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Production from my 33 230wDC SunPower Panels via Sunnyboy (SMA) 7000US Inverter (7.59kW DC)
Pre-Solar Average Monthly Electric Bil - $250, prior to recent price increases

2016 AC Production/Electric Bill (APS)
Jan 939 ----------$91.62
Feb 1162 -------- $9.30

2015 AC Production/Electric Bill (APS)
Jan 863 ---------- $76.96 (old rate plan)
Feb 1060 -------- $9.90 (new rate plan)
Mar 1333 ------- $9.30
April 1441 ------ $9.30
May 1447 ------- $9.62
Jun 1329 -------- $9.93
Jul 1354 --------- $9.62
Aug 1358 -------$9.62
Sept 1197-----$28.28
Oct 1122 ------- $9.62
Nov 1064 ------$10.60
Dec 891 --------$70.86

2014 AC Production
Jan 1048
Feb 977
Mar 1347
Apr 1438
May 1476
Jun 1413
Jul 1346
Aug 1368
Sep 1242
Oct 1193
Nov 1053
Dec 844

2013 AC Production
Jan 910
Feb 1105
Mar 1328
Apr 1444
May 1474
Jun 1447
Jul 1284
Aug 1230
Sep 1280
Oct 1050
Nov 955
Dec 1005

2012 AC Production
Mar 1228
Apr 1217
May 1416
Jun 1325
Jul 1189
Aug 1168
Sep 1118
Oct 603
Nov 970
Dec 851

Link to my Solar Production - http://pvpwrev.webs.com/
 
Production from my 33 230wDC SunPower Panels via Sunnyboy (SMA) 7000US Inverter (7.59kW DC)
Pre-Solar Average Monthly Electric Bil - $250, prior to recent price increases

2016 AC Production/Electric Bill (APS)
Jan 939 ----------$91.62
Feb 1162 -------- $9.30
Mar 1330 --------$9.30

2015 AC Production/Electric Bill (APS)
Jan 863 ---------- $76.96 (old rate plan)
Feb 1060 -------- $9.90 (new rate plan)
Mar 1333 ------- $9.30
April 1441 ------ $9.30
May 1447 ------- $9.62
Jun 1329 -------- $9.93
Jul 1354 --------- $9.62
Aug 1358 -------$9.62
Sept 1197-----$28.28
Oct 1122 ------- $9.62
Nov 1064 ------$10.60
Dec 891 --------$70.86

2014 AC Production
Jan 1048
Feb 977
Mar 1347
Apr 1438
May 1476
Jun 1413
Jul 1346
Aug 1368
Sep 1242
Oct 1193
Nov 1053
Dec 844

2013 AC Production
Jan 910
Feb 1105
Mar 1328
Apr 1444
May 1474
Jun 1447
Jul 1284
Aug 1230
Sep 1280
Oct 1050
Nov 955
Dec 1005

2012 AC Production
Mar 1228
Apr 1217
May 1416
Jun 1325
Jul 1189
Aug 1168
Sep 1118
Oct 603
Nov 970
Dec 851

Link to my Solar Production - http://pvpwrev.webs.com/
 
March 2016 ended with 1498 kWh having been produced. This is only 97% of last year's record of 1547 kWh and only 86% of the 2012 smaller-system record of 1350 kWh (after multiplying that old record by 1.29).

The peak production day this month was on the 29th at 82.9 kWh. The daily production record for February of 84.7 kWh was previously set on March 18, 2015.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737          1899   kWh
May       1583      0   1477   1491   1457   2069          2074   kWh 
June      1268      0   1478   1368   1521   1585          1666   kWh
Code:
July      1448    595   1395   1406   1880   1823          1902   kWh
August    1442   1347   1447   1333   1794   1887          1875   kWh
September 1209    910   1295   1414   1577   1495          1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067   3990  18330   kWh
Our system has produced 72.870 MWh from installation through the end of March 2016.

Net grid consumption since August 2011 (when PV was turned on permanently) has been 14.6 MWh. Solar production during this period was 72.0 MWh. Total consumption equals 86.6 MWh. Solar has provided 83% of that total.

It appears that for the first time ever we have produced more electricity than we have consumed during the past 12 months! :D We will know for sure on April 3, when we have an "official" meter reading from our electricity co-op. I will post in the "net producer/consumer" thread on Sunday with the result.
 
New one-week production record!

Anyone who has clicked on the solar array link in my signature has likely noticed that we rarely have strings of cloudless days around here. But during the seven days from April 12 through April 18 we had nearly-cloudless weather. Since this occurred in April when production is very high, we managed to set a new 7-day production record:

Energy_April_12_18_2016.png


That works out to an average of a bit over 80 kWh per day!

(But I will note that QueenBee has me beat by a mile in this department. Have a look at his production during last June!)
 
April 2016 ended with 1754 kWh having been produced. That is 101% of last year's record of 1738 kWh but only 91% of the 2013 smaller-system record of 1929 kWh (after multiplying that old record by 1.29).

The peak production day this month was on the 5th at 87.9 kWh. The daily production record for April of 89.1 kWh was previously set on April 24, 2015. That record is also the all-time daily production record for this system.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069          2074   kWh 
June      1268      0   1478   1368   1521   1585          1666   kWh
Code:
July      1448    595   1395   1406   1880   1823          1902   kWh
August    1442   1347   1447   1333   1794   1887          1875   kWh
September 1209    910   1295   1414   1577   1495          1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067   5744  18330   kWh
Our system has produced 74.624 MWh from installation through the end of April 2016.

Net grid consumption since August 2011 (when PV was turned on permanently) has been 14.2 MWh. Solar production during this period was 73.8 MWh meaning total consumption was 88.0 MWh. Solar has provided 84% of that total.

During the past 12-month period, production was 18,160 kWh and consumption was 17,917 kWh meaning our system was a net producer of 243 kWh.
 
Production from my 33 230wDC SunPower Panels via Sunnyboy (SMA) 7000US Inverter (7.59kW DC)
Pre-Solar Average Monthly Electric Bil - $250, prior to recent price increases

2016 AC Production/Electric Bill (APS)
Jan 939 ----------$91.62
Feb 1162 -------- $9.30
Mar 1330 --------$9.30
Apr 1410 ---------$9.30

2015 AC Production/Electric Bill (APS)
Jan 863 ---------- $76.96 (old rate plan)
Feb 1060 -------- $9.90 (new rate plan)
Mar 1333 ------- $9.30
April 1441 ------ $9.30
May 1447 ------- $9.62
Jun 1329 -------- $9.93
Jul 1354 --------- $9.62
Aug 1358 -------$9.62
Sept 1197-----$28.28
Oct 1122 ------- $9.62
Nov 1064 ------$10.60
Dec 891 --------$70.86

2014 AC Production
Jan 1048
Feb 977
Mar 1347
Apr 1438
May 1476
Jun 1413
Jul 1346
Aug 1368
Sep 1242
Oct 1193
Nov 1053
Dec 844

2013 AC Production
Jan 910
Feb 1105
Mar 1328
Apr 1444
May 1474
Jun 1447
Jul 1284
Aug 1230
Sep 1280
Oct 1050
Nov 955
Dec 1005

2012 AC Production
Mar 1228
Apr 1217
May 1416
Jun 1325
Jul 1189
Aug 1168
Sep 1118
Oct 603
Nov 970
Dec 851

Link to my Solar Production - http://pvpwrev.webs.com/
 
May 2016 was extremely rainy and ended with 1574 kWh having been produced. That is 24% below last May's all-time monthly production record of 2069 kWh. May's result was even lower than last June's miserable production of 1585. (OTOH, the grass in the field is *literally* three feet tall.)

The peak production day this month was on the 16th at 87.7 kWh. This beats the previous daily record for May of 84.0 kWh which was set on May 14, 2015. Only two days have seen higher production: April 24, 2015 at 89.1 kWh and April 5, 2016 at 87.9 kWh.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585          1666   kWh
Code:
July      1448    595   1395   1406   1880   1823          1902   kWh
August    1442   1347   1447   1333   1794   1887          1875   kWh
September 1209    910   1295   1414   1577   1495          1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067   7318  18330   kWh
Our system has produced 76.198 MWh from installation through the end of May 2016.

Net grid consumption since July 2011 (when PV was turned on permanently) has been 13.7 MWh. Solar production during this period was 75.4 MWh meaning total consumption was 89.1 MWh. Solar has provided 85% of that total.

During the past 12-month period, production was 17,665 kWh and consumption was 17,803 kWh meaning our system was a net consumer of 138 kWh. Put another way, our system produced 99.2% of our consumption over this period, including driving the LEAF 8000 miles.
 
June 2016 was quite sunny and ended with 1932 kWh having been produced. That is 23% above last June's miserable production of 1574 kWh and only slightly below 2014's record of 1962 kWh (after multiplying by 1.29 to account for the addition of the field array).

The peak production day this month was on the 9th at 82.2 kWh. This beats the previous daily record for June of 80.1 kWh which was set on June 24, 2015.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823          1902   kWh
August    1442   1347   1447   1333   1794   1887          1875   kWh
September 1209    910   1295   1414   1577   1495          1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067   9250  18330   kWh
Our system has produced 78.130 MWh from installation through the end of June 2016.

Net grid consumption since July 2011 (when PV was turned on permanently) has been 12.9 MWh. Solar production during this period was 77.3 MWh meaning total consumption was 90.2 MWh. Solar has provided 86% of that total.

During the past 12-month period, production was 18,012 kWh and consumption was 17,643 kWh meaning our system was a net producer of 369 kWh. Put another way, our system produced 102.2% of our consumption over this period, including driving the LEAF approximately 8000 miles.
 
July 2016 was sunny and hot and ended with 1887 kWh having been produced. That result just barely edges out 2014's record of 1880 kWh. Unfortunately, July 2016 was very hot with most days over 90F. The result was that net energy production for the month was very low.

The peak production day this month was on the 11th at 78.1 kWh. This falls short of the daily record of 80.7 kWh for July of 80.1 kWh which was set on July 25, 2014.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823   1887   1902   kWh
August    1442   1347   1447   1333   1794   1887          1875   kWh
September 1209    910   1295   1414   1577   1495          1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067  11137  18330   kWh
Our system has produced 80.017 MWh from installation through the end of July 2016.

Net grid consumption since July 2011 (when PV was turned on permanently) has been 12.8 MWh. Solar production during this period was 79.2 MWh meaning total consumption was 92.0 MWh. Solar has provided 86% of that total.

During the past 12-month period, production was 18,087 kWh and consumption was 17,928 kWh meaning our system was a net producer of 148 kWh. Put another way, our system produced 100.8% of our consumption over this period, including driving the LEAF approximately 8500 miles.
 
Like July, August 2016 was sunny and hot and ended with a record 1932 kWh having been produced. Unfortunately, due to the heat we had significant air conditioner usage, so net energy production for the month was approximately zero.

The peak production day this month was on the 7th at 76.8 kWh. This falls short of the daily record for August of 19.1 kWh which was set on August 15, 2014.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823   1887   1902   kWh
August    1442   1347   1447   1333   1794   1887   1932   1875   kWh
September 1209    910   1295   1414   1577   1495          1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067  13069  18330   kWh
Our system has produced 81.949 MWh from installation through the end of August 2016.

Net grid consumption since July 2011 (when PV was turned on permanently and a new electricity meter was installed) has been 12.8 MWh. Solar production during this period was 81.1 MWh meaning total consumption was 93.9 MWh. Solar has provided 86% of that total.

During the past 12-month period, production was 18,121 kWh and consumption was 18,366 kWh meaning our system was a net consumer of 245 kWh. Put another way, our system produced 98.7% of our consumption over this period, including driving the LEAF approximately 8500 miles.
 
On September 27, 2016, I was sure our system would set a new record for the month of September, but it was not to be. The following three days were very overcast due to the hurricane and averaged only about 10 kWh each day. Still September ended with 1552 kWh having been produced, 22 kWh shy of the record set in 2014.

The peak production day for September was a three-way tie on the 5th, 12th and 27th at 72.3 kWh. This falls short of the daily record for September of 78.0 kWh which was set on September 15, 2015.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823   1887   1902   kWh
August    1442   1347   1447   1333   1794   1887   1932   1875   kWh
September 1209    910   1295   1414   1577   1495   1552   1555   kWh
October   1304    931    981   1034   1258   1415          1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067  14621  18330   kWh
Our system has produced 83.501 MWh from installation through the end of September 2016.

Net grid consumption since July 2011 (when PV was turned on permanently and a new electricity meter was installed) has been 12.5 MWh. Solar production during this period was 82.7 MWh meaning total consumption was 95.2 MWh. Solar has provided 87% of that total.

During the past 12-month period, production was 18,178 kWh and consumption was 18,495 kWh meaning our system was a net consumer of 281 kWh. Put another way, our system produced 98.5% of our consumption over this period, including driving the LEAF approximately 8500 miles.
 
At 1593 kWh, October 2016 blew away last year's record October production by 12%. In fact, this system produced more electricity this October than any previous September (September 2013 times 1.29 excepted).

The peak production day for October was on the 10th at 77.2 kWh. This replaces the previous daily record for October of 74.2 kWh which was set on October 26, 2014, and also on October 19, 2015.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823   1887   1902   kWh
August    1442   1347   1447   1333   1794   1887   1932   1875   kWh
September 1209    910   1295   1414   1577   1495   1552   1555   kWh
October   1304    931    981   1034   1258   1415   1593   1713   kWh
November   864    949   1041   1018   1227   1277          1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067  16214  18330   kWh
Our system has produced 85.094 MWh from installation through the end of October 2016.

Net grid consumption since July 2011 (when PV was turned on permanently and a new electricity meter was installed) has been 12.0 MWh. Solar production during this period was 84.3 MWh meaning total consumption was 96.3 MWh. Solar has provided 87.5% of that total.

During the past 12-month period, production was 18,356 kWh and consumption was 18,396 kWh meaning our system was a net consumer of 40 kWh. Put another way, our system produced 99.8% of our consumption over this period, including driving the LEAF approximately 8500 miles.
 
While November 2016 set a new production record of 1340 kWh, this result was essentially tied with the November 2012 production when multiplied by 1.29.

The peak production day for November was on the 4th at 69.4 kWh. This replaces the previous daily record for November of 69.1 kWh which was set on November 13, 2015.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823   1887   1902   kWh
August    1442   1347   1447   1333   1794   1887   1932   1875   kWh
September 1209    910   1295   1414   1577   1495   1552   1555   kWh
October   1304    931    981   1034   1258   1415   1593   1713   kWh
November   864    949   1041   1018   1227   1277   1340   1154   kWh
December   820    803    612    669    812    865          1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067  17554  18330   kWh
Our system has produced 86.434 MWh from installation through the end of November 2016.

Net grid consumption since July 2011 (when PV was turned on permanently and a new electricity meter was installed) has been 12.0 MWh. Solar production during this period was 85.6 MWh meaning total consumption was 97.6 MWh. Solar has provided 89.6% of that total.

During the past 12-month period, production was 18,419 kWh and consumption was 18,339 kWh meaning our system was a net producer of 80 kWh. Put another way, our system produced 100.4% of our consumption over this period, including driving the LEAF approximately 8500 miles.
 
RegGuheert said:
While November 2016 set a new production record of 1340 kWh, this result was essentially tied with the November 2012 production when multiplied by 1.29.

Reg;
Off topic, but have you found a good method to clean your panels? Mine are roof mounted, so limited access. It's a rural environment - lots of bird crap! Don't have water readily available either - plus the water is really "hard". Experimented with a detergent, but left a "sheen". Next try is scrubbing in a rain storm - not looking forward to that.
 
Marktm said:
Off topic, but have you found a good method to clean your panels? Mine are roof mounted, so limited access. It's a rural environment - lots of bird crap! Don't have water readily available either - plus the water is really "hard". Experimented with a detergent, but left a "sheen". Next try is scrubbing in a rain storm - not looking forward to that.
Here is something I wrote on this topic back in May 2014:
RegGuheert said:
mwalsh said:
Think I need to get me on the roof and clean the panels in the absence of any natural help.
Yeah, drought cannot be great for PV production, even if you get lots of sunshine. I've decided that the best cleaner for our panels is sleet. As it slides off the panels, it scrubs the surface quite well! Snow also works, but last winter the first frozen precipitation was just snow and the grime on the panels was enough to keep the snow from shedding!
In June of this year I had the opportunity to clean the bottom two rows of panels on the garage roof. I did this because I had to remove the lower and middle rows of panels to upgrade their inverters from M190s to M215IGs. While I had the PV panels on the ground I washed them in the same way I wash a car: I used hot water with Ivory liquid dish detergent. I rinsed the panels using a garden hose which provides rather hard water. Fortunately it was cool and overcast, so I was able to wipe the panels dry before the calcium deposited onto the panels. I will say that I could definitely feel the grit and grime being removed from the panels as I washed them.

After I put them back up on the roof you could see a marked difference in appearance from the top row of PV modules when viewed nearly edge-on. However, I did not notice any real difference in energy harvest. As such, I do not think I will bother cleaning them again.

FWIW, I was still working on the roof during the next few days after washing those panels. One thing I quickly learned was how dangerously slippery those clean panels were with the morning dew on them after the grit was removed! My hands slipped on one and I nearly fell because I was used to the grit.

If I were to make recommendations how to clean them in situ, I would probably use high-quality window-washing equipment including a wide scrubber on a pole. Wash the panels when it is heavily overcast and cool outdoors to prevent hard water deposits. Then dry with a squeegee on a pole. I have done this approximately once with the field array. I have to say that the equipment worked O.K. for the panels I could easily reach, but the metal parts of the squeegee touched the glass of the panels I had difficulty reaching.
 
All makes good sense - I have already purchased an extended-pole floor scrubber (soft pad about 18" wide) to use. I've thought of installing a rain barrel and use a swimming pool pump to pump soft water up to the panels so I can do it during dry weather (slipping hazards). Just not sure the pump has the oomph to get it 15 feet up but going to check. I guess Ivory Liquid Soap is the best of the cleaners? Some of the bird "piles" appear to be enough to restrict a cell's production - don't know for a fact, but suspect.
 
Records, records, records! Our system set a new one-year production record of 18,555 kWh. That beats the previous record of 18,067 kWh set last year by 488 kWh, though it comes up just a bit short of the record set in 2012 (when multiplied by 1.29 to account for the expansion of the system since then).

Our system also set a new milestone in 2016 by producing over 1 MWh in every calendar month.

December 2016 set a new production record of 1002 kWh, though this result come up about 3% short of the record set in 2011 (when multiplied by 1.29).

The peak production day for December was on the 15th at 63.3 kWh. This falls short of the daily record for December of 66.0 kWh which was set on December 7, 2014.

Below are all our numbers for 2011, 2012, 2013, 2014, 2015 and 2016 along with the PVWatts predictions for the old array (PVW42: good through June 2014) and the new array (PVW54: good starting with July 2014):
Code:
Month    PVW42   2011   2012   2013   2014   2015   2016  PVW54  Units
----------------------------------------------------------------------
January    916    669    869    822    857   1006   1300   1229   kWh
February   702    158   1085    866   1054   1361   1192    915   kWh
March      965      0   1350   1152   1113   1547   1498   1240   kWh
April     1465      0   1465   1495   1338   1737   1754   1899   kWh
May       1583      0   1477   1491   1457   2069   1574   2074   kWh 
June      1268      0   1478   1368   1521   1585   1932   1666   kWh
Code:
July      1448    595   1395   1406   1880   1823   1887   1902   kWh
August    1442   1347   1447   1333   1794   1887   1932   1875   kWh
September 1209    910   1295   1414   1577   1495   1551   1555   kWh
October   1304    931    981   1034   1258   1415   1593   1713   kWh
November   864    949   1041   1018   1227   1277   1340   1154   kWh
December   820    803    612    669    812    865   1002   1108   kWh
----------------------------------------------------------------------
Totals   13986   6362  14495  14068  15888  18067  18555  18330   kWh
Our system has produced 87.435 MWh from installation through the end of December 2016.

Net grid consumption since July 2011 (when PV was turned on permanently and a new electricity meter was installed) has been 13.2 MWh. Solar production during this period was 86.6 MWh meaning total consumption was 99.8 MWh. Solar has provided 86.8% of that total.

During the past 12-month period, production was 18,555 kWh and consumption was 18,855 kWh meaning our system was a net consumer of 300 kWh. Put another way, our system produced 98.4% of our consumption over this period, including driving the LEAF approximately 8500 miles.
 
My 2170 watts of panels produced 3227 kWh in 2016, up a bit from the previous two years. This figure was almost exactly the same as my total usage of 3237 kWh for the year to fuel my car and run my house. I have a carryover credit of about 1000 kWh with my local power co-op, so I don't pay anything for electricity except for the monthly service charge.

My production numbers:

Code:
2008   232 kWh (700 watts of panels, partial year)
2009  1165 kWh
2010  1132 kWh
2011  1203 kWh
2012  1409 kWh (2170 watts of panels, partial year)
2013  3327 kWh
2014  3217 kWh
2015  3159 kWh
2016  3227 kWh
 
DNAinaGoodWay said:
December and 2016 were records here too, and as nice as that was, it coincided with extreme drought, so on average I'd be happy to lose a little production.
I'm sorry to hear you are having drought up there. Interestingly, it was quite wet here this year, in spite of the insolation records. In fact, it was so much wetter than normal that we lost control of the weeds in the garden in the middle of summer when normally we would have some drought and therefore would have them at bay.

But it was HOT this summer. Not 100-degree hot like some years, but a long stretch of 90-degree days during most of July and August. That caused us to run the air conditioner much more than we typically would. So we did not "store up" 4 MWH of electricity for the winter as I had hoped. Instead we only managed to bank about 3 MWh.

El Nino years bring changes in the weather around the globe. Different places experience it in different ways. Here on the East Coast we can expect a pretty cold winter as the La Nina sets in and North Atlantic Ocean continues its decade-long drop in heat content.

Unfortunately the combination of a hot El Nino summer followed by a cold La Nina winter likely means we will be purchasing some electricity around March.
 
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