Off the Grid setup

maxxmaxx Registered Users Posts: 5 ✭✭
Hey guys I'm new to this I want to set up an off the grid solar panel system...
I have access to 13 375 w 7 amp panels..... mono...
 question is how to set this up..???... I am looking to get close to 4500 watt. 220 v Peak delivery to the house
If you could take it from here I will follow your instructions

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,639 admin
    Welcome to the forum Maxx,

    A few questions... Is this going to be a "Grid Tied" solar power system (solar panels => GT INverter => Home power panel)? This type of system only works when there is utility power... If the utility power fails (weather, car knocks down power pole, etc.), there is no solar power (there are a few GT type systems out there than can supply ~1,500 Watts to an AC outlet--In the middle of a sunny day.

    And if you are looking for power GT Solar--There are "central inverters" (one or several) larger inverters mounted on the wall of the home... Or there are "micro inverters"--Basically one inverter per solar panel that then connect to 240 VAC power line from main panel to your roof.

    Each has its advantages and disadvantages.

    For GT Solar--Generally you need building permit (with Engineering Racking drawings and Electrical drawings) from your local building department. And you need approval from the local utility and need to sign up for a net metering plan. There are some utilities, and even some states where GT Solar/Net Metering is either not allowed, or the rate plans have almost no economic savings.

    Or, are you looking for a full Off Grid Solar power system (battery bank+solar charger+AC inverter, etc.)? This will supply power to your home without utility connection. There are "variations" in systems... There are Hybrid AC inverters that does both OG and GT connections (or use Hybrid AC inverter--They work for both OG and GT/Hybrid)...

    For off grid systems, depending on where it is installed, you may or may not have local building permit requirements.

    Lots of other questions too... Such as will the array be installed on your roof or on the ground? Will the array be in full sun from, at least, 9am to 3pm or more? Solar PV panels simply do not collect any "useful" energy if shaded (even a "little shading" can easily cut the array output by 1/2.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 5,822 ✭✭✭✭✭
    maxx said:
    Hey guys I'm new to this I want to set up an off the grid solar panel system...
    I have access to 13 375 w 7 amp panels..... mono...
     question is how to set this up..???... I am looking to get close to 4500 watt. 220 v Peak delivery to the house
    If you could take it from here I will follow your instructions
    So much more info needed.

    You say you want to get close to 4500 watts at 220v peak delivered to the house.

    Is the 220v AC or DC?
    You have 13 x 375 watt panels so an array of (13x375=) 4875 watts, so usually it won't deliver more than 75-80% of that or roughly 3656 watts. Panls are rated at Standard Test Conditions(STC), but produce under Normal Operating Cell Temperature about 75% of that. Typically you will have 2 -3 hours average in winter, less in some areas, to 5-7 hours in summer.

    Really to build a system to meet your needs you must start by knowing your needs. Do you know how many kWhs you use each month/day? And where you live?

    FWIW - 13 is just an awful number of panels, usually 53 volt vmp(?) 7 amp isp(?) panels can only be in strings of 2 for common MPPT solar panels, and strings of 3 or 4 with high voltage charge controllers.
    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.
  • Marc KurthMarc Kurth Solar Expert Posts: 953 ✭✭✭✭
    edited April 9 #4
    I would strongly suggest spending some serious reading time on the subject. This forum is the perfect place to start.


    I always have more questions than answers. That's the nature of life.
  • maxxmaxx Registered Users Posts: 5 ✭✭
    Thank you for your response...
     this will be a total off grid solar system I intend to put it on a roof of a 950 square foot home which has plenty of Sun and the roof is perfectly angled for the Sun during the day ....
    I have been reading up on the all different type of inverters I found a solar panel inverter with charging system built in it produces 4000 watts of power and chargers at 40 amps and puts out 220 volts which is good for me so when I build the electrical panel like an alternate the heavy loads from side to side .

    I have in my possession many I new flooded acid batteries which I intend to use for a year or so but I would like to switch to AGM.... as I mentioned before I have new model panels which produce 375 watts I have 14 of them... what I'm trying to figure out its how to configure the wiring for the panels.... the panels have a voltage of 36 volts at/ 7.0 amp.... should I wire that in series or parallel.... to produce the voltage and the amps needed for the prospective solar controller and inverter ....if you could guide me through that ......I would appreciate it.....thanks
  • BB.BB. Super Moderators, Administrators Posts: 32,639 admin
    Can you give us a link to the "all in one" inverter-charger unit? And (roughly) where will the system be installed...

    Will this be in Europe/elsewhere using a 230 VAC @ 50 Hz unit? No need for 120 VAC (or 120/240 VAC @ 60 Hz common to North America)?

    If this is out on open lands (vs suburbs or city)--Would you be able to do the racking on the ground? Doing solar racking on a roof can have issues (leaking roof, flashing, needing to go on roof for installation and servicing, any animals that may like to live under the panels and chew the wiring, etc.)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Wheelman55Wheelman55 Registered Users Posts: 176 ✭✭✭
    You need to supply the team here with model numbers for panels and electronic gear as well as all of the specs. 

    For instance, solar modules (panels) have two different specs for voltage (VMP and VOC) and two different specs for current/amps (IMP and ISC). 

    The electronic gear will have specs for output and specs for input.  The input spec helps determine how many modules/panels your gear can support in series. 

    Best of luck with your journey. 
    Building Off-Grid in Terlingua, TX
    14 CS 370 watt modules. HZLA horizontal tracker. Schneider: XW6048, Mini PDP, MPPT 80-600, SCP. 3 - Discover AES 42-48-6650 48 volt 130ah LiFePO4 batteries
  • mike95490mike95490 Solar Expert Posts: 9,581 ✭✭✭✭✭
    220V is often single phase, 50 hz european
    240V is often split phase, 60 hz north america

    In northern california, I get by with a 5,000w PV array and a 48V split phase inverter, runs
    a standard house and shop, 3 fridges, microwave, water plant and a bunch of phones and laptops at about
    10kwh daily

    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 ,

  • maxxmaxx Registered Users Posts: 5 ✭✭
    Okay thanks for your feedback I will attempt to answer those questions in order it was received they system will be installed on the roof /a house on 66 Acres in Georgia just north of Tallahassee Florida... if the pictures have come through it will say I have a choice of a 24 volt setup for 48 V.  Setup ...
    my panels ../Vsun 370 W panels... under normal operating temperatures.....
     you will see..P Max Watt.. 277..3
                           Voc. Volt.......44.3
                            Isc.  Amp ......8.2
    Now to get back to the solar controller charger/ inverter and one unit ...
    I have the two choices... 24 volt or 48 volt I am thinking maybe go with the 24 V & to my knowledge I would hook the panels up in parallel
     I also have other choices of a solar controller and on a separate inverter...also
    As Mike ...you stated that you could run a house on 5,000 w...
    All I'm looking for is is that or less I have a refrigerator a few fans TV everything else will be propane Heat /hot water/range.. the water will be supplied my an alternative source

  • mike95490mike95490 Solar Expert Posts: 9,581 ✭✭✭✭✭
    Go with 48V, batteries are easier to move.
    8 golf cart batteries will give you a 9,600 watt hour bank, of which 4,800 wh are available for overnight. 
       ( duh, that's not going to be enough if you are going to consume 5kwh overnight )

    When you have a better handle on your loads, then you create a battery bank.  Then you get the solar to recharge it.
    And a generator for when the sun is absent for 3 or 4 days


    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 ,

  • maxxmaxx Registered Users Posts: 5 ✭✭
    Great that was the advice I was looking for thank you very much
         did you get a chance to look at the inverter controllers I pictured in the earlier post which one would you go with or ....what would you buy for your charge controller and inverter... and last question is how I should wire the panels I'm guessing divide them in half and run them to a junction box to create 48 bolts at the junction box then run the 48 volts to the charge controller does that sound right
  • PhotowhitPhotowhit Solar Expert Posts: 5,822 ✭✭✭✭✭
    maxx said:
    Okay thanks for your feedback I will attempt to answer those questions in order it was received they system will be installed on the roof /a house on 66 Acres in Georgia just north of Tallahassee Florida... if the pictures have come through it will say I have a choice of a 24 volt setup for 48 V.  Setup ...
    my panels ../Vsun 370 W panels... under normal operating temperatures.....
     you will see..P Max Watt.. 277..3
                           Voc. Volt.......44.3
                            Isc.  Amp ......8.2
    Now to get back to the solar controller charger/ inverter and one unit ...
    I have the two choices... 24 volt or 48 volt I am thinking maybe go with the 24 V & to my knowledge I would hook the panels up in parallel
     I also have other choices of a solar controller and on a separate inverter...also
    As Mike ...you stated that you could run a house on 5,000 w...
    All I'm looking for is is that or less I have a refrigerator a few fans TV everything else will be propane Heat /hot water/range.. the water will be supplied my an alternative source

    Your inverter charger will give you parameters on what it's acceptable input voltage is.

    Looks like 120-450 volts with a hard limit to avoid damage at 500 volts, The 500 volts would be max VOC, at your coldest temps, around 0-10 degrees in Tallahassee, perhaps a bit cooler in south Georgia. It has a max output of 60 amps for solar changing, this is an Output current, so around a 5000 watt array producing around 3800 watts would create a max 3800/24= 158 amps or at 48 volts 3800/48=79amps. This is fine if the inverter charger can handle being over paneled, though at 24 volts it's pretty wasteful.

    Looks like the output AC voltage is only described as 230 volts, I would assume a European design inverter. A US designed inverter would say something like 240 volt split phase, so you could have 120 volt outlets NOT available on a 230 volt European style inverter.

    I'd suggest looking at Midnite's DIY inverters, they are a reputable company and these are similar designs.

    I use to live in Tallahassee, bought my first solar panel from Al at Simpler Solar Systems in the early 90's. Might walk in with your info and pay for some time to help you understand what you are looking at...

    I would suggest NOT buyng anything until you have a better understanding of Solar equipment and it's uses.
    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.
  • Wheelman55Wheelman55 Registered Users Posts: 176 ✭✭✭
    maxx said:
    ... and last question is how I should wire the panels I'm guessing divide them in half and run them to a junction box to create 48 bolts at the junction box then run the 48 volts to the charge controller does that sound right
    If you divide your 14 panels into two strings, that is called 2P7S. 

    For each string of 7 panels the VOC is additive, meaning 44.3 x 7 = 310 volts per string. Then you add a percentage for cold weather. I’m not sure what the correct % to add is, so call it 5% for a total of approximately 325 volts per string. 

    When you parallel strings together and combine them, the ISC Amps add together and the voltage stays the same. 

    In your case 325 volts will be pushing 16.4 amps. 2P7S. 

    There are some important things that you are missing, like a DC disconnect at the combiner box, grounding, lightning, fusing, etc. . 

    On another topic, I’m guessing that you might want air conditioning. 5,000 watts plus will get you that. 

    Good luck!

    Building Off-Grid in Terlingua, TX
    14 CS 370 watt modules. HZLA horizontal tracker. Schneider: XW6048, Mini PDP, MPPT 80-600, SCP. 3 - Discover AES 42-48-6650 48 volt 130ah LiFePO4 batteries
  • maxxmaxx Registered Users Posts: 5 ✭✭
    Thank you both for responding I am beginning to understand this and a little better and yes you are correct I will not be buying anything until I have a full comprehension of what I need now I will do more research and most likely I will have questions for you again ....thank you very much for your time
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