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

[LLB]

Thanks for doing the calculations, I like your 1.8% a lot better than 5%. Bruce

and from #98
"...I personally have a couple of the same failed panels in my possession..."

littleharbor
I thought in the quote above you said you had some of these panels or panels that looked just like them? So just some random picture from the net of some "not even sure if they're dead" SP panels. I'm sure I can't similar pictures of LG or Pana, that seals it, I hate SP they're a much of liars.
Seems my version of the story is more likely than yours, since you're not providing one that is. The picture is more likely from 1970, improperly designed system in the Salton Sea area, that's my story and I'm sticking to it.

And the dealers should take the fall, why should SP? The dealer decides so many things SP has no control over; which inverter, panel location, electrical runs, grounding, etc...

Bruce / JPM
Can JPM or Bruce explain what we learned or the reasoning for doing the math? Obviously it doesn't matter mono to mono as my joke might have been misconstrued as meaning. So were you guys figuring out what advantage poly had in surface area (1.8%) and if it moves the needle in any significant way?

Also I have been meaning to say I think the old guards attitude towards SP has been misguided as I think it is really the installers markup that upsets them. Obviously SP doesn't paint the installer into a corner forcing them to charge higher prices, because we hear of some SP installers (granted not enough) bidding with a reasonable premium. That alone puts it squarely on the installer in my eyes. Again websites assisting in transparency are the key.

What I think I'm resenting is this "don't buy SP" attitude or as some like to say only the ignorant buy SP. When in reality they contradict themselves by saying they make a solid product, its just "they" feel SP stretches the marketing too much. Yet deep down if a newb comes along and says I have 2 bids one from SP and the other "X", they are the same price who should I go with, I think they would say, "you can't go wrong with either of those manufacturers, its the reputation of the installer you want to consider."

You can try to bring bad customer service into this, but to that I say manufacturers are just that. Their job is to provide a quality product (high QC and materials) and brand recognition (marketing). The customer service they outsource (pay for) to the dealer, so lets leave it out. Just because you bought a Ford doesn't mean you get to call the factory and ask questions. They would likely ask you which dealer you bought it from and send you packing. If you picked a bad dealer like I did, then thems the breaks. (It just seems a un-proportionately high percentage of them are bad -from all manu., not just SP) but that's a systemic industry money-grab problem for another day.

[bcroe]

Bruce: Based on what I measured, the S.P. 327's on my roof have cells that are ~ 124 mm square, giving
a gross square area of 15,376 mm^2 before the corner triangles are removed. The removed triangle at each corner has a
side of ~ 11.9 mm, giving an area for each (removed) triangle of ~ 71mm^2, or ~ 283 mm^2 for all 4. That would give the
lost area of the triangles as a % of a square cell as : 283/15,3765 = ~ 1.8%. based on cell area alone.

Thanks for doing the calculations, I like your 1.8% a lot better than 5%. Bruce

[J.P.M.]

Hmm, I wonder if those cut corners amount to 5%? Need some dimensions to do the
calculations. Bruce Roe

Bruce: Based on what I measured, the S.P. 327's on my roof have cells that are ~ 124 mm square, giving a gross square area of 15,376 mm^2 before the corner triangles are removed. The removed triangle at each corner has a side of ~ 11.9 mm, giving an area for each (removed) triangle of ~ 71mm^2, or ~ 283 mm^2 for all 4. That would give the lost area of the triangles as a % of a square cell as : 283/15,376 = ~ 1.8%. based on cell area alone.

A Sunpower panel has a gross area of 1.63 m^2 based on spec sheet dimensions of 1558 X 1046 mm. So, based on gross panel area, cell area is ~ (15376-283)*(96)/1630000 ~ 0.889 of the gross panel area. That jibes reasonably well with the published spec sheet data that was in effect when my array was installed that lists a cell STC efficiency of 0.225 and an STC efficiency based on panel gross area of 0.2006/0.225 = 0.892

But, as we all know, most all arrays of equal (electrical) size will, in the same service, location and orientation, produce about equal or vary similar annual output. Smaller (physical) size arrays of the same (electrical) size as other arrays using less (area) efficient panels will have one (possible) advantage - taking up less real estate by virtue of a smaller footprint.

Bottom line example: All 5 kW arrays that are competently and professionally installed in the same place and orientation will produce about equal output for probably longer than most folks will own them.

To LLB: Sunpower stuff is good, but no more fit for purpose than other quality PV equipment. S.P. comes with what may be important to the solar ignorant, and therefore needs no further justification: bragging rights, but with little else to justify the premium. S.P.'s success is more than a bit due to their advertising and hype which many see as disingenuous and full of misleading innuendo and hype. Also seems to me that informed folks often see the S.P. B.S. for what it is sooner than others who are less informed. FWIW, thank you for buying S.P. I made a tidy profit owning their stock based partly on the belief that no one ever lost a dime betting on the ignorance of the general public - in this case, and IMO only, but an opinion that seems to be shared by more than a few informed people, the price was run up by folks swallowing the S.P. hype.

[littleharbor]

Your getting a little to cryptic for me. I'm not following you.
That link has nothing to do with the pictures you posted. What is that story? It looks to be a whole roof worth of SP panels and every single cell is orange. How come you don't want to talk about that?



This new link that's 5yrs. old that has 3 cells in Palo Alto...who cares. When your the big dog everyone wants to knock you off the hill. If LG was on top there would be extra people gunning for them.

You aren't showing us anything that can't be found with LG or Pana as well.
Show us a report of a multi-million dollar SP farm were a extra-ordinary amount of panels went bad.

If I could find the source of the photos I would. Don't remember where I got them, Oh well...Point is it DOES happen. I'm not saying an extraordinary amount of their panels have failures.

,

As far as being the "Big Dog"

well everybody has their opinion. I don't own a Sunpower system, wouldn't own one and don't have to justify overpaying for one. That's MY opinion. Got better things to do now than bicker about who's the better panel MFG. Enjoy your day.

[LLB]

Not an isolated incident No, I don't have the only ones.

http://guntherportfolio.com/2013/03/new-sunpower-solar-cell-discoloration-anomalies-at-the-photovoltaic-demonstration-project/

Your getting a little to cryptic for me. I'm not following you.
That link has nothing to do with the pictures you posted. What is that story? It looks to be a whole roof worth of SP panels and every single cell is orange. How come you don't want to talk about that?

This new link that's 5yrs. old that has 3 cells in Palo Alto...who cares. When your the big dog everyone wants to knock you off the hill. If LG was on top there would be extra people gunning for them.

You aren't showing us anything that can't be found with LG or Pana as well.
Show us a report of a multi-million dollar SP farm were a extra-ordinary amount of panels went bad.

[littleharbor]

Not an isolated incident No, I don't have the only ones.

http://guntherportfolio.com/2013/03/new-sunpower-solar-cell-discoloration-anomalies-at-the-photovoltaic-demonstration-project/

[LLB]

I got it from my humorous bone. Try it, you may like it. It was suppose to be the hint to make it clear it was a joke.
I guess the joke is on me.

[LLB]

You did say that they are the only company that cuts 5% out of the corners. Where did you get that data?

I see you havn't gone to post #73 yet.

[littleharbor]

You did say that they are the only company that cuts 5% out of the corners. Where did you get that data?

[LLB]

You're revealing your ignorance here. The 5% clipped corners, as you call them are indicative of monocrystalline cell manufacture. Half of all solar panels sold are monocrystalline. Fact is the corners aren't clipped at all. the cells are made from round ingots which have the sides squared off to be able to fit tighter together in the module. that's why the clipped corners as you call them are slightly curved.

The panels were removed from a roof in costal Southern California. because of this failure. BTW Mr. Fanboy, do you know that Sunpower systems are only installed by authorized Sunpower agents so any design flaw would be on Sunpower dealers. N, they weren't abused, sometimes chit happens and even your precious Sunpower panels have problems.

Monocrystalline cells.jpg

Thank you Bruce, at least someone got it.

littlenarbor - see the beginning of post #73 from inetdog.

They are obviously not 5%, but the strawman m.o. just won't die. Can't someone have a differing opinion and prefer another brand without being called a fanboy.

Did it occur to you that if I've seen my share of SP cells the missing stripes down the front of the cell might be the first thing I notice. Not to mention you put SUNPOWER across the top. Not my ignorance showing.

Wow, "coastal" California did that? No design flaw or anything out of the ordinary? That wasn't really much of a story, no more details? Surely you would like to explain where the weakness in the SP panel is?
The failure rate of panels is 5 in 10,000.
https://www.nrel.gov/news/program/20...gradation.html
Never said SP didn't have problems (yet more strawmaning) just saying they are worth a reasonable premium.

Bruce, I apologize in advance for the above. I don't want any association with me to accidentally infect you via strawmanits.

[bcroe]

Hmm, I wonder if those cut corners amount to 5%? Need some dimensions to do the
calculations. Bruce Roe

[littleharbor]

You're revealing your ignorance here. The 5% clipped corners, as you call them are indicative of monocrystalline cell manufacture. Half of all solar panels sold are monocrystalline. Fact is the corners aren't clipped at all. the cells are made from round ingots which have the sides squared off to be able to fit tighter together in the module. That's why the clipped corners as you call them are slightly curved.

The panels were removed from a roof in costal Southern California. because of this failure. BTW Mr. Fanboy, do you know that Sunpower systems are only installed by authorized Sunpower agents so any design flaw would be on Sunpower dealers. No, they weren't abused, sometimes chit happens and even your precious Sunpower panels can have problems.

Monocrystalline cells.jpg

[LLB]

[QUOTE=littleharbor;n377251]

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.

Of course I noticed, they're the only company that cuts 5% of their surface area (corners) and still out performs everyone.
70's area? Oh I don't know, looked like an old roof and you were leading everyone to think they were new by not clarifying their age, so why not.

"Yes their cells can get hot". Are you trying to infer SP cells get hot and others don't? I don't think anyone has been saying SP cells have a heating problem.

You have the panels! Great! What's the story behind them? Were they in Saudi Arabia? On a poorly designed system? Abused in some way?

[LLB]

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

Mike the copper comments started I believe a few pages before your comment, regardless irrelevant. What are you saying, I can't refer to two comments I read in a thread, especially when I didn't put any names to them, oh OK. Actually I believe I said "you guys" so maybe don't take it personally you are in good company!

To your other point (the windshield argument) of gluing copper to silicon doesn't make silicon flexible". True and not, because I think we both understand this is a microscopic situation. I would much rather have the new windshield tech then the old. Most of the time they keep making power other panels can't go on.

Here I want to address the constant strawman technique used to constantly bash SP. The OP said he saw a .70/watt premium and was OK with it. He mentioned other benefits like efficiency , shading, quality of build and warranty. And everyone jumped on the warranty and dismissed everything else with "efficiency is a muted point there are others that do just as good".

Agreed all warranties are a bitch to file a claim against because they make the rules and give themselves ever out.

In rereading mine, even though I bought it, I can't touch it in a any way. Only "licensed" and "certified" SP techs or SP dealer techs. So technically I can't even say I took a reading with my meter and I think there is something wrong, please check it out. All claims have to originate from a software reading. Nice little package they have created.

I'm trying to say I see a high quality build and higher quality materials. Since I attached the white paper earlier I'll refer to it.

The design does not look very different to the casual observer

What the heck! mod
You cut 50% of my post!!
If this board doesn't allow you to quote something then say so and leave the rest of my words. Don't just cut everything below it!

Well everyone you'll have to believe it was a good post.
It covered Mikes thermal expansion and how SP only receives 25% more performance but it cost them 33% more. (base metal price of copper $3, alum $1)
It had a NASA space analogy paragraph in there about them using premium materials and tech.
And basically wrapped it all up by saying they are reaching their high efficiency somehow. I say it is by using high quality materials. Its not like they are under-performers and charging a 20% premium. Anyone care to say how you think they are achieving the highest marks in the industry, using the same stuff as everyone else?
Then drove it home with saying the original poster said he thought SP was worth the ~.70/watt premium and I agree.
I just disagree emphatically to reduce the argument to a "commodity item", because they are putting in high quality commodities and better tech and the high quality commodities alone demand premium pricing. I don't think anyone would argue that there are different grades of aluminum or copper. While I can't prove what grade they use, neither can you prove they don't. At least I can say if every company is using the same grade/quality of components then why aren't they achieving the same life spans of efficiencies. Efficiency is nothing without build quality.

We all should really go back and read # 1 and 7 on page 1, they said all this already much better than I.

Just in case this deletion of half my post was a computer glitch I'm going to retry to add the text that belongs under "The design does not look very different to the casual observer"
The design does not look very different to the casual observer
Nope looks like the mods don't allow quoting other works, most be a copywrite issue, so i'll put it in my own words... but you can read it on page 12.

Both have cells encapsulated in a polymer that is bonded to the front and back. Materials and their quality can very widely and their specific properties can have important impacts on performance. Materials and suppliers for other laminate components, such as glass, encapsulant and backsheet, vary between manufacturers and these properties have ramification on long-term reliability.

And to those that say don't believe everything you read. I would hate to live in that world. (It might throw a wrinkle in religion-for heavens sake) The devil is always in the details and we don't have them, so in my book you can't through the baby out with the bath water.

[Sunking]

Those small fires are nothing compared to Dietz & Watson factory solar panel fire. All fire fighters could do is sit and watch a 300,000 ft/2 burn to the ground. Good news is they had one heck of a BBQ when the fire burned itself out.