small off grid solar options

niknik Registered Users Posts: 4
Hi folks,

so I'm looking at loading up a truck with some sort of kit and moving down to my little patch in Baja California Sur. Lots of sun, not a whole lot of cash. Sufficient setup would probably be about a 2.2kW by my estimations, but looks like I'll need to start with 1/4 of that, so my calculations are backwards and sideways and I'm trying to make sense of the variables, but looking at maybe

4 used Sunpower 230W panels in series (for total $300)
Epever 40A controller (Tracer 4215BN) ($215)
4 Weize SLA 100Ah 12v batteries in parallel pairs for 24v ($700)
and then it looks like the minimum viable 24v inverter would be a 2000W Aussy Giandel ($390)

How do those numbers and value priorities seem for starters? 

then there's the cabling (10 AWG from panels, about a 20' run) with a 15A breaker / fuse to controller
batteries and inverter (2 AWG short runs) with a 200A fuse
and maybe a combiner box of some sort but not sure if absolutely necessary or not (given it's only me that I can blow up and there's no code requirements) but I would like to be practical / semi-sensible.
Looking at a possible "ECO LLC 4 string combiner box with lightning arrester - Max.connection PV array---4; Max input current per array---10A; Total input current---40A" for $135.

So that configuration would run me around $1800 all told.

What are my main flaws in thinking, where am I better spending the money?

Thanks for your thoughts!!!


Comments

  • mike95490mike95490 Solar Expert Posts: 9,099 ✭✭✭✭✭
    Why do you choose SLA over flooded ?    I'd consider 4 golf cart batteries wired for 24V @200ah instead, and when you get things tuned enough so that they last 2 years, then swap to the SLA.    I prefer to direct you to SLA 6v 200ah golf cart batteries, all in series.  Putting SLA in parallel causes current hogging issues

    For a 24V system, having PV being more than 2x battery voltage (4 in series is way over 50V I think) and you loose efficiency in the downconversion to 24v battery .  If the PV requires a long cable run, or you are at the conduit stuff limit, then higher voltage is worth the tradeoff.
    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 ,

  • niknik Registered Users Posts: 4
    Hi mike. Thank you for your input. I chose SLA's perhaps partly out of naivety, but primarily for apparent cost effectiveness (400ah for $700) but I will have another look. (the link you posted did not resolve)

    I'm also making assumptions about 24v vs 12v series/parallel based on initial research. It may be smarter to start smaller though and work with 2 batteries / 2 panels, 20A controller, 12v inverter, but don't want to limit myself too much if I can get better gear for $1500-2000 max. 

    Cable runs will be short so don't need higher voltage for that reason - just juggling efficiencies all round with preliminary knowledge.

    If I get (4) 230W Sunpower panels rated at 48v - less a few volts as they are a few years old (pulled off of a commercial application, but appear to still have plenty life left) connected in parallel (I did not mean to state "series" initially) - then am I still heading in the right direction!?

    Thanks again!
  • littleharbor2littleharbor2 Solar Expert Posts: 1,572 ✭✭✭✭
    edited October 1 #4
    nik said:


    If I get (4) 230W Sunpower panels rated at 48v - less a few volts as they are a few years old (pulled off of a commercial application, but appear to still have plenty life left) connected in parallel (I did not mean to state "series" initially) - then am I still heading in the right direction!?

    Thanks again!
    What are the specs of the panels?  I doubt they are "rated" at 48 volts. They are likely 72 cell (24 volt, nominal) panels with a voc. in the high 40 volt range and a vmp. in the high 30's, maybe 41.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mike95490mike95490 Solar Expert Posts: 9,099 ✭✭✭✭✭
    Somehow the forum made my text into a link.  That was not intended.

    >  4 Weize SLA 100Ah 12v batteries in parallel pairs for 24v ($700)

      Wired 2S2P gives you a 200Ah 24V battery for your $700.  
      Batteries in series add their volts. Batteries in parallel add their amps

    That's an extremely good price you list for the batteries, Most AGM are in the $300 ballpark.   I figure the GC2 (generic Golf Cart flooded battery) runs about $100 and you can get 2-4 years from them   GC2 batteries are 6V, 200ah  (some are 195ah, some rated at 230ah) weight is the indicator of how much lead (capacity in ah) you are buying.


     

    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 ,

  • niknik Registered Users Posts: 4
    littleharbor2 said:

    What are the specs of the panels?  I doubt they are "rated" at 48 volts. They are likely 72 cell (24 volt, nominal) panels with a voc. in the high 40 volt range and a vmp. in the high 30's, maybe 41.


    Yes, 72 cell:

    Model: SUNPOWER SPR-230-WHT-U



    Wattage: 230
    Voltage:48.7

    Here's a pic of the equivalent 210W panel boiler plate. (Could get these instead as they are only $65 each!)


  • niknik Registered Users Posts: 4
    edited October 1 #7
    mike95490 said:

      Wired 2S2P gives you a 200Ah 24V battery for your $700.  
      Batteries in series add their volts. Batteries in parallel add their amps

    That's an extremely good price you list for the batteries, Most AGM are in the $300 ballpark.   I figure the GC2 (generic Golf Cart flooded battery) runs about $100 and you can get 2-4 years from them   GC2 batteries are 6V, 200ah  (some are 195ah, some rated at 230ah) weight is the indicator of how much lead (capacity in ah) you are buying.
    Thanks for clarifying  :)

    Not finding anything close in price for equivalent GC2s, but these are the SLAs in case curious 

    Still not entirely sure which way to go, the real issue being, once geared up for my location (driving from California down to Mexico), there will be limited options for new supplies for some time!
  • PhotowhitPhotowhit Solar Expert Posts: 5,426 ✭✭✭✭✭
    nik said:

    Not finding anything close in price for equivalent GC2s, but these are the SLAs in case curious 
    Not sure where you are looking, Sam's Club and Costco sell flooded lead acid 6 volt batteries around $90 + core charge (I think around $15 currently, they have been VERY lenient on what they accept as a core, I've used a tiny lawn tractor battery easy to ask around at lawnmower repair shops offer $5 for them, much more than they get for lead)

    If you aren't a club member there are some options too buy without becoming a member, find a friend who uses them, buy gift certificate. Ask for a 1 day pass to check them out, sometimes comes with a premium 5-10%.


    These will be 6volt, 200-210 amphours. 4 in series would give you a 24 volt 200-210 ah battery bank.

    I've heard they may not be as good as in the past, I have purchase Energizer labeled GC batteries at Sam's Club several times. Them last set for me lasted 5 years even though I tortured them over the summer running them down to <50% of capacity every evening running an air conditioner, the last 4 years of their life.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • mike95490mike95490 Solar Expert Posts: 9,099 ✭✭✭✭✭
    He's talking about sealed AGM batteries, not the ultra common flooded.
    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 ,

  • TrukinbearTrukinbear Registered Users Posts: 74 ✭✭
    Photowhit said:
    nik said:

    Not finding anything close in price for equivalent GC2s, but these are the SLAs in case curious 
    Not sure where you are looking, Sam's Club and Costco sell flooded lead acid 6 volt batteries around $90 + core charge (I think around $15 currently, they have been VERY lenient on what they accept as a core, I've used a tiny lawn tractor battery easy to ask around at lawnmower repair shops offer $5 for them, much more than they get for lead)



    The Interstate GC2's at Costco are rated 1.8 out of 5 by people who bought them - most give it a 1, probably isn't a zero option.

    I can't speak for batteries from Sam's Club - but I took all my 'deep cycle' batteries back to WalMart for refund as they were not deep cycle in any meaning of the words. Garbage. 

    Batteries are where you probably shouldn't try to cheap out - $850 worth of WalMart batteries didn't last 3 months trying to cycle them down to 60% every day. My Trojans were still ok when I replaced them at 2 years, and the guy that bought them is still happy with them 2 years later. 

    SMA Solar Sunny Island SI6048
    JA Solar 330W 'Cypress series' 72 cell panels (18)
    MidNite Solar Classic 250 MPPT charge controllers (2)
    MidNite Solar MODBUS/Canbus communications adaptor for Sunny Island
    MidNite Solar SMA-OG E-panel
    MidNite Solar WhizBang Jr current sensor
    MidNite Solar MNSPD300V surge protection device (3)
    MidNite Solar MNSHUNT 50mv/500A DC shunt
    MidNite Solar MNSOB3R-4P PV array shut off box
    MidNite Solar Birdhouse 1 RSS initiator
    MidNite Solar Battery disconnect module
    MidNite Solar Disconnect PSB
    Atkinson GSCM mini-i generator start module
    Cummins Onan Quiet Diesel QD-8000 8HDKAK diesel inverter generator
    Cummins Onan Quiet Diesel QD-3200 3.2HDZAA diesel cycloconverter generator
    24-125-11 Monterey Industrial 'Big Sur' 986Ah 48V battery
    285-gallon diesel fuel tank
    Off the grid on the PNW coast
  • PhotowhitPhotowhit Solar Expert Posts: 5,426 ✭✭✭✭✭
    I can't speak for batteries from Sam's Club - but I took all my 'deep cycle' batteries back to WalMart for refund as they were not deep cycle in any meaning of the words. Garbage. 
    As far as I know, Walmart doesn't sell true 'deep cycle' batteries. Maybe some 'Marine' batteries which are rarely deepcycle.
    Batteries are where you probably shouldn't try to cheap out - $850 worth of WalMart batteries didn't last 3 months trying to cycle them down to 60% every day. My Trojans were still ok when I replaced them at 2 years, and the guy that bought them is still happy with them 2 years later. 
    Sounds like a lot of batteries in parallel, never a good situation. I've not used the Costco batteries, I understand Costco is very good on returns, but I don't have one near me. The Energizer labeled GC batteries from Sam's had a better rep than the Duracell as I recall, and the Duracell have a 4.5 stars out of 5.

    As I stated above; I have purchase Energizer labeled GC batteries at Sam's Club several times. The last set for me lasted 5 years even though I tortured them over the summer running them down to <50% of capacity every evening running an air conditioner, the last 4 years of their life.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • PhotowhitPhotowhit Solar Expert Posts: 5,426 ✭✭✭✭✭
    mike95490 said:
    He's talking about sealed AGM batteries, not the ultra common flooded.
    He stated;
    nik said:
    Not finding anything close in price for equivalent GC2s,...

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • TrukinbearTrukinbear Registered Users Posts: 74 ✭✭
    edited October 4 #13
    Photowhit said:
     I've not used the Costco batteries, I understand Costco is very good on returns, but I don't have one near me. The Energizer labeled GC batteries from Sam's had a better rep than the Duracell as I recall, and the Duracell have a 4.5 stars out of 5.

    As I stated above; I have purchase Energizer labeled GC batteries at Sam's Club several times. The last set for me lasted 5 years even though I tortured them over the summer running them down to <50% of capacity every evening running an air conditioner, the last 4 years of their life.
    The WalMart batteries were bought out of expediency and desperation. You are correct that what they sell, despite the label is NOT deep cycle. I'm 80 miles from a Costco (and wasn't a member) and almost 200 miles from a Sams Club (and wasn't a member). The Trojans seemed to be a decent upgrade from the WalMart batteries, and I got them locally for not much more than that low rated battery I just saw listed at Costco. I had 32 of them in 4-12V banks (split with 2 per system) - I hated watering 96 cells, and all the interconnecting cabling and fasteners required maintenance also. Once I realized I wasn't just temporarily off the grid I ditched them for a real battery and ditched my hastily cobbled together system (twin systems). I'm glad you had great service from your GC batteries, but do note you are using a real battery now, vs a bank. 
    SMA Solar Sunny Island SI6048
    JA Solar 330W 'Cypress series' 72 cell panels (18)
    MidNite Solar Classic 250 MPPT charge controllers (2)
    MidNite Solar MODBUS/Canbus communications adaptor for Sunny Island
    MidNite Solar SMA-OG E-panel
    MidNite Solar WhizBang Jr current sensor
    MidNite Solar MNSPD300V surge protection device (3)
    MidNite Solar MNSHUNT 50mv/500A DC shunt
    MidNite Solar MNSOB3R-4P PV array shut off box
    MidNite Solar Birdhouse 1 RSS initiator
    MidNite Solar Battery disconnect module
    MidNite Solar Disconnect PSB
    Atkinson GSCM mini-i generator start module
    Cummins Onan Quiet Diesel QD-8000 8HDKAK diesel inverter generator
    Cummins Onan Quiet Diesel QD-3200 3.2HDZAA diesel cycloconverter generator
    24-125-11 Monterey Industrial 'Big Sur' 986Ah 48V battery
    285-gallon diesel fuel tank
    Off the grid on the PNW coast
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