Our solar production

[SilverLeaf]

Production from my 33 230wDC Sunpower Panels via Sunnyboy (SMA) 7000US Inverter (7.59kW DC)

2013 AC Production
Jan 910
Feb 1105
Mar 1328
Apr 1444
May 1474
Jun 1447
Jul 1284
Aug 1230
Sep 1280

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/" onclick="window.open(this.href);return false;

All Data computed via JSunnyReports

 

[dgpcolorado]

It must be October, fall colors yesterday and reduced solar output this morning:

 

[Wennfred]

46 Sharp 170 watt Panels, 2 Strings facing East & South on 3.8k Xantrex inverters installed back in 2007, 6.8KW system.

Read a few post on here, one thing you guys need to read on is the Solar Cycle, Solar Minimum & Solar Maximum. It turns out that this solar maximum in 2013 has been the weakest in 100 years. As we move to Solar Cycle 25, between now and peaking around 2015. You should see more production.

2006 & 2007 was great years for Solar output as the Solar Maximum was banging. During that year I saw 50kw daily, since then more like 40 to 45kw on average, but as we move to 2015 those numbers will jump up once again.

I use GT-View to monitor my stats on a laptop I have hooked up to both Xantrex 3.8 inverters.

Lots of good info on the Solar Guppy forum. You can download the GT-View software there.

http://sgtechnology.dyndns.org/forum/?sid=637d02fc48b5dadfb7219113c3b552fd" onclick="window.open(this.href);return false;

Fred

 

[DaveEV]

Read a few post on here, one thing you guys need to read on is the Solar Cycle, Solar Minimum & Solar Maximum. It turns out that this solar maximum in 2013 has been the weakest in 100 years. As we move to Solar Cycle 25, between now and peaking around 2015. You should see more production.

2006 & 2007 was great years for Solar output as the Solar Maximum was banging. During that year I saw 50kw daily, since then more like 40 to 45kw on average, but as we move to 2015 those numbers will jump up once again.

The effect of the solar cycle on solar PV production is not measurable - the noise introduced by weather and soiling far outweigh any changes in the amount of sun reaching the earth.

 

[Becky50]

How often should the solar panels be cleaned? And is hosing them off the way to do? Thanks in advance.

 

[mwalsh]

How often should the solar panels be cleaned? And is hosing them off the way to do? Thanks in advance.

I try to do mine twice a year. I'd do them more, but they're up on a two story roof. So not my favorite place to be.

I wouldn't just hose them off though - that would leave counter-productive water spotting down here, what with our hard water and all. I use car wash soap in water, and a pole fitted with a cloth mop. Then I hose off and squeege dry.

 

[camasleaf]

We had over 4" of rain last week, does that count as one wash :lol: ? Do any of the owner of solar panes in PNW, west of the mountains wash theirs?

 

[Wennfred]

I need to get up on the roof, 1 story ranch style house and clean all 46 panels, will probably be an all day event, its been years since I washed them.

 

[dgpcolorado]

I usually let rain or snow wash the panels. But in recent years we've had several mud rain/snow events due to windstorms raising red/orange dust in Utah and Arizona (which also accelerates the melting of the mountain snowpack due to increased solar heating). When that happens I have to wash the panels. I spray them, squeegee them (same one I use for snow removal in the picture above), then dry with a towel wrapped around the squeegee. Our water here has a lot of mineral content, so water spotting would be a problem if I didn't dry the panels.

Given the hassle, I am fortunate that I get plenty of (usually clean) rain in the summer and snow in the winter to keep the panels clean. Washing panels on the roof of a two story house would be a major undertaking; ground mounted panels are a lot easier to clean!

 

[QueenBee]

We had over 4" of rain last week, does that count as one wash :lol: ? Do any of the owner of solar panes in PNW, west of the mountains wash theirs?

The neighbors evergreens love to leave pollen (and needles) everywhere in the spring and then in the summer the lack of ran they can get a bit dusty as well. Since they are on a one story roof I get up on the roof and clean them whenever I notice they look dirty and I'm bored, which is probably more than I should

 

[RegGuheert]

Read a few post on here, one thing you guys need to read on is the Solar Cycle, Solar Minimum & Solar Maximum. It turns out that this solar maximum in 2013 has been the weakest in 100 years. As we move to Solar Cycle 25, between now and peaking around 2015. You should see more production.

2006 & 2007 was great years for Solar output as the Solar Maximum was banging. During that year I saw 50kw daily, since then more like 40 to 45kw on average, but as we move to 2015 those numbers will jump up once again.

The effect of the solar cycle on solar PV production is not measurable - the noise introduced by weather and soiling far outweigh any changes in the amount of sun reaching the earth.

Except it appears that solar flares result in reduced production of fine aerosols and subsequently cloud water content. If we do go into a solar quiet period in the near future we should expect more clouds and hence less production from our solar panels.

 

[Wennfred]

If we do go into a solar quiet period in the near future we should expect more clouds and hence less production from our solar panels.

Clouds are a good thing to have, I generate the most power on cloudy days as the rays are magnified by double off the edges of the clouds.

 

[DaveEV]

If we do go into a solar quiet period in the near future we should expect more clouds and hence less production from our solar panels.

From what I understand, there is much debate about the effects of solar activity (not to mention cosmic activity in general) in relation to cloud cover, in particular it seems to have variable effects depending on your latitude. At the very least, the effect seems to only be a few percent so local weather will still be the dominant effect of any short term variability on a solar system.

Clouds are a good thing to have, I generate the most power on cloudy days as the rays are magnified by double off the edges of the clouds.

While edge of cloud effects can spike production, the overall effect is less energy production overall. I have never seen a partially cloudy day produce more energy than a clear day, even though the cloudy day may have a 20% peak production.

 

[dgpcolorado]

While edge of cloud effects can spike production, the overall effect is less energy production overall. I have never seen a partially cloudy day produce more energy than a clear day, even though the cloudy day may have a 20% peak production.

I have. My best production days have been boosted by cloud edge effects. But it is a fluke and the day has to be mostly sunny, cold, and the clouds (usually cumulus or lenticular) positioned correctly. It does happen on occasion, however.

 

[RegGuheert]

If we do go into a solar quiet period in the near future we should expect more clouds and hence less production from our solar panels.

From what I understand, there is much debate about the effects of solar activity (not to mention cosmic activity in general) in relation to cloud cover, in particular it seems to have variable effects depending on your latitude.

Yes, it is still being debated, but some of the research shows strong correlations between cosmic rays and clouds. But the formation of clouds is still very poorly understood.

At the very least, the effect seems to only be a few percent so local weather will still be the dominant effect of any short term variability on a solar system.

Agreed. That is why the author of the paper had to use extreme conditions to be able to clearly show the relationships. But that does not mean that cosmic rays, as modulated by solar activity, are not always affecting the weather and climate. On the contrary, it indicates that perhaps they always do, at least where other sources of aerosols do not dominate.

Clouds are a good thing to have, I generate the most power on cloudy days as the rays are magnified by double off the edges of the clouds.

While edge of cloud effects can spike production, the overall effect is less energy production overall. I have never seen a partially cloudy day produce more energy than a clear day, even though the cloudy day may have a 20% peak production.

+1

Our largest production days occur when it is very cool and clear and the sun is near the boresight of the array. Note that on those days, the inverters are running at their limits, so any spikes due to edge-of-cloud effect above that level would not make it out of the inverters anyway. Perhaps a different outcome would be realized if the inverters were sized such that they would not be the limiting factor.

 

[dgpcolorado]

Our largest production days occur when it is very cool and clear and the sun is near the boresight of the array. Note that on those days, the inverters are running at their limits, so any spikes due to edge-of-cloud effect above that level would not make it out of the inverters anyway. Perhaps a different outcome would be realized if the inverters were sized such that they would not be the limiting factor.

If you have inverters that ordinarily clip at midday then of course it is unlikely you would see much of a boost from cloud edge effects over a whole day.

With my old panels — 4 x 175 Watts = 700 W — my Sunny Boy 725 inverter clips at 715 Watts; I've watched it do that several times. That is substantially more wattage than I can usually get from 700 Watts of panels on a clear cold day pointed right at the sun at solar max. It happens with the cloud edge effect. My highest production days have had some clouds and have been enhanced by the cloud edge effect. Yes, it's real.

 

[RegGuheert]

If you have inverters that ordinarily clip at midday then of course it is unlikely you would see much of a boost from cloud edge effects over a whole day.

Just to be clear, they do not "ordinarily" clip in the middle of the day unless it is particularly cold or it is cool and the sun is close to the boresight. It happens about 30-or-so times per year. On the peak production days, the clipping can last for three to four hours. I've estimated that I lose about 3 kWh on max-production days like that (but I produce as much as 68 kWh).

Yes, it's real.

No argument about edge-of-cloud being real or not. I've seen 3300W from my old 2880Wp off-grid array at the edge of big clouds.

For reference, here are three images which show three of the peak production days from this year. Note that with our system peak production days always occur in the springtime and solar noon occurs at about 1:00PM standard time.

April 2, 2013: 67,991 Wh produced. Note inverter clipping from about 11:30AM until 15:30PM. As noted, I estimate we lost about 3 kWh of production due to clipping on this day. This would have almost certainly been our all-time peak production day at over 70 kWh had the clipping not occurred.


April 25, 2013: 67,301 Wh produced. Inverter clipping from about Noon until 15:00PM. Note this clipping is much less significant than was seen on April 2, 2013.


May 26, 2013: 68,059 Wh produced. This is our all-time high production day. Almost no inverter clipping is seen due to temperatures and the fact that the sun does not approach the array boresight as closely as it does in April.

 

[RegGuheert]

October 2013 set a new record for October, which isn't saying much. Still, it beat 2012 by 53 kWh and 2011 by 103 kWh.

We are now off last year's pace by 433 kWh.

Here are all our numbers for 2011, 2012 and 2013:

Month     2011   2012   2013  Units
-----------------------------------
January    669    869    822   kWh
February   158   1085    866   kWh
March        0   1350   1152   kWh
April        0   1465   1495   kWh
May          0   1477   1491   kWh 
June         0   1478   1368   kWh
July       595   1395   1406   kWh
August    1347   1447   1333   kWh
September  910   1295   1414   kWh
October    931    981   1034   kWh
November   949   1041          kWh
December   803    612          kWh
-----------------------------------
Totals    6362  14495  12381   kWh

 

[TonyWilliams]

Link to my solar production

2012 Year: 13.9 MWh
2013 Year to Date: 12.3 MWh

Mnth Calc   2011   2012   2013   2014
-----------------------------------
Jan   913     0    937    955   
Feb   937     0    970    999   
Mar  1191     0   1210   1252   
Apr  1276     0   1267   1241   
May  1400     0   1390    ---   
June 1376     0   1455    ---  
July 1403   ---   1402    ---  
Aug  1356   ---   1318   1350  
Sept 1213   ---   1250   1250  
Oct  1072   ---   1120   1130  
Nov   946   ---    910         
Dec   839   ---    716         
-----------------------------------
Tot 13922  ---   13900   12300   kWh

 

[dgpcolorado]

October was fairly cloudy and snowy here, so production was down a lot compared to last year, which was my best October ever by a wide margin.

Results for October in recent years:

                Old panels   Old+New panels
               (700 Watts)   (2170 Watts)
October 2013       98 kWh       276 kWh
October 2012      113 kWh       322 kWh
October 2011      100 kWh
October 2010       98 kWh
October 2009       87 kWh
October 2008       96 kWh