Solar panel actual outputs

Discussion in 'Solar Power' started by manda3000gt, Nov 9, 2014.

  1. manda3000gt

    manda3000gt Funster

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    I was wondering on actual outputs from solar setup's at different times throughout the year, especially later/ earlier in the year as less sunlight is available,
    As an observational experiment
    Size of solar panels fitted (watts):
    Type of charge controller PWM or MPPT:
    Time of day (prob best around midday)
    Weather conditions:
    Location in the UK:


    Amp figure actually being generated by solar shown on the charge controller not on a battery NASA type monitor that would deduct amps being drawn off

    Today with:
    560w of panels
    PWM charge controller
    11:55 am
    Clear & bright
    10 miles south of Doncaster, South Yorks
    7.8amps
     
    Last edited: Nov 9, 2014
  2. JJ

    JJ Funster

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    When I first got my first solar panel I used to spend hours pressing buttons to see how many amps and volts were going in and out...

    Now, years later, I just switch on the light/pump/computer and if it works all is well.

    If it doesn't work I don't know what I'll do because it hasn't happened yet... probably just fire up the whisper quiet Kipor...


    JJ :cool:
     
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  3. wizzer59

    wizzer59 Funster

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    Scuse me? can you repeat that, didn't quite hear you:wink:
     
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  4. Wildman

    Wildman Read Only Funster

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    if your solar is outputting 7.8 amps your batteries must be pretty flat to start with.
     
  5. manda3000gt

    manda3000gt Funster

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    ??? Would have thought whatever state of charge batteries are at would have no bearing on what the solar panels generate, whether the charge controller puts any available charge into the battery's depends on their state of charge. If battery's are fully charged at midday the panels are still going to generate their max output.
     
  6. Techno

    Techno Funster Life Member

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    My solar today (grey sky) with inverter running, 11:30a.m. best 1.7 amps from 300 watts.
    A clear sky from experience at this time of year 6 amps.
    February near 10 amps
    Best 6 months up to 21 amps
     
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  7. manda3000gt

    manda3000gt Funster

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    Showing 1.7 on a battery monitor ? So a net figure after what your inverter is drawing off or 1.7 on charge controller so is gross being produced by panels ?
     
  8. Wildman

    Wildman Read Only Funster

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    the panels do operate at max output however the regulator adjusts the input to batteries relative to rate of charge. It is the input amps that my solar regulator displays it can only read amps being passed if they remained at full output then the regulator would not be working.
    The meter will show max VOLTAGE that the panel is producing but current (amps) depends on the rate of flow to the batteries, no flow, no amps being produced.
     
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  9. Techno

    Techno Funster Life Member

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    No showing 1.7 on regulator i.e. the most the sky could deliver in said light or lack of it.
    However my solar battery bank is 500ah so it is not a problem to use it in short bursts.
     
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  10. manda3000gt

    manda3000gt Funster

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    Today with:
    560w of panels
    PWM charge controller
    12:30pm
    Clear & bright
    Newark Showground
    6.4amps
     
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  11. funflair

    funflair Funster Life Member

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    Our solar computer thingy that is connected to the regulator only shows what is going into batteries.

    As far as output 320 watts at this time of year = not a lot, mid summer = 20+
     
  12. Dazzlin

    Dazzlin Funster Life Member

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    What's the best/cheapest way of monitoring amps.
    I have a solar controller with no display, only led for 80% or full. On the inverter it has a voltage which I know is not the most accurate and only gives state of charge ie 12.6-14.4.
    Can I use this multimeter on the solar inputs into the controller? If so, on what setting? 20141230_172157.jpg
     
  13. Bartyfixedit

    Bartyfixedit Funster

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    Two days ago.
    Full sun, middle of the day near Newbury.
    Battery bank at 70%.
    MPPT outputting 4A at 13.1V with 300W of panels.
    Battery monitor showing -2A as compressor fridge freezer was running at the time.
     
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  14. andy63

    andy63 Funster

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    just fitted a 100w panel with a 10a mppt controller.
    today with no sunshine but clear skies it was showing .3A to .5A with a battery voltage of 12.7 /12.8 V
    no idea what to expect but panel max current is around 5.6 amps I think.
    its working anyway lol and hope its been worth the bother
    ta andy
     
  15. John Laidler

    John Laidler Funster

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    You could wire it in series with the panels and on a dc current setting it will tell you what current the panels are generating, but on its own this doesn't tell you much as I think all you want to know when not on EHU is whether the batteries are being charged or discharged.

    Figures such as those given in the OP are on their own pretty meaningless without knowing if the current figure is meeting the load or not, if the latter the batteries will be being drained and will eventually become flat. Conversely, if the entire current is going into the batteries then they were either pretty flat to begin with or there is a fault somewhere and they are going to be boiled dry.

    Put another way, if the batteries are well charged and the load is zero or negligible then it will seem as if the solar panels aren't working as little current would be measured coming from them. In these circumstances the solar controller, be it an MPPT or shunt type will effectively isolate the panels from the circuit.

    A typical MPPT controller will have separate terminals for the load and battery and can thus give you information on were the current is going but large capacity MPPT controllers are not cheap. A lower cost option would be one of these:
    http://www.seamarknunn.com/acatalog...Zkn31JARIYC0SpMVoVYKdJBoCGrvw_wcB#.VKLl1II-XA

    Still not cheap and it will only tell you whether the batteries are being charged or discharged and what the current is but what else do you want to know?
     
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  16. Don Quixote

    Don Quixote Funster

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    I have the Victron BMV 600S - This is by far the best thing for monitoring everything about your 12 volt system.

    When I first fitted it I watch it more than the TV. Also has an alarm system which can be user set for when batteries reach a low level. Well worth the money and easy to fit provided your follow the diagram.
     
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  17. Peter A Forbes

    Peter A Forbes Funster

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    Most if not all controllers have two output current paths, one to the battery and one to the load.

    The battery is also connected to the loads that are not routed through the load terminals but go direct.

    A centre-zero panel ammeter, analogue or digital will show current flow in and out of the battery if it is wired into the positive or negative lead of the battery so that ALL charge and discharge currents flow through it. For high capacity batteries with inverter loads a shunt may be required as the meter is not normally rated fior much more than 10A or so.

    Solar panel output at this time of year is pretty low, bearing in mind that quoted maximum figures are under ideal conditions, not an English winter day.

    If the battery is fully charged, the solar controller will reduce the charge to the battery to prevent it being overcharged. There will still be power available but the battery cannot take any more, so the power isn't used.

    Peter
     
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