With a Deye system with microinverters there is a device called an MECD that’s used for logging. What I can’t figure out is where it gets info on consumption, import from, and export to the grid. My understanding is that this would normally come from CTs either connected to a smart energy meter or to a gateway, but the MECD has no CT inputs and the RS485 port for connecting to a smart energy meter is labeled as Reserved. In theory it could connect to an energy meter using PLC but there is no mention of CTs or energy meters or consumption or import or export in the MECD User Manual. I’m missing something obvious, I just know it.
Question about Deye microinverter system
- Thread starter Haysdb
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shavermcspud
Solar Enthusiast
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It doesn't, it even states on DEYE website that is for per panel level monitoring only and rapid shutdown.
shavermcspud
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By the inverter itself, either by the use of a CT coil or a modbus meter and coil combo
shadowmaker
Solar Addict
You have only microinverters and not any hybrid inverter those MIs are AC coupled? IF so this means your setup is grid tied and can only "push" power to your loads and backfeed excess to grid. It has no way to tell your import/export, at least according to manual it has no CT connection. It can tell you panel specific production, but not how it is used. Only way to determine import/export is reading your utility meter.
zanydroid
Solar Wizard
Post above mine is how Enphase and Hoymiles monitoring works.
You’ve gotten the same answer 4 times. Maybe next take screenshots of manual where you think it disagrees with these answers so we have a basis for further discussion?
You’ve gotten the same answer 4 times. Maybe next take screenshots of manual where you think it disagrees with these answers so we have a basis for further discussion?
profesor79
...
There is nice teardown on EEV blog:
zanydroid
Solar Wizard
Lost
. This thread is for microinvertersBut I am going to scrutinize this video for hybrid education
That’s the conclusion I have come to and it doesn’t make sense. How can you have a system where you can’t monitor import from and export to the grid? Who would be satisfied with that?
I’ve retread this thread and I’m missing where my question has been answered at all, much less 4 times.
I’ve asked Deye support and not really gotten an answer from them either. It would be done with CTs, but what are they connected to? There is no “gateway” like other microinverters connect to for logging. There’s only the MECD and it’s definitely not obvious how a smart meter is connected to it.
zanydroid
Solar Wizard
Fair enough but most of us don’t have Deye microinverters and you haven’t linked a manual, so I don’t know how you are expecting to progress the discussion. I only know what I bought (Hoymiles) and the industry leader in my country (Enphase).
You are probably right with your analysis
zanydroid
Solar Wizard
And reviewing the thread, when I said "answered 4 times" I mean folks have gone and found the manual/explained the capability or lack thereof.
I think another disconnect is that I have a similar capability to what post #2 says (HoyMiles management box, unlike yours it does have zero export compatible energy port, that connects to an energy meter, that connects to CT, but I don't care about it and it's very rarely installed in the US), and have no problem with lack of consumption information. And I definitely have per-panel and per-microinverter monitoring.
The export information is collected from the microinverters. They have internal energy meters and voltage meters. Dunno if they use shunts or CTs (below the level of abstraction, if interested you can go look for disassembly videos for your microinverter). The export information from Enphase is collected by PLC signaling over the AC wires. The export information in Hoymiles is collected either by 2.4GHz or sub-1G depending on generation.
Sounds like you are asking about a product capability question.
I think another disconnect is that I have a similar capability to what post #2 says (HoyMiles management box, unlike yours it does have zero export compatible energy port, that connects to an energy meter, that connects to CT, but I don't care about it and it's very rarely installed in the US), and have no problem with lack of consumption information. And I definitely have per-panel and per-microinverter monitoring.
The export information is collected from the microinverters. They have internal energy meters and voltage meters. Dunno if they use shunts or CTs (below the level of abstraction, if interested you can go look for disassembly videos for your microinverter). The export information from Enphase is collected by PLC signaling over the AC wires. The export information in Hoymiles is collected either by 2.4GHz or sub-1G depending on generation.
Sounds like you are asking about a product capability question.
shadowmaker
Solar Addict
Well, yes and no. My two 15kW Bluesun GT inverters have no way to tell me their import/export (my hybrid Deyes do as they have CT meters for that). Bluesuns show production curves but have no idea of my loads (import/export = production - load). But I can always check my POCO app next morning and see how much was imported/exported. At least I don't need to get that information from my GT inverters (your microinverters are GT inverters too) straight away as it wouldn't tell me anything so important that couldn't wait until next morning. From app I can only see import/export in 1 hour intervals, but at least that is more than enough for me.
Why you need to know your import/export in real time?
It’s not necessarily about real time. I don’t know how this information is known at all if the MECD doesn’t have access to it. I can’t believe that it doesn’t, I just can’t figure out how it does.
shadowmaker
Solar Addict
You have 2-way utility meter? Got your PoCo app?
If that doesn't work for you then get Chint or Eastron CT meter, connect it next to your utility meter and use their readings for import/export. I'm using Eastron as my Deye CT meter because my main panel is 70m away from my inverters and normal CT has trouble to send information over 30m distances. They have LCD screen where you can check many things including import/export.
DIYrich
Solar Wizard
Energy Meter Inverter Company, Supplier | Deye Inverter Technology
NingBo Deye Inverter Technology Co.,Ltd is China Energy Meter inverter company and supplier。 The SDM 230 Modbus Single-phase electronic type guide rail mounting electric energy meters. It is used to moni...
www.deyeinverter.com
I’ve never gotten a satisfactory answer but I think I’ve figure out how it’s done. “Algorithms”. I just had a system installed with no energy meter but my monitoring app is reporting load and import from the grid? How? “Algorithms”. So the answer is, I think, there are no CTs, but the inverter (or MECD in this case) somehow figures out usage and import and export to within 5% to 10% from what I’ve read. Close enough for what I need it for.
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