Is Sunpower price difference worth it? -- thoughts, posting as new topic

[Kingram]

I went to Google Images searching for "burnt solar panels" and found these. Funny scrolling for pages I could find any SP.

Wow that is some scary pictures ,Here is another.

http://www.breitbart.com/london/2015...ove-town-hall/

[littleharbor]

[QUOTE=LLB;n377227]

Wow I was about to let this go as well, to each his own, but you guys are just relentless. Please post more pictures of 1970 panels on abandoned houses.



In case you haven't noticed, these are Sunpower panels. Not sure how you figured these are 70's era panels on abandoned buildings. I personally have a couple of the same failed panels in my possession that were mfg. in this millennium. Yes their cells can get hot.

[Mike90250]

Wow I was about to let this go as well, to each his own, but you guys are just relentless. Please post more pictures of 1970 panels on abandoned houses. If you can get the data from that SP system and a LG or Panasonic near by this house, I'd like to compare.

My understanding from the SP brochures is the copper makes for a more resilient cell, that's all. I can't find any sales literature mentioning it being a heat sink. Seems most panels fail do to corrosion and tab failure and from the research literature I can find from LG, Panasonic (which I find very lacking) SP has really focused on those issues better than everyone else - see attached report.

Well , that's about all for me. I'm sure I'll go down in a ball of flames in about an hour. Had other questions but I guess I'll have to settle for being a lurker here. Just trying to say you old dogs are greatly appreciated and knowledge valuable but things do change. After reading that report (and some was conducted by 3rd parties and some by SP themselves - see conclusion/Summary and final 4pgs. of references) I got a hold new respect for SP and think the cell technology they've achieved is worth a few more cents per watt.

First, if you are quoting me about copper heat spreaders, and refer to a photo I did not post, it poor reflection on you.
Copper is flexible. As is aluminum, silver and gold

Silicon wafers are not. Gluing silicon wafer to something flexible, does not make Silicon flexible, it simply keeps the pieces together like a broken car windshield laminate. The ads don't show how many tests were done that failed the flex demo before they got one to work.


Coefficients of Linear Thermal Expansion
Silicon 3 - 5
Silver 19 - 19.7
Glass, plate 9.0
Gold 14.2
Copper 16 - 16.7
Aluminum 21 - 24 ( from https://www.engineeringtoolbox.com/l...ents-d_95.html )

Because microcracking takes years to show up, things will work fine for a while. Maybe SP uses some compliant interface between the copper and Si. But it's showmanship

[LLB]

I'd respectfully suggest you consider that not everything you read is unbiased or just maybe not meant in your best interests. Most of the Sunpower white paper and other such hype falls under that category.

Point behind a lot of these caveats is that Sunpower stuff is a lot of hype, considered by more than a few in the know to be disingenuous and biased in ways that seem be and meant to separate the solar ignorant from their assets. FWIW, I've seen such ignorance time and again, upfront and personal from neighbors and friends for years.

If you consider those statements to be flaming in nature, so be it. This is, among other things a place for opinions, and opinions vary.

Take what you want of the above. Scrap the rest.

Who could consider those comments flaming. It was one of your milder replies. I am somehow oddly honored. It did not go unnoticed that you commented a few days ago something to the effect (it maybe that SP is not trying to charge 20% premium all the time and is trending down) I'll take that, little steps are good. I think forums and review sites that help people compare prices brings transparency and has a leveling effect.

I just wish I could find a LG or Pana white paper that went to as much trouble as SP. Sure SP used their best numbers and the competitions worst, but that's what everyone does (and some was very straight up 3rd party) . It's up to us to read between the lines, even though we shouldn't have to. If LG and Pana aren't going to defend themselves than so be it.

[J.P.M.]

Wow I was about to let this go as well, to each his own, but you guys are just relentless. Please post more pictures of 1970 panels on abandoned houses. If you can get the data from that SP system and a LG or Panasonic near by this house, I'd like to compare.

My understanding from the SP brochures is the copper makes for a more resilient cell, that's all. I can't find any sales literature mentioning it being a heat sink. Seems most panels fail do to corrosion and tab failure and from the research literature I can find from LG, Panasonic (which I find very lacking) SP has really focused on those issues better than everyone else - see attached report.

Well , that's about all for me. I'm sure I'll go down in a ball of flames in about an hour. Had other questions but I guess I'll have to settle for being a lurker here. Just trying to say you old dogs are greatly appreciated and knowledge valuable but things do change. After reading that report (and some was conducted by 3rd parties and some by SP themselves - see conclusion/Summary and final 4pgs. of references) I got a hold new respect for SP and think the cell technology they've achieved is worth a few more cents per watt.

I'd respectfully suggest you consider that not everything you read is unbiased or just maybe not meant in your best interests. Most of the Sunpower white paper and other such hype falls under that category.

Point behind a lot of these caveats is that Sunpower stuff is a lot of hype, considered by more than a few in the know to be disingenuous and biased in ways that seem be and meant to separate the solar ignorant from their assets. FWIW, I've seen such ignorance time and again, upfront and personal from neighbors and friends for years.

If you consider those statements to be flaming in nature, so be it. This is, among other things a place for opinions, and opinions vary.

Take what you want of the above. Scrap the rest.

[LLB]

I went to Google Images searching for "burnt solar panels" and found these. Funny scrolling for pages I couldn't find any SP.

[LLB]

That copper heat sink is useless unless there are fins on it. otherwise, it's a heat spreader, and only insures all parts are the same temperature. SP has lots of marketing hype.

Wow I was about to let this go as well, to each his own, but you guys are just relentless. Please post more pictures of 1970 panels on abandoned houses. If you can get the data from that SP system and a LG or Panasonic near by this house, I'd like to compare.

My understanding from the SP brochures is the copper makes for a more resilient cell, that's all. I can't find any sales literature mentioning it being a heat sink. Seems most panels fail do to corrosion and tab failure and from the research literature I can find from LG, Panasonic (which I find very lacking) SP has really focused on those issues better than everyone else - see attached report.

Well , that's about all for me. I'm sure I'll go down in a ball of flames in about an hour. Had other questions but I guess I'll have to settle for being a lurker here. Just trying to say you old dogs are greatly appreciated and knowledge valuable but things do change. After reading that report (and some was conducted by 3rd parties and some by SP themselves - see conclusion/Summary and final 4pgs. of references) I got a hold new respect for SP and think the cell technology they've achieved is worth a few more cents per watt.

[littleharbor]

Maybe Sunpower cells should have fins.
Sunpower brown cells 2 (2).jpgSunpower brown cells (2).jpg

[Mike90250]

That copper heat sink is useless unless there are fins on it. otherwise, it's a heat spreader, and only insures all parts are the same temperature. SP has lots of marketing hype.

[J.P.M.]

This seemd like a good thread to revive instead on starting a new one.

If you are in the city you are "almost" always space constrained. What I mean by that is, you may have 2500sqft of roof that can hold 50 panels and you only need ~20. But you only have limited sqft of south roof.
So I think an interesting thought experiment would be at what point does the space constrained argument even lose once you have to go to the W or E roof?
If you need 16 SP panels and only 12-13 fit on your S roof and you have to put the rest W or E and W or E has plenty room. Is it then better to go with say 20 LG panels even though only half face S and the rest W or E? Unfortunately it is beyond my math abilities.

second point
Are we saying that there are no SP farms. All commercial customers bean-counting accounting depts always steered away from SP? Oh wait, they did it at cost or a loss for the marketing "Brand recoginition". Maybe they just like living in the high-markup residential arena.

last point
I have only come across 2 times someone mentioning the actual patented construction. Once it was brought up as a copper heat-sink which I think was an injustice.
Then the strawman arguments stared flying.
I do not care for SP jumping-the-shark marketing either, but marketing is marketing and that's their job, to stand out and set themselves apart.
So maybe getting a patent is just another market maneuver, but it does come across to me as a more solidly built cell that will "last longer" while giving higher output because of the better degradation numbers. Only time will tell as no one has reported their readings from their 35yr. old SP panels with the copper backing, accelerated aging tests be damned.

So if you don't plan on adding to your system or moving and only want to buy once then SP I think is worth it. (If you didn't pay a 20% premium which I keep hearing about). Hopefully if more and more people report their numbers it will bring SP more in line and keep them from trying for the 20% which could get them cut from the bidding process.

I question the usefulness of dredging up old threads. This one seemed to have fried the S.P. marketing B.S and stuck a fork in it, but the S.P. B.S. persists even if the S.P. price premium may have dropped a bit. More proof that there's a sucker born every minute. They're probably headed for two price/quality system now that they've bought SolarWorld.

You don't need a thought experiment, just a little knowledge of the time value of money and a spreadsheet, and maybe a little bit of knowledge about process economics/time value of money stuff, but arithmetic, a spreadsheet and a brain will do quite nicely.

These days, what was a drudge 30 - 40 years ago (believe me - did it lots by hand and paper spreadsheets - well, with a calculator too) is now a cake walk.

Synopsis:
- Find the LCOE of PV production for various orientations of 1 STC kW PV at various orientations using assumptions that fit your situation and your lifestyle for the length of time you deem appropriate.
- Then, compare those LCOE's to the LCOE of any alternate (like grid supplied) sources of power. If alternate (like grid power ) LCOE's are less, and cost effectiveness is the criteria, PV is not an option
- Also compare any PV LCOE to the levelized costs of any savings from conservation measures done before PV as most common conservation measures will almost always be more cost effective.
- Run different sizes of array to get the best (least LCOE combination) mix of PV and conventional method of meeting the load.
- Iterate by varying array sizes and orientations for different equipment mfgs. Choose the mix of conservation, PV (electrical) size and equipment mfg. that produces the lowest overall LCOE that fits your lifestyle and PITA tolerance level.

With LCOE type analysis (a form of lifecycle cost analysis for estimating the long term cost of producing (or buying) energy), if you use realistic (whatever that means when talking about the future) assumptions, and are honest with yourself about it by taking the time and making an effort to understand the basics, you will likely find that after reasonable conservation measures and a few possible lifestyle adjustments, PV from S.P. will have a very hard time competing with most any other quality manufacturers' equipment in terms of cost effectiveness. You may also quite likely find that offsetting 100% of a conservation reduced electrical load has a higher LCOE than simply living without PV, at least until PV prices change more than the estimates your LCOE analysis uses, or POCO prices rise more than your LCOE analysis uses.

Overall and in spite of what those with skin in the game and all their advert. hype, innuendo, half truth, twisted logic and just plain B.S. would have you believe, residential PV may not be cost effective for many, even most residential consumers, particularly those who are ill informed about its possibilities and more importantly, its limitations.

Everyone who tells you what you think sounds nice is necessarily your friend or teeing you the truth.

Take what you want of the above. Scrap the rest.

[ButchDeal]

This seemd like a good thread to revive instead on starting a new one.

If you are in the city you are "almost" always space constrained. What I mean by that is, you may have 2500sqft of roof that can hold 50 panels and you only need ~20. But you only have limited sqft of south roof.
So I think an interesting thought experiment would be at what point does the space constrained argument even lose once you have to go to the W or E roof?
If you need 16 SP panels and only 12-13 fit on your S roof and you have to put the rest W or E and W or E has plenty room. Is it then better to go with say 20 LG panels even though only half face S and the rest W or E? Unfortunately it is beyond my math abilities.

this is an old thread. Other brands have very similar efficiency now taking away the little sunpower advantage.

As for the longevity, well warranties are only as good as the company backing them.

E and W are at worst 20% less production than S and often closer to 15% or even 10%
W in some locations is actually financially better than south due to TOU billing changes.

[LLB]

You guys need an accountant to figure this out.....a 345 watt Sunpower panel (with a 9% greater efficiency factor) vs a 250 watt Chinese (with a .75% greater degradation factor) will out produce the Chinese by 65.3% over a 25 year life in the same space and assuming both panels receive an average 7 sun hours a day.

But a 345 watt Sunpower will cost ~$2.50/watt or $862.50 for the panel. The 250 watt Chinese will cost ~$1.00/watt or $250.00 for the panel. Dividing the panel cost by lifetime production results in the Sunpower panel costing $.03591 per watt of production vs the Chinese at $.01720 per watt of production.....a significant cost difference. The only reason you would install a Sunpower is if you are space constrained. Cost wise it is a poor economic decision.

This seemd like a good thread to revive instead on starting a new one.

If you are in the city you are "almost" always space constrained. What I mean by that is, you may have 2500sqft of roof that can hold 50 panels and you only need ~20. But you only have limited sqft of south roof.
So I think an interesting thought experiment would be at what point does the space constrained argument even lose once you have to go to the W or E roof?
If you need 16 SP panels and only 12-13 fit on your S roof and you have to put the rest W or E and W or E has plenty room. Is it then better to go with say 20 LG panels even though only half face S and the rest W or E? Unfortunately it is beyond my math abilities.

second point
Are we saying that there are no SP farms. All commercial customers bean-counting accounting depts always steered away from SP? Oh wait, they did it at cost or a loss for the marketing "Brand recoginition". Maybe they just like living in the high-markup residential arena.

last point
I have only come across 2 times someone mentioning the actual patented construction. Once it was brought up as a copper heat-sink which I think was an injustice.
Then the strawman arguments stared flying.
I do not care for SP jumping-the-shark marketing either, but marketing is marketing and that's their job, to stand out and set themselves apart.
So maybe getting a patent is just another market maneuver, but it does come across to me as a more solidly built cell that will "last longer" while giving higher output because of the better degradation numbers. Only time will tell as no one has reported their readings from their 35yr. old SP panels with the copper backing, accelerated aging tests be damned.

So if you don't plan on adding to your system or moving and only want to buy once then SP I think is worth it. (If you didn't pay a 20% premium which I keep hearing about). Hopefully if more and more people report their numbers it will bring SP more in line and keep them from trying for the 20% which could get them cut from the bidding process.

[sunnyguy]

If you take the 1.21 energy/w and the 1.38w/area you get 67% but if you are space constrained you should look at lg and solar world.

For lg 315 it drops to 1.095w/area and probably 1.1 energy/w so now you're down to 20% and if lg is $1.15/w then sunpower should be $1.38/w.

FWIW, someone had mentioned they were getting insider pricing on sunpower panels at $1.04/w.

[DanS26]

You guys need an accountant to figure this out.....a 345 watt Sunpower panel (with a 9% greater efficiency factor) vs a 250 watt Chinese (with a .75% greater degradation factor) will out produce the Chinese by 65.3% over a 25 year life in the same space and assuming both panels receive an average 7 sun hours a day.

But a 345 watt Sunpower will cost ~$2.50/watt or $862.50 for the panel. The 250 watt Chinese will cost ~$1.00/watt or $250.00 for the panel. Dividing the panel cost by lifetime production results in the Sunpower panel costing $.03591 per watt of production vs the Chinese at $.01720 per watt of production.....a significant cost difference. The only reason you would install a Sunpower is if you are space constrained. Cost wise it is a poor economic decision.

[rhedayi]

Wait.....70% more energy in same space means...if you have a roof that holds 10 panels (actual space), you can place 10x345 vs 10x250. So that alone is a difference of 38% more power in the same space. Add degradation over time, it may add up to 70%. RIght from the start you get 38% more power in the same space, sure you pay for a 3.45kw sunpower system verseu for chinese 2.5kw system. But space is space.