Forum Discussion

BFL13's avatar
BFL13
Explorer II
Feb 07, 2014

Panels For Mena

Mena will be using PWM so Isc and panel cost is what counts. He was looking at two 150w panels with Isc of 8.95 and $165 each.

So that is lower Isc than usual for 150w (9.46a usual) but cost per Isc amp is $330/17.9 = 18.43 cents.

Compare with same brand's 120w panels at 7.5a and $132. Get three panels for $396/22.5 = 17.6 cents

Now look at the Evergreen 120w at 7.68a and $114 Get three for
$342/23a = 14.9 cents

http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Panels/c1_269/p2833/Evergreen-EC120-120-Watt-12-Volt-Solar-Panel/product_info.html

So compared with the two 150s, for another $12 he gets 5 more amps. (5 amps is normal Isc for an 80w panel BTW)

Also the frames on those 120s are 1.4" instead of 1" so they should be stronger for mounting.

The only thing is roof real estate open spaces for what will fit where and if mena can do three panels.

Any more ways to spend mena's money for him? (He already bought the 45a PWM controller so we have to work with that.)
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Feb 07, 2014
    I want solarvoltaic astroturf...

    Slip a roll off the roof, unfurl it. Instant 100 amps minus the shading of chairs and people stumbling across it. Got to be resistant to martini spills, wandering burros walking across it and be uglier than sin so no one steals it.

    Ten cents a watt otter do it.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Feb 07, 2014
    Hi mena,

    You are "locked in" to low voltage panels--they cost more per watt.

    $136.99 is not $150 and it includes shipping.

    mena661 wrote:
    Those Evergreens look good but they're 62.5 inches long. I have 120" x 48" to play with. The 150W are 58" long so I could mount two lengthwise. Those Renogy's look like I could put 4 in that space. $150 is a pricey for 100W though. Thanks for the thread BFL.

    PT, Tristar 45A PWM.

    Wish I had some cardboard. Need to look around the house tomorrow and see what I can use.
  • landyacht318's avatar
    landyacht318
    Explorer
    Feb 07, 2014
    I'd shoehorn in as much wattage as you can fit in the space available and not worry about price as much.

    You'll never meet the minimum bulk current requirements for your large battery bank, but there is a lot to be said for offsetting one's daily usage by some factor, So I'd aim for that.
  • mena661's avatar
    mena661
    Explorer
    Feb 07, 2014
    Those Evergreens look good but they're 62.5 inches long. I have 120" x 48" to play with. The 150W are 58" long so I could mount two lengthwise. Those Renogy's look like I could put 4 in that space. $150 is a pricey for 100W though. Thanks for the thread BFL.

    PT, Tristar 45A PWM.

    Wish I had some cardboard. Need to look around the house tomorrow and see what I can use.

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