Jeffinpa: Large Off Grid system with Aquion Batteries, looking for feedback

Comments

  • Jeffinpa
    Jeffinpa Registered Users Posts: 4
    I'm rather a novice at off grid. I got into it in a similar way. I bought a farm and built a house on top of a hill on it. It was over $100k to run electric, so off grid was an easy decision. Our house uses LED for everything that lights and propane for most things that heat with 2 notable exceptions. A wood gasification boiler feeding (2) 400 gallon pressurized water tanks feed the radiant heating system. The hot tub runs electric although I ran pex there in case I want to run it off the boiler in the winter. We have a propane 15kW backup generator. 

    The electricity is produced by 17 kW of ground mounted panels. The brains are all Outback. The storage is Aquion. I started with 24 S30's. My (novice) theory was to go overboard on panels since they are the cheaper part and see what happens with batteries. The battery bank charges very quickly. I'm not sure that the batteries are going to last in the winter based on use this summer. I have the very heavy batteries on a pallet rack and figured I'd just max the rack out which is why I now am getting a total of 42 batteries. 

    The Aquion have a few disadvantages. They are not cheap. Depending on who is pricing and by what means and variables, they do well or poorly in life time costs. They are maintenance free and rather worry free. I had our local fire department over since it's not exactly their normal setup. They were rather pleased with the safety except that there is no way to shut the system off from the outside. 

    This past summer I figured I would exercise the system to find its limits. We have whole house AC and I ran that all day along with heating the hot tub. The system couldn't keep up with that and crapped out in the middle of the night. Looking at the graphs the system provides, it looks like the batteries did not hit their low point with SOC but ran low on voltage. Another problem was that the Outback equipment does not have a profile for Aquion. So it screams when the system hits 50% SOC. Aquion can go to zero. 

    Comments would be appreciated since as I said, I'm not really sure what I'm doing. 
    Off grid - 17 kW ground mounted panels, (42) Aquion S30 batteries
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Jeffinpa said:
    I'm rather a novice at off grid. I got into it in a similar way. I bought a farm and built a house on top of a hill on it. It was over $100k to run electric, so off grid was an easy decision. Our house uses LED for everything that lights and propane for most things that heat with 2 notable exceptions. A wood gasification boiler feeding (2) 400 gallon pressurized water tanks feed the radiant heating system. The hot tub runs electric although I ran pex there in case I want to run it off the boiler in the winter. We have a propane 15kW backup generator. 

    The electricity is produced by 17 kW of ground mounted panels. The brains are all Outback. The storage is Aquion. I started with 24 S30's. My (novice) theory was to go overboard on panels since they are the cheaper part and see what happens with batteries. The battery bank charges very quickly. I'm not sure that the batteries are going to last in the winter based on use this summer. I have the very heavy batteries on a pallet rack and figured I'd just max the rack out which is why I now am getting a total of 42 batteries. 

    The Aquion have a few disadvantages. They are not cheap. Depending on who is pricing and by what means and variables, they do well or poorly in life time costs. They are maintenance free and rather worry free. I had our local fire department over since it's not exactly their normal setup. They were rather pleased with the safety except that there is no way to shut the system off from the outside. 

    This past summer I figured I would exercise the system to find its limits. We have whole house AC and I ran that all day along with heating the hot tub. The system couldn't keep up with that and crapped out in the middle of the night. Looking at the graphs the system provides, it looks like the batteries did not hit their low point with SOC but ran low on voltage. Another problem was that the Outback equipment does not have a profile for Aquion. So it screams when the system hits 50% SOC. Aquion can go to zero. 

    Comments would be appreciated since as I said, I'm not really sure what I'm doing. 
    I suspect you hit the voltage disconnect point, due to voltage sag with such a high demand. I'm pretty sure this can be set in Outbacks profile, but unless that is a normal "over night load" you should probable leave it where it is...

    While the Depth of Discharge may not be adjustable, it too can be tampered with by adjusting the capacity settings, again this would require looking at the overall system. Although these can be taken down to zero and recover, I thought I had read that it was harmful to the battery...

    Bill will likely be along in a minute and split this off into a thread of it's own...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    Outback will be shipping "Skybox" in April but that won't help you now.
     To me, it seems a no brainer to use mini-split heat pumps and and figure another way to power your hot tub. 
    They both are discretionary loads so where is your winter concern? I do not get it?
    What is your number when conserving energy? Most of my users are 4 to 15KWH depending on bank size.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • Mangas
    Mangas Solar Expert Posts: 547 ✭✭✭✭
    What is your AC unit? 
    Ranch Off Grid System & Custom Home: 2 x pair stacked Schneider XW 5548+ Plus inverters (4), 2 x Schneider MPPT 80-600 Charge Controllers, 2 Xanbus AGS Generator Start and Air Extraction System Controllers, 64 Trojan L16 REB 6v 375 AH Flooded Cel Batteries w/Water Miser Caps, 44 x 185 Sharp Solar Panels, Cummins Onan RS20 KW Propane Water Cooled Genset, ICF Custom House Construction, all appliances, Central A/C, 2 x High Efficiency Variable Speed three ton Central A/C 220v compressors, 2 x Propane furnaces, 2 x Variable Speed Air Handlers, 2 x HD WiFi HVAC Zoned System Controllers