Best Deal in UPS Shippable 12v Panels?

First, let me say thanks to Wind-Sun/Solar-Electric for hosting this great forum and having one of the better websites I've come across as well as a nice selection of product at attractive prices. I've learned a lot from this forum and the website already.

Somewhere around 135 watt panels are the largest that can be shipped UPS. I only want 2 panels so if they have to ship freight the price per watt goes way up.

So what's the most bang for my buck? I'm looking for the largest panels I can get via UPS at the lowest dollars per watt delivered.

These are for battery charging up north (47 degrees latitude) so they'll be in less than optimum sun much of the year. The best deals I've found so far seem to be:

Kyocera KD135GX-LPU 135 Watt ($2.89/watt delivered)

UL Solar STP115P 115 Watt ($2.74/watt delivered)

They're both multicrystalline, have similar Vmp's, warranties, etc. While the Kyocera panel is almost 6% more expensive per watt, it's also higher output, a well respected brand, and I'm leaning towards giving Solar-Electric my business with their generosity to the DIY community. Comments?

Does anyone know much about UL Solar panels? Do they meet their specs?

Does anyone have any other 12 volt choices in the 110 - 135 watt range and under $2.90/watt with shipping?

The details on both can be found here:

Kyocera KD135GX-LPU

UL Solar STP115P

Thanks in advance!

Comments

  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    Check out SolarBlvd.com I think they have some for $2 Watt.

    Of course check out WindSun Store also and support them if they have what you want.
  • brulazbrulaz Solar Expert Posts: 31 ✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    I am doing almost exactly the same as you and decided to purchase the Kyocera's, primarily because they are a well-known manufacturer with a good reputation.

    It is unclear to me just who manufactures UL Solar's products, but I suspect it's one of the new Chinese companies. They may be fine, but I'm not sure if anybody knows at this point.
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    Those are made in China, but no idea by who, they don't have a spec sheet on their site.

    But personally, when I do a Google search and only 4 results come up for a part number, it makes me think that it is not widely sold.

    "Results 1 - 4 of 4 for STP115P. (0.81 seconds)"
    "Results 1 - 10 of about 1,450 for kd135gx-lpu"
  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    RWB wrote: »
    Check out SolarBlvd.com I think they have some for $2 Watt.

    Of course check out WindSun Store also and support them if they have what you want.
    Thanks! The only $2/watt panels they have are the big 24v Chinese SunTech monocrystalline models. And, while UPS shippable, they qualify as "oversize" making them more expensive to ship. However, even with shipping two of them come in around $2.40/watt which is tempting. They do, however, require use of a more expensive MPPT 24vin/12vout controller for anyone with a 12 volt battery set up (like me).

    It's also interesting the Suntech Power website only has data for the 180 watt version of the above panels (Solar Blvd only has 150 - 170 versions listed). I'm thinking all the lower power versions use lower grade cells that didn't test out as well?

    And thanks for the input Brulaz. The Kyocera's seem like a safe bet. My view is most of us expect the panels to last a long time both to help recover some of their cost, and also because it's a lot of work to install a solar system. Everyone's panels are different sizes and don't play so nice with other panels in a series (i.e. 24 volt) configuration. So if you have one fail a few years down the road, replacing it might be somewhat complicated both in terms of the physical mounting and electrical characteristics.

    Given the huge amount of investment going on in Solar, I'm betting the landscape of manfuactures will be continuously changing for a while. Companies like UL Solar and Suntech may not even be around 5 years from now let alone long enough to honor their warranties. Kyocera, however, is a huge company and hence are more likely to still be around. So, if nothing else, they should have more of an interest in making products that won't prematurely fail.

    What I don't get are all the companies charging over $4/watt for what otherwise seem like very similar panels to the Kyocera's?
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    From time to time we are tempted to pick up a truckload of those cheap panels, but we have gotten burned a couple of times in the past on similar deals. In one case, about 15% of the panels went bad in less than a year, and by then the mfg had stopped selling them in the US, so we had to eat the loss.

    On the other hand, we have seen Kyocera warranty panels that are over 10 years old, replacing it with a new panel.
  • solarvicsolarvic Solar Expert Posts: 1,053 ✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    Solar geek, Have you checked the freight charges verses UPS? I don,t trust UPS personally. If the glass gets broken , They will claim it wasn,t packed well. With a trucking co you have a good posibility that they will honor a claim if something gets broken. You didn,t say where you live. I have ordered solar panels from 4 different dealers in arizona, New Mexico and california. I live in western Pa. and solar panels were usually dropshiped from NY. Or Tenn. The last panels truck freight was $200 for 2 180 watt panels. Usually if you get more panels the shipping isn,t much more as the charge mostly is for delivery. S:Dlarvic
  • RandomJoeRandomJoe Solar Expert Posts: 472 ✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    Don't know anything about the others, but I do have nine of the Kyocera panels on my roof, purchased from NAWS. I got them in two separate orders (one last spring, one in December) shipped UPS. All arrived in good condition in spite of the UPS horror stories I've heard...! :p

    They perform quite well. STC 135W / PTC 95W, and on good sunny days I easily exceed the 95W rating usually getting up to around 120W per panel. (That's with an MPPT charge controller though, so they get to run at their MPP voltage, around 17.2-17.5V when I check.)

    Edit:
    Went back to see what my shipping costs were. I never ordered just panels, but from looking at the orders I'd say it's about $30 per panel for shipping. That's from Flagstaff, AZ to OKC, OK - not sure how much the price varies with distance...

    My second set of panels, the rail kit I had used before (that was able to be shipped UPS) had been discontinued. The new rail kit - which overall was identical to the first, just in longer (12 foot) pieces - had to ship freight. The freight bill was *INSANE*! I paid as much to get them here as I did for the product!
  • brulazbrulaz Solar Expert Posts: 31 ✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    Also when you calc $$/watt (including shipping) the kyocera's come pretty close to the chinese stuff because they are 135W versus 120W, and yet the UPS shipping is similar ($30-35/panel for my destination).

    And the Kyocera's have MC4 connectors, which I think are pretty cool. The chinese ones don't AFAIK.

    Finally I think they are being sold for $720 a pair at NAWS.
  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    brulaz wrote: »
    Also when you calc $$/watt (including shipping) the kyocera's come pretty close to the chinese stuff because they are 135W versus 120W, and yet the UPS shipping is similar ($30-35/panel for my destination).

    Finally I think they are being sold for $720 a pair at NAWS.
    I was using actual charges in the shopping cart with freight to my northwest location. So my $$/watt numbers take all of the above into consideration. The numbers:

    2 Kyocera 135 watt $782 shipped = $2.89/watt (from NAWS)

    2 UL Solar 115 watt $629 shipped = $2.74/watt

    2 SunTech 150 watt $718 shipped = $2.39/watt

    NAWS sells the 170 watt version of the SunTech panels but at a much higher price which is why they didn't make my initial list. Several people report good results with SunTech. So, I agree with Windsun, given the unknowns around UL Solar, I'd pick, the SunTech's or Kyocera's.

    The Kyocera's are 13.5% efficient, while the SunTech's are 11.8% - 13.3% depending on which "grade" you get. So while one is poly and the other is mono it doesn't seem to make a big difference in terms of size vs output.

    So the choice is really down to the Kyocera or the SunTech's. But, as I mentioned, the SunTech's in my application would require a 24v input/12v output controller with decent ones starting around $300 and going up from there. So I have to factor that in as well to the total cost. There is the advantage of less wiring loss with a 24v array.
  • solarvicsolarvic Solar Expert Posts: 1,053 ✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    I have 16 kc 158g panels and I like the construction, also some sharp NDu-167 panels that are very good also. The problem I had is the moduls of panels went obsolete before I could get any more. So With these KC 135 panels just coming out you might be able to get more of the same model later if you want them. I would recomend the kc or sharp from my personal experience. S:Dlarvic
  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    solarvic wrote: »
    Solar geek, Have you checked the freight charges verses UPS? I don,t trust UPS personally. If the glass gets broken , They will claim it wasn,t packed well. With a trucking co you have a good posibility that they will honor a claim if something gets broken.
    Thanks. I wondered about UPS breaking panels. If I needed 4 or more, truck freight would be a no-brainer. But it's rather expensive for just two panels.

    I would have to trust whoever is shipping them to deal with getting them here in one piece and, if there is any freight damage, hopefully getting it handled at no cost to me. It's similar with large flat screen TV's. They're famous for being damaged in shipping and are usually worth many times more than even an expensive panel. I saw a bunch of them stacked up in a warehouse of a damaged goods company. Several looked like someone threw them off the roof. The guy working there saw the amazed look on my face and said "UPS!". Sure enough, nearly all the boxes had UPS shipping labels on them. It was probably a $20,000 stack of TV's that will likely end up in a landfill somewhere.

    Thanks to Solarvic and RanomJoe also for your helpful input.
  • RWBRWB Solar Expert Posts: 168 ✭✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    The MPPT Charge Controller is well worth the extra money.

    I would never use a charge controller that was not MPPT because I would always know that I was probably getting less current out of my panels then what I could be with a good MPPT Charge Controller.
  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    RWB wrote: »
    I would never use a charge controller that was not MPPT because I would always know that I was probably getting less current out of my panels then what I could be with a good MPPT Charge Controller.
    Thanks I mostly agree. The difference in this case is the relatively inexpensive decent quality MPPT controllers, like the Blue Sky 2512, don't support going from a 24 volt array to a 12 volt battery.

    I'm not aware of any MPPTs under $300 that would work (besides the BZ Products, but from what I've read, it doesn't properly double the charge current going from 24v down to 12v and has other problems).

    The Morningstar Sunsaver can't handle 300+ watts. So the least expensive MPPT controller I know of that would work is the $300 Rogue 3024 and it's missing at least one key feature I need. So I'd probably be looking at one of the higher end Blue Sky's or the Morningstar Tristar 45 in the $430+ range. With a 12 volt array, however, the Blue Sky 2512 would work great for about half that price.

    The bottom line is the Suntech panels go from $2.39/watt to $3.06/watt if you factor in another $200 for a more expensive 24/12 charge controller.
  • brulazbrulaz Solar Expert Posts: 31 ✭✭
    Re: Best Deal in UPS Shippable 12v Panels?
    SolarGeek wrote: »
    I'm not aware of any MPPTs under $300 that would work (besides the BZ Products, but from what I've read, it doesn't properly double the charge current going from 24v down to 12v and has other problems).

    Have you looked at the Rogue controller?
    http://www.roguepowertech.com/products/mpt3024.htm

    There's a thread about it in this area of the forum. I think it would work with the Suntechs. It includes a temperature sensor and digital read-out in the price.

    Personally, I'm going with the Rogue and the Kyoceras. Most chinese companies are just too new and unknown to justify the few $$ savings.
  • mikeomikeo Solar Expert Posts: 386 ✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?
    Rogue 3024 and it's missing at least one key feature I need

    I'm just curious, which feature do you need that is missing? The only feature I have found lacking so far is I wished is that it would handle a VOC of at least 90 volts instead of 60 volts so I could series 3 panels for a 24 volt system.
  • solarvicsolarvic Solar Expert Posts: 1,053 ✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?
    SolarGeek wrote: »
    Thanks. I wondered about UPS breaking panels. If I needed 4 or more, truck freight would be a no-brainer. But it's rather expensive for just two panels.

    I would have to trust whoever is shipping them to deal with getting them here in one piece and, if there is any freight damage, hopefully getting it handled at no cost to me. It's similar with large flat screen TV's. They're famous for being damaged in shipping and are usually worth many times more than even an expensive panel. I saw a bunch of them stacked up in a warehouse of a damaged goods company. Several looked like someone threw them off the roof. The guy working there saw the amazed look on my face and said "UPS!". Sure enough, nearly all the boxes had UPS shipping labels on them. It was probably a $20,000 stack of TV's that will likely end up in a landfill somewhere.

    Thanks to Solarvic and RanomJoe also for your helpful input.

    I unloaded freight on my job at the foundry. One time a trucker come in with freight with a bunch of tv.s in front of the freight I was suposed to receive. There must have been at least 20 tvs. He just threw them in front of the freight I was suposed to get . It was a local tv shop and he should have gone there first.
    S:Dlarvic
  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in Panels & MPPT Controllers
    brulaz wrote: »
    Have you looked at the Rogue controller?

    I have, I mentioned it in the same post you quoted... :)
    mikeo wrote: »
    I'm just curious, which feature do you need that is missing? The only feature I have found lacking so far is I wished is that it would handle a VOC of at least 90 volts instead of 60 volts so I could series 3 panels for a 24 volt system.
    First let me say the Rogue MPT-3024 looks like a really good deal in many ways and I've read many favorable comments on it. I also really like the fact it's made in Oregon by an entrepreneur who's trying to support the DIY solar community.

    The big thing for me is the Rogue doesn't have a low voltage disconnect (LVD). Most of the other MPPT controllers have that feature--even cheaper ones like the Morningstar Sunsaver and lowly BZ Products. I'm not always around to babysit the system, and in cloudy weather, an expensive bank of batteries could be easily damaged by DC (non-inverter) loads. It's cheap insurance to have an LVD. Granted there are other ways I could implement one but it really belongs in the controller in a small system like mine. If the only load on your batteries is an inverter, you probably don't need LVD as the inverter will shut down on its own.

    The Rogue also doesn't have any sort of agency approval but I don't think Blue Sky or BZ do either. Even Morningstar only has CE approval which probably doesn't help you much in the USA. From what I've seen you have to spend a lot more to get a true UL certified controller.

    That said, a neighbor had a fire in their house while they were away and their insurance company refused to pay for the damage claiming it was due to un-permitted wiring that was done during a minor remodel job. The insurance business isn't what it used to be with the likes of AIG, corporate greed, etc.

    I suspect in many small DIY systems the surge suppression in the charge controller is the closest they have to lightning protection (even though it's not intended for that). It's also the most likely ground point in a lot of systems. So if there is a nearby or direct lightning strike, the controller is the most likely thing to blow up. And if there's a fire it's conceivable an inspector could point to the fried controller as being suspect.

    But, in fairness to the Rogue, I suspect many DIY solar systems have other brands of unapproved controllers and multiple other code violations. So I'm not sure how much it would really matter if there were a problem? In the case of lightning, for example, the inspector might blame improper grounding of the panels rather than the controller.

    IMHO *anyone* with a DIY solar system who has a fire or injury where the system could be blamed is probably in for an expensive legal battle with their insurance company. And, just ask my neighbors, the huge insurance companies have way more legal resources than the average homeowner can stand up to.

    And, yeah, some similarly priced controllers support 36 volt arrays like the Sunsaver MPPT. One thing to note, however, is the efficiency of all the charge controllers I've seen drops off dramatically when the array voltage is more than twice the battery voltage. They're all most efficient when the nominal Vin is the same as the battery voltage.

    If the above issues are not a problem for someone, the Rogue is a great deal. I think the DIY solar community should, whenever possible, support their own including companies like NAWS and Rogue.
  • BB.BB. Super Moderators, Administrators Posts: 30,629 admin
    Re: Best Deal in UPS Shippable 12v Panels?

    And to be clear--the LVD (low voltage disconnect) is only rated at 8 amps or so for the few controllers I have seen... For larger loads (including inverters without the inhibit function, you are going to need an external switch for those loads.

    LVD is not something I plan on for an unattended off-grid system to really save my batteries... It is not a very accurate measure of state of charge.

    The newer Xantrex Battery Monitors do have a configurable digital output that can be used to "turn off" at 50% and "turn on" at 80% of bank capacity (or whatever numbers you like to use)... Tie that in with remote inhibit/external contactor/switch and you have a very nice setup that should not stress the battery bank.

    I also recommend configuring an alarm in a house/cabin that the spouse, kids, and guests use--turn on a red light/bell/start the backup genset... Frankly, the only person that watches the battery bank closely is the person that paid for the bank in the first place. :roll:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 8,812 ✭✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?
    RWB wrote: »
    The MPPT Charge Controller is well worth the extra money.

    I would never use a charge controller that was not MPPT because I would always know that I was probably getting less current out of my panels then what I could be with a good MPPT Charge Controller.

    But another factor is, how much your batteries will accept ? Even really flat batteries, as they charge, in a couple minutes, start to reduce their amps. At that point, a MPPT may have only bought you 15 minutes of "better" charge, once the batteries slow down.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    BB. wrote: »
    And to be clear--the LVD (low voltage disconnect) is only rated at 8 amps or so for the few controllers I have seen... For larger loads (including inverters without the inhibit function, you are going to need an external switch for those loads.

    LVD is not something I plan on for an unattended off-grid system to really save my batteries... It is not a very accurate measure of state of charge.
    I agree on the accuracy. It's more of a last ditch failsafe. FYI, however, both the SunSaver and BZ Products have 15 amp LVD outputs which would work for my application. Unfortunately the SunSaver can only handle about 200 watts and the BZ has other serious problems.
    BB. wrote: »
    The newer Xantrex Battery Monitors do have a configurable digital output that can be used to "turn off" at 50% and "turn on" at 80% of bank capacity (or whatever numbers you like to use)...
    I agree with you in a bigger more expensive system you probably want to use other means to protect the batteries. My needs seem to fall into a "no man's land" around 300 - 400 watts. Most small systems seem to be 12v/12v and under 200 watts. And there's a big jump above that to 600+ watt 24+ volt systems. The BZ Products controller would be perfect for me if it worked as advertised.
  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    mike90045 wrote: »
    But another factor is, how much your batteries will accept ? Even really flat batteries, as they charge, in a couple minutes, start to reduce their amps. At that point, a MPPT may have only bought you 15 minutes of "better" charge, once the batteries slow down.
    I would say that's simply not true with properly sized batteries in good condition and a decent MPPT. Batteries that are really low should stay in the bulk charge phase at max current a lot longer than 15 minutes.

    If you're seeing that the batteries are probably badly sulfated or severely undersized. Or perhaps you're referring to the BZ Products MPPT which others have reported does exactly what you describe. Either way, something is wrong.

    Also, a lot of times you have some load on the batteries while they're charging. So that also will tend to keep the MPPT in bulk mode at max current.

    Finally, if you're using 24 volt panels, like the Suntech's being discussed here, and have a 12 volt battery, an MPPT is essential. Otherwise you'll get less than half the panel's rated power.
  • mike95490mike95490 Solar Expert Posts: 8,812 ✭✭✭✭✭
    Re: Best Deal in UPS Shippable 12v Panels?
    SolarGeek wrote: »
    I would say that's simply not true with properly sized batteries in good condition and a decent MPPT. Batteries that are really low should stay in the bulk charge phase at max current a lot longer than 15 minutes.


    I'm not saying they drop out of bulk or that they are bad batteries, I'm saying the first minute, say they pull 15A from the MPPT, 15 minutes later they are 12A,
    Where a PWM that only can deliver 12A from the PV, is only going to see a 15 minute shortning of the total charge time, when upgrading to a MPPT controller of the same amp class. I've got 2 MPPT controllers, and it's easy to watch any battery charger, and see the initial amps drop, as the battery charges. That's how most automotive "automatic" chargers work too.

    MPPT shines when you rewire panels to series, and loose the power loss in the cables, and have enough voltage on hot days.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • SolarGeekSolarGeek Solar Expert Posts: 25
    Re: Best Deal in UPS Shippable 12v Panels?
    mike90045 wrote: »
    I'm not saying they drop out of bulk or that they are bad batteries, I'm saying the first minute, say they pull 15A from the MPPT, 15 minutes later they are 12A,
    Where a PWM that only can deliver 12A from the PV, is only going to see a 15 minute shortning of the total charge time, when upgrading to a MPPT controller of the same amp class. I've got 2 MPPT controllers, and it's easy to watch any battery charger, and see the initial amps drop, as the battery charges. That's how most automotive "automatic" chargers work too.
    If you have a typical 60 ah car battery, and you put a 25 amp charger on it, I agree with you. But in a proper solar system with a controller and array that can produce 25 amps, the batteries should be more like 250+ ah. And if the batteries are nearly "flat" as you said, they should accept the full output of a PWM or MPPT controller for many hours. Otherwise the batteries are not sized properly or there is some other problem.

    To look at it another way, if one 60ah car battery tapers from 25 amps down to 12 amps of charging current. Three of them in parallel (180 ah) would accept 3 times as much or 36 amps so the MPPT would stay maxed at 25 amps.

    The battery bank should be sized so you can capture the full output of your array when the batteries are significantly discharged. Otherwise you paid for lots of array capacity you can't use.
  • System2System2 Posts: 6,290 admin
    Re: Best Deal in UPS Shippable 12v Panels?

    I believe Suntech had about 100 pieces of 140watt 12 volt available not too long ago.
  • thenderson4thenderson4 Registered Users Posts: 16 ✭✭
    Re: Best Deal in UPS Shippable 12v Panels?

    I had Wind-Sun send me a KD 135 SX a few days ago. I like it. This is the one with a junction panel. I am from the old school and I like to do things the way I always have. Which is wiring things up myself. The higher price for the SX (junction panel model) may scare you away but when you add the cost fo the cables and such for the one you mention the two panels are about the same price, UPS shippable too.

    I wish all of them were still making the panels the way they used too. You could re-wire them and have a chioce of one of two voltage outputs. For example, an old one I have can be wired to operate as a six volt charger or twelve volt. I looked at the new one I received from Wind-Sun to see if they were still doing this, and they are not doing it on the one I received.

    This is what I would like to see. A 12 or 24 volt panel, configured in the junction box. The wattage would work inversely, meaning in the 24 volt mode, the wattage out would be half that of the 12 volt mode. I am operating a 12 volt system now but want to up it to 24 in a year or two. That way, I could just re-wire the panels.

    Just my thoughts, I know you all have yours.
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