Solar compressor

jgotthold
jgotthold Registered Users Posts: 1
We want to run a compressor directly from solar which supplies 48 Volts at 50 amps DC (2400 watts). The compressor requires 220 Volts at 9 amps (2000 watts) AC..
Most inverters require a battery bank to function, but this is not practical as the system needs to be light weight for portability.
What type of switcher inverter can you recommend to meet this power requirement?

jgotthold

Comments

  • Solray
    Solray Registered Users Posts: 246 ✭✭✭
    10 240 watt panels are not going to be portable.
    A 2000 watt inverter is not going to be lightweight.
    Never mind the voltage losses and the actual watts produced by the panels will be about 75% of the rated output.
    The short answer is it isn't going to work as you have it laid out.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Portable solar, without batteries powering a 2-3hp compressor is a tall order, replace the electric motor with a gasoline engine, would be way cheaper, and call it a day. My opinions, others may differ.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    The only two methods that I can think of... One is to use a "universal" (brush type) DC motor. Brush motors have (relatively) short brush lives (roughly 6 months in full time use). So you would end up with extra maintenance. Given that you may run 4-6 hours per day with solar, you may get a few years between brush service.

    The other is to use a three phase motor (permanent magnet type would be more efficient) with a VFD (variable frequency drive) that is setup to run with solar power input.

    The variable frequency drive is in common usage these days for water pumping and could be used with an air compressor--But compressors tend to have very high starting torque--And solar panels are not able to supply surge current, and morning/evening time, not much light means that you may only be run the compressor during the middle of the day (a few hours).

    You did not say what type of air you needed (high pressure or low pressure)--Low pressure compressors with solar panels have been used to aerate water ponds.

    This link is just an FYI... I do not know anything specific about the company or product.

    http://new.abb.com/drives/low-voltage-ac/machinery/ABB-solar-pump-drives

    Some older information from 2012:
    Help required to design off grid system (information on possibilities to connect "standard VFDs direct to solar panels) (new link 1/13/2013)
    And from a new poster, link to solar VFD (looks interesting):
    VeichiElectric said:
    u really should read this article about solar pumps: http://www.veichi.org/solar-water-pump-inverter.html.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    The key word is portable, the  definition of portable is ambiguous,.pop up a few panels to get a 2 -3hp compressor  running is not realistic, brushed, brushless, 3 phase or otherwise, it would take an array much larger than most would consider "portable ". Define portable, because anything is possible within thr confines of a description. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    If you're moving the inverter around with the compressor, the wire to get 50a any distance from the pv isn't going to be light. 2400w of pv and racking isn't really portable. If the inverter stays with the pv and you run 240v to a mobile compressor, batteries don't need to be portable?

    If it really needs to be lightweight and portable, a generator or gas driven compressor seems right.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,036 ✭✭✭✭✭
    "Portable" solar panels sort of implies freestanding panels. A good gust of wind would really ruin your day

    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,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    jgotthold said:
    We want to run a compressor directly from solar which supplies 48 Volts at 50 amps DC (2400 watts). The compressor requires 220 Volts at 9 amps (2000 watts) AC..
    Most inverters require a battery bank to function, but this is not practical as the system needs to be light weight for portability.
    What type of switcher inverter can you recommend to meet this power requirement?
    jgotthold
    There is nothing without batteries that can work as you ask.  You will need a gasoline powered compressor, or a battery pack to go with the large solar array.
    Solar power is not very "dense".   Gasoline is extremely dense and portable,
    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 ,