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  • beesley121
    Junior Member
    • Jan 2012
    • 1

    #1

    3KW system installed - not impressed with production

    Hi guys,

    Im new here, after much thought, research and advice, I decided to have a 3KW solar panel system put on my roof at the cost of 10k. It was installed on the 20th november and upto date, has produced a total of 122kw of power!! so on average 2.44kw per day. I feel this is quite low. I seem to be producing a maximum of around 1.6kwph at its peak in the day providing its not over cast and the sun is beaming. most of the time im producing under 1kwph

    is this right?? I know we are in winter and the days are shorter but even when the sun is at its peak and theres not a cloud in the sky, im still only getting 1.6kwph for say half an hour then it drops again. Surely i should get somewhere near the the 3kw im supposed to get.

    any advice much appreciated
  • Naptown
    Solar Fanatic
    • Feb 2011
    • 6880

    #2
    If the modules are not perfectly aligned with the sun meaning at your latitude they should be latitude+23 degrees for this time of year or production will be lower. So say you are like me at 39deg N lat and your panels are mounted at 22deg this means they at best will be 40 degrees off from ideal pitch. At 40 degrees off the angle of incidence is fairly high meaning that the panels are getting less light on the surface. Generally speaking don't use only the worst months of the year to judge. Your installer probably gave you a production estimate of the system but that is based on annual production.
    You could go to PVWatts and plug in your system and see what that comes up with for production for this time of year.
    NABCEP certified Technical Sales Professional

    [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

    [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

    [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

    Comment

    • russ
      Solar Fanatic
      • Jul 2009
      • 10360

      #3
      From PV Watts for London/Gatwick - closest available on PV Watts

      Seems you are in the ball park - PV Watts will be correct over a number of years though any particular year may be somewhat different.

      "Station Identification"
      "City:","London/Gatwick"
      "State:","GBR"
      "Lat (deg N):", 51.15
      "Long (deg W):", 0.18
      "Elev (m): ", 62
      "Weather Data:","IWEC"

      "PV System Specifications"
      "DC Rating:"," 3.0 kW"
      "DC to AC Derate Factor:"," 0.770"
      "AC Rating:"," 2.3 kW"
      "Array Type: Fixed Tilt"
      "Array Tilt:"," 51.2"
      "Array Azimuth:","180.0"

      "Energy Specifications"
      "Cost of Electricity:"," 0.1 pound/kWh"

      "Results"
      "Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value (pound)"
      1, 1.45, 96, 0.07
      2, 1.90, 113, 0.08
      3, 2.55, 171, 0.13
      4, 3.99, 260, 0.20
      5, 4.60, 304, 0.23
      6, 4.38, 276, 0.21
      7, 4.63, 297, 0.22
      8, 4.52, 293, 0.22
      9, 3.56, 227, 0.17
      10, 2.64, 174, 0.13
      11, 1.61, 103, 0.08
      12, 0.97, 59, 0.04
      "Year", 3.07, 2372, 1.78
      [SIGPIC][/SIGPIC]

      Comment

      • Sunking
        Solar Fanatic
        • Feb 2010
        • 23301

        #4
        Just like the restaurant biz it is about Location, Location, Location. Your location suks. Just about anywhere in Europe suks with respect to solar.
        MSEE, PE

        Comment

        • solarpowered
          Junior Member
          • Jan 2012
          • 21

          #5
          Its winter right now sun is at its lowest. Summer it should pick up better numbers.
          $10,000 for 3k of solar sounds great!

          Comment

          • Naptown
            Solar Fanatic
            • Feb 2011
            • 6880

            #6
            Originally posted by solarpowered
            Its winter right now sun is at its lowest. Summer it should pick up better numbers.
            $10,000 for 3k of solar sounds great!
            That's probably 10K euro's or pounds
            A bit more than US 10K
            NABCEP certified Technical Sales Professional

            [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

            [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

            [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

            Comment

            • Mike90250
              Moderator
              • May 2009
              • 16020

              #7
              Just for comparison, today, my 3KW system, is putting out 32 watts mid-day, in rain.

              If you don't have bright sun, perpendicular to the panels, your output will suffer. You have to measure on a bright sunny day.
              Powerfab top of pole PV mount (2) | 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

              Comment

              • Sunking
                Solar Fanatic
                • Feb 2010
                • 23301

                #8
                Originally posted by Mike90250
                You have to measure on a bright sunny day.
                I have been to England a few times both in Winter and Summer. Cannot recall ever seeing the Sun there, just gray and gloomy
                MSEE, PE

                Comment

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