Mountain cabin off-grid

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Comments

  • cow_rancher
    cow_rancher Solar Expert Posts: 117 ✭✭✭✭
    I think you made the best choice based on your situation, myself I'm waiting for the Krypton-Iron batteries to come down in price before I make the plunge to an off-grid solution.

    Rancher
  • Wbuffetjr1
    Wbuffetjr1 Registered Users Posts: 92 ✭✭
    I love the install Horsefly! It looks great! So clean! 
  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
    I love the install Horsefly! It looks great! So clean! 
    Thanks Chad! I still wish you could have seen it in person. Maybe next time. Yours sure looked like it was going to be sweet, so now that it is working, I will assume it is!   :)
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    Horsefly said:
    It's been a while since I posted about my project. Now that it is up and running, I thought I should post a follow-up. Here's the electronics, in the basement of our cabin:

    And here's the PV array ground mount:

    The first day we hooked it up the batteries (which we had been using prior to the PV hookup with periodic generator charging) didn't get to float until after noon. For the next several days until I left the cabin, the wife and I did what we could to challenge the system. We took showers at night (causing the well pump to run), warmed dinner in the microwave, she used a curing iron, and we enjoyed lights and cell phone charging, and laptop usage at will. Still, the system returned to float by 11:00am pretty much every day for the 3 days we were there. Oh, and it was raining off and on for two of those days!

    I owe a TON of thanks to the people on this forum. You guys are kind, helpful, and smart. Thank you so much for educating me over the past 8 months. We're very pleased (so far) with what we ended up with. 

    EDIT - Credit where credit is due: The major electronics (inverter, charge controller, and Midnite E-Panel) and lots of the little things (battery cables, etc) were purchased from NAWS, the forum sponsor. Great prices and great support to my questions. The PV panels and some of the other stuff I found here in Colorado so I could avoid freight costs.
    Wow...........I am simply amazed! Congrats! It's as if an EE built it or something!

    I'd say the panel configuration is ~99% safe. Looks like ~45%? Perfect I think.

    Wind speed does increase significantly as one gets away from the ground. This is why wind generators tend to sit so high. The threat is winds from the north and those are the strongest winds, by far, as a rule. Perhaps a cable going to the closest aspen tree?

    I wouldn't mention wind threat but last December the wind came out of the north at over 100mph. Even breaking the 1/4" bolt that held a small security camera. Lots of other damage of course. C. Springs also realized wind speeds over 100mph. Perhaps you are in a sedate wind zone as you alluded to...

    I frequently get trojan agents while writing around here. Odd.

    Solray would have done 48 volts. Gee whiz.

    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
    Thanks @softdown.  It's all still working great. I may have oversized everything, because we can't seem to get the batteries below about 70% SoC.  We've actually tried a couple of times, taking showers after the sun went down, using the microwave more than we really needed to, etc. It still only got down to about 75% or so, and was back at float before 10:30am the next day. I guess that's a good thing.

    The panels are at 40 degrees. My sister and her husband are convinced that any snow accumulation will only be for a few days. Since no one is using any power during the winter, my AGM batteries should be fine even if they are covered for a week or more.

    There are some aspen trees to the north of the ground mount, so maybe that will cut the wind a bit. The wind is about the only thing I have left to worry about, but even that doesn't worry me too much.
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    At what point does your CC realize HyperVOC? I'm guessing ~150 volts. Memories are rusty...

    Hitting 107 seems safe enough. I do remember an Outback employee telling me not to serial three of my panels due to HyperVOC. I get up to 80 volts with frequency. 120 with three panels would make HyperVOC theoretically possible though I probably could have gotten away with it. Until the day that I didn't. It was a close call.

    I think charge controllers are supposed to shut down when the voltage gets too high. Maybe 140 for my Outback MX80? The theory is that the highest voltage may come before the charge controller wakes up and thus lowers the voltage.

    It all sounded theoretical and scary at the same time.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    I think winter *may* bring the strongest winds. You lose the leaves but the tree is also less likely to buckle I would think. I'm thinking a 1/4" wire rope....would make the perfect clothes line as well. Perhaps the birds will sit on that instead of the panels. Nah.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
    edited August 2017 #159
    softdown said:
    At what point does your CC realize HyperVOC? I'm guessing ~150 volts. Memories are rusty...

    Hitting 107 seems safe enough. I do remember an Outback employee telling me not to serial three of my panels due to HyperVOC. I get up to 80 volts with frequency. 120 with three panels would make HyperVOC theoretically possible though I probably could have gotten away with it. Until the day that I didn't. It was a close call.

    I think charge controllers are supposed to shut down when the voltage gets too high. Maybe 140 for my Outback MX80? The theory is that the highest voltage may come before the charge controller wakes up and thus lowers the voltage.

    It all sounded theoretical and scary at the same time.
    Yeah, my CC shuts down at 140V, and would be damaged by 150V or more.  I did the math applying the Voc Temperature Coefficient from my panels, and the Voc of 3 panels in series would reach 140V at -46 deg F, so I feel pretty safe.  The lowest temperature ever recorded at Telluride (which is colder than at our place) is -34.
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    Sometimes this is the coldest spot in the continental US: http://denver.cbslocal.com/2013/01/04/with-temps-30-and-below-alamosa-is-coldest/

    I have seen -30F a few times. A chilling experience. Sometimes I wonder what I was doing when I built here. A lot of pros and cons. Things were generally acceptable until the county decided that my pole barn is actually a castle for tax purposes. Some bad apples in the neighborhood too. Need three guard dogs, security system, and fence repairs where they crawl over and in between.

    You got lucky.

    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries