Our solar production

[AndyH]

Warranty is marketing.

Sorry, but a 5:1 ratio in warranty period is not all about marketing. Central inverters do not have a long MTBF and the manufacturers know it. You know it and are planning to replace parts to make up for their shortcomings.

Don't misunderstand - I maintain all my equipment for the long haul. My last car didn't run to 401,000 miles because I left it to Jiffy lube. I will do PM as I see fit because that's what I do.

I have been a sales rep for more than 10 years and have started and run my own company. I've consulted with marketing heads and corporate attorneys about the exact ins and outs of warranty, and have consulted with experts when setting the warranty for the products I manufactured. That's how I developed my understanding about exactly what a warranty is intended to be from the company's perspective. My focus always has been on service life, not warranty, not engineering estimates. Again - in my world, when two competing pieces of equipment can do the job, I'll select the one I can open up and fix without having to use heat guns and dental picks.

Older string inverters did have very short service lives. Current tech devices, however last much longer - even in grid-tied service. SMA isn't the only inverter company with an available 20 year warranty. Diehl, AE, and Kaco do as well, as do others. Kaco has a standard 10, with optional 15 and 20 for a fee.

You are free to accept a VERY broad-brush average inverter life rule of thumb that makes absolutely no distinction on how the devices are fielded if you wish - that's fine! I don't.

I have verified the reliability claims made by the manufacturer of my inverters and their calculation of the predicted MTBF for their inverters matches my calculation of actual field performance.

That's fine! Good on you! I, too, have verified the claims made by Outback and have found that they engineer the devices to last 15-20 years. While the company's only been around since 2001, the engineers that designed the inverters were designing inverters before that - there is a history there as well, and there are warm human bellybuttons to poke if things go awry (formally and informally... )

Outback inverters have been out for a decade now and I do not see any published MTBF information, nor have you provided any. The problem with those inverters is that any failures outside of warranty is unknown, even to the manufacturers. In other words, they may know how many units fail within five years, but they have no way to know beyond that point. And since the other BOS components including batteries and charge controllers also have low MTBFs, many systems are simply shut off once the failures occur.

You're kidding me, right? Do you really think the off-grid community would give anyone a pass if their equipment started dying? I watched SolarGuppy and the other alpha and beta testers when Xantrex fielded their GT inverters - It Was Brutal! The community makes it clear when products are junk, and they also get the word out when things work. (Like the comment in HomePower 151, Oct/Nov '12 - the gent is using a pair of Trace C30 charge controllers in his system (2 year warranty) that were installed in 1984 and haven't been touched since). Just because YOU don't know about service history doesn't mean it's not known or communicated. I'd expect you'd know that, though, as I've read some of your posts on solar forums...

The folks that manufacture the equipment that I've chosen have stated that I can expect a comfortable 20 year life,...

Of course they do, they are trying to sell you an inverter. And when it fails, they would be happy to sell you another one.

...and that's supported from the field by others using the devices as I intend.

Like they would know. Their inverters are all less than ten years old.

Enjoy your yuks. 2001 is more than 10 years old - and the engineers that designed these didn't start their careers at Outback. It's pretty funny to me that you'll try to trivialize more than 15 years of history while fighting tooth and nail for a product with what, almost five years on the streets?

I've used both a string inverter and µinverters in the past and have no use for micros - especially down here (I had hot potting oozing out of one micro...). You're already tracking heat related problems, and folks in Arizona are reporting that micros are not recommended in their heat - San Antonio's farther south than all of Arizona.

I'm interested in knowing about any Enphase failures out there. Was the failure you had with microinverter or another brand?

Should I choose to use these devices at some point, I'll get into your spreadsheet. Don't hold your breath, though.

With that, it's probably best we hang it up.

Sorry for the off-topic excursion.


edit...fixed quotes

 

[RegGuheert]

With that, it's probably best we hang it up.

Sorry for the off-topic excursion.

Yep. My apologies to the others on this thread, as well.

 

[dgpcolorado]

With that, it's probably best we hang it up.

Sorry for the off-topic excursion.

Yep. My apologies to the others on this thread, as well.

I found the discussion interesting. I had hoped to use Enphase inverters on my new panels but I couldn't because code won't allow AC and DC lines in the same conduit and I wasn't about to dig another trench through glacial moraine and lay another conduit. So I ended up with a Solectria inverter for the new panels, but the production is about 10% lower than expected when compared to the old panels on an SMA (Sunny Boy) inverter. In retrospect I wish I had just used two new Sunny Boy 725s. The other alternative was to go all Enphase but that figured to be very expensive and I didn't want to throw away the existing Sunny Boy 725, which I like a lot.

At least neither of my inverters has fans or anything like that. I presume those are for gigantic scale installations where a lot of heat needs to be dispersed. If/when my string inverters fail perhaps the tech and prices will have improved somewhat in the interim. Sort of like electric cars...

 

[RegGuheert]

I found the discussion interesting.

Thanks, but three pages of off-topic discussion is enough. We should probably have a thread to discuss the benefits and drawbacks of different inverter architectures.

I had hoped to use Enphase inverters on my new panels but I couldn't because code won't allow AC and DC lines in the same conduit and I wasn't about to dig another trench through glacial moraine and lay another conduit. So I ended up with a Solectria inverter for the new panels, but the production is about 10% lower than expected when compared to the old panels on an SMA (Sunny Boy) inverter. In retrospect I wish I had just used two new Sunny Boy 725s. The other alternative was to go all Enphase but that figured to be very expensive and I didn't want to throw away the existing Sunny Boy 725, which I like a lot.

It would be cool to see the two operating side-by-side, just for comparison's sake. But I wouldn't trench a line just to be able to do that!

At least neither of my inverters has fans or anything like that. I presume those are for gigantic scale installations where a lot of heat needs to be dispersed. If/when my string inverters fail perhaps the tech and prices will have improved somewhat in the interim. Sort of like electric cars...

Without a fan you likely will have a good long life from your SunnyBoys, particularly given your cool climate. Fans are the Achilles heel of electronics.

 

[RegGuheert]

After three months, 2013 is already down 464 kWh versus 2012.

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          kWh
May          0   1477          kWh 
June         0   1478          kWh
July       595   1395          kWh
August    1347   1447          kWh
September  910   1295          kWh
October    931    981          kWh
November   949   1041          kWh
December   803    612          kWh
-----------------------------------
Totals    6362  14495   2840   kWh

Thinking sunny thoughts for April...

 

[SilverLeaf]

March 2013 Solar Production
1,305 kWh AC from my 7.59 kW PV System

 

[dgpcolorado]

...Thinking sunny thoughts for April...

I'm thinking wet thoughts. The mountain snowpack is well down from the thirty year average and the mountains here supply water for much of the southwest*. So, I'll trade solar for a snowy/rainy April. (Last Spring was the driest I've seen in twenty-eight years in Colorado; I don't want a repeat of that.)

March here was unseasonably warm and fairly sunny, but still down 7% in solar from last year.

              Old panels    + New panels for LEAF
March 2009      108 kWh
March 2010      101 kWh
March 2011       95 kWh
March 2012      115 kWh
March 2013      107 kWh       302 kWh

* Major river headwaters here: Colorado, Rio Grande, Arkansas, Platte.

 

[RegGuheert]

Woohoo!! New single-day production record for our PV array yesterday: 67.9 kWh. Given that it was pegged at maximum for about five hours, it likely would have gone over 70 kWh if we had M215 microinverters instead of M190s.

 

[dgpcolorado]

Ended up having to pull yet more snow off my panels this morning, for at least the fifth day this month. At least the panels are warm enough, once exposed, that the snow falling all morning has melted as it hit. My panels are currently at 25º pitch, which makes pulling the snow off more difficult than with steep Winter pitches of 65º and 55º. Next week I will raise them to the Summer Solstice pitch of 15º and hope that I don't get any more snow. Much as I like having the water for the May wildflowers and fire safety, rain would be preferred this time of the year!

Male Cassin's finch on my bird feeder, 23 April 2013.

 

[QueenBee]

First day with most of the new panels up. One of the Enphase M215 connectors didn't get clicked all the way in so it was offline today. So this relatively cool temperature and mostly sunny day sure exceeded my expectations for production!

I really didn't know what to expect with the east/south orientation as far as peak power. I'm wondering if I need to rethink my subpanel. I left it at 60 amp circuit with #6 that only goes a few feet through a meter base and a disconnect because my disconnect is only rated at 60 amps but if this kind of production is the norm I might be regularly exceeding the 80% number of 48 amps. Also didn't think I would see the M215's hitting near their limits so quickly. Unfortunately it didn't last long so I didn't get to see if production flatlined because of that or if they would go up to 225 watts like others have seen.

https://enlighten.enphaseenergy.com/pv/public_systems/2Kkg31401" onclick="window.open(this.href);return false;
https://enlighten.enphaseenergy.com/public/systems/2Kkg31401" onclick="window.open(this.href);return false;

 

[RegGuheert]

First day with most of the new panels up.

Very nice! I bet you are glad to have it running again!

One of the Enphase M215 connectors didn't get clicked all the way in so it was offline today.

I think you need to unclick that panel since it is obscuring your roofdogs!

So this relatively cool temperature and mostly sunny day sure exceeded my expectations for production!

Very nice! Even with the morning clouds you produced nearly 65 kWh!

I really didn't know what to expect with the east/south orientation as far as peak power.

I'm a little unclear on all of your roof orientations. It appears that all of the panels are on 4/12 roofs, but you have them listed as "south roof", "west roof", "north east roof" and "south east roof". Does your house have a 45-degree angle in it? In any case, can you provide the exact azimuth for each roof? Also, you can put up to four pictures up on the new website. That would be great to help us see your new installation!

I don't think it will be a problem, since the sun cannot be in the boresight of multiple subarrays at the same time. The highest current situation will likely be in late spring when it is cool and the sun can get close to all the boresights. You should have the answer within two months.

I'm wondering if I need to rethink my subpanel. I left it at 60 amp circuit with #6 that only goes a few feet through a meter base and a disconnect because my disconnect is only rated at 60 amps but if this kind of production is the norm I might be regularly exceeding the 80% number of 48 amps. Also didn't think I would see the M215's hitting near their limits so quickly.

You are fine up to about 11.5 kW. The most you could possibly see is 12.8 kW and that would require all 57 M215s to be at their limit of 225W. That would require very cold weather and the sun to be very near the boresight of the 230W panels, which would make it unlikely you would also be at the limit on all the 250W panels.

But it also may depend upon the grid voltage at your house. My house runs close to (or above) the 250V limit, so my currents are lower than expected. But if you are near the 230V lower limit, you likely will be exceeding the 48A occasionally.

Frankly, I wouldn't worry about it. If it happens, it is not something which will last for a long time. I think that's the main reason for the reduced limit.

Unfortunately it didn't last long so I didn't get to see if production flatlined because of that or if they would go up to 225 watts like others have seen.

One thing about East- and West-facing roofs is that the sun will go much closer to their boresights in the summertime than it does for a South-facing roof.

Based on some comparisons I have done with other roofs in that region, I'll guess that your annual production will be fairly similar to ours, but your peak daily production will dwarf ours, particularly in late spring and early summer! We see 14 to 14.5 MWh/year from ours. What are your expectations for your system?

Enjoy your new array!

 

[QueenBee]

I'm a little unclear on all of your roof orientations. It appears that all of the panels are on 4/12 roofs, but you have them listed as "south roof", "west roof", "north east roof" and "south east roof". Does your house have a 45-degree angle in it? In any case, can you provide the exact azimuth for each roof? Also, you can put up to four pictures up on the new website. That would be great to help us see your new installation!

Sorry that wasn't clear. They are both facing east but the 250 watt panels are on the north end of the east roof and the 230 watt panels are on the south end of the east roof. I added more pictures that will also explain

I don't think it will be a problem, since the sun cannot be in the boresight of multiple subarrays at the same time. The highest current situation will likely be in late spring when it is cool and the sun can get close to all the boresights. You should have the answer within two months.

I'm wondering if I need to rethink my subpanel. I left it at 60 amp circuit with #6 that only goes a few feet through a meter base and a disconnect because my disconnect is only rated at 60 amps but if this kind of production is the norm I might be regularly exceeding the 80% number of 48 amps. Also didn't think I would see the M215's hitting near their limits so quickly.

You are fine up to about 11.5 kW. The most you could possibly see is 12.8 kW and that would require all 57 M215s to be at their limit of 225W. That would require very cold weather and the sun to be very near the boresight of the 230W panels, which would make it unlikely you would also be at the limit on all the 250W panels.

But it also may depend upon the grid voltage at your house. My house runs close to (or above) the 250V limit, so my currents are lower than expected. But if you are near the 230V lower limit, you likely will be exceeding the 48A occasionally.

Frankly, I wouldn't worry about it. If it happens, it is not something which will last for a long time. I think that's the main reason for the reduced limit.

Yeah, if I see any extended periods of ~12kw production I'll have to check the temperature on the 60 amp breaker and #6 wire to see if it even gets elevated. Using 225 watts as the max and 240 volts that's only 54.4 amps so still below breaker tripping which is good. My voltage seems to stay right in the very low 240s.

Based on some comparisons I have done with other roofs in that region, I'll guess that your annual production will be fairly similar to ours, but your peak daily production will dwarf ours, particularly in late spring and early summer! We see 14 to 14.5 MWh/year from ours. What are your expectations for your system?

Well, if I get that much my calculations are going to be way off! I'm only expecting 11.6MWh/year which is just a smidge less than my production. This is based on the solar survey I had done on the east roof, my previous arrays performance and then making a ton of assumptions which I hope are conservative. 12MWh is roughly my annual consumption. If I produce too much more than that I'll have start coming up with ways to consume more

 

[RegGuheert]

QueenBee: I must say that your new system has the most bizarre power production curve I have ever seen! It looks more like a roller coaster! I suppose the sun is moving into and out of the boresight of different arrays. Very cool! :ugeek:

 

[RegGuheert]

After three anemic months, April has managed to produce the largest one-month total ever for this system. I had hoped it would cross the magic 1.5 MWh boundary, but it was not to be. In the last three days, the system could not muster the 63 kWh needed to get there. Oh, well.

So now we are only off last year's pace by 434 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          kWh 
June         0   1478          kWh
July       595   1395          kWh
August    1347   1447          kWh
September  910   1295          kWh
October    931    981          kWh
November   949   1041          kWh
December   803    612          kWh
-----------------------------------
Totals    6362  14495   4335   kWh

 

[SilverLeaf]

April 2013 Production (AC) was 1,445 kWh

2013
----
January----- 911
February---- 1,106
March------- 1,328
April--------- 1,445

My Solar Production Website is now active at http://pvpwrev.webs.com/" onclick="window.open(this.href);return false;

It is a very interesting JSunnyReports generated website.

 

[davewill]

Still churning along.

My production page

System: 9.1kW DC - 28 SunPower 327w panels
	   2012         2013
Jan		       1029.29
Feb		       1097.92
Mar		       1399.86
Apr		       1369.36
May		
Jun		
Jul	 380.47	
Aug	1468.97	
Sep	1348.08	
Oct	1206.23	
Nov	 968.34	
Dec	 720.29	
       ======     ======
	   6092.38    4896.43

 

[RegGuheert]

My Solar Production Website is now active at http://pvpwrev.webs.com/" onclick="window.open(this.href);return false;

It is a very interesting JSunnyReports generated website.

Yes, very cool! Nice looking system and the production is great!

Can you please tell me why the power production from your system has about 200W of ripple with a period of 12 minutes? Does your inverter perform its MPPT sweep slowly over that period? If so, it would seem like you are losing an average of about 100W of production continuously due to this effect. But perhaps it's not as it seems...

 

[dgpcolorado]

April here was down 7% over last year. I've been down every month since November. Since that generally means wetter weather, and we need the water, I can't complain too much. Snowed again today, but only a half inch so not enough to be useful. Eastern Colorado is getting dumped on and I am envious.

Results for April in recent years:

            Old panels   Old+New panels
           (700 Watts)   (2170 Watts)
April 2013   100 kWh       282 kWh
April 2012   107 kWh
April 2011    95 kWh
April 2010   105 kWh
April 2009    99 kWh

Some of you make more in a couple of days than my small system does all month! But my array covers all my LEAF driving plus most of my household usage (~4.9 kWh/day on average).

 

[SilverLeaf]

My Solar Production Website is now active at http://pvpwrev.webs.com/" onclick="window.open(this.href);return false;

It is a very interesting JSunnyReports generated website.

Yes, very cool! Nice looking system and the production is great!

Can you please tell me why the power production from your system has about 200W of ripple with a period of 12 minutes? Does your inverter perform its MPPT sweep slowly over that period? If so, it would seem like you are losing an average of about 100W of production continuously due to this effect. But perhaps it's not as it seems...

I really don't know. I thought this was normal, just environmental fluctuations (sun, shade, temp, etc.). Should I look into this more thoroughly?

 

[RegGuheert]

I really don't know. I thought this was normal, just environmental fluctuations (sun, shade, temp, etc.). Should I look into this more thoroughly?

It looks too regular to me to be environmental. If you look at the curves for the week at the bottom of our system's page you will see that on a sunny day, the production curve is very smooth. On a cloudy day, it is very erratic.

BTW, what type of inverter do you have?