Author Topic: Question about Sunforce products,. (Read 3702 times)

chubbytrucker01 · « **on:** June 14, 2008, 06:25:17 PM »

Has anybody been using or testing Sunforce brand panels and controllers? Our local farm store has 10 watt panels on clearance for $71 each and he told me to make an offer on them he has like maybe 5 of them. He also has 7 and 30 amp charge controllers. He has larger panels also but they are some kind of piggyback together system that looks like trouble. It looks like a corrosion and loose connection headache to me. I know $7.10 a watt is high but I was thinking of offering him $50 apiece for them. Would appreciate some help. Thanks again for all the advice and help everyone on this board provides. When a question gets answered it helps everyone who is struggling to figure it out.

Thanks,

Doug

dnix71 · « **Reply #1 on:** June 14, 2008, 05:20:45 PM »

10 wattts used for $71 is high.

What do you plan to do with them, experiment or full-time use?

DanG · « **Reply #2 on:** June 14, 2008, 06:28:37 PM »

Sunforce usually re-brands others product lines - I just got a unopened new-in-box 123W Sharp module with Sunforce 'value added' package of mounting brackets, connection cables and LED voltage tester that is marketed for RV installation (bought as freight salvage @ $3.80/watt)

http://sunforceproducts.com/english/results.asp?catid=1

Are the '10w' panels listed on above link?

If they are thin-film type I'd avoid them; if they are polycrystalline start your offer at $45 but small wattage panels have a built in $20+ per piece premium it seems.

Can you identify the 'piggy-back' ones from the website?

chubbytrucker01 · « **Reply #3 on:** June 15, 2008, 12:54:13 PM »

I believe these panels are are like the first one in the link. I will go look at them again and see if I can open the boxes and look at them. He caught me looking at them and told me he would make me an offer on them. I wasn't interested at first then I got to thinking about it. By thin film cells do you mean Amorphous? These are new in the box but I guess nobody has bought any and he just wants to move them. The piggyback panels weren't in the link. They had some kind of edge connector where the panels just snapped together. I'll get a part number off of those also. They were really pricey and I didn't pay any attention to them. They were like 65w at $550. I am going to install them on my barn to charge a couple of golf cart batteries to run some lights and maybe a fan for a couple of hours a day,and the fence charger. I was interested in the 7 watt charge controller for this. Thank you for the help.

Doug

kenputer · « **Reply #4 on:** June 15, 2008, 01:17:01 PM »

I have had some of those controllers,they disconnect the panels from the batteries @ 14.4 volts and reconect when battery voltage drops to 13 volts.

Ken

ghurd · « **Reply #5 on:** June 15, 2008, 05:51:56 PM »

Ken,

Thats horrid! Buy new controllers.

G-

kenputer · « **Reply #6 on:** June 15, 2008, 07:11:42 PM »

Thats horrid! Buy new controllers.

I don't have them anymore, I have a c-40 at home and MPPT controller at the cottage.

Ken

chubbytrucker01 · « **Reply #7 on:** June 16, 2008, 09:15:56 AM »

OK. I'm confused. DanG you said if they are thin film type avoid them. Then you said if they are polycrystalline offer 45 bucks. Aren't polycrystalline and thin film the same? Or are there thick film polycrystalline? Help!

Doug

DamonHD · « **Reply #8 on:** June 16, 2008, 09:26:14 AM »

Thin file is not the same as polycrystalline!

Typical retail solar panels in order of increasing cost, lifetime and efficiency (power for a given area) are:

thin-film/amorphous (not just silicon-based these days though)
polycrystalline silicon
monocrystalline silicon (and hybrids including thin films too)

Rgds

Damon

Matrix1000 · « **Reply #9 on:** June 18, 2008, 09:04:45 PM »

Not to de-rail the thread but does that mean that Unisolar panels like the US-64 aren't that good? Just checking because if not then I don't want to buy any more.

DamonHD · « **Reply #10 on:** June 19, 2008, 01:07:14 AM »

I like my UniSolar panel, which is the biggest in my little off-grid system, for several reasons:

1) It was the cheapest per Wp that I could buy.

2) It doesn't have a glass front so is light and is safe to have at ground level in my garden with a small child running around.

3) It is said to give better winter output per Wp compared to crystalline silicon because of its triple-junction construction. It certainly seemed to do OK for me last winter.

So, different not necessarily worse. Depends on your application.

Rgds

Damon

DanG · « **Reply #11 on:** June 19, 2008, 08:18:40 AM »

I apologize for showing bias against thin-film PV modules. It's just a knee-jerk reaction to all the horrible ones that have not worked out well, where I've never heard of a monocrystalline panel falling apart after a year or two. The Uni-Solar specifications and warranty look to be inline at $5.70/watt for 64w panels.

Their warranty has unique language beyond usual, customary and reasonable (UCR) "repair or replace" though... "United Solar Ovonic will refund an amount equal to lost power times the amount paid for the module per watt of Rated Power. Lost power is the difference between exhibited power and 80% of the Rated Power both at Standard Test Conditions."

That sounds like cut a check for pennies on the dollar to avoid replacement on top of their exclusion "The warranty does not cover any transportation costs for return of Modules or for reshipment of any repaired Module..."

I guess that is for accountants to battle over though, for the average joe they may excel in all the ways claimed...

DamonHD · « **Reply #12 on:** June 19, 2008, 12:59:19 PM »

Well, who knows! Next year I may be cursing my thin-film (but I did buy a different flavour for other spots on the east and west of the house).

I only have one pure (mono)crystalline panel (20Wp) out of a grand total of ~1.3kWp on- and off- grid, so I have rather nailed my colours to the mast on this...

Try me in 12 and 24 months! B^>

Rgds

Damon

chubbytrucker01 · « **Reply #13 on:** June 20, 2008, 09:13:09 AM »

so if a panel is monocrystalline thats the best? If it says crystalline it could be mono or multi? Is multicrystalline another name for amorphous? If not is multi better? Still Lost,

Doug

DamonHD · « **Reply #14 on:** June 20, 2008, 09:34:41 AM »

Monocrystalline ("single crystal") is the opposite of amorphous ("formless mass").

"Best" depends on whether you are optimising for cost for unit power out (amorphous wills there) or space required (monoscrystalline or a hybrid wins there) or longevity (probably monocrystalline there too) or something else (eg prettiness).

You'll have to go and search for a glossary of these terms and learn the differences.

Rgds

Damon

ghurd · « **Reply #15 on:** June 20, 2008, 09:34:55 AM »

Amorphous is Thin-Film. Avoid it at that price!

It looks like brown paint, with lighter stripes going one way.

Crystalline, mono or multi, looks like squares, or octagons, or semi-circles, or something. But you can see each piece is seperate, and can see the ribbon wire connecting them.

Mono and Multi. Not much real-world difference. Look at the brand and $/watt.

Multi often looks like blue cracked ice.

Mono often looks like tiny glitters on a blue or brownish piece.

Make sure they have at least 36 cells (squares, semi-circles, etc). 32 or 33 will not work out so great in a 12V system.

G-

ghurd · « **Reply #16 on:** June 20, 2008, 09:43:42 AM »

Here you can see the pieces, wire ribbon, and a bit of the 'blue cracked ice' look of multi crystalline panel.

http://www.otherpower.com/images/scimages/2050/VWPVCntrlr.jpg

Tritium · « **Reply #17 on:** June 20, 2008, 10:36:39 AM »

The correct term for the Blue "cracked ice" look cells is Polycrystalline.

Thurmond

chubbytrucker01 · « **Reply #18 on:** June 20, 2008, 03:29:57 PM »

Well I did look up the definitions of the terms. Apparently someone (sellers) are blurring terms to push cheap panels and I am still confussed. Loike in the last couple of comments I got. Ghurd says blue cracked ice was multicrystalline and the last post says it is polycrystalline. I don't understand and I don't seem to be the only one. Thanks again,

Doug

ghurd · « **Reply #19 on:** June 20, 2008, 06:37:15 PM »

That's what you used, so that's what I used.

They are the same.

If you said "Two inches", most people would not reply with "5.08cm".

If you said "Two quarts", most people would not reply with "half gallon", or "Four pints", or "64 fluid ounces".

You are completely confusing yourself.

There are 3 kinds...

Mono

Multi/Poly

Thin-film/amorphous

That is about what Damon said.

I myself would not include the hybrids, but the feed store doesn't have used ones anyway.

elvin1949 · « **Reply #20 on:** June 20, 2008, 09:44:08 PM »

Doug

They will all work. The thin film will not last as long as the others,but they are also a lot cheaper. Beening dirt pore that is what i use.

It is all in what you are willing to pay.The polycrystalline are the most second most expensive i think.

Then the mono crystalline are the most expensive and more than likely the best {out of my price range}

I use thin film myself and they do what i want. Keep my battery's hot.

Good luck finding what you need at a price you can afford. Have fun

later

Elvin

dnix71 · « **Reply #21 on:** June 21, 2008, 08:10:28 PM »

The papers that come with the Harbor Freight kit state plainly that the output of thin film amorphous panels declines 20% during the first few months break in. That implies you had better borrow a new one for testing and then derate it for calculating how many you will need to power your setup.

ghurd · « **Reply #22 on:** June 21, 2008, 10:28:47 PM »

The HF panels degrade to about 1A. They start as high as 1.3A.

In good sun.

G-

chubbytrucker01 · « **Reply #23 on:** June 22, 2008, 12:08:43 AM »

Thanks everyone for your help. I have learned a few things from this posting.

A. Don't ask too general of a question.

B. The people on this board are extremely helpful.

C. I didn't think I wanted the panels from the start.

D. Everyone has a different idea of what value is.

E. Some of you answer questions like a teacher on test day.

But in my defense some people have minds like beartraps and mine is more like a paperclip. If you thought I didn't get the concept of panel construction just wait until the questions start rolling about wiring them up!

Thanks everyone for the help,

Doug

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Author Topic: Question about Sunforce products,. (Read 3702 times)