New system installed and new to forum

[Sando]

I had install completed late 12/2022. System size is 4.4, offset was supposed to be 131%. I have since had heat pump system installed. Jan. production was only 239 kWh. Feb was 297, March so far 305. I went to the power company, they came out and confirmed their meter was working correctly. The solar company confirmed remotely that the panels were okay. I have eleven 400 watt panels facing East and West on a 2 story house in Northern NM. I'm on net metering, no battery. I'm really concerned about whether I have made a mistake in having this system installed since the production has been so low so far and am looking for opinions of others who might have experienced this. I'm hoping the production greatly improves with the longer days/better weather. The app I have is solaredge.

[Ampster]

Winter production is always lower. Run an estimate on PV Watts to see the difference between December and June. Hang in there, the days are getting longer.

[SunEagle]

At least the production values are going up. I agree with Ampster that you should see more during the summer months.

One of my questions is what type of inverter are you using and what is the rating in kw. In some cases even though you might have 4400 watts of panels the inverter may not be outputing that much. Also due to the E / W orientation you may not get the output you expect or were told.

[Mike 134]

Winter production is always lower. Run an estimate on PV Watts to see the difference between December and June. Hang in there, the days are getting longer.

What Ampster said.

[J.P.M.]

I had install completed late 12/2022. System size is 4.4, offset was supposed to be 131%. I have since had heat pump system installed. Jan. production was only 239 kWh. Feb was 297, March so far 305. I went to the power company, they came out and confirmed their meter was working correctly. The solar company confirmed remotely that the panels were okay. I have eleven 400 watt panels facing East and West on a 2 story house in Northern NM. I'm on net metering, no battery. I'm really concerned about whether I have made a mistake in having this system installed since the production has been so low so far and am looking for opinions of others who might have experienced this. I'm hoping the production greatly improves with the longer days/better weather. The app I have is solaredge.

I lived in NM for several years and travelled widely in the state. FWIW. prettiest place I ever lived.

While your winter system output is lower, for the same panel orientations and for several reasons including altitude above sea level, low(er) winter temps and winter generally being the dry season in most of NM, your location in northern NM will produce more output in winter that just about any other place in the continental U.S.
Still, you could have had a rainy winter as much of the SW U.S. has experienced this year.

As Ampster suggests, do a PVWatts run. I'd only suggest getting the input correct and use a 10% system loos parameter rather than the10 % the model defaults to.

Given good input, PVWatts is a reasonable model that can give reliable long term average output, especially in climates without a lot of irradiance variation such as yours. However, expect a lot more production come the other 3 seasons.
Higher tilts in east/west orientations will lower output, particularly in the winter.

What are your array tilts ?
What's your zip ?
Any shading ?
I will assume the 4.4 number is the system size in STC kW ?
Did you get an expected monthly output from the vendor ?

[RichardCullip]

Here in San Diego County I would be disappointed with your solar production. In spite of more rain and cloudy days than usual my 4kW system (3.88kw inverter) is averaging 500kWh for the past 5 months. I do have a nice mostly south orientation (190deg) with no shade.

[SunEagle]

Here in San Diego County I would be disappointed with your solar production. In spite of more rain and cloudy days than usual my 4kW system (3.88kw inverter) is averaging 500kWh for the past 5 months. I do have a nice mostly south orientation (190deg) with no shade.

I think the OP has a lower production rate due to the E / W panel orientation and possibly due to the inverter rating

[Sando]

I'm the original poster (70 yr. old female) and am going to try to answer some of the questions. By the way, I really appreciate everyone's input. My inverter is a solaredge SE3800H, and there is a number saying Max output Wac 3800 W. (I'm looking at the contract I signed). For the system it says 4.4 kW DC. Zip is 87740, Raton, NM right up by the Colorado border. We have not had a lot of rain or snow this winter, but lots of cloudy days. I have 2 big trees on the East side of the house and some smaller trees on the West side. Two story house with the panels at an angle. I'm not sure if I got a monthly output estimate from the vendor, will look for that. (They are in Albu. and not very helpful. But I haven't pushed very hard, I'm going to wait and see what happens production-wise) I'm not sure I'll be able to run an estimate on PV watts, but will look into that also.

[SunEagle]

I'm the original poster (70 yr. old female) and am going to try to answer some of the questions. By the way, I really appreciate everyone's input. My inverter is a solaredge SE3800H, and there is a number saying Max output Wac 3800 W. (I'm looking at the contract I signed). For the system it says 4.4 kW DC. Zip is 87740, Raton, NM right up by the Colorado border. We have not had a lot of rain or snow this winter, but lots of cloudy days. I have 2 big trees on the East side of the house and some smaller trees on the West side. Two story house with the panels at an angle. I'm not sure if I got a monthly output estimate from the vendor, will look for that. (They are in Albu. and not very helpful. But I haven't pushed very hard, I'm going to wait and see what happens production-wise) I'm not sure I'll be able to run an estimate on PV watts, but will look into that also.

Thanks for the update. IMO the problem of low production could be shade from the trees or clouds above the panels based on the time of day. Without more details on the system and what is actually expected this time of year it could be a system not working up to par or just crappy weather causing a reduction of output. Too bad you can't run the PV watts estimate to see what history says the system should produce.

[oregon_phil]

I ran a hypothetical PVWatts E/W array of 5 East/6 West x 400 watt panels on a 34 deg pitch roof at Zip Code 87740. See attachment NM estimate. We can do a better estimate if the OP can give us the actual number of panels East and West, the actual house orientation and the actual roof pitch. But maybe it's a starting place.

Since the system is a Solar Edge system, minimum and maximum strings lengths are specified: 8 panels minimum, 25 panels maximum. This implies that the installer used one string for all panels since there are 11 total panels. See SE String Length attachment.

I remember reading an article from MC Electric regarding issues with SolarEdge production issues due to voltage blocking. See attachment SE Blocking. The part that concerns me in the article is where it says "However, if we have a string with 6 or fewer panels in the sun, the system will suffer voltage blocking at best, or it will just shut down at worst. This is even when the electrician installs to SolarEdge guidelines." You can read the full article googling MC Electric and SolarEdge. If this was a flat roof, then no issues. The steeper the roof and/or the more shading on the panels, my guess is that voltage blocking would have a greater chance of impacting inverter output.

I am not an installer nor do I own SolarEdge equipment so I am not an expert. I'm just a retired mechanical engineer with an interest in Solar. Please take anything I have said with a grain of salt. A solar professional designer should review any and all data.

[J.P.M.]

I'm the original poster (70 yr. old female) and am going to try to answer some of the questions. By the way, I really appreciate everyone's input. My inverter is a solaredge SE3800H, and there is a number saying Max output Wac 3800 W. (I'm looking at the contract I signed). For the system it says 4.4 kW DC. Zip is 87740, Raton, NM right up by the Colorado border. We have not had a lot of rain or snow this winter, but lots of cloudy days. I have 2 big trees on the East side of the house and some smaller trees on the West side. Two story house with the panels at an angle. I'm not sure if I got a monthly output estimate from the vendor, will look for that. (They are in Albu. and not very helpful. But I haven't pushed very hard, I'm going to wait and see what happens production-wise) I'm not sure I'll be able to run an estimate on PV watts, but will look into that also.

Thank you.

What is the vendor's name in Albuquerque ?
I've been through the Raton pass and in/around Raton several times. I remember BBQ at the Ice House.

Do the trees shade the panels during daylight hours ? If so approximately how much of the time ?

For many reasons I'd encourage you to check out PVWatts on the net. It's a user friendly model that takes about 20 minutes to read through the help screens. After that, the input and familiarization may take another 20. After that it'll become old hat. What you learn will be well worth the investment of your time.

If you provide a tilt off horizontal for your arrays and given your zip and azimuth, any number of folks here will most likely be willing and able to answer any questions you may have to get you going. Just provide an estimate of the arrays' tilt (horizontal = zero degrees tilt, vertical = 90 degrees).

As a rough 1st approximation, I'd expect about twice the output from your arrays in the summer months vs. the winter months.

Good luck.

[J.P.M.]

I think the OP has a lower production rate due to the E / W panel orientation and possibly due to the inverter rating

We'll have to see if the OP comes back with an array tilt. If it's greater than say 45 degrees or so, the E-W orientation and a high tilt will hurt production, more than a DC/AC ratio of 1.16, which doesn't seem too bad to me, especially if tilts are higher than, say, 30 degrees or so.

[SolTex]

Our system in Midland, TX will generate (on a good clear sunny day) between 2.25 and 2.50 kWh per panel per day. We have 380W (STC rating) panels with IQ7+ micro inverters. Our output is limited (clipped) by the max AC output of our inverters. The OP's numbers in the first post indicate she is getting (so far in March) a little over 1.0 kWh per panel per day. ("March so far" = 305kWh divided by 24 days = 12.71kWh per day divided by 11 panels = 1.16kWh per panel) That seems kinda low to me.

[Sando]

I read through all the comments and found some more info regarding my system. Also used the PVWatts calculator, although I did not break it up like previous poster into 2 calculations for east (5 panels) and 6 on the west side. I have monthly estimates by NM Solar (they should say 2023, not 2022), the project overview with array details and what I got from PVWatts. Jan. and Feb. are closer to installers estimates, March looks like it is going to be a lot less. Also read the article from AC Electric, not sure I understand it completely.

[Sando]

Sorry, here's the attachments: