Nightime power on enphase micro inverters

[csadoian]

I recently installed a 13.5kW system using 41 Panasonic VBHN330SA17E panels and 31 IQ-7X-96-x-US Enphase Micro Inverters. While I get basic monitoring of my system from Enphase, it is not real time, it only gets updated about 4 times a day. It does give me total daily production. I recently purchased a power monitoring system made by Emporia (the Vue), and have had some problems with erroneous readings. I started out by monitoring just the net, but at night without solar generation the power usage was always much higher than what my PG&E smartmeter said. So I took a different route and switched the main monitoring to just monitor my consumption and with the Vue's ability to monitor 8 other circuits via an expansion box, I put a sensor on the solar feed. It seems to work fine during the day, but at night there is over 800 watts of (apparently) phantom power being drawn by the 41 inverters (approximately 19.5 watts per micro inverter). I know this isn't right because of the lower power factor, but is there a way around this with a power monitoring system that uses the "doughnut" sensors? I have looked inside the Enphase box and see they also use a "doughnut" sensor to monitor the solar panel output, but they also have a large controller board in there that processes the sensor's output and apparently compensates for it (or maybe the correction is done at the Enphase monitoring facility). I have never read of anyone having this sort of problem with the more popular SENSE Energy monitor (they have a model specifically to handle sites with Solar), so I have no idea if their readings would be inaccurate as well. I'd appreciate any thoughts on this.



Thanks, Chuck

 

[jaggedben]

Your question for me constitutes a bad review of the Emporia product. Evidently it isn't engineered to handle low power factor very well. I would try just about anything else.

By the way, the circuit board in the Enphase combiner is a lot more than the meter for the solar production. That is your Envoy, which also communicates with the microinverters, performs updates on them, etc. It is also a network device with an IP address, and you can use either that IP address (if on the same network) or the installer toolkit app to view the real-time output of the solar production meter.

 

[Rayb]

Hi Chuck. Here are some thoughts that might relate to your situation.

1. i've got an 48 panel system using the earlier generation Enphase M250 micros. I get 15 min updates in real-time. I have seen weird data during the night due to noise on the powerline interfering with Enphase powerline communications. That was due to putting the Envoy in the house, 400' (of power line) away from the ground arrays. Note I was seeing phantom production, not usage. No more problem once I moved the Envoy to the Array.
2. I can see real-time data on several IQ7 installations using an aggregating web service, PVoutput.org. They are all getting 15 minute real-time updates. (It's worth checking out PVoutput if you'd like to see other people's solar sites around the world... it's also a great way to view your own site, both real time and history, mobile and desktop... no affiliation, but I like it very much.
3. I found an Enphase support page that suggests why you would get only periodic updates of your real time data. I can't post a link (I'm too new to the forum), but you can google "how often does Enphase update" and you'll find the page.

I hope that is of some use.

Ray