Where is the power going???

[nova-exarch]

Our system is NEM (HI), 12 panels (255W Solar World Sunmodule SW 255) with Enphase M215-60-2LL inverters on the panels. The design sheet says it has a max of 2.58kW AC. Quick internet searches for 2.5W systems show they can produce 250-300ish per month (depending on conditions). The previous owners showed us their utility bill showing 250-270 was fairly common in summer months.

In the year we've been here we've seen a steady decrease on the power sent to the grid (I double checked, they're reading the meter correctly):

DATE REC
6/10/2023 26
5/11/2023 30
4/12/2023 37
3/13/2023 42
2/9/2023 68
1/11/2023 79
12/12/2022 53
11/10/2022 41
10/11/2022 79
9/9/2022 152
8/10/2022 140
7/12/2022 179
6/10/2022 207

At first I attributed the decrease to the rainy season, cloudiness, and maybe even dirty panels. I finally located the Enphase Envoy unit (it was disconnected and shoved in a corner of the garage by previous owners) and got it connected and have had it running for over a week now. It's showing that the system is producing 80/week:

Time Period Energy Generated
Currently 1.08 kW (it's somewhat cloudy today, I've seen this go as high as 2.2-2.3)
Today 1.61 kWh (early in the day)
Past Week 82.5 kWh

Meanwhile... the wonderful meter is only showing 7kWh difference from the last meter reading from a month ago.

Any ideas on where the juice is going???

 

[BentleyJ]

Lots of information related to how the solar is connected to your house and how the utility meter arrangement is set up is missing. Difficult to answer your question completely. However, the following is what we do know.
1) 82.5/7days = 11.8kWh per day is in the correct range for a somewhat aged 2.5kW system. That averages to 354kWh per month so if the previous owners were REALLY frugal and only used 100kWh a month. The excess would be about 250kWh. Seems like you are just using more than them?
2) The Envoy should allow you to view the output of individual panels to see if they are all still producing about the same or if some are degraded more than others. This will help you determine if the system is performing up to full potential.
3) Do you have a separate utility meter on the solar system itself? The most common way a grid-tied Enphase system is connected is via a 20A breaker that back-feeds into your main or maybe a subpanel. Therefore any solar electricity produced is FIRST consumed by the house and only EXCESS production that is left over goes through the utility meter to the grid. Thus the utility meter may ONLY show NET electricity usage which is either positive (consumption) or negative (excess production).
4) Electronic utility meters are sometimes not actually bi-directional they can be 2 channel meters. For example our meter. Channel 001 totals incoming power and channel 082 totals outgoing power. Its necessary to subtract the reading from ch 082 from ch 001 to get the NET which is what is reported on the bill.

 

[nova-exarch]

My apologies, I was completely misinformed. I was under the impression that we are fed off the grid 100% of the time and our production goes to the feed the grid 100% of the time. Which kinda made since because the one time power went out on my wife in the daytime we had no power at all (even though it was plenty sunny and the system should've been producing.

Thank you for helping me figure out what I was misunderstanding. I see in the NEM brochure that it spells it out just like you explained. That's what I get for trusting the person on the phone and not confirming through my own reading. It was suspicious to see a steady decline in the electricity received by HELCO, but I guess it's just circumstantial (cloudiness/energy hogs/etc...). FWIW... it's a three channel meter FROM TO and NET.

The envoy interface is very limited. It lets me see the status of the inverters, but I don't see where it shows individualized production. I was trying to log into Enphase's Enlighten system to see if there were more details there or maybe historical graphs, but they want $200 to transfer ownership and I haven't quite decided if that is worth it or not. Any thoughts on that?

 

[BentleyJ]

No need for apologies, this what the DIY forum is for. I posted an Elighten screen shot of our 3.0kW system in CA. It shows individual panel data.

Alternatively, the 2nd screen shot is a direct login to the Envoy. Enphase told me not to do that because its possible to mess up the settings and deactivate a microinverter. So far that has not happened because I'm careful. Honestly don't remember how I logged in the first time to set a fixed IP and password. Will let you know if I remember.

I purchased my Envoy used from ebay and had the same experience with customer service. They did help me somewhat but would not erase the previous users historical data or reset to zero for me.

Also worth mentioning, each microinverter can display a series of charts in Enlighten. I would say its worth $200 to have access to this data. For clarification, I'm using M250's. Not sure about the M215's if they have the same amount of data available for graphing.

 

[nova-exarch]

No need for apologies, this what the DIY forum is for. I posted an Elighten screen shot of our 3.0kW system in CA. It shows individual panel data.

Alternatively, the 2nd screen shot is a direct login to the Envoy. Enphase told me not to do that because its possible to mess up the settings and deactivate a microinverter. So far that has not happened because I'm careful. Honestly don't remember how I logged in the first time to set a fixed IP and password. Will let you know if I remember.

I purchased my Envoy used from ebay and had the same experience with customer service. They did help me somewhat but would not erase the previous users historical data or reset to zero for me.

Also worth mentioning, each microinverter can display a series of charts in Enlighten. I would say its worth $200 to have access to this data. For clarification, I'm using M250's. Not sure about the M215's if they have the same amount of data available for graphing.

That is wonderful! I do believe it's worth it for the historical graphs.

Thanks again!

Next challenge... design/source/build a stand alone for the 1500 watt AC that is chugging all the juice!

 

[BentleyJ]

Next challenge... design/source/build a stand alone for the 1500 watt AC that is chugging all the juice!

A variable speed mini split is as good as it gets as far as efficiency but AC is still going to be a major consumer or power, especially with the humidity.

 

[nova-exarch]

No need for apologies, this what the DIY forum is for. I posted an Elighten screen shot of our 3.0kW system in CA. It shows individual panel data.

Alternatively, the 2nd screen shot is a direct login to the Envoy. Enphase told me not to do that because its possible to mess up the settings and deactivate a microinverter. So far that has not happened because I'm careful. Honestly don't remember how I logged in the first time to set a fixed IP and password. Will let you know if I remember.

I purchased my Envoy used from ebay and had the same experience with customer service. They did help me somewhat but would not erase the previous users historical data or reset to zero for me.

Also worth mentioning, each microinverter can display a series of charts in Enlighten. I would say its worth $200 to have access to this data. For clarification, I'm using M250's. Not sure about the M215's if they have the same amount of data available for graphing.

Good news / ugh news...

It looks like stuff is all normal. However, it looks like the prev owners only left the envoy connected for a few months before relegating it to a corner in the garage...

But from the last two weeks since I reconnected it seems comparable considering it's 11yrs old.

 

[shopman]

One thing worth mentioning. With a grid tied system, if the grid goes down your solar production will be shut down also. This is by design in order to protect the linemen working on the grid from being electrocuted by the power your solar system is feeding into the grid.

 

[Tulex]

One thing worth mentioning. With a grid tied system, if the grid goes down your solar production will be shut down also. This is by design in order to protect the linemen working on the grid from being electrocuted by the power your solar system is feeding into the grid.

That depends on the system. Sol-Ark 15K, and maybe others, is designed to be fed directly from the grid, the main panel then comes off the inverter. If you have batteries, it will still use the PV. It simply isolates from the grid.

 

[DIYrich]

That depends on the system. Sol-Ark 15K, and maybe others, is designed to be fed directly from the grid, the main panel then comes off the inverter. If you have batteries, it will still use the PV. It simply isolates from the grid.

Original poster had an older enphase system that would require additional hardware to island if grid goes down.

 

[Tulex]

Original poster had an older enphase system that would require additional hardware to island if grid goes down.

That's fine, I was just pointing out that with today's newer AIO systems, that's no longer a valid blanket statement.