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Re: Our solar production

Posted: Tue Jul 11, 2017 9:33 am
DuncanCunningham wrote:i'm new to this solar thing. I got a ground mount system. 24 panels. 12 inverters...
Nice data collection system. Since 2008 I've been reading my meters manually, before the inverters shut down for the evening, and later entering the data on a spreadsheet — very "old school," but fun!

Re: Our solar production

Posted: Tue Jul 11, 2017 10:23 am

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`Solar production for May:            700 W        2170 W          Old Panels    Old+New PanelsMay-09      108 kWhMay-10      122 kWhMay-11      111 kWhMay-12      127 kWhMay-13      119 kWh      338 kWhMay-14      111 kWh      313 kWhMay-15       90 kWh      250 kWhMay-16      106 kWh      300 kWhMay-17      112 kWh      319 kWh`

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`Solar production for June:             700 W        2170 W          Old Panels    Old+New PanelsJune-09      101 kWhJune-10      117 kWhJune-11      134 kWhJune-12      120 kWhJune-13      124 kWh      356 kWhJune-14      122 kWh      349 kWhJune-15      117 kWh      333 kWhJune-16      107 kWh      303 kWhJune-17      127 kWh      365 kWh`

Solar panels at summer solstice 15º pitch:

Re: Our solar production

Posted: Tue Jul 11, 2017 10:37 am
I would love to have tracking on mine. Maybe another day? You have a lot of kwh totals from those panels. Really over 100kWh per day?

Re: Our solar production

Posted: Tue Jul 11, 2017 12:21 pm
DuncanCunningham wrote:I would love to have tracking on mine. Maybe another day? You have a lot of kwh totals from those panels. Really over 100kWh per day?
No! those are monthly totals for the various years! A good day for me here is 13 kWh.

A good way to look at production is total energy produced divided by the rated power of the panels. So, for a sunny day production of 13.3 kWh divided by 2.17 kW I get 6.13 hours of rated production. Of more interest is the annual total divided by days and rated power. For 2016 I got:

3227 kWh/365 days = 8.84 kWh/day average
8.84 kWh/2.17 kW = 4.07 hours, which is pretty good for my latitude, 38ºN, and climate zone (mountain snowbelt; lots of clouds in the mountains).

This is a good way to compare the overall production of a system to installations in other geographic areas.

Re: Our solar production

Posted: Tue Jul 11, 2017 1:10 pm
i've only been going for about 3 weeks. I'll have to see how it goes. I have no preconceived notions of how it should look. just going with the flow right now. the limit in our city was 10kW system. I should have taken it to the max but I'm happy so far.

Re: Our solar production

Posted: Mon Jul 17, 2017 11:59 am
I installed 13.2 KW system last year using 44 SolarWorld 300 watt panels. 10 each on my east & west facing garage roofs and 24 on the south facing roof of my home.

Since install in late June 2016, I have produced 12.4 MWh while using 9 MWh. 3.4 MWh sent back to the grid. There were a few weeks in there where I wasn't able to monitor while they installed various meters and equipment.

This has been a very worthwhile, long-term investment a little over a year in.

Re: Our solar production

Posted: Mon Jul 17, 2017 1:21 pm
mnsolardriver wrote:I installed 13.2 KW system last year using 44 SolarWorld 300 watt panels. 10 each on my east & west facing garage roofs and 24 on the south facing roof of my home.

Since install in late June 2016, I have produced 12.4 MWh while using 9 MWh. 3.4 MWh sent back to the grid. There were a few weeks in there where I wasn't able to monitor while they installed various meters and equipment.

This has been a very worthwhile, long-term investment a little over a year in.

I"m not allowed to add to my solar system now.. if I do it would have to be classed as a NEW system and I would be put onto a tariff metering which is not as nice for me. Right now it's net metering and kwh for kwh the same in as the price is out.

I could do a stand alone system on my garage, like yours. It has a gable end facing south so I could do a east and west setup on it. I'd have to collect the power into batteries and then I could use them to charge my cars. Not sure how to do that, probably have to get a bunch of Tesla power walls for that.

I do have a TED energy monitor that I could hook up to my circuits feeding the car charging and see what daily numbers I get.

Re: Our solar production

Posted: Mon Jul 17, 2017 1:28 pm
DuncanCunningham wrote:
mnsolardriver wrote:
I"m not allowed to add to my solar system now.. if I do it would have to be classed as a NEW system and I would be put onto a tariff metering which is not as nice for me. Right now it's net metering and kwh for kwh the same in as the price is out.

I could do a stand alone system on my garage, like yours. It has a gable end facing south so I could do a east and west setup on it. I'd have to collect the power into batteries and then I could use them to charge my cars. Not sure how to do that, probably have to get a bunch of Tesla power walls for that.

I do have a TED energy monitor that I could hook up to my circuits feeding the car charging and see what daily numbers I get.

I see Tesla is taking pre-orders for their solar roof, which are nice looking shingles and they roll the cost of the powerwall into the pricing. A 14 kWh powerwall would cover a lot of driving (50 miles / day or so in a LEAF) without you losing the excess power to the utility.

Net metering is really what gives you the payback and I'm fortunate that this is the set-up in Minnesota.

Re: Our solar production

Posted: Thu Nov 02, 2017 3:26 pm
October seemed unusually sunny here and so it turned out to be — my solar production was the second highest since I started tracking it in 2008, coming close to my best October in 2012.

Solar production for October:

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`            700 W        2170 W          Old Panels   Old+New PanelsOct-08       96 kWhOct-09       87 kWhOct-10       98 kWhOct-11      100 kWhOct-12      113 kWh      322 kWhOct-13       98 kWh      276 kWhOct-14      100 kWh      279 kWhOct-15       84 kWh      235 kWhOct-16      106 kWh      299 kWhOct-17      110 kWh      311 kWh`

My panels are currently at a 45º pitch; I'll lower them to 55º next week for the next few months around the solstice. A couple of days before the end of the October I cut a piñon pine that had grown up high enough — they do like to do that! — to shade the panels in the late afternoon when the sun is in the current position, about two months before and after the winter solstice. Adds about a half kWh per day on sunny days this time of the year.

Re: Our solar production

Posted: Fri Dec 08, 2017 5:47 am
Since I saw a new momentary production peak yesterday, I thought this would be a good time to update this year's production.

First, the peak: With my recent upgrades, the AC rating of the array now stands at 12.775 kW. Yesterday, just before noon, production peaked at 12.0 kW:

Due to the pointing angle of the M250s on the roof, I don't expect to see the full 12.775 kW at any time this winter, but I do think we might see over 12.5 kW, particularly on a cold, clear day when there is snow on the ground (and none on the arrays).

2017 is turning out to be the lowest production year since the array was expanded to include 54 inverters. Production should come in below 18 MWh. Production will likely fall short of last year's record production by nearly a full MWh.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015, 2016 and 2017 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):

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`Month    PVW42   2011   2012   2013   2014   2015   2016   2017  PVW54  Units-----------------------------------------------------------------------------January    916    669    869    822    857   1006   1300    756   1229   kWhFebruary   702    158   1085    866   1054   1361   1192   1241    915   kWhMarch      965      0   1350   1152   1113   1547   1498   1572   1240   kWhApril     1465      0   1465   1495   1338   1737   1754   1654   1899   kWhMay       1583      0   1477   1491   1457   2069   1574   1618   2074   kWh June      1268      0   1478   1368   1521   1585   1932   1916   1666   kWh`

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`July      1448    595   1395   1406   1880   1823   1887   1792   1902   kWhAugust    1442   1347   1447   1333   1794   1887   1932   1778   1875   kWhSeptember 1209    910   1295   1414   1577   1495   1551   1612   1555   kWhOctober   1304    931    981   1034   1258   1415   1593   1587   1713   kWhNovember   864    949   1041   1018   1227   1277   1340   1205   1154   kWhDecember   820    803    612    669    812    865   1002          1108   kWh-----------------------------------------------------------------------------Totals   13986   6362  14495  14068  15888  18067  18555  16731  18330   kWh`
Our system has produced 104.166 MWh from installation through the end of November 2017.