Panel Susgestion

[bazz]

Can anyone give me any suggestions for something in the $300 range? I found this on amazon

http://www.amazon.com/Sunforce-50044-60-Watt-Solar-Charging/dp/B000CIADLG/ref=sr_1_23?ie=UTF8&s=



automotive&qid=1243440108&sr=8-23

but dont know what is good and what is not.

The battery I'm using is here

http://www.powerfactorinc.com/Batteries/ups12-370.htm

I'll be running 7 in parallel.

[ghurd]

Good and cheap do not usually fit in the same sentence with solar.

It's about the same as the HF kit, just 4 x 15W instead of 3.

Can get the HF kit on sale for ~$200, and with a 20% email coupon it is $160.

So for about $320, can get 90W.

Plus they come with cool 12V DC CFLs, and last I knew the HF mounting brackets were steel.

With luck you will get a 25 or 30% coupon when the kit is on sale.  Rare.

The linked kit's 175W inverter is not worth considering in the total cost.

G-

[bazz]

Silly question....HF kit? Could you give me a link as to what kit you are talking about so I could read a bit more about it?

Thanks.

[ghurd]

Are you in the US?  I thought you were.

HF is Harbor Freight.  The "HF kit" is the "45W HF kit".

Best real info about them is on the site you are reading.

"Google search the board" for variations and any more key words you find.

Link,

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599

Do not trust the controller with any of the kits.

G-

[bazz]

Yes...I am in the US....just wasn't thinking...lol

Bummer they dont have any stores near me. I'll have to keep my eyes on the site.

[bazz]

So what would be considered a good solar panel? What types of things to look for?

Are Monocrystalline the best of the bunch? What brand would you suggest to look at?

Thanks

[ghurd]

Mono is "best".  Yea, I read that too.

I never saw any real difference between mono and multi/poly.

Can get a larger watt poly than mono in the same PV dimentions, so that "smaller size" is out the window.

Mono usually costs more.  No rhyme or reason to most of the wholesale pricing.

I recall I could get 85W cheaper than the same brand and model 70W in the same package dimensions.  And I recall getting 70W mono cheaper than the "special weekly deal" 55 or 60W poly with a different model (and maybe brand).

I never saw much difference between REAL brand names.

"Billy-Bob Chang's Hong Kong video and solar panel ebay store with always goodest price and bestest quality for you" is not a real brand name.

If you can not find the brand name available for sale at 50 places, don't trust it.

And some "always on sale" places have about 20 mirror websites selling the same thing.

Personally I won't use amorphous or thin-film.  Some guys love them.

That $300 thing puts a serious damper on something suitable.

My advice with a ~$300 limit is 2 HF kits and a MorningStar SS-10 (no LVD) for the controller.  Over the limit a bit, but much better performance for a few $ more.

G-

[bazz]

Yeah...I'm thinking of scrapping the $300 limit and looking for something a bit more....ahh powerful?

Just need to figure out what might work best.

I saw a few things on ebay that looked interesting like here

http://cgi.ebay.com/Solar-Panel-100-watt-Sunwize-SW100C_W0QQitemZ270397431498QQcmdZViewItemQQptZLH_D
efaultDomain_0?hash=item3ef4f15eca&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|3
9%3A1|240%3A1318|301%3A1|293%3A1|294%3A50

and here

http://cgi.ebay.com/100-Watt-Solar-Panel-2-60-per-watt-Best-price-now_W0QQitemZ220420063025QQcmdZVie
wItemQQptZLH_DefaultDomain_0?hash=item33520f3f31&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66
%3A2|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|294%3A50

Just dont know if I could use it on a 12v system....Not that, that matters, I still have an extra 7 batteries I could play with.

Think they look worth it? (funny...its still in that range. just no controller or anything.)

[ghurd]

Sunwize is argualbly an established brand name.

SunPower brand is a bit too new for my personal taste, but they have UL if I read it correctly.

Both of those are arguably 12V panels.

IMHO, The one with 32 cells is not a decent 12V panel because it has 32 cells.  A decent 12V panel has at least 36 cells.  I was told they have a higher voltage per cell, but am very skeptical for 12V use.

Shouldn't take much looking to find more info about the 32 cell panel and seller on this board.

They are in the range at this moment.  They won't be for long.

Be lucky if they sell under $5/W on ebay.

[bazz]

So other than sun being a bit new... I found this here

http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=245

It has 48 cells.....so now I'm kinda lost....what does that tell me if anything? (once again..in range)

[bazz]

ahhh...never mind...just saw the spec and it says 32 cells in series.

[mettleramiel]

    Not that I like disagreeing with Ghurd, but I have to say that I have 5 36cell panels that run about 100' to the batteries. Once I added a 6th panel not knowing that it was only a 32 cell. I was a little worried at first, but I hooked it up and while my initial voltage direct off the panels went down from 21v to 17v, I've never had any less charging capabilities from them. I would, however, avoid 32 cell panels if I was to hook them up in series.

    I agree full heartedly about the thin-film panels, though. I bought a few when I first got into solar and have been watching their output slowly decrease every year. I've also found that of the 3 different brands I have, 2 of them have flexed so much that their outer casings no longer fit tight. They're cheap for a reason.

    That battery that you link to says that it is 100ah and you want 7 of them? I hope you don't plan on draining those too much, because you're gonna need alot more solar power to fill them back up. If you get that 100watt panel you were considering, 2 of those batts should be fine. Also, they're SLA's, meaning (to me, at least) that they also don't really last more than a couple years. I find that 2 years of life is lucky.

[bazz]

Well I got the batteries for free so its just for testing different things out. (Learning phase)I think I may have a year I can get out of them.

[Airstream]

SunPower is a value-added reseller - they don't actually make anything, just bundle established products and market in niches the OEM will not. I have two Sharp 123w panels that were simply overboxed with SunPower carboard & graphics with some accessories thrown in, then supplied to the RV aftermarket sector...

[Airstream]

Plus an afterthought - if SunPower can find enough margins to make it profitable for them to distribute then everyone is paying too much. I paid about $3.75/watt for those two panels off eBay and used picking them up myself as an excuse to go visit family...

[ghurd]

I do not see where you even slightly disagreed with me.  But it is nice to be backed up.

My "The one with 32 cells is not a decent 12V panel because it has 32 cells"

matches perfectly with your "avoid 32 cell panels"

Bazz, others, and I discussed the merits of too many batteries and system voltage earlier.

http://www.fieldlines.com/story/2009/5/16/172457/139

And I agree that 2, maybe 3 or 4 max, would be plenty for 100W of solar.  And I tend to oversize the battery bank.

If the bank is too big for the charging amps, then you will not be happy with the system performance.

Everything is a balance, and a ~$300 limit on solar is not going to work well with 700AH of battery.

G-

[RandomJoe]

In addition to all that was said above, I'll add to take the wattage claims of those "kit" panels with some skepticism.  My 45W Harbor Freight Kit has never gotten anywhere near 45W.  Best I ever got - fresh out of the box, carefully aimed at the July noonday sun - was 30W and I more routinely get 20-25W since.

Besides, it takes quite a bit more space to fit the same wattage with amorphous panels.

Over the past few months I have installed several Kyocera 135W panels on the roof, and I consistently see only slightly below STC and well above PTC ratings.  (STC is the "ideal" test you really aren't ever going to get.  PTC is the "real world" test rating that you should realistically be able to get.)  That's without any careful aiming, just flat to the roof.

You get what you pay for!

Have you tried the actual solar stores?  I have never been very trusting of anyone dealing through Amazon or (especially) E-Bay.  But then I'm a big-time cynic and don't trust much of anyone...!

I did a quick run through the store I bought my new panels from - Northern Arizona Wind & Sun - and came up with these items:

http://store.solar-electric.com/kykc50wasopa.html

50W Kyocera multicrystalline panel - $279

http://store.solar-electric.com/ss-6.html

SunSaver 6 amp charge controller - $44

Pretty close to your $300 limit, although you will have to provide some wiring.  Might be able to run two of those panels on the charge controller, if desired - it's pushing the limits if you use the STC ("ideal") ratings, PTC shows 2.5A max.  (You can get manufacturer data sheets on their site too, which will have the specs and output charts.)  All in a panel just 2 foot square, instead of four separate ones!

[ghurd]

Value Added often results in buying crap Sharp would not risk putting their own name on, deemed worthy of selling them on craigs list with local pickup only.

http://www.otherpower.com/images/scimages/9313/2sizes2_s.jpg

From

http://www.fieldlines.com/story/2009/2/22/145152/526

[bazz]

Well its easy enough to remove batteries. I guess all the extras I have will be good to try different things. Unless there is any one in NH that needs a few. I do admit...I do have a lot of them....Once again...not knowing what I was doing so I just went for overkill.

Once I have a grasp on what I'm doing and get an idea of what I need to do....hopefully I wont Well I'm sure the process will be fun.

[Opera House]

"The one with 32 cells is not a decent 12V panel because it has 32 cells"

I bought a 32 cell SUN 90 and it puts out more current than my two Photowatt 75W together.  Your 32 cell reasoning does not apply to this panel because each cell puts out more voltage than a typical cell.  For the life of me these cells do not look like any other technology I have seen on other panels.  Look more amorphous but not.  On just an average day with a watt meter and an electronic load, peak power was 93W at 17.7 volts.    Ebay cost shipped was only $309.  Sun Electric is a weird company to deal with.

[hydrosun]

I installed 10 of these 90 watt 32 cell Sunelec panels on a 24 volt system. According to the specs on the panels they should produce about 26 amps into a 24 volt battery. They kept popping open a 30 amp breaker this spring when the sun came out from behind a cloud. I changed breakers and it still popped it open. The 30 amp meter would go over the top. So I'm convinced that they are putting out more power than they are rated at. This was without a mppt controller. I don't know what happens in the heat of the summer. They look funny because they are back contact cells. Essentially the power is collected on the back by putting small connections through the cell from the front to the back. Why that allows a higher voltage per cell I don't know. Could be similar to partially shading a cell causing the whole cell to drop out of the circuit.

Just thought I'd pass on my experience. I don't when these panels will be available again.

Chris

[bazz]

Couple more questions....

What math do I need to know to find out what the correct bank would be? How is that determined? I'm sure one of the books I bought will tell me, but I'm not at that point yet.

Also what determines the size of the charge controller? How can I tell what size to get? I'm gonna guess that this is another simple math equation.

Is there anyone in the NH/MA area that may want a few batteries? They were from a critical system that was removed part of a yearly PM. Anyway..just thought I'd offer.

Thanks

[ghurd]

Usually people start with the loads they want to run, then size the battery and panels to match.

You are sort of starting in the middle.

It is easier to think about solar in amps.

Two HF kits (6A) and a SS-20?  Good for two 100AH batteries, which is probably a bit much battery.

I have pretty good luck with 10X or 20X more battery amp-hours than solar charging amps.

So 6A charging for 60 to 120 AH.

Find a few different solar worksheets and play with the numbers.  It will give you a better understanding.

Depends on the loads too.  A hunting cabin used on weekends can have a bigger battery to supply a lot of power for 2 days, and then has 5 days to recharge.

G-

[CmeBREW]

I totally agree with RandomJoe.

I have had the exact same results from my two SETS of HF solar panels. (bought about a year apart- the results were the same)

They did 40 watts for a month, then started dropping fast each month. In about 3 months they did only 30 watts each, and in about a year they had 50 percent (!) degradation. (and still going)

BOTH sets of HF together are only doing 3 amps in max sunshine now.  Wish I had got the Kyocera!  I will from now on.

Those HF panels must be very thin film panels.  It would be MUCH better to just buy a QUALITY panel like Kyocera or apparently the Sunelec mentioned above. (Do your research, there are many other quality panels out there)

Quality panels last for decades.  With the way things are going, I'll be doing good to charge a flashlight in 10 years with these two HF sets.

Just buy the cool 12v cfl lights on internet or RV store.

[ghurd]

I agree too.

("Personally I won't use amorphous or thin-film.  Some guys love them.")

Except usually a few bucks more than a 50W gets a 70~85W class panel.

And the SS-6 is too small if any expansion is planned.  Only $6 more moves up to the SS-10 from the nice people in the link.  They do not have the SS-20 (Without LVD) at this time.

The installed $/W (and quality) gets a lot better with a little more money to work with.

Shipping, brackets, controller, fuses & holders, wire, nuts & bolts, etc. all cost "about" the same if the PV is 40W or 80W.

Be very careful with larger PVs (over 80W?) and their shipping cost.  Get the actual real Total S&H before committing to the purchase.

Some ship as oversized ($$$), and some only ship on a pallet ($$$$$) even if you order just one.

Many places charge a re-boxing fee and/or palleting fee.  I do understand it, but the special S&H costs can be crazy expensive to the point where 4 50W PVs end up costing less than one 100W PV.

I learned the hard way. (IIRC, with paperwork fees, surcharges, and a special circumstance, I paid $8 per mile to have a 1/3rd full skid shipped ~60 miles)

G-

[Billystack]

I recently bought a kit system from Costco (http://tinyurl.com/d9kw92) that is in this same category.  60w on three panels, a 4 amp charge controller and cheapy inverter.  I've used it once with good results (didn't check the charge rate), to charge my 110 ah marine battery.  The quality of the product is not great: the inverter has already stopped working (no surprise), and the frame around one of the panels came apart when I opened the box.

I'm using this primarily for LED lights for my camping trips, and have built up some 12v christmas light strings.  I  can still return the system to Costco and replace it with the above mentioned 50w panel which would be a lot smaller and lighter.  I have no doubt that the product quality would be better, but I don't really know enough to gauge if the panel will produce enough (I'm planning for < 20 amps/day).  

I've been told that on a 12v system you can divide wattage of the system by 3 to get a good estimate of your amperage supply for the day.  Sound reasonable?  After putting this post together, I've pretty much talked myself into returning the Costco kit but definately am asking for advice...thanks.

[Tritium]

I have 2 of the Sun-100 32 cell (no longer available)  panels tied in parallel. They put out a lot. I have seen over 240 watts into my 150ah battery bank during a cloud edge effect. Lasted over 5 minutes and that was at 95 degrees air temp. I regularly see the rated output from these panels. I wonder if the increased voltage is due to the lack of surface metal conductors that "DO" block some of the cells surface in a "normal" panel?

By the way the 2 were about $550 delivered.

Thurmond

[ghurd]

"Amp-Hour" is the word you are looking for.

Amp-Hour output could be around rated watts divided by 3, in summer.

Amp output of a typical 12V panel is about the rated watts divided by 17.

The Amp-Hour output is probably about 5 hours x the amp output, in summer in a decent location (Not a camp site in the woods).

A 50W PV will make about 3A, multiplied by about 5 hours, for about 15AH/D.

It can be boosted up a bit by manual tracking (point the PV east in the morning, south for noon, and west in the evening).

G-