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How is mains source decided?

Discussion in 'Renewable Energy' started by DaveS, Aug 9, 2012.

  1. DaveS

    DaveS New Member

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    Hi all,

    Sorry if this is a dumb question.

    In a typical solar installation we have a mains grid supply and a Solar Panel / inverter mains supply joined together. This combined mains supply supplies the house. If an excess of power is generated by the solar panel after supplying the house it is exported to the grid.

    How does the house "know" to take it's supply from the inverter first and not the grid?

    Dave.
     
  2. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    It doesn't need to 'know' anything - essentially your house is just fed from a single 'supply', the actual source makes no difference.

    Try thinking of it as always been fed from the grid, and your inverter as always feeding the grid.
     
  3. DaveS

    DaveS New Member

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    Yes, that works Nigel. Just something I'd never thought about before.

    Thanks for that.

    Dave
     
  4. dave

    Dave New Member

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  5. Jules_Theone

    Jules_Theone Member

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    But what makes the power flow from the GTI inverter onto the grid, does the inverter lead the voltage or current sinewave or the voltage from the inverter is slightly (marginally) higher?
     
  6. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Measure the on-load and off-load output voltages from an inverter, and I suspect you will have your answer :D
     
  7. debe

    debe Active Member

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    The output voltage needs to be higher than the mains for any current to flow. This also creates a problem in suburbs that have a lot of GTI solar systems, It can cause higher mains voltage.
     
    Last edited: Aug 10, 2012

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