What equipment needed for solar panels on FX 24v inverter

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castilloj
castilloj Solar Expert Posts: 208
I just was given 8 Astropower AP-120 panels aswell as 9 Photowatt PW 1000.
Im using a outback fx 24 v inverter with 8 rolls S-600 batteries. Right now im charging my batteries by a 150k generator. but im getting ready to move to a very remote location , so itll be using a 6500kw diesel generator and i was hoping to be charging my batteries with the Solar panels aswell.
any sugestions on what extra equipment i need?
Thanks
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
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    Re: What equipment needed for solar panels on FX 24v inverter

    Looks like all you need is a couple of MPPT charge controllers.

    I would put the Astros and Photowatts on separate charge controllers.

    Could put two in series (or more) to get voltage higher, then parallel series strings depending on wire run length to panels. I'd be a little apprehensive of just single panels in parallel, particularly the Astros with their lower MPPT voltage.

    Should put in a battery monitor like a Trimetric.
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    Ok . caus i was debating about getting a outback FM60. any MPTTP models you recommend? Im really a newby on this. Also with my type of setup what wattage should i be getting? Im actually in the Carribean island of Haiti so sunny days are always the norm.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    6,500 kW generator??? That is enough to power 3,000-6,000 homes... Or is this a 6,500 Watt (or 6.5 kW) genset (depending on how you guys use "." vs "," for decimal points).

    The MorningStar 60 amp pwm controller [note: this link is wrong and points to a much less expensive PWM type charge controller The following is the correct link]: Morningstar TriStar 60 amp MPPT solar charge controller is probably the latest and greatest right now... Efficient over a wide range of input voltage and even has an internal web server (if you want one).

    The panels appear (at a quick look) that you can put 2 Astro power in series for every 1 Photowatt. And for a 24 volt battery bank, you can put 2-3 Photowatts in series to properly charge a 24 volt battery bank.

    So, depending on how far the array is from the battery shed--you would perhaps choose the 3 photowatts in series if you have to run the wiring a fair distance. If the distance is short, either 2 or 3 series panels of photowatts would be fine.

    Now, comes the mix and match issues (sorry, this is probably confusing)...
    • 2x photowatt in series (9 panels, one left over) and you can use 4x Astro power in series (2x4=8 panels)
    • 3x photo watts in series (3x3 panels = 9 total); and you could only use 6 of the astro power (1 string x 6 panels, two left over).
    Or, you can use two MPPT charge controllers (extra expense) to use all of the panels.

    Or you can purchase a few more to add the missing panels... However, with additional panels, you probably will exceed the 60 amp capacity into a 24 volt battery bank of the 60 amp MPPT charge controller--and need a 2nd charge controller anyway.

    Or, not my favorite, you could look at the Outback FM 80 controller for extra capacity.

    Wattage wise, you can start your assumption that the array+charge controller will probably output around 77% of the panel's STC rated power output (reasonable maximum power on a clear day with panels pointed somewhere near the actual sun position during the middle of the day).

    If you take other losses into account (batteries, inverters, etc.)--I would plan on a maximum average panel to 120/240 VAC output of useable power of 52% for end to end efficiency. And, if you want to be conservative (allow for growth of power usage, etc.)--planning for 33-40% end to end efficiency is not out of the question either.

    Say you have 1,800 watts of panels and average around 6.5 hours of "full sun" per day for most of the year. The estimated maximum useful AC power we would expect:
    • 1,800 watts * 6.5 hours * 0.52 eff = 6,048 WH per day (6.0 kWHr per day)
    The above is just a very rough estimate--but gives you a reasonable maximum amount of power you can draw from your system per day... There are a lot of things that will drop the efficiency to 40% or less (how you charge your battery bank, actual inverter losses, bad weather, I guessed too high on the hours of sun per day, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    Sorry i meant a 6.5 KW diesel generator. :-)
    Anyways the MorningStar 60 amp MPPT controller seems like a very economical controller especially if i can purchase 2. And they would still be cheaper than purchasing a FM80. So basically i can use all of the panels if i purchase 2 controllers, as long as each controller is assigned to the Photowatts and the other to the Astros?
    Also is there a diagram online that would show me how to wire the panels? right now the panels are connected 2 together. They used to be an a system that moved with the sun.
    Thank you very much for your Information.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    Whoa--big mistake on my part... that was the PWM 60 amp controller... This is the MPPT charge controller:

    Morningstar TriStar 60 amp MPPT solar charge controller

    About 2.5x more expensive... Sorry. :blush::cry:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    Well maybe just one wil do then , but hey its way cheaper than a FM80.
  • blackswan555
    blackswan555 Solar Expert Posts: 246 ✭✭
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    Re: What equipment needed for solar panels on FX 24v inverter

    An often overlooked and very important in your climate component, Is battery temp sensing on ALL charge sources,
    have a good one
    Tim
  • jeffkruse
    jeffkruse Solar Expert Posts: 205 ✭✭✭
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    Re: What equipment needed for solar panels on FX 24v inverter

    Can he use all the panels without damaging the CC? Then he would have the benefit of the extra panels when the light was not optimum and only loose the "extra" power he could have had if the CC could handle 80amps.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    MPPT charge controllers have the ability to regulate their output to their maximum listed/rated current... So, adding more solar panels than the controller can use is fine.

    If there where a huge amount of extra solar panels, a series fuse/breaker would be required to protect the wiring/charge controller from fire in the case of a short somewhere.

    If, for example, the charge controller is rated at 60 amp array input current, and the array has Isc>60 amps rated, then I would use 60amp*1.25=75amp or an 80 amp fuse/breaker on the input.

    And, as Tim says, get the Remote Battery Temperature Sensor option... Much better voltage/regulation of battery charging voltage. Hot batteries require a lower charging voltage (and colder batteries require a higher voltage). Charge controllers otherwise just use an estimate of the ambient air temperature as the battery voltage (and, many times, tend to guess high/hot because the controllers heat up during normal operation).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    hey guys i just found a morningstar Pro-Star 30 Solar Charge controller.
    would this work also?
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    okay so i just hooked up the panels . and on the breaker by the panels im getting
    140 v on astro panels
    270 v on photowatt
    does that seem right?
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
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    Re: What equipment needed for solar panels on FX 24v inverter

    do not connect the cc to those pvs with the voltage that high as it will blow out the cc. you may need to break those up into smaller series strings and parallel them.
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    what kind of voltage should i be getting on these?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    No--do not connect... Something is wrong. Either your connections are incorrect (series connected panels instead of parallel connections) or your meter is setup wrong/incorrect.

    If this is a PWM controller, then Voc (voltage open circuit) should be ~21 volts for a 12 volt bank or around 42 volts for a 24 volt battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    ok im now getting 49v on the astro and im getting 41v on the photowatts. also im using
    a trace c60 on each.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
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    Re: What equipment needed for solar panels on FX 24v inverter

    without reading the whole thread you are most likely with a 24v battery bank seeing as how you mention a 24v inverter in the thread title. with a straight pwm controller you will want the pvs to correspond to a voltage more appropriate for charging 24v battery banks. this is most likely around 34 or 35v on the vmp. 41v and 49v seems too high and maybe you are looking at the open circuit voltage instead of the vmp voltages? list the vmp specifications for the pvs you have and we can verify what you want to do with it.
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    those voltages i was getting directly from the panels.
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    So i purchased the "Morningstar mppt60 solar controller"
    Im just waiting to go back into haiti in 2 weeks to test it. But i was wondering , i purchased the one without an lcd display would that be ok? i was able to purchase one for $485. also is there a website that may help me get the correct voltages fixed on my panels? I was able to hook the 8 separate from the other 9 panels.
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    hey guys, how do i connect the photowatts and the astros on one mppt 60?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    Can you tell us exactly the Imp/Vmp of each panel and how many of each you have?

    Also, where will the system be installed (hot, cold, etc.).

    Also, this is still for a 24 volt battery bank?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    well i just checked the load from the panels direct. i have 8 photowatts and it gave me a voltage of 29 . The 8 astros gave me 56v. also im in a hot climate(Haiti)
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    I'm getting 14.9 on each photowatt
    And 18.8 on each astro.
    yes this is for a 24v system.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    What do you mean by getting 14.9 volts? Open circuit, on a charge controller, from Vmp=14.9 on a spec. sheet?

    In general, 15 volts vs 19 volts is a relatively large difference in Vmp between solar panels---Connecting them in series will probably lead to some inefficiencies.

    You may be able to series / parallel the sets of panels into a working array... Just need the exact rated Vmp/Imp (if you have it).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    all of these reading are open circuit. i havent installed the charge controller yet.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    Hmmm... I will have to get back to you after I look up the specifications later today when I have some time (and quiet :roll:).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    ived been afraid to hook up the mppt controller in fear that im gonna burn it if the voltage from the panels is wrong.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    Not really a problem... Your MS MPPT 60 amp controller can take Voc (Voltage open circuit) of 150 VDC maximum... You can hook your array up and to easily 100-120 volts DC (reading from your meter) and connect it to the Charge Controller very safely.

    Connect 4 of the PhotoWatts in series... That should give you around 60 VDC open circuit voltage... The minimum input to the MPPT controller for a 24 volt battery bank should be around 30-32 volts or so (needed to properly charge your battery bank).

    You can connect each set of 4 series panels to the controller and read the voltage/current from them (and write it down) in full sun (if the battery is less than ~80% charged, the controller should be in MPPT mode pulling as much power from the panels as it can).

    Once you get the operating voltage/current from each string we can look at how to optimally connect them together.

    By the way, is the the PW 1000 panels you have (PDF)?

    And the AP-120 Data Sheet?

    Your voltage readings do not quite match what these panels should output as Voc (voltage open circuit--i.e., measured with a voltmeter in sunlight).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    Ok so i connected 4 astros in series and im currently getting 18.7 v
    on the photowatts im getting 28.7. Both connected in series at 8:42 am haiti time.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: What equipment needed for solar panels on FX 24v inverter

    Hmmm...

    That does not make sense... Are you sure?

    Series connections is stacked + to - to + to -, etc.... Like stacking 2, 3 or more D Cell batteries in a flashlight. And the voltage should add with each additional panel:
    • 4 x 18.7 volts = 74.8 volts
    Placing cells in parallel will keep voltage the same, but add current from each panel...

    You might try each group of 4 panels separately--And write down the Vmp/Imp as displayed from the controller... You might have a bad panel in there somewhere.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castilloj
    castilloj Solar Expert Posts: 208
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    Re: What equipment needed for solar panels on FX 24v inverter

    ok i just re checked the wiring , and im now getting 64-65 on the photowatt
    and 54-56 on the astros.
    and i guess its fluctuating because its getting cloudy.
    also just to clarify , im checking these voltages straight from the panels before going into a breaker. then from the breaker i ran wire to connect it to controller( but havent connected yet)