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OffGridInTheCity Build
#1
Living off-grid can bring to mind moving to the country...  but the 'country' has it challenges so why not transform my city home to be off-grid capable?    Water via rain-harvest (20,000g/year),  Serious Heat via wood stove (Dec/Jan/Feb).  Solar power for all the rest (18,000kwh/year). 

The Solar power design goal is to consume all that is produced.  Its an ongoing, off-grid, power production focus.  I'll use later posts to show details/pics.  If there's additional metrics you're interested in, let me know and I can add here or share.

Recap:
Year      Panels(285w/ea)        Produced      Bat-Cycles            18650-Bat-Bank-Config                         Avg-DOD     
2018      15->24 (6.9kw)         3,492 kwh         178             1 x 100-120p14s  (260ah@48v - 13kwh)        50%          
2019      24->45 (12.9kw)       8,932 kwh          332            3 x 100-120p14s  (780ah@48v - 40kwh)        32%

Currently (see next post for pics)....
  • Panels - 45*285w = 12.825kw.  Avg 22deg angle facing south (Southern Oregon)   
  • Charge Controllers - 3 x Midnite Classic 150s
  • Battery Bank - 780ah@48v   (aprox 5,000 18650 cells)
  • BMS - Batrium watchmon 4 
  • Inverter - AIMS 12,000watt  
  • ATS/MTS - Progressive + Go-Power / Reliance 
  • UPS  - APCs
Off-grid expansion  for 2020....
  • Battery Bank - 2 more 260ah@48v batteries.   
  • Power - 2nd AIMS 12,000w inverter 
  • Heat - Install Wood stove 
Wobbleszo and jdeadman like this post
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#2
========= Currently.... ==============

45 Panels in 2 arrays...
- Roof array is 24 SolarWorld 285w panels:


- Yard array is 21 Hyundai 285w panels (the 21st panel is off to the right):



MidniteClassic150s -  Each handles 3 x 5 (15) panels for total of 45 panels.  



Batteries/Batrium/AIMS-Inverter  - 3 rows of 100-120p14s at 260ah@48v each = 40kwh battery bank.   AIMS = 12,000w (240v@50a)



ATS+UPS (Go-Power + APCs) for 6,000va of power for computers, tv, coffee-pot (things that cannot be interrupted during PV/Grid daily switch-overs)
 
The APCs have 18650 7x7 battery packs with iSDT balancing/BMS from left-over cells Smile



ATS (Progressive) + MTS (Reliance) combo for main house panel.   


Solar/Battery workbench
Redpacket, Sleonard2649, cowpen And 4 others like this post
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#3
Great job... that's a lot of wall!
If you need to remove a pack that's misbehaving, do you just unbolt a pair and slide them out to get to the backside series connection?
Would love to see a diagram of your ATS / MTS setup.
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#4
(01-06-2020, 09:27 PM)cowpen Wrote: Great job... that's a lot of wall!
If you need to remove a pack that's misbehaving, do you just unbolt a pair and slide them out to get to the backside series connection?
Would love to see a diagram of your ATS / MTS setup.

>If you need to remove a pack
Yes, unbolt and slide out.   Since the + and - are on opposite ends, I have to slide them out in pairs as the back end (against the wall) are bolted as well as the front.

Here's a loose drawing on ATS / MTS.     The MTS is just hooked up as you would any MTS with generator input.   Then you feed the output of the ATS as input to the MTS.   The ATS has grid power in one side and inverter power in the generator side.    All  #6 awg,  240v/120v  (split phase US) power/wiring.  #6 AWG is standard for 50amps.

You might think there is some kind of risk of wire short thru shore power -> ATS -> MTS -> panel, but the MTS takes care of that. The Reliance Pro/Tran MTS has 2 modes per circuit depending on how you flip the switches on the top row....
* GEN mode - Power comes from the ATS instead of the panel. The ATS gets power either from Shore (240v@50a bottom right circuit breakers) or AIMS 12,000w Inverter (also 240v@50a). So shore and inverter inputs to ATS are matched - either one has same power. The ATS automatically takes Generator (Inverter) power when it senses it's present... so it automatically switches to the Inverter when the inverter is on/delivering power.
* LINE mode - e.g. MTS connects the panel circuit breakers -> Circuits. This bypasses the ATS as if it weren't there - ignores it.

This setup let's you choose how much load is on the ATS by switching between GEN and LINE - as you can have some circuits on GEN and some on LINE and re-arrange by simply flipping the switch on that circuit.

Here's a loose drawing


Here's a shot with some wiring exposed...
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#5
Thanks for the detail. Very ingenious setup.
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#6
Do you charge the Batterys with the chargers inside the UPSes? Lithium ion 7S7P? Or do you charge them external?
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#7
(01-13-2020, 11:44 AM)Maniac_Powerwall Wrote: Do you charge the Batterys with the chargers inside the UPSes? Lithium ion 7S7P? Or do you charge them external?
I create 7s7p battery packs out of 7s8p cell holders that have the same foot-print and Anderson plug as the original battery:


And plug them in the same as the the original battery - e.g. the APC does the charging.  You can see one charged up - the float is 27.7v (3.95v/cell) +/- a .1  depending on the particular APC.  
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#8
I'm always afraid of using charging made for lead batteries. Also I've seen many, like you doing it. Without any problems. Very cool. That's for sure.
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#9
(01-13-2020, 09:09 PM)Maniac_Powerwall Wrote: I'm always afraid of using charging made for lead batteries. Also I've seen many, like you doing it. Without any problems. Very cool. That's for sure.

No need to be afraid.  Lithium-ion does not care about float etc..  you simply need CC (constant current) up to float level where you go to CV (constant voltage - e.g. current goes lower and lower in a curve as the float voltage is reached).   This is standard for all batteries.

Lead chargers 'may' have a function called "Equalization" - which temporarily raises the voltage high - so just make sure that's turned off or set to 0 minutes.    Of course you must avoid chagrining when temp is too low (may be a bit different for lead compared to 18650) OR if the charge current exceeds the max charge of the cells.

The APCs only charge at 50-70watts which is only 400ma/cell in a 7s7p - which is quite modest.
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