Grape Solar Question

8n-bob
8n-bob Solar Expert Posts: 35 ✭✭
Hi:
Got a quick question

I am looking at the following PV panel. Just looking to see if anyone has had experience with this brand. Can get them for $1.43/watt including shipping. I think this is an OK price. I live in the middle of no where so shipping is always a issue. That's the out the door price delivered to my house. The Specs are Below.

Thanks
Bob O.




MFG: Grape Solar
Poly-crystalline
18% Eff.

Maximum Power Pmax 280 W (0%, +3%)
Voltage at Maximum Power Point Vmpp
35.8 V
CEC PTC Rating 251.0 W
Current at Maximum Power Point Impp 7.82 A
Open Circuit Voltage Voc 44.6 V
Short Circuit Current Isc 8.43 A
Temperature Coefficient of Voc -0.156 V/ºC (-0.35

Comments

  • 8n-bob
    8n-bob Solar Expert Posts: 35 ✭✭
    Re: Grape Solar Question

    I was hoping some one knew about Grape Solar then their quality etc.

    Just don't want to waist money on junk.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Grape Solar Question

    Some posts from a couple years ago:

    http://forum.solar-electric.com/showthread.php?12715-Really-good-panel

    Just not too much experience one way or another on the forum (I don't have any more information other than to above links).

    At this point, if you can get them for a good price delivered to your front door--They appear to not have any big issues (one person did not like the US company, another found them very nice to talk with).

    Make sure you know which panels you are getting and know they will work with your battery bank/charger configuration. With the wide variation in solar panel specifications these days, it is possible to save a lot of money on the panels and find out that you need an "expensive" MPPT charge controller to use them with your battery bank.

    For example, these panels would work fine with a PWM controller on a 24 volt battery bank. But would need a MPPT charge controller for use with a 12 volt battery bank. Or use two panels in series for a PWM controller on a 48 volt battery bank.

    Three panels in series may be an issue with Voc-cold-array -- You are getting very close to the 140-150 VDC maximum input voltage on many higher end MPPT charge controllers. Depends on your minimum temperatures, charge controller, and battery bank voltage as to how to make everything work together.

    In general, for smaller systems (400 watts or less), PWM controllers tend to work fine and are a lot less money. For larger systems (800 watts or more), MPPT controllers tend to be a better choice because you can use a higher Vmp-array voltage and use smaller diameter wiring from the array to the battery bank/charge controller.

    Always do a paper design first and make sure that everything makes sense.

    Your mileage may vary.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • 8n-bob
    8n-bob Solar Expert Posts: 35 ✭✭
    Re: Grape Solar Question

    Thanks Bill:
    I did see those comments but they were several years old. I was wondering if any thing newer was out there and if anyone here had the brand installed.

    I am anticipating on buying one now and one a little bit down the road.
    Feeding them Parallel into a Morningstar 45 MPPT controller and a 12V bank.
    Two panels is just produce slightly over the 45 amp output (from the controller) and that's with everything at 100% which never happens. :cry:

    I priced other panels at other places and the cost per watt is less until you factor in the $300.00or over shipping cost, then it's all over. So that's why I'm looking at the Grape. Home Depot has free delivery on them.

    All the reviews on the internet seem favorable but I just want to make sure that I am not getting burned in the end.
    Every thing except my inverter is up scale-able to 24V on the battery side. When I do that I can move them over to Series connected to supply 60+V. All should be well.

    The guys here have been most helpful with how to do all the math for sizing up a system.

    Thanks for the Reply
    BobO.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Grape Solar Question

    BobO, sorry, I am not in the business, so I don't have any more information. Usually "bad reviews" spread like wild fire. Lack of bad reviews is probably a good thing.

    Home Depot, in general, seems to be a reasonable organization--So I don't have any concerns buying from them.

    Yea--These are large sheets of single weight glass panels. Shipping a pallet or a single panel is almost the same price for shipping and handling. Cost to your front door is critical in the pricing of your various options.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • 8n-bob
    8n-bob Solar Expert Posts: 35 ✭✭
    Re: Grape Solar Question

    Thanks for the Reply Bill.
    I never thought about the no news is good news logic.

    I'll probably order the panel and the morningstar mppt45 controller today and then I'll have them to put on line when I get the chance.

    Thanks again for all the help guys
    BobO.