Off-Grid Automatic Generator Startup

LifeLong5050
LifeLong5050 Registered Users Posts: 6 ✭✭
YES, I inherited this system when I bought the property.  I have a Generac 8KW standby generator connected to the system and the only way to charge the battery bank is to manually start the generator.  My solar panels show voltage but no Amperage at all (replacing them with new ones soon).  Here's what I have:
1. 400W of panels
2. Generac 8KW generator with its panel connecting to a subpanel that connects to the Load Center to charge the batteries
3. TRACE DC Disconnect / Overcurrent Module
4. Xantrex Inverter DR 3624 (3600 W)
5. QO403L100S Load Center
6. Xantrex C40 (40A) Charge/Load Controller
7. TRACE DC Disconnect / Overcurrent Module
8. 4 S5500 Surrette Batteries (brand NEW)

TWO important items I need your help with PLEASE :):
1. How I can have the Generac automatically start when the batteries reach a certain point in voltage?  Am I missing a needed item?
2. Anybody can share with me any sort of schematic/diagram on how things should connect to each other?

I look forward to your feedback.

LongLife 

Comments

  • LifeLong5050
    LifeLong5050 Registered Users Posts: 6 ✭✭
    Sorry ALL, the panel on item 2 is actually an Automatic Transfer Switch and Emergency Load center
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    edited September 2016 #3
    Assuming this is an pure off grid system (no utility power at all)?

    Your first task it to make sure your batteries are charged correctly... More or less, you want to cycle them 50% to 80% state of charge (with the genset) and ideally get to >90% state of charge at least once per week. This last charging to >90% is going to be (usually) fuel inefficient (not much charging current, but ~4+ hours of running the genset to get the batteries full). You can save fuel/money if you run the "absorb" charging at the same time as you run other loads (washer, well pumping, shop, electric cooking appliances).

    And to do this, you need a good volt meter (suggest DC current clamp DMM like this inexpensive one from Sears) and a good hydrometer.

    Next--What are your expectations for this off grid power system? Are you living there full time off grid, or is this a 3 season use, and shut down during the winter? Are you concerned about fuel+genset costs? Where is the system installed (nearest major city)?

    In general, for an off grid solar system, we suggest 5% to 13% rate of charge to keep the battery bank happy and not need to run the genset every day (not even talking about loads yet)--And 10% or higher rate of charge for a full time off grid system. You have a pretty good size battery bank (24 volts @ 428 Amp*Hour). So--The solar array should be something like:
    • 29 volts charging * 428 AH battery * 1/0.77 panel+controller deratings * 0.05 rate of charge = 806 Watt array minimum
    • 29 volts charging * 428 AH battery * 1/0.77 panel+controller deratings * 0.10 rate of charge = 1,612 Watt array nominal
    • 29 volts charging * 428 AH battery * 1/0.77 panel+controller deratings * 0.13 rate of charge = 2,096 Watt array "cost effective" maximum
    And if you assume 2 days of stored energy (bad weather) and 50% maximum discharge (for longer life), your battery bank would be good for:
    • 24 volts * 428 AH * 0.85 AC inverter eff * 1/2 days storage * 0.50 maximum discharge = 2,183 Watt*Hours per day
    If you are up in the Ontario Canada region--You do not get much sun during the winter:
    http://solarelectricityhandbook.com/solar-irradiance.html

    Brampton
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 46° angle from vertical:
    (For best year-round performance)
    Jan Feb Mar Apr May Jun
    2.71
     
    3.50
     
    4.04
     
    4.50
     
    4.75
     
    5.12
     
    Jul Aug Sep Oct Nov Dec
    5.24
     
    4.98
     
    4.58
     
    3.68
     
    2.47
     
    2.24
     
    Toss the bottom three months (assume you must use genset, or system is not used in winter):
    • 1,612 Watt array * 0.52 off grid system eff * 3.5 hours a day (avg February) = 2,934 Watt*Hour per day (typical February day)
    Your present 400 Watt array is not much more than able to "float" the battery bank for storage.

    Anyway--My first guesses/suggestions.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • LifeLong5050
    LifeLong5050 Registered Users Posts: 6 ✭✭
    Bill,  I appreciate the feedback.  Yes i live in Coe Hill, Ontario Canada in a TOTAL off-grid setting as I have NO utility coming into the property and where the closest big city is 1.5 hours away.  YES it will be used in the Winter months - how much is the question as it depends on many factors but probably one weekend a month.  I am changing my panels soon as they have problems, charging with NO amperage coming to the batteries so I am depending on the Generac generator to charge them for now but I will NOT be going full array at this stage as I do not have a major load - just a fridge and few lights, chargers ... - just basic.  I am hoping to get direct answers to my questions as this my FIRST time on a forum :) - YAY.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    OK, the good news ....  good on ya for wanting to stay on solar and start small....  I think this is your battery http://rollsbattery.com/catalog/  428Ah...
     The bad news,.... you will need 42 Amps to get a good charge on those cells ~ 10% of the rated rate, at 24 volts, to get that with a PWM /c-40 charge controller you will need to be very choosy  as to exactly which panels you buy... Know that there is a difference , for example , between a TRUE 24 volt panel and a panel that has a VOC of 24 volts (open circuit voltage ie a shorted panels max) ... the latter will NOT CHARGE a 24 volt battery properly! the former will as it will have a VMP of  ~ 34V ( that is the continuous operating voltage)

    You probably will need an MPPT if you want to use the cheaper Grid-Tie type panels

    OH, and that fridge is not a small load, you have the ability to kill your batteries in a short time if not careful...
    I need to generate at least 1000W x 3 hrs for my place, lately I have been generating 2.5 to 4 Kwh a day due to clouds, rain etc... to run the fridge and a few lights...





     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Johann
    Johann Solar Expert Posts: 245 ✭✭✭
    Are you sure the panels are bad?
    It could be the charge controller, maybe a fuse or breaker.
    Did you disconnect the panels from the system and check the voltage and/or the amperage of the panels.
    Are the panels in the shade?
  • LifeLong5050
    LifeLong5050 Registered Users Posts: 6 ✭✭
    Thanks WB & Johann.  Panels were disconnected and tested and they are not in the shade.  TWO important items I need your help with PLEASE :
    1. How I can have the Generac automatically start when the batteries reach a certain point in voltage?  Am I missing a needed item?
    2. Anybody can share with me any sort of schematic/diagram on how things should connect to each other?
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Not all generators are capable of automatic starting, they need special choke module for cold starting

    Most off grid systems require a AGS (automatic generator start) module controlled by either the inverter or charge controller (brand specific)

    You are woefully short of PV for the size of your battery and loads,  May as well  buy a honda eu2000 and run your house off that.

    If you are going to replace solar panels (PV panels don't usually all break, I suspect you are not testing them correctly)  you may as well upgrade to about 1,000 watts of panel and a modern MPPT controller, 

    But if you don't get a good charger hooked up to those new batteries, you will kill them in a couple weeks.

    Look for the free (early edition) PDF of this book Solar Power Your Home for Dummies 2nd Ed (ISBN - 0470596783)
    I'll attach my schematic of a large off grid system, the names of things are different, generator is manual start. Auto Start just means
    some controller will decide to start the generator, unattended, and then things go downhill quickly,





    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • LifeLong5050
    LifeLong5050 Registered Users Posts: 6 ✭✭
    Thanks so much Mike.  I will compare and go from there.  BTW, I am having the Generac generator, manually, charge the batteries for now and I am hoping to have it automatically start when the charge is low on the batteries.  By looking at your schematic and browsing the web, I found different ways to connect the PV.  Should the PV be connected first to the Charge Controller (Your schematic calls it Main Disconnect Panel)?  Then I am assuming it goes from Charge Controller to DC Disconnect to Batteries to Inverter.  My apologies if wrong as I inherited this system when I purchased the property and it was not functional so I am trying to get it rolling, while learning the basics.  I have a Wind Turbine as well but I have not connected it to the Charge Controller yet.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    With more than 2 parallel strings of PV, a combiner with breakers or fuses is mandatory, (mine is at the pole for the array mount, and I run just 1 pair of wires back to the battery shed)  Inside the battery shed, the array power goes to a handy breaker before it enters the Charge controller.  This is to allow for ease of disconnecting the array when booting up the controller or updating the firmware or programming,  That breaker is not electrically needed, but the ease of using it, is better than walking 70 feet to flip 3 breakers in the combiner box
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • LifeLong5050
    LifeLong5050 Registered Users Posts: 6 ✭✭
    Mike thanks so much for the feedback.  To manually start my generator, I have to walk, at least for now 75 feet as it might go to 200 ft once my cabin is done, to start my generator in between wolves and black bears, NOT all the times though :), but I have proof of those guys - look at my profile PIC :).. If you would connect ALL the component I have listed below, how would you connect them:
    1. 400 W of panels (Will be changing soon to 1000 W as my use, I believe is VERY basic, just a Fridge, few lights, mobile phones charging, early morning coffee maker, early evening Tea Kettle, and a laptop from time to time).  With the cabin, I will have more lights but the rest is contained with NO electrical power need (Proposan Range, Propane Water Heater, Wood Stove).
    2. Generac 8KW generator with its AUTOMATIC TRANSFER SWITCH
    3. TRACE DC Disconnect / Overcurrent Module
    4. Xantrex Inverter DR 3624 (3600 W)
    5. QO403L100S Load Center
    6. Xantrex C40 (40A) Charge/Load Controller
    7. 4 S5500 Surrette Batteries (brand NEW)

    Thanks in advance Mike and I appreciate the guidance.

    LifeLong - AKA Richard
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    forget about the electric water heaters, use the stove.  While the inverter could serve the power, after a couple minutes, the battery voltage is likely to sag enough to shut down the inverter.   And I think the charger has adjustable output, set that for no more than 20% of the battery bank capacity, for fastest charging with out excess damage to the batteries - check the battery spec,
    I expect you will need to run the generator some (at lest weekly) to keep the batteries healthy until you get more PV installed
    I have 900' to walk to start my genset, bobcats, deer, bear and turkey are the main hurdles, but they hide in the rain.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Bee
    Bee Registered Users, Users Awaiting Email Confirmation Posts: 1
    I am wondering why you would choose to be so far in the woods when you are afraid of wolves and bears while walking 75'. Do you go from your car to your cabin and never venture out? Weird. lol