New System - PVOutput/Monitoring Questions

[NYHeel]

So I just got my town approval yesterday on a 10.85 kW PV system (with 10 kW Solaredge inverter) in Northern New Jersey (Bergen County to be more specific). Waiting on my POCO approval (PSEG) which can take up to 5 weeks from when they get the approved Uniform Construction Code from my installer. I'm testing my system out and I had some questions around monitoring the system and getting as much data as possible. I'm an actuary so I generally like as much useful data as possible and am trying to figure out the best ways to do that.

I've set up my system on PVOutput using the API from Solaredge that I got from my installer. All seems operational on that end. What settings are generally recommended for Solaredge systems? It looks like I currently have my poll interval set to 15 minutes. Also, is there any way to monitor consumption? I'm kind of curious around my daily consumption patterns but have no idea how to accurately monitor it short of looking at my utility meter. Is there any additional equipment I would have to buy or can it be done with my utility meter? I currently have an old analog meter though I believe the POCO will replace it once they formally provide final approval for my system.

[sensij]

You'll probably need a 3rd party meter to monitor consumption. Some power companies are moving to smart meters that can be read by Zigbee, in which case you might find the Eagle sold by Rainforest Automation to be useful. EGauge, Smappee, EKM meters, TED 5000 are a few of the meters that forum members have posted about.

If you donate to PVOutput (<$10 annually), you can shorten the status interval from 15 minutes to 5 minutes, track heat sink temperature and AC output voltage, and perform net consumption calculations by looking at the difference between what is going to (or coming from) the grid, and what your system is generating. PVOutput has pre-programmed uploading routines for a number of uploaders, so you can look in their documentation for the current list for ideas of consumption sources beyond those I listed.

[DaveDE2]

Interesting. How do you track heat sink temperature? Is that a telemetry point that SE inverters put out?

[ButchDeal]

you can get the consumption meter from SolarEdge which will give you the consumption on solaredge site.
if you get another meter as Sensij suggests (which is a decent option) you will need to donate annually to get the enphase updated to 5 minute intervals to match the other meter OR get the other meter set up to monitor both. For Example with the TED you can get two sets of MTUs to monitor the generation and the net (and mathematically get the consumption) .

Honestly the you will want to either get the SolarEdge consumption meter or another system that will monitor both. Other wise the math will always be a bit off for consumption.

[NYHeel]

A donation to PVOutput seems pretty reasonable. Is there an issue from the Solaredge side to have more frequent intervals? I thought I recalled reading something regarding potential problems from too frequent pulls from Solaredge. Am I making that up?

On the consumption side of things, I'll look at the Solaredge consumption meter. Is that something I can install myself if my level of electricity expertise is at the level of being able to change out a light switch or install a light fixture? I also wouldn't want to void any warranty, especially my installer warranty.

[ButchDeal]

SolarEdge is ok with 5 minute data pulls.
The math will be a bit off with one system measuring generation and one measuring net as they will not be measured at the same instant, but should be pretty close.
As long as you shut off AC and DC disconnects and follow instructions should be fine with self install.

[DanKegel]

BTW I have a couple TED5000's, and that powerline networking they use is pretty iffy. Mine are gathering dust at the moment.

My power company's electric meter might have zigbee, but I don't think they let anyone connect to it

Rainforest Eagle said "LADWP has not done a general deployment of smart meters, but they did do a limited pilot using Itron Openway meters. If you have one of these meters, then it should have the ZigBee radio needed to connect to our devices. However, the meter must also be provisioned by LADWP to turn on the radio and enable it to communicate with our HAN (Home Area Network) device. Please check with your utility to ensure that they are willing to do this before purchasing our product."

[ButchDeal]

Ted pros have greatly improved communication but s t up is still tricky.

[NYHeel]

I've noticed that, as has been mentioned by others on this forum, that the Solaredge daily energy production is a little overstated compared to the PVOutput daily energy production, even though the data is coming from the same place. More interesting though is that even the PVOutput daily production is overstated compared to my revenue grade production meter I have to calculate my SRECs. PVOutput is about 2-4% high compared to my SREC meter.

Do others see the same thing?

[sensij]

I've noticed that, as has been mentioned by others on this forum, that the Solaredge daily energy production is a little overstated compared to the PVOutput daily energy production, even though the data is coming from the same place. More interesting though is that even the PVOutput daily production is overstated compared to my revenue grade production meter I have to calculate my SRECs. PVOutput is about 2-4% high compared to my SREC meter.

Do others see the same thing?

Yes. On clear days I find the pvo energy (based on solaredge power) to be about 1% over my revenue grade meter, and the solaredge energy to be about 4% over.

[NYHeel]

One other unrelated question, how hot does the Solaredge inverter run. It's in my basement so it's not terribly warm and it obviously gets no direct sunlight. However, the inverter was running at almost 130 degrees in the middle of the day yesterday and was pretty warm to the touch. Is that normal?

[brewbeer]

I have the 7600 solaredge inverter also in the basement and when my 8.5 kW system is running at peak output (which has been in the 6.8 to 7.2 range lately) the inverter temp runs about 130 to 135.

[NYHeel]

For DaveDE2, the SE inverters show it on its LCD screen. Or at least mine does. You can also get it from PVOutput.

[ButchDeal]

It is on solarEdge monitoring site under reports if you have access to that.

[NYHeel]

I don't think I get the reports on the solaredge monitoring site. I can click on a panel and see the current power if I click info but I don't have the component details on the bottom of the screen like the solaredge manual says I should. Are the component details something my installer needs to provide access to?

[NYHeel]

A few other questions about collecting data from the various monitoring sites.

1) What does the insolation curve on PVOutput represent? I looked at a perfectly sunny day (or at least most of the day) and at the peak part of the day my system was producing about 1,000 watts less than the insolation curve, despite no clouds. Is that just temperature or does the insolation curve already account for temperature? The output is usually on target in the morning but then starts to fall off around 9:40 AM.

2) Do you guys log the by panel performance for each month or even day? I can't seem to bring up historical information for the panel by panel monitoring. Is that normal and if so do you typically save down the daily, weekly or monthly performance for each panel in a spreadsheet? That seems like the only way you'd know if one panel is degrading from the previous year. I assume there's no way to get the panel level data onto PVOutput, correct?

3) Am I supposed to see the component details on the Solaredge monitoring site on the Layout page. The Solaredge monitoring user guide seems to say that I should have the component details on the bottom of the screen but I don't have it anywhere on the page. Is that something my installer needs to allow?

4) Sometimes the panel by panel status doesn't jive with the system status. For example right now on the panel by panel monitoring the sum of the panels is producing 300-400 more watts than the main page says the system is producing. Is the panel power DC power and the difference is the loss from the conversion from DC to AC?

[sensij]

1) The insolation curve is a clear-sky model of what your system might produce. It takes into account your location, array rating, and panel orientation. If you included a temperature coefficient in your system setup, and provide temperature data from Wunderground (or wherever), it makes an adjustment for temperature. However, this adjustment is poorly implemented and not very accurate. The insolation curve is a nice way to roughly see how your system might perform with an ideal clear sky, useful (in my opinion) for estimating the consequences of shade. If you want more accurate modeling, it will take a lot more work. But yes, temperature effects are a big reason why the curves do not match in the middle of the day. When we get into winter, some of the other weaknesses of the "insolation" model will be apparent.

2) Panel data is accessible through the SolarEdge portal. If your installer gave you "reports" access, you can see the historical data. Figuring out year to year degradation is difficult... changes in environmental conditions are responsible for larger swings in production, making the degradation a signal that is hard to tease out from the noise. Simple fouling (dust, etc) on the array is probably larger in magnitude at first. Over enough enough time, the degradation will be easier to pick up, but if you are really interested, you may want to invest some time to learn more about PV modeling and ways to measure and account for the other inputs into the system.

3) I think the screen has been changed, I can't figure out how to get the details on the bottom now either. In the upper right of the layout view, there is a "information" button that shows you the data from the selected panel, and a "charts" button that let's you see the optimizer data over time. If you don't see those, it is possible your installer did not give full report access, which is kind of silly.

4) Panel status updates at random intervals (by design), and the data freshness of any one panel may vary between 1-15 minutes, typically, maybe more for larger systems. Summing up all the panels is not giving an accurate measurement of power, since the data are not from the same time and conditions change (the sun moves, if nothing else). The inverter data updates at more regular intervals. There are also calibration differences that exist as well, but yes, since the optimizers are producing DC and are unaware of the inverter efficiency, that should also be considered.


For me, the panel data is not so useful in an absolute sense, but relationships between panels should be pretty consistent over time. If one panel typically outperforms another on a clear day, it should stay that way within some margin that accounts for difference in cooling that may occur from changes in wind direction, etc. Comparing "instantaneous" readings is almost useless, since there is no control over freshness. Comparing daily totals, especially on clear days, is more informative. If you take a series of panel voltage and current measurements, plot them into a curve (as the charts view does), and compare those, some insight can be gained there as well.

[NYHeel]

Thanks Sensij. Very helpful.

I did put in a temperature coefficient and I'm using temperature data from Wunderground, but I'm thinking that it's probably temperature that's causing me to miss the insolation curve in the middle of the day. We'll see what happens on a cooler clear day if we have one any time soon.

I have the information button but no charts button. It seems that my installer didn't give me access to the "reports" feature. If I have the API (the installer gave me that when I asked) could I provide myself the access to the reports feature or do I need to go back to my installer?

[sensij]

I have the information button but no charts button. It seems that my installer didn't give me access to the "reports" feature. If I have the API (the installer gave me that when I asked) could I provide myself the access to the reports feature or do I need to go back to my installer?

Unfortunately, you can't get optimizer data through the API, or change the level of access you have in the portal. You'll need your installer to bump up your portal access level, and I see no reason why they wouldn't do that for you.