Finally doing it, well, after the rains pass, anyway.

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  • ILFE
    Solar Fanatic
    • Sep 2011
    • 236

    Finally doing it, well, after the rains pass, anyway.

    I am finally getting to put into practice what I have wanted to do for a pretty long time. That is to finally install a solar array.

    Okay. Now that I have this time, and much needed information mostly taken from this very site, I have decided that I am going (initially) build either a 300 watts or a 405 watts solar array. I would use either 3 - 100 watts, or 3 - 135 watts PV panels, along with a MorningStar ProStar 30amp controller, and the (3 - 120 AH batteries and 1- 150 AH battery I purchased earlier this year. Yes, I have learned that it isn't a good idea to put batteries of different sizes, ratings, and ages together. I realize I should reconsider that part. But, I figured it probably wouldn't hurt to have them installed together for a short time, perhaps two months? By then I will be able to buy a complete set (4) of brand new batteries, each at 130 AH.)

    My reasoning for considering the 405 watts array now is, I have the money to go with the larger panels at the moment. So, I am considering doing that, as the panels will be the most difficult thing for me to install - having to climb, put them on the roof, drill holes and mount them in brackets, etc.) And, I can buy more batteries as money permits, in time.

    Any advice, regarding this install? I hope to be finished with it by the end of next week, depending on the weather.
    Paul
  • Naptown
    Solar Fanatic
    • Feb 2011
    • 6880

    #2
    You realize that controller is a PWM
    and you will be wasting a good bit of potential power.
    If you haven't bought anything yet consider going to an MPPT controller and 2 60 cell grid tie panels of 200 watts. May cost less and you will harvest more
    NABCEP certified Technical Sales Professional

    [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

    [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

    [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

    Comment

    • Sunking
      Solar Fanatic
      • Feb 2010
      • 23301

      #3
      Ditch the controller and get a MPPT controller, and wire the panels in series. I would also ditch the 3 battery panels and buy 2-200 watt Grid tied panels. If you do both of those things it will be less expensive and will give you a full 400 watts of charging power. If you use the 3-135 watt panels with a PWM controller you only get 260 watts of charging power and will cost more for less power.

      I would also ditch th e30 AH battery as it is of no real use and will do more harm than good.
      MSEE, PE

      Comment

      • ILFE
        Solar Fanatic
        • Sep 2011
        • 236

        #4
        First, thanks for replying.

        Yes, I know the controller is PWM.


        There are reasons for me doing this, in this - not-such-a-good-idea manner.

        1. I am limited in funds at the moment for this project, and will have to wait a couple of months for more expansion of the system.
        2. I want to move into this home as soon as I possibly can. The longer I delay, the longer it will take me to accomplish this and move on to other projects.
        3. While ordering parts from outside the country would definitely be cheaper, if I wait for more panels, it will delay me months longer.
        4. The parts I am looking at currently, are available within 30 kilometers of where the home is located. An MPPT controller is not available.

        Unfortunately, we do not have the convenience of many suppliers, cheaper priced parts, and many options to choose from here in Cambodia. Here, quite often, you have to make do with what you can get, unless you are very patient. I will, however, look around and see if I can find these parts locally.

        Sunking, I am not sure what you meant by the following quoted text. Were you saying I should remove the 1-150AH battery from the planned system?
        Originally posted by Sunking
        I would also ditch th e30 AH battery as it is of no real use and will do more harm than good.
        I have 3 batteries, currently, at 120AH. I have 1 battery, currently, at 150AH. I was going to put them together for a couple months until I could buy a complete set of brand new batteries for the array battery bank.
        Paul

        Comment

        • Sunking
          Solar Fanatic
          • Feb 2010
          • 23301

          #5
          Paul do some homework my friend. Battery panels are way more expensive than grid tied panels. Battery panels cost about twice as much as Grid Tied panels. Once you get above 200 watts panel power, MPPT systems are less expensive.

          Additionally with Grid Tied Panels you also save some big bucks on wiring and hardware. With 2 200 watt panels in series means smaller wire, less wire, and no need for fuses or breakers. With 2 - 200 watt Grid Tied panels with a 40 amp MPPT controller, assuming you are silly enough to use 12 volt battery (use 24 volts my friend, then all you need is 20 amp MPPT, but no growth at 400 watt input) will take a 600 watt PWM controller.

          You need to stop and rethink things right now before you make a huge mistake. You are making a huge mistake using PWM, battery panels, and 12 volt battery. You are throwing money away for no reason other than ignorance. Wise up now before it is too late. You will thank me later once you grasp what I am telling you.
          MSEE, PE

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