Power company not accepting production power

[jandrese]

Here are some more examples of my listed solar output. Here are my thoughts on each day:

• 5/26: Mostly sunny day, consumption tracks production closely and is much higher than expected
• 5/27: Another mostly sunny day, consumption tracks production closely and is much higher than expected
• 5/28: Mostly cloudy, consumption tracks production again, save for a little bit in the evening. My son apparently discovers that you can leave Twitch streaming all day to earn some kind of twitchbucks leading to high power usage for a few days.
• 5/29: Cloudy, A little hard to say on this one because the base load is so high, but I think production was working normally.
• 5/30: Cloudy, Again it seems to be working normally
• 5/31: Sunny, production is working normally.
• 6/1: Mostly sunny, production is working normally.

If we get a couple more sunny days I'm expecting to go back to the behavior seen on 5/26.

[jandrese]

The wires from the CTs are the black and white ones twisted together. As you can see from the full frame shot they are routed out to the left, then go down to the bottom around to the right, and back up to the exit on the top of the box. The exit is shared with the power feed for the consumption meter itself (wires from that run into a pair of breakers on the left side of the box).

full-box.jpeg

[bcroe]

Moderators: In post 20, I made the mistake of
correcting grammar without giving a reason and now it's unapproved.

My experience here is that immediately going back to correct those things
will put it into moderation. So I just leave it till the next day, though maybe
a couple hours or even less is enough to avoid moderation approval.
Bruce Roe

[oregon_phil]

Moderators: In post 20, I made the mistake of correcting grammar without giving a reason and now it's unapproved. You can delete post 20 since I'm posting the contents below. Thanks and I will remember from now on to always give a reason for editing so the machine is happy.


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jandrese ,while this document isn't exactly your system, CT installation guidelines would still apply. "Application Note – HD-Wave Inverters with Built-In RGM & Consumption Monitoring for North America Version History Version 1.0, March 2020 – first version". I suggest you read this document.

Problem: SolarEdge power reporting system doesn't appear to match actual power usage . What possibly could explain your power discrepancies?

1) Equipment malfunction
2) Incorrect installation
3) Data reporting errors
4) SolarEdge power reporting system is correct; actual power usage pattern assumptions are incorrect.

In post #19, you give two qualitative observations. Could you provide pictures of the 10kw day, cloudy day and "normal" production?

In post #16, you show the CT's and comment the wires are buried in the box and go around to the box to the energy meter.

It appears the unshielded CT wires exit the power panel in the same conduit as some AC wires. Is this true? If yes, what AC circuit are those wires attached to?

Read the solaredge document above. A better practice would be to run the CT wires out of the electrical box in a knockout by itself without AC wires.

[jandrese]

Sorry about the quality of the images, the space is pretty tight and there isn't a good place to angle the camera in there. I have been careful not to touch anything inside of the box.

I have gone around the house and verified that no major appliances (water heater, washing machine, dishwasher, refrigerator, hvac, microwave, toaster, stove, oven) are on when the system is showing 10kW of draw in mid-day. Some low draw appliances are still on, including the internet router so the inverter and consumption monitor can update the cloud service.

One more observation: I just had another normal production day, where it seems that all of my excess power went back to the grid as expected. It happened on the day after 2 net-negative days (it was cloudy all weekend).

[oregon_phil]

From what I can tell from the photos, jandrese has an energy meter hooked up to measure power to and from the grid. The inverter infers consumption because it knows solar power produced and power to/from the grid.

The photos are fuzzy, but the CT's appear to be the correct part number, in the correct orientation and wired to the energy meter correctly. There is a big wad of black electricians tape where the L1, L2, N wires are connected to the energy meter.

I don't have a SolarEdge system, but if it was me, I would 1) check all connections to make sure they are tight, 2) make sure the RS-485 is wired correctly & terminations are set correctly, and 3) when you think the system is acting up, force your consumption to zero to see what the meter reads. Oh and if there are any firmware updates, that should be investigated too. There are a lot of inverter settings that need to be correct too for communication.

It is possible the energy meter is bad or the assumption on energy consumption are incorrect.

Just my thoughts.

Added thoughts,

jandrese , I just realized that my original warning about working with electricity is on the first page of this thread. Your CT's are upstream of your main breaker and will be live no matter what. If there is any additional electrical work to be done, I think your installer should perform the task. CT's might look harmless, but it is an inductor that might harm you when you make or break connections in the wrong order. Look up "what happens when you unplug an inductor".

After I proved the meter is not performing correctly by forcing my consumption to zero during suspect periods, I would ask the installer to verify the installation.

[Ampster]

I have never heard of a meter having the ability to."choke back power". I would focus on calibration issues between your two sources of data. I actually have several methods of checking the data on my system. Learn how to read your meter and see if the power (kWs) it is registering corresponds with the power net of consumption recorded by your instruments at that same moment. Try it during different times of day.
You may also want to recalibrate your expectations based on real world data not some theory about flux power. Watts law would be a good place to start.

[jandrese]

consumption-hookup.jpegPower does get exported. We saw the credits in the last bill, just not as many as we were expecting.

Here are the pictures of the CTs. The only thing I didn't do is trace which cables goes back to which port on the consumption meter, because they are buried a bit in all of the other wires in the box and take the long way around going all around the outside perimeter of the box before exiting out the top. I've included a top and bottom view as well as a shot of the hookups on the consumption meter itself. If necessary I can trace the wires to verify they are plugged into the correct ports, but if that can't be the issue then I'd prefer to avoid it.

Andy,
Thanks for the clarification about the grid. What I didn't mention is that the hypothesis of jandrese is about what happens on the utility side of the meter and whatever happens on that side of the meter should not affect the meter reading. A more likely scenerio is the meter is not programmed correctly.

My thought was if the consumption meters are just measuring the flux on the wire going out to the meter, then if the meter is choking back the power they'll read it as low flux and assume that it must be self-consumption. My theory depends mostly on the inverter only measuring the indicated voltage of each panel and using that to work out the production figure, not measuring the flux actually going out to the house like the consumption meter does.

Also, thanks to everybody in the thread taking the time to help me out with this.

[Ampster]

It could just be a programming issue with the meter or power company configuration of the meter. Or the CTs may be configured wrong and no power is actually being exported and the CTs are misreporting.

[Ampster]

Ampster

What you say is true for a radial grid. It may not be true if he's on a network grid where customers are fed from multiple transformers at the same time. Some of the protective devices in network grids don't allow backfeed. Network grids are found mostly in urban areas. See https://www.nrel.gov/docs/fy09osti/45061.pdf

Andy

Andy,
Thanks for the clarification about the grid. What I didn't mention is that the hypothesis of jandrese is about what happens on the utility side of the meter and whatever happens on that side of the meter should not affect the meter reading. A more likely scenerio is the meter is not programmed correctly.

[PVAndy]

Interesting theory but not one that is consistent with my understanding of how the grid works. Transformers are Bidirectional and solar generation just looks like a reduction of load to a substation. I have heard of issues in places like Hawaii but not likely in Virginia.

Ampster

What you say is true for a radial grid. It may not be true if he's on a network grid where customers are fed from multiple transformers at the same time. Some of the protective devices in network grids don't allow backfeed. Network grids are found mostly in urban areas. See https://www.nrel.gov/docs/fy09osti/45061.pdf

Andy

[Ampster]

I do have one theory. In my neighborhood there are three other homes with solar panels. I'm guessing the substation can't feed back on the main grid, ......

Interesting theory but not one that is consistent with my understanding of how the grid works. Transformers are Bidirectional and solar generation just looks like a reduction of load to a substation. I have heard of issues in places like Hawaii but not likely in Virginia.

[oregon_phil]

Since you don't know what you are looking for:

You will be working near live line voltage that cannot be turned off. If you do something wrong or in the wrong sequence you could cause injury or death to yourself. I am not an alarmist but electricity must be respected.

I don't know your skill set. I am not a sparky either so I am going to install my CT's in my two electrical panels and inverter after my automatic transfer switch is installed. That way I can shut off all power to all of my power panels.

So the one thing you can do is to located the CT's. There should be three of them. Two should be in your main power lines in your main power panel. The other one is probably in your main power panel on a wire going from your inverter to the breaker.

A photo of the CT is attached.

Take a picture of the CT's and the revenue grade meter.

[jandrese]

Hello Jandrese, I am a owner of a Solar Installation company in Costa Rica. We have installed hundreds of SE systems and was the first company to install the meters back in 2013 or so in the Northern Hemisphere.

First things first, confirm the CTS are placed correctly that is about 90% of the problems. With the new inverters it is getting simpler and simpler with more automation. The CTs of course measure the import and export the inverter shows the production. All the rest is calculated in the portal such as self consumption. You can see by this photo, this system is zero export. Using the battery and solar they are 88% self consumption. We will be getting that closer to the 99% by using soft starters on his well pump.


Screen shot ph.jpg

Is it possible for me to verify the CTS placement or do I need to call my contractor? I'm technical enough to trace wires, but I don't know what to look for.

[oregon_phil]

SE-RGMTR-3Y-208V-A is one of their current offerings. A call to SE or your installer would clear up any uncertainty.