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DIY Solar panel setup on a budget

Discussion in 'Hobby Engineering' started by Mathuisella, Oct 15, 2013.

  1. Sunder

    Sunder Member

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    Err 25? No, that's not enough. 12v x 100Ah = 1200wh. But if you want them to last, you can only use 600wh.

    So you need roughly 50 if you want them to last.

    Like Recharge said. It's going to be more than you want to pay for. To put it into context, I use about half of what you're proposing to use - And my wife owns an electric car, and I own an electric motorcycle.

    1300w is not a lot of power. But 1300w over 24 hours, even with zero buffer (Someone else pointed out - rainy days?), is a huge amount of energy.
     
  2. aXis

    aXis Member

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    1300W constantly 24/7 is more than a typical household's total average consumption. People spend $20k - $40k to get an off grid system that big.

    If you have access to mains then skip the batteries and go for a 2kW -ish grid connect system for around $3k. It will only supply during the day but because there are less parts and you use nearly 100% of the power the payback will be shorter, maybe 5 years.
     
  3. Recharge

    Recharge Member

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    making power isn't expensive via solar (considering), storing it, forget it, it's insane.
    I agree, as big a system as you can both afford and that your state grid owner will allow you to put up (it varies area to area as the grid is a friken mess and one local grid can only handle so much solar input so it depends on how many already have solar in it and what it's wiggle room is)
    min 6KW if your roof is faced the right way, ~3-6 grand depending on who does it and what kind of quality you want.
    here in QLD, I'd always go with origin, as they're every unlikely to fold so you warranty will be good. (in fact, they transfered the warranty on my existing panels to me from the previous owner, which is amazing) and a top tier inverter, the best you can get, as it's got to last if you want your ROI to hold for ~4-5 years.

    solar is most worth it if you can use the power during the day to offset your normal usage, even the best feed in is shit and will take longer for ROI.
    we're home all the time so we use all out solar, I'd like more and plan to upgrade in the next 3 years before the home loan goes variable.
     
    Last edited: Jul 11, 2018
  4. aussie-revhead

    aussie-revhead Member

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    Yeah a plain solar might be the go for me, I'm also limited to 5kw solar but I don't think any will go back to the grid anyway.. i have mining gear running so cutting the peak consumption would be useful.

    I was hoping it might be feasible to run one miner off solar 24/7 but I was wanting wrong on that one.

    :)
     
    Last edited: Jul 11, 2018
  5. rainwulf

    rainwulf Member

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    Not even close. Power is cheap. CONSTANT power is ridiculously expensive.
     
  6. aussie-revhead

    aussie-revhead Member

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    I never realised it was that expensive .... Forget that ...

    :)
     
  7. aXis

    aXis Member

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    Might be an interesting option to start and stop the miner processes to match your excess power generation.
     
  8. aussie-revhead

    aussie-revhead Member

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    So only run it when it's sunny? That will cut it down to about $2 a day return (per miner) .... But yes it would not add to the electricity bill. I guess you could run heaps of them during daytime only so it's basically free.

    :)
     
    Last edited: Jul 11, 2018
  9. mtma

    mtma Member

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    Depends on how you calculate your hardware costs. If you've purchased hardware specifically to mine, then you are competing with others for the ROI so only running the hardware ~8-10 hours a day average over the course of a year is going to erode your earnings considerably, as the time before your hardware becomes market non-competitive remains the same regardless of whether you are 24/7 or not. The guys running 24/7 are going to be much further ahead even if they've paid for energy from the grid.
     
  10. vk2fro

    vk2fro Member

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    Decided that when I put the poles in I WONT be using quick set concrete as it is not as strong as regular mix. I can brace my poles to keep em vertical and set them in the concrete in the morning, and remove the braces the next morning in preperation to install the "head" that holds the solar racking. If I do it right, I can join the two pieces of racking and it will become a rather sound structure, supporting 8 panels :)

    I've been a bit quiet in this thread lately but I did buy some new solar toys with the new credit card, a 1.2kW Victron inverter and a 150/45 smart solar charge controller (I just don't trust the $230 cheapie off ebay). If anyone wants it, shoot me a pm. Be great for an experimental system, but no way am I putting 2kW of panels on it, and it has a little (aka noisy) fan. I want my energy "board" to be as silent as possible.

    So my next step is to pay off the card, then get the two heads that will support the racking on the tops of the poles, then racking, and put this whole shebang together, and finally toss the macgyvered UPS :)

    oh and find my raspberry pi and install Venus OS on it, which is victrons CCGX software for monitoring.
     
    Last edited: Aug 6, 2018
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  11. rainwulf

    rainwulf Member

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    Summer is on its way, and the winter solstice has passed, starting to get some light back onto my panels, and im going to get cracking back on this project.

    I'm going to continue on with the automatic load switching system. I want to get a 24 volt bank of LTOs into production and see how they behave.
     
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  12. rainwulf

    rainwulf Member

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    Guess what just arrived!!!

    [​IMG]
     
  13. Sunder

    Sunder Member

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    Very nice :) Have fun with them.
     
  14. rainwulf

    rainwulf Member

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    i have 20 of them to play with for a few weeks, so thats 80ah at 24 volts. Its not a huge amount, but should be enough to characterize them for the cycle use they will get in their final resting place, a large shed at samford. Boss is going to china soon to look at cheaper prices/better distribution channels. My aim is 400-600ah at 24 volts which will suit my house and my ability to recharge them.

    I also see the camping/RV market as being HUGE for these. Imagine a permanent battery installation? Never need to buy batteries again. damn.
     
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  15. MUTMAN

    MUTMAN Member

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    A slab of beers ?

    Epic cell, be carefull thats a reasonable amount if energy if it lets go all at once
     
  16. rainwulf

    rainwulf Member

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    That's one of the reasons i love these LTO cells. they are nearly as safe as an alkaline cell. They flew the batteries here on a plane heh.
     
  17. vk2fro

    vk2fro Member

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    Don't stick 6 of them together to power a car clock - cops might think its a bomb :)
     
  18. rainwulf

    rainwulf Member

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    Hahaha

    I am so psyched. 5 of these things basically simulate an AGM lead acid battery, so AGM profiles will mostly work on charger units. I am so damn excited. Today i pick up the hardware to make the 4 12 volt packs.
     
  19. rainwulf

    rainwulf Member

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    [​IMG]


    4 banks of 12 volts. Now to get terminations, and 3d print some battery holders so i can mount them safely.

    Then its battery management time, i have current sensors, and going to make ethernet monitored battery management modules. Im still researching balancing for these, since they are 2.3 volts, no normal BMS will balance them properly.
     
  20. Recharge

    Recharge Member

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    my fastidiousness is itching at the square positive tops not lining up with the busbars... something is wrong with me lol
    how heavy is that pack?
     

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