DIY Solar panel setup on a budget

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

  1. Adam 33

    Adam 33 Member

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    This is exactly something I'm after too..
     
  2. money_killer

    money_killer Member

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    Yes there is but it wouldn't be cost effective as a renter. U could make a portable setup but again it wouldn't be cost effective unless U have prolly 5k spare. But it wouldn't be grid connected, so U would have a battery charger charging the system on a voltage sensitive relay to keep it separate from the grid and running a inverter off a battery bank
     
  3. Sunder

    Sunder Member

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    Not easily or cheaply. You could run it off a small inverter on a small battery, with a charger that only turns on either when:

    1) it doesn't detect any voltage from the solar panels
    2) when the battery voltage falls below a certain amount.

    Simple set up, but not cheap. Acts as a kind of de facto UPS though, so if you were already thinking of getting one of those...
     
  4. Stanza

    Stanza Member

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    You got a digital power meter? Or an old spinner one?
     
  5. bonox

    bonox Member

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    search for "Plug in Grid connect solar inverter"
     
  6. bradleyk

    bradleyk Member

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    Last edited: Jan 6, 2021
  7. Sunder

    Sunder Member

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    If you find out, let me know. I looked at those a while back for my dad's holiday home, and figured they were too cheap for what they offered, so went a more expensive one. Might want one for myself just to run a few things off it and as a UPS. I have a big Lithium battery now I could use as the power source.
     
  8. nic55

    nic55 Member

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    Digital, there is actually a very old small solar system on the house already but I've never seen the inverter report more than 700w of generation.

    Pretty interesting, the description seems to only mention balancing battery charge so I wonder if it would backup the load from grid AC as well.
     
  9. nic55

    nic55 Member

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    I guess I could slap a grid tie inverter like this on to the same circuit the servers are on. https://www.ebay.com.au/itm/MPPT-10...-Sine-Wave-Inverter-230V-Output-/371278810524

    Downside being you can pickup 2kw worth of panels pretty cheap and wouldn't want to feed back a high load constantly over 50 year old wiring, there's a 15a socket nearby that isn't used which might ease that concern.

    Does your standard hard-wired sunnyboy/fronius etc work in the same way as these portable grid tie? Will it shut off when the grid goes down etc, could easily turn one in to a 'plug in grid tie' if that's the case as they're selling secondhand for peanuts too, again putting too much load back in to one circuit would be a concern.
     
  10. vk2fro

    vk2fro Member

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    Those MPP solar things can do what you want, sans backfeeding to the grid, which you really don't want to do unless its profesionally installed and signed off.

    Certain MPP solar's don't need a battery - you plug them in, stick some solar panels on them, and they switch over to mains when there isn't enough solar or at night.
     
    nic55 likes this.
  11. Recharge

    Recharge Member

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    while cleaning up and such in the garage, I came upon my pile of UPS's and decided I'll rewire my battery bank 1 to 24v and hook the best one up, it's 2000va which should manage a few things. just have to wait for restrictions to lift to go get some ring crimps and some decent sized cable to wire it up. 8x12v deep cycle, so make a 4 pairs of 24v
     
  12. th3_hawk

    th3_hawk Member

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    I was just updating my power data excel sheet and found some interesting data. The dip in October 2018 was due to the lag of solar being installed and the power company catching up with the meter.
    2019 saw an increase of about 20% to previous years thanks mostly to a new aquarium and my son getting more into PC gaming.

    The COVID factor:
    2020 looks to be following along the same curve... until march when we were all sent home, power usage has gone up an average of 25%, September was +51% over previous years!
    That's 2,101 extra kWh's in 2020!
    That's 40kWh / week
    Solar export is down an average of 17%
    Solar self-consumption is up by about 15%
    Total savings are down by about 12% as a percentage of total usage but up in raw dollars (since I spent considerably more over the course of the year).

    I wonder what the average power consumption per person is for an office building and how that compares to us all using power at home?

    upload_2021-1-11_12-35-16.png



    Of course this doesn't include my gas bill over winter which was on a lot more... but then it also doesn't account for the public transport I didn't pay for.
     
  13. cvidler

    cvidler Member

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    interesting thoughts.

    - I'd expect, aircon/heating to be much more efficient per-person in an office block than per individual at home
    - lighting probably less efficient, due to workplace standards for illumination, there's a lot more lights above me today in the office, than the one desklight and window I use at home. office has plenty of windows too. (both home and office are all LED lighting).
    - PC's would be same/same. I use the same laptop at home or work.
    - elevators/other building systems (security, parking lots etc. etc.)

    I'd say overall office space per person is using more power than per-person at home.
    #no_numbers_guestimate
     
  14. Recharge

    Recharge Member

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    has his own online shop.
    this is a sweet arse design.
     
  15. vk2fro

    vk2fro Member

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    I agree Recharge, that is a neat design. Especially the nickel strips acting as cell level fuses and the car blade fuses acting as pack level fuses.
     
  16. Phido

    Phido Member

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    That is pretty sweet.

    I have a huge sealed lead acid setup to go out to the farm (~20KWh). While they would offer a tremendous amount of storage, they don't like being hit often or hard (they are really backup batteries).
    I've been looking at some sort of low cost Lithium setup that I can use day to day. I can then limit the amount going into and out of the lead acid array and try to protect them. Keep them in say the 80-100% range.

    A lot of thought has gone into that..
     
  17. vk2fro

    vk2fro Member

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    I figured how I'm going to put my panels up using no racking and no drilling!

    I was watching youtube last night, and came across two guys pulling a MOTORCYCLE out of a canal with these super strong "fishing" magnets. They were something like 500kg of holding force. Put four or six of those on each panel and they arent going anywhere.

    I'm lucky to be sheltered on 3 sides from the wind, so its highly unlikely they'll break loose with 2000/3000kg of magnetism holding them down. The magnets have a screw in the middle to attach to a ring that normally has a rope attached for fishing stuff out of canals/rivers but I'd remove the ring and use suitable bolts and lock washers to mount them to the panel frames.

    Dumb idea?
     
  18. cvidler

    cvidler Member

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    such magnets will exceed the cost of your panels.
    (quick Google says they're ~$50 each)
     
  19. vk2fro

    vk2fro Member

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    Should have googled myself. Yep - for the cost of six magnets I can get enough racking etc for 6 panels. Magnets loose :p
     
  20. MUTMAN

    MUTMAN Member

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    if it were me, my thinking would be
    racks - known by insurance companies
    magnets - unknown by insurance companies
     

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