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Measuring electricity consumption and generation

Discussion in 'Renewable Energy' started by Jules_Theone, Jun 14, 2012.

  1. Jules_Theone

    Jules_Theone Member

    Jan 22, 2009
    Exeter, England
    I am having a 4kWp solar system installed in a couple of weeks and currently have a 500W solar system grid-tied at the moment to play with and noticed that my energy monitor provided by the electricity supplier reads a positive power whether I'm consuming or generating. Is there a way to measure in realtime which direction the energy is flowing? I currently have a digital elec meter that only reads consumption (one way) and will have a digital meter to read generation but I want to know when energy is flowing out onto the grid (so I can try to use it locally).

    I have tried both an AC ammeter and AC current clamp meter on the output of the GTIs and on loads but it's always positive. Is there only way to do it is to have two ammeters (clamp meters), one on the generation only line and one of the consumption only line and subtract one from the other?


  2. johansen

    johansen Member

    Mar 11, 2009
    buy an old wattmeter off ebay for 20$.

    rewind the current sense coil for 2x 10 turns instead of 2 turns to make it more sensitive, typically its 7.2 watt hours per revolution, and if the meter's lowest dial is KWH x10 then you'll have to wait 10 hours to get an accurate number. so just rewind it for 10 turns and its easier to read.

    did you contact the electric company about grid tying your solar?
    if not, you're probably getting billed for the power going into the grid too..

    the industry is moving to separately metered grid tie, and they only pay you the industry rate, which is typically half or one third the residential rate

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