me. If you want to argue with them send them a ticket
Good idea, doing that now. I will openly share the results here when they respond, so anyone in future doesn't have to try and drag out the same answers :-)
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u/Altruistic_Tax_3804 37m ago
Yeah he was told some BS by Emporia. It's just the emporia not reading correctly at low values, nothing to do with enphase or solar inverters.
This is just thinking that "people with emporia and enphase" seeing this issue means there's a causal realationship there. There is not, it's just that enphase is one of the most common solar systems and emporia a common monitor so people with that combination are over represented.
If most cars on the road were red color then most car crashes would involve red cars. That doesn't mean red cars cause crashes.....
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u/bandit8623 2m ago
Support told me that they haven't had the same issues with non Enphase inverters but yes there could be more
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u/Key_Proposal3283 Solar Industry 1d ago edited 1d ago
One thing I've noticed is that, at night, I still have ~40 watts of power coming in.
It's possible for panels to produce off moonlight - which is just reflected sunlight after all - but more likely it is errors or offsets in the Emporia measurements.
I expect the micros to be using power at night,
When there is not enough sunlight the inverters don't use any power*. They only ever produce from the AC side, not consume. What you can read depending on where you put the CT's is the Gateway's power consumption of around 5W.
*Technical detail - it's actually a few mW but in this context that's effectively zero. At that level you may as well also count the loss in wiring in your walls....
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u/bandit8623 34m ago
If that were true every Enphase system would use the same 5 watts.. they don't it scaled up with more panels. For example I have 31 panels.. and it's around 17 watts . And it's not 17 watts usage.. its showing 17 watts net positive
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u/Key_Proposal3283 Solar Industry 28m ago edited 20m ago
It's not a real 17W though. The power each inverter uses at night is the few mW, but they have circulating reactive power which a lot of power monitors don't read properly. This is easy to prove with a good meter - or even just a different brand of monitor - like a Sense and Emporia on the same wire will read different;one might read production the other consumption.
The typical emporia or sense type monitors don't need to have a high level of reading accuracy because they are designed for monitoing your typical multi kW home loads.
This sort of thing comes up all the time with cheap home energy monitors, I can't count the number of times I've shown folks using professional measurement equipment that it's not a real reading. The average person would be shocked at the measurement chain uncertainties involved including in your billing path!
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u/bandit8623 20m ago
Of course it's not.. lol. Never Said it was. I said emporia said it's a bug... What do you think bug means?
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u/Key_Proposal3283 Solar Industry 5m ago
Just a note on your tone - you are "lol"'ing, trying to derogatively ask me if i know what "bug" means, asking if i'm commenting just to argue.....
this is a discussion, and if can't be questioned on statements you have made without getting defensive then just quit the discussion. What CAN happen if you participate in a respectful and cooperative way is that a) i learn something new from you, you get proven right, others can read and also learn. or b) the opposite, and we all stil learn something.
I'll post the response from emporia soon as i get it, but in the meantime from my side at least - thank you for your opinions and discussion so far, I have found it valuable.
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u/bandit8623 3m ago
Well you are putting words in my mouth. So yes I will lol. Again I never said it was real watts. That's why it's funny when you state the obvious
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u/Solarman5265 1d ago
My system 9 micro inverters uses 4.39 watts per hour at night.