Grid tie inverter

Discussion in 'General Electronics Chat' started by 3ldon, Jan 17, 2010.

  1. 3ldon

    Thread Starter Active Member

    Jan 9, 2010
    Having short circuited my feeder before, I can tell you the impedance is on the order of a tenth of an ohm. also there is about 10% voltage drop on a 10 KVA load.
    Also keep in mind that the meter running backwards is running off your voltage, so it don't matter.
    I think most states are on to the fact that RE people want to use it as a big battery, so they now force you to have a separate meter and they pay you the wholesale rate.
    At one point it was sorta legal to back feed the grid with grid commutated inverters, or induction generators, and they make exceptions for 4 quadrant motor controllers, as they are inherently intermittent, but the regulations have been getting retarded since 2003-2005

    Unless you know for sure you can make that grid ti inverter pay for itself, i would look into lithium battery storage, its now on par with lead acid for cost effectiveness (depending on who you ask), and they require less maintenance.
  2. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    It's easier to understand if you think in terms of "power flow", not potential difference.

    So if your home lighting is consuming 1000W and your grid tie is generating 800W, then there is still a power flow of 200W coming into your house from the grid, and technically your grid tie is NOT supplying any power back to the grid (no power flow back to the grid).

    It's a crude analogy but it's a good enough way to wrap your head around it.

    AAC Fanatic!

    May 15, 2009
    I have to disagree very seriously with "thingmaker3" on the bit about hunderds of amps times at few millivolts etc. Has this man ever heard of ohms law? Amps, (flow of current) is a function of the potential difference over the load ( resistance) With some mods for AC.
  4. someonesdad

    Senior Member

    Jul 7, 2009
    I think thingmaker3 knows exactly what he's talking about, as 100 A times 0.001 Ω is 0.1 V. I'd say his comment indicates he is very aware of Ohm's law -- you, however, may want to review your knowledge of it.
  5. davidgstoll

    New Member

    Jan 17, 2010
    Hi gregtomko,
    Did you ever find someone to answer your inverter efficiency questions? I, too, would like to know whether the inverter needs to be a higher voltage, and if so, how much higher, i.e., what the optimum voltage difference should be to obtain maximum efficiency.
  6. beenthere

    Retired Moderator

    Apr 20, 2004