Our solar production

[AndyH]

No idea if this has been covered here:
My solar production this year has taken about a 10% hit. After a sub-par May, usually my best month, I climbed up on the roof and gave the panels a good scrub. We're in a nasty drought so I had some guilt for using the water (prob only about 10 -15 gal). My production shot right back to what I had come to expect, an immediate increase of about 10-12%.

The Saudi Arabian 'Kobayashi Maru'

http://www.treehugger.com/solar-tec...s-dusty-solar-panels-without-using-water.html

 

[RegGuheert]

The Saudi Arabian 'Kobayashi Maru'

http://www.treehugger.com/solar-tec...s-dusty-solar-panels-without-using-water.html

O.K. That's VERY cool!

 

[RegGuheert]

July 2014 is the first month which includes the addition of 2880 Wp of old panels which were brought online by the addition of 12 new M215 microinverters. This change increases the DC rating of the array by 29% and the AC rating by 32%. (The AC rating should have very little impact this time of year, since the PV panels produce less power in the warm temperatures.) With only 29% more PV power available, the system produced 34% more electricity than the higher of the previous two years. Of course weather has an impact, but part of the reason the increase is more than 29% is because the additional PV panels are more optimally pointed for this time of year.

I'm no longer sure how to easily make comparisons with previous years. Does anyone know if there is a way in Enlighten to easily determine the production of a subarray (rather than an individual inverter or the total array).

Here are all our numbers for 2011, 2012, 2013 and 2014:

Month     2011   2012   2013   2014  Units
------------------------------------------
January    669    869    822    857   kWh
February   158   1085    866   1054   kWh
March        0   1350   1152   1113   kWh
April        0   1465   1495   1338   kWh
May          0   1477   1491   1457   kWh 
June         0   1478   1368   1521   kWh
July       595   1395   1406   1880   kWh
August    1347   1447   1333          kWh
September  910   1295   1414          kWh
October    931    981   1034          kWh
November   949   1041   1018          kWh
December   803    612    669          kWh
------------------------------------------
Totals    6362  14495  14068   9220   kWh

Since installation, our system has produced 44.145 MWh as of the end of July 2014.

 

[jstack6]

SunPower panels are the best efficiency but I have Solon panels that were made closet to our home in Chandler AZ. Buy local live local.

My little 4 kW system makes more than we use for our 100% electric home, LEAF and the utility pays us each year since we still make 10% more that we use. I made the home very efficient with radiant barrier, LED lights, 18 SEER Heat Pump and we drive super efficient at 5-6 mile per kW hour. I prefer bicycling anytime I can.

Solar is great, I even have a friend in upstate NY with 1/2 our Sun that is ahead on his power each month but needed over 10 Kw to do it. The Southwest has the best Solar resource in the world.

 

[RegGuheert]

Buy local live local.

All of our panels are from nearby, as well. The old panels out in the field were made by Solarex in Frederick, MD, which is about 40 miles away. The newer panels on the roof were made by Sharp in Lexington, KY, which is about 400 miles away.

All of our microinverters were manufactured in China.

Unfortunately, neither of those two PV plants are operating today. It's not so easy to buy local PV these days unless you happen to live in China.

 

[dgpcolorado]

...My little 4 kW system makes more than we use for our 100% electric home, LEAF and the utility pays us each year since we still make 10% more that we use. I made the home very efficient with radiant barrier, LED lights, 18 SEER Heat Pump and we drive super efficient at 5-6 mile per kW hour. I prefer bicycling anytime I can...

You manage house plus LEAF with a 4 kW array in Chandler? You have done an amazing job making your house efficient, I am very impressed!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
July here was pretty average, although up 2% from last year. First monthly year-over-year gain since January. I sure would have liked more rain though, July is often one of the wettest months here.

Results for July for the last six years:

                Old panels   Old+New panels
               (700 Watts)   (2170 Watts)
July 2014         105 kWh       295 kWh
July 2013         103 kWh       290 kWh
July 2012          97 kWh       179 kWh (partial month)
July 2011         108 kWh
July 2010         105 kWh
July 2009         112 kWh

 

[mctom987]

...My little 4 kW system makes more than we use for our 100% electric home, LEAF and the utility pays us each year since we still make 10% more that we use. I made the home very efficient with radiant barrier, LED lights, 18 SEER Heat Pump and we drive super efficient at 5-6 mile per kW hour. I prefer bicycling anytime I can...

You manage house plus LEAF with a 4 kW array in Chandler? You have done an amazing job making your house efficient, I am very impressed!

This greatly depends on the area in which you live, but a reasonable expectation for a 4kW PV system would be about 550-650kWh/mo production.

That's pretty much what I'm planning. Do it right, and you can hit <~500kWh/mo, including Leaf charging.
Taking an average of 32mi RTT for commute, this is ~700mi per month. At 5mi/kWh, this comes out somewhere around 150kWh for driving purposes.

A small, energy efficient home could easily keep consumption under 300kWh/mo. This totals 450kWh/mo, which means that 4kW system is perfect.

Of course, I'm making a lot of assumptions, but it's not difficult to achieve.

 

[dgpcolorado]

This greatly depends on the area in which you live, but a reasonable expectation for a 4kW PV system would be about 550-650kWh/mo production...

jstack6 lives in Chandler AZ, part of the Phoenix metro area. It is very, very hot there and most houses use a lot of electricity for cooling. To cover that plus LEAF mileage with a 4kW array suggests to me that he is way below average energy usage for his climate zone. From what I've seen, typical solar arrays in the Phoenix area tend to be considerably larger than 4 kW and often don't cover all the electricity usage of the household, despite excellent solar production in that sunny climate.

I cover my household electricity and LEAF mileage with just 2170 kW of solar panels. But there is no comparison to jstack6's situation because my cool climate doesn't require any AC use and I heat with natural gas and passive solar, as opposed to electricity. I remain quite impressed with jstack6's ability to make do with a 4 kW array.

 

[pchilds]

March 2014, 529.6 kWh
April 2014, 554.6 kWh
May 2014, 606.8 kWh
June 2014, 584.0 kWh
July 2014, 545.8 kWh

 

[SilverLeaf]

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

2014 AC Production
Jan 1048
Feb 977
Mar 1347
Apr 1438
May 1476
Jun 1413
Jul 1346

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

 

[Websterize]

Because of the relatively cool July temperatures, my ~10 kW array set a monthly record last month, yielding 1.47 MW. That's the highest generation since it commissioned in June 2012. In March of this year, the array set a daily record of nearly 75 kWh, yielding enough energy for about three day's worth of demand. In the past 24 months, the panels have produced about 175% of the house's demand. (It's oversized, but I wanted to fill as much surface area as possible for aesthetics.) To get the grid-tied array closer to net zero, I took delivery of a Leaf last week

(Pardon the bird droppings on the panels. Rain rinses it.)

Maryland is a fantastic state for green incentives. Earlier this week, I applied to MVA for the vanity plate "SUNLOCO". Commuting to Metro each day powered by the sun is pretty cool. With the PV surplus, I'd love to get a second EV to replace my wife's Golf TDI.

More details and historical data on the array:

https://www.sunnyportal.com/Templates/PublicPageOverview.aspx?plant=1f1f7434-5eef-4fe0-b8cf-d3be9d686a2b" onclick="window.open(this.href);return false;

 

[sksingh]

2014 kWh
Jan 581
Feb 602
Mar 806
Apr 948
May 953
Jun 892
Jul 839

 

[RegGuheert]

Welcome, Websterize! It's nice to have another LEAF and PV owner in the neighborhood!

Because of the relatively cool July temperatures, my ~10 kW array set a monthly record last month, yielding 1.47 MW. That's the highest generation since it commissioned in June 2012.

O.K. Perhaps that partly explains why I saw a 34% more output from out array last month after adding only 29% more PV.

In March of this year, the array set a daily record of nearly 75 kWh, yielding enough energy for about three day's worth of demand.

With the original 9780Wp array here, we never exceeded 69 kWh in a single day. Part of the reason for that is that the microinverters limited the output on cold, sunny days. Perhaps 75 kWh would have been possible with higher-power inveters.

In the past 24 months, the panels have produced about 175% of the house's demand.

That's amazing! Is your house all electric, or do you heat water and/or air with something else? Or do you have time-of-use metering?

By way of comparison, our original array produced an average of 14.25 MWh/year, but our demand, including the LEAF, is about 20 MWh. The heat-pump water heater and the LEAF account for about 2 MWh each. (Your LEAF likely will consume more due to your commute.) Perhaps 4 MWh/year. The heat pump is the big unknown in our home. With our net metering arrangement, we get no useful information about energy consumption during the various months of the year. If I want the data, I need to read the meter myself, which I haven't been doing. I suspect the heat pump/electric furnace consumes about 8 MWh/year. That load alone is close to your total consumption (before the LEAF). The electric clothes dryer may consume several MWh/year. The other major appliances likely consume about 1 MWh/year each: two refrigerators, electric oven and dishwasher.

(It's oversized, but I wanted to fill as much surface area as possible for aesthetics.)

It looks great on your roof and your daughter is very cute!

More details and historical data on the array:

https://www.sunnyportal.com/Templates/PublicPageOverview.aspx?plant=1f1f7434-5eef-4fe0-b8cf-d3be9d686a2b" onclick="window.open(this.href);return false;

Great stuff! Your array is a little steeper than ours, but it is points about 26 degrees farther West. Our azimuth is 194 degrees while yours is 220. That likely accounts for the slightly lower annual production of your system.

You can see the public page for our array in my signature. We live near Berryville, which is a doable round trip in the LEAF from Frederick, especially with a new battery! We'll have to get together sometime!

One question: Do you have any issues with snow and/or ice slides damaging the roof or the gutter on your front porch? For reference, see PSA: Don't park your car below snow-covered PV!

 

[Websterize]

Hi, and thanks much for the welcome.

… Is your house all electric, or do you heat water and/or air with something else? Or do you have time-of-use metering?

Natural gas water heater and furnace. Everything else is electric. TOU is unavailable where I live (I think). FirstEnergy charges about $0.12/kWh at all hours.

By way of comparison, our original array produced an average of 14.25 MWh/year, but our demand, including the LEAF, is about 20 MWh. The heat-pump water heater and the LEAF account for about 2 MWh each. (Your LEAF likely will consume more due to your commute.) Perhaps 4 MWh/year.

PVWatts says our array will generate between 12-13 MW per year. I commute about 40 miles/day roundtrip, at about 4 miles/kWh (based on 10 days of I-270 masochism.) If my math is right, that's ~10kWh/day consumption * 5 days, for about 200-300 kWh/month just commuting. So, right, about 2.5-4 MW demand by el Sunloco Leaf.

It looks great on your roof and your daughter is very cute!

Thank you. She likes plugging in the charging gun in the car's front port — the self-appointed "charging helper." Because the array had to go out front, and because I wanted to stay married, the aesthetics bar was very high.

You can see the public page for our array in my signature. We live near Berryville, which is a doable round trip in the LEAF from Frederick, especially with a new battery! We'll have to get together sometime!

Sounds great. I like the heat map dataviz of your output -- more visually interesting than bar charts and fever lines. I'd be interested to see your 2011 and, since I'm a Leaf rookie, to hear about EV life from a Leaf elder (in Leaf years, of course!) Just in case you didn't know, there's not one, but two, DC fast charge stations at the Mom's Organic Market in Frederick. They're free, with lots of places to eat nearby. Mom's owner is a great supporter of EV and backs that up with significant EV incentives for his employees. Check out Lanny's (an amazing EV activist) post at http://pluginsites.org/dc-quick-chargers-at-moms-in-frederick-md/" onclick="window.open(this.href);return false;

One question: Do you have any issues with snow and/or ice slides damaging the roof or the gutter on your front porch?

Thanks for that link. Nothing apparent after two winters, although the shutter hardware on the sides of the front windows began rusting after the array went up. (You can see the rust stains in my photo.) I assume this is because of increased rain flow down the front of the house, or it could be a coincidence. I removed the hardware, and it was cheap-looking, like something you'd buy from Lowe's that was made in China. As you know in Berryville, this past winter was brutal in the mid-Atlantic, with extreme cold and above-average snowfall. The only unnerving experience with the array (yet) has been when, after a large snowfall, an avalanche of powder sitting atop the panels came crashing down and over the little porch roof and onto the landscaping below it. The house rumbled as the snow slid off. Felt like that 2011 Va. earthquake! The only casualty has been flattened azaleas.

 

[RegGuheert]

… Is your house all electric, or do you heat water and/or air with something else? Or do you have time-of-use metering?

Natural gas water heater and furnace. Everything else is electric. TOU is unavailable where I live (I think). FirstEnergy charges about $0.12/kWh at all hours.

O.K. That explains the difference. I highly recommend moving to a heat-pump water heater if your water heater is in a room larger than 700 cubic feet in volume. Such a unit will air-condition the space around it in the summertime and can be switched to work just like a normal water heater if you do not want it to cool and dry in the wintertime. We leave ours in heat-pump mode year-round and I expect it uses about as much electricity as the LEAF: ~2MWh/year (and saves about twice that much!)

PVWatts says our array will generate between 12-13 MW per year. I commute about 40 miles/day roundtrip, at about 4 miles/kWh (based on 10 days of I-270 masochism.) If my math is right, that's ~10kWh/day consumption * 5 days, for about 200-300 kWh/month just commuting. So, right, about 2.5-4 MW demand by el Sunloco Leaf.

Your EV calcs sound right but PVWATTS is almost always low. I expect you will produce close to 14MWh/year with your PV array.

Because the array had to go out front, and because I wanted to stay married, the aesthetics bar was very high.

It seems that both of our homes face south, so the array is visible from the street. I would have preferred having the array invisible. OTOH, it has generated lots of discussions with people who have asked about it.

You can see the public page for our array in my signature. We live near Berryville, which is a doable round trip in the LEAF from Frederick, especially with a new battery! We'll have to get together sometime!

Sounds great. I like the heat map dataviz of your output -- more visually interesting than bar charts and fever lines. I'd be interested to see your 2011 and, since I'm a Leaf rookie, to hear about EV life from a Leaf elder (in Leaf years, of course!)

Based on the age of your daughter, I expect I am also elder in years, also! I was out your way last Friday, but I suspect you were at work. I'll send you a PM next time I may be in your area.

Just in case you didn't know, there's not one, but two, DC fast charge stations at the Mom's Organic Market in Frederick. They're free, with lots of places to eat nearby. Mom's owner is a great supporter of EV and backs that up with significant EV incentives for his employees. Check out Lanny's (an amazing EV activist) post at http://pluginsites.org/dc-quick-chargers-at-moms-in-frederick-md/" onclick="window.open(this.href);return false;

I didn't know, so thanks a lot for that tip! My wife's family lives in MD and PA. While I can make the one-way trip on a nice day, it would be a problem in the wintertime. As such, I have been hoping for quick-chargers to show up in Frederick sometime soon! Even "slow" quick chargers are much better than Level 2 since our LEAF only has a 3.3kW charger. And they are free to boot! Unfortunately, the one on the right was showing an error, but neither were ICEd, so I was able to charge at the left one. Thanks again!

The only unnerving experience with the array (yet) has been when, after a large snowfall, an avalanche of powder sitting atop the panels came crashing down and over the little porch roof and onto the landscaping below it. The house rumbled as the snow slid off. Felt like that 2011 Va. earthquake! The only casualty has been flattened azaleas.

Apparently shrubbery take the brunt of these PV slides. But it could be worse if the snow is not powdery. Hopefully you won't ever have an issue with it. For us, the main thing is remembering to NOT park any vehicles in front of the garage when snow is forecast.

 

[RegGuheert]

August 2014 had lots of clouds and a bit of rain. In spite of the addition of 29% more PV DC capability, the production was only 24% above the peak August production month in 2012 (compared with a 34% boost last month). Weather is certainly the explanation here.

I'm no longer sure how to easily make comparisons with previous years. As such, I have added two columns to my table labeled PVW42 and PVW54. These columns contain the PVWatts predictions (with AC Derate Factor set to 0.9) for the original 42-module array and the current 54-module array. The PVW42 column is useful for comparisons with the months from January 2011 through June 2014 while the PVW54 column is useful for comparison with months beginning July 2014.

Below are all our numbers for 2011, 2012, 2013 and 2014 along with the PVWatts predictions

Month    PVW42   2011   2012   2013   2014  PVW54  Units
--------------------------------------------------------
January    916    669    869    822    857   1229   kWh
February   702    158   1085    866   1054    915   kWh
March      965      0   1350   1152   1113   1240   kWh
April     1465      0   1465   1495   1338   1899   kWh
May       1583      0   1477   1491   1457   2074   kWh 
June      1268      0   1478   1368   1521   1666   kWh
July      1448    595   1395   1406   1880   1902   kWh
August    1442   1347   1447   1333   1794   1875   kWh
September 1209    910   1295   1414          1555   kWh
October   1304    931    981   1034          1713   kWh
November   864    949   1041   1018          1154   kWh
December   820    803    612    669          1108   kWh
--------------------------------------------------------
Totals   13986   6362  14495  14068  11014  18330   kWh

Since installation, our system has produced 45.939 MWh as of the end of August 2014.

 

[dgpcolorado]

August solar production here surprised me: up 8% from last year. It seemed so cloudy, albeit unusually dry. But August is always one of the cloudiest months in Colorado, thanks to "monsoon" season: usually clear mornings and afternoon thunderstorms. I only had one day all month that was sunny almost the whole day.

Results for August for the last six years:
                Old panels   Old+New panels
               (700 Watts)   (2170 Watts)
August 2014        97 kWh       274 kWh
August 2013        91 kWh       253 kWh
August 2012        97 kWh       271 kWh
August 2011       102 kWh
August 2010        99 kWh
August 2009       109 kWh

Annual production:
2014      2248 kWh (thus far)
2013      3327 kWh 
2012      1409 kWh 
2011      1203 kWh 
2010      1132 kWh 
2009      1165 kWh 
2008       232 kWh (partial year)

 

[SilverLeaf]

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

2014 AC Production
Jan 1048
Feb 977
Mar 1347
Apr 1438
May 1476
Jun 1413
Jul 1346
Aug 1368

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

 

[pchilds]

Mar 2014, 529.6 kWh
Apr 2014, 554.6 kWh
May 2014, 606.8 kWh
Jun 2014, 584.0 kWh
Jul 2014, 545.8 kWh
Aug 2014, 595.8 kWh

 

[RegGuheert]

September 2014 was an average month right at the PVWatts prediction. In spite of the addition of 29% more PV DC capability, the production was only 12% above the peak September production month in 2013. I did lose 15 kWh this month due to a failed inverter that took a couple of weeks to be replaced.

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

Month    PVW42   2011   2012   2013   2014  PVW54  Units
--------------------------------------------------------
January    916    669    869    822    857   1229   kWh
February   702    158   1085    866   1054    915   kWh
March      965      0   1350   1152   1113   1240   kWh
April     1465      0   1465   1495   1338   1899   kWh
May       1583      0   1477   1491   1457   2074   kWh 
June      1268      0   1478   1368   1521   1666   kWh
July      1448    595   1395   1406   1880   1902   kWh
August    1442   1347   1447   1333   1794   1875   kWh
September 1209    910   1295   1414   1577   1555   kWh
October   1304    931    981   1034          1713   kWh
November   864    949   1041   1018          1154   kWh
December   820    803    612    669          1108   kWh
--------------------------------------------------------
Totals   13986   6362  14495  14068  12591  18330   kWh

Since installation, our system has produced 47.516 MWh as of the end of September 2014.