Evaluating my new system performance

[Crash]

I finally went online in NE FL with my sunpower system. I have 32 x22-360-c-ac panels. 20 panels face mainly east catching the morning sun while 12 on the southern roof catch more of the afternoon rays. According to their monitoring i did about 50kwh yesterday with a mostly sunny day. Today I did 41kwh with a mainly cloudy day. Does that seem to be good production for my setup? I really wish I could monitor my production at the panel level. I'd like to see how my roof and panel layouts affect my production. Thanks.

[Kingram]

My 9.3 system ( 26 X22 360 watt SunPower panels ) hasn't gone online yet but on paper it is supposed to produce 42.3 kwh a day and my son's system also not online yet is a supposed to produce 34 kwh using 22 X21 345 watt SunPower panels . So 50 kwh on a good day for you may be about right.

[J.P.M.]

I finally went online in NE FL with my sunpower system. I have 32 x22-360-c-ac panels. 20 panels face mainly east catching the morning sun while 12 on the southern roof catch more of the afternoon rays. According to their monitoring i did about 50kwh yesterday with a mostly sunny day. Today I did 41kwh with a mainly cloudy day. Does that seem to be good production for my setup? I really wish I could monitor my production at the panel level. I'd like to see how my roof and panel layouts affect my production. Thanks.

Check out PVWatts. run it once for each orientation and sum the results. Get the hourly output and look for clear day outputs near/around this date for a rough guestimate of clear day output this time of year. Know that output will vary over a year with the seasons. Make sure you get the array orientations for the model as close to actual as possible.

[J.P.M.]

My 9.3 system ( 26 X22 360 watt SunPower panels ) hasn't gone online yet but on paper it is supposed to produce 42.3 kwh a day and my son's system also not online yet is a supposed to produce 34 kwh using 22 X21 345 watt SunPower panels . So 50 kwh on a good day for you may be about right.

You do know that output will vary as f(time of year, array orientations, weather) ?

[Kingram]

Yes I understand production output will vary from summer to winter and cloudy days to clear days. I also heard 77 degrees is the ideal temp for panels to operate at so I guess a clear 77 degree day is better than a clear 110 degree day here in Arizona. Here is a chart I was given with my proposal. Is this a standard chart they give out to everyone or does the chart vary in different parts of the country ?

[littleharbor]

Kyocera KD 135 2.JPG
The actual cell temperature will be higher than the ambient air temp. There isn't an ideal temp for solar panels. Their voltage will vary with the temperature of the cells. The numbers you are referring to are the STC, i,e. Standard Test Conditions. They are an agreed on set of test conditions to have a level playing field for testing solar panels. This is the temp and irradience conditions when the panels are flash tested in a lab., not really real world .
You may also see NOCT i.e. Normal Operating Cell Temp. They will always be lower output than STC numbers. They are more "real world" numbers to expect, unless you live at very high elevations where it is very clear and cold.You can actually see higher output from the panel than it is rated at under the right conditions.This Kyocera data label has both sets of numbers. Not all panel Mfg. include these NOCT numbers. As you can see there is a substantial difference between the two.

[J.P.M.]

Kyocera KD 135 2.JPG
The actual cell temperature will be higher than the ambient air temp. There isn't an ideal temp for solar panels. Their voltage will vary with the temperature of the cells. The numbers you are referring to are the STC, i,e. Standard Test Conditions. They are an agreed on set of test conditions to have a level playing field for testing solar panels. This is the temp and irradience conditions when the panels are flash tested in a lab., not really real world .
You may also see NOCT i.e. Normal Operating Cell Temp. They will always be lower output than STC numbers. They are more "real world" numbers to expect, unless you live at very high elevations where it is very clear and cold.You can actually see higher output from the panel than it is rated at under the right conditions.This Kyocera data label has both sets of numbers. Not all panel Mfg. include these NOCT numbers. As you can see there is a substantial difference between the two.

I wouldn't pay too much attention to NOCT numbers. They're no more than estimated output at a different set of defined conditions. That they may or may not be more representative of real world conditions has always been a dubious claim to me. Seems like NOCT does little more than muddy the waters without adding much useful information.

For normally intelligent potential PV users, 20 minutes with PVWatts help/info screens and a few runs will be much more informative, helpful and useful than NOCT information.

[Rpeacock1950]

I am new to this forum, so please bear with me.
My location is in mid Michigan which is Consumers Energy territory. My 8.28kw array went on line Oct. 18, 2017. The array is a SunPower equinox system. We supposedly have net metering with Consumers (they don't credit back the distribution charges).
I just received from Consumers what my usage and generation was from Oct.11 to Nov.8. Their usage is about what my Sunpower app says was used (+or- 5%). The generation, however, is way off from what they say and what the app says. They show my generation at 105kwh but the app says I generated 204kwh.
The question is: where do I go from here? Is the SunPower app that inaccurate?

[littleharbor]

The other 101 Kwh was consumed by you and never went out to the POCO.

[Rpeacock1950]

Thanks for replying littleharbor. So if I'm using 2 kw and generating 4 kw, at any point in time, only 2 kw is flowing back into the grid. Do you, or anyone else, know if SunPower is relatively accurate with their reporting? Should there be any concern that the power company is accurate with their reporting or metering?

[J.P.M.]

Thanks for replying littleharbor. So if I'm using 2 kw and generating 4 kw, at any point in time, only 2 kw is flowing back into the grid. Do you, or anyone else, know if SunPower is relatively accurate with their reporting? Should there be any concern that the power company is accurate with their reporting or metering?

FWIW, my Sunpower system monitor, which has been on line since 10/17/2013 has reported generation in such quantities that are pretty close to 0.5 % greater than my electric meter would have me believe the PV system has produced. Over the period from 10/17/2013 to this A.M. startup, the S.P. monitor says system has produced 37,609 kWh. I figure actual production has been closer to 37,416 kWh. Long, boring story how I figured that out without a production meter, but with some ingenuity and care, it can be done. The POCO meter is of some (but not a lot of) help figuring daily, or any period, solar production by supplying what I've sent to the grid and what the POCO has sent me. Note that I'm comparing POCO meter and S.P. meter numbers, and not making any claims about any meter accuracy. Correctly or not, I define the POCO meter as accurate for my use and purposes.

[Guest]

I finally went online in NE FL with my sunpower system. I have 32 x22-360-c-ac panels. 20 panels face mainly east catching the morning sun while 12 on the southern roof catch more of the afternoon rays. According to their monitoring i did about 50kwh yesterday with a mostly sunny day. Today I did 41kwh with a mainly cloudy day. Does that seem to be good production for my setup? I really wish I could monitor my production at the panel level. I'd like to see how my roof and panel layouts affect my production. Thanks.

Is there a way to monitor energy production at panel level?

[J.P.M.]

Is there a way to monitor energy production at panel level?

Yes, with micro inverters or optimizers. Why do you ask ?