Off grid inverters

sridharTS
sridharTS Registered Users Posts: 33
I planned for 10 kw inverter input dc current is 48vdc is there 10kw inverter for off grid system is there or we want to combine by buying 3 x 3kw inverter and 1 kw inverter

Comments

  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    What in the world do you need 10kw of inverters for?  Welding?  I have 4kw and have only ever seen that level of output once in 10 years.

    Ralph
  • sridharTS
    sridharTS Registered Users Posts: 33
    To run the school i needed
  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Victron Energy have 5kVA/120V and 10kVA/230V inverter/chargers. Up to ten of them can be connected in parallel for increased output:
    http://http//www.victronenergy.com/inverters-chargers/quattro#datasheet
  • sridharTS
    sridharTS Registered Users Posts: 33
    how this inverter works. it takes current  from battery and sent to the load. any other function it does

  • sridharTS
    sridharTS Registered Users Posts: 33
    DIfference between string inverters vs off grid inverters

  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    sridharTS said:
    DIfference between string inverters vs off grid inverters

    There are two (and one half) basic kinds of inverter:
    1. Grid tied: These will ONLY work when connected to a stable grid voltage from a utility. They provide power to your local loads to supplement power from the grid or push extra power you are not using at the moment back into the grid. They can either be "string inverters" where you have a series string of many panels connected to a single inverter OR microinverters where there is on inverter for each panel and they interconnect on the AC side.
    2. Off grid inverters. These require batteries and will produce power completely on their own, with no grid connection. If you have grid available you need a switch to connect your loads either to the grid or to the off-grid inverter.
    2.5. Hybrid inverters. These have batteries and a grid input and combine the ability to generate power on their own when the grid is down or to work together with the grid to power your loads whenever the grid is up. They have an internal transfer switch to disconnect themselves and your load from the grid whenever the grid goes down.
    SMA SB 3000, old BP panels.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    inetdog said:
    sridharTS said:
    DIfference between string inverters vs off grid inverters

    There are two (and one half) basic kinds of inverter:
    1. Grid tied: These will ONLY work when connected to a stable grid voltage from a utility. They provide power to your local loads to supplement power from the grid or push extra power you are not using at the moment back into the grid. They can either be "string inverters" where you have a series string of many panels connected to a single inverter OR microinverters where there is on inverter for each panel and they interconnect on the AC side.
    2. Off grid inverters. These require batteries and will produce power completely on their own, with no grid connection. If you have grid available you need a switch to connect your loads either to the grid or to the off-grid inverter.
    2.5. Hybrid inverters. These have batteries and a grid input and combine the ability to generate power on their own when the grid is down or to work together with the grid to power your loads whenever the grid is up. They have an internal transfer switch to disconnect themselves and your load from the grid whenever the grid goes down.
    PS: You can only parallel off grid inverters of the same manufacturer that have been designed for "tandem" or "stacked"  operation.
    Two or more grid tie inverters can be put in parallel because they all synchronize to the power grid.
    SMA SB 3000, old BP panels.
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    (3) Outback VFX3648 inverters will give you 10.8kw continuous. And you can have up to 10 total to produce almost any kind of voltage, even 3-phase.

    But your bigger problem is that if you think you really need 10kw of inverters, you are going to need a HUGE/Expensive battery bank.
    I'd focus more on energy conservation first. I can't imagine what you would be running that would need that kind of power. 

    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Mangas
    Mangas Solar Expert Posts: 547 ✭✭✭✭

    I am running off grid, two stacked pairs of XW 5548 inverters (4 total) fed by 64 Trojan L16 REBs' (32 each bank) which power two high efficiency 3 ton air conditioners and a boat load of appliances.

    The key consideration to sizing a system after judicious conservation is not only the loads but the efficiency of the appliances run by the system.  During the past two years my experience has been HVAC and appliance manufacturer power consumption efficiencies have been improved very substantially in the U.S. 

    Also, building construction type is a major factor too.

    To illustrate the importance of efficiencies, my original rule of thumb 10 years ago was to size and build a system (after conservation calcs) to deliver about 20% system capacity headroom.  Within the last two years, replacing existing the HVAC system and appliances with high efficiency units increased system capacities probably 15% more.

    As mentioned here, larger off grid systems require a sizeable recurring battery bank investment every 7-8 years if going a flooded cel solution.

    Happy with mine.










    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
  • Surfpath
    Surfpath Solar Expert Posts: 463 ✭✭✭
    Hi Mangas,
    Don't mean to get off topic, but (quickly) how are your Trojan RE-B's going?  I'm almost 4 years into mine (no probs), but I think you are ahead of me timeline wise.  You have 64 so your experience (especially with running such a large system) is valuable.
    -SP
    Outback Flexpower 1 (FM80, VFX3048E-230v, Mate, FlexNetDC) 2,730watts of "Grid-type" PV, 370 AmpHrs Trojan RE-B's, Honda 2000 watt genny, 100% off grid.
  • Mangas
    Mangas Solar Expert Posts: 547 ✭✭✭✭

    They are 5 years old.  The newer REB paste formula is better than my older L16s (40% or so less water consumption).

    Trojan makes great flooded cel batteries and these are again holding up very well so far. 

    Plan to replace them in 2 1/5 years if all goes well.




    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
  • sridharTS
    sridharTS Registered Users Posts: 33
    Hi guys help me in choosing the inverter.
    I am get confused with exsisting all types of inverters. 
    On which situation these following  inverters are used
    1. string inverters with MPPT tracking.
    2.Grid tied inverter.
    3.Grid tied inverter with recharging the battery.
    4.Inverter/charger.

    Above four types we need grid connection?

    5.Off grid inverter. 
  • sridharTS
    sridharTS Registered Users Posts: 33
    How you will combine 2 pairs of inverters. They should be in phase?
    How will you combine the 2 Scheinder Charger controllers
  • Mangas
    Mangas Solar Expert Posts: 547 ✭✭✭✭
    edited November 2015 #15

    Moderator please delete this double post.

    Thanks

    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
  • sridharTS
    sridharTS Registered Users Posts: 33
    I can"t understand