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Thread: Newbie with a question!

  1. #1
    Junior Member
    Join Date
    Mar 2012
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    Default Newbie with a question!

    Hi all!

    I've currently got a 2.4kW PV system installed on my property in the UK. I'm trying to work out how many kWh/year it'll generate but am struggling with the equations I've read.

    From the SAP 2005 calculations, it states the generation = 0.75 x kW(peak) x S x Zpv

    where S is the irradiance and Zpv is the overshading factor, being 1126 and 1 respectively.

    The problem I'm having is where does the solar panel efficiency come in to the equation? My panels are rated at <16% according to the specification sheets.

    Sorry for the question, any help would be greatly appreciated.

    Thanks!

  2. #2
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    Jul 2009
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    Default

    Quote Originally Posted by emJayOwen View Post
    From the SAP 2005 calculations, it states the generation = 0.75 x kW(peak) x S x Zpv

    The problem I'm having is where does the solar panel efficiency come in to the equation? My panels are rated at <16% according to the specification sheets.

    Thanks!
    The panel efficiency is already accounted for in the kW(peak)

  3. #3
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    off grid retirement in Northern Calif
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    I would just use PV watts http://www.nrel.gov/rredc/pvwatts/ which uses 20 years of weather data, and you just enter your panel / array info.
    Since the dawn of time it has been mankind's dream to blot out the sun.
    Montgomery Burns

    "Always listen to experts. They'll tell you what can't be done and why. Then do it."

    spreadsheet based voltage drop calculator:
    http://www.solar-guppy.com/download/...calculator.zip
    http://www.solarpaneltalk.com/showth...oss-calculator

    http://www.mike-burgess.org/PVinfo_2.html

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,
    battery lugs http://tinyurl.com/LMR-BigLug
    Setting up batteries http://tinyurl.com/LMR-NiFe

    gear :
    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 || || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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