Grid tied system that wont feed surplus energy to grid?

I am looking for a residential grid tied PV system that wont feed ac energy to the external grid.

Whenever the solar cells produces more energy than my house consumes, I would not want that surplus energy to be fed to the external AC grid. I would want that energy to go to some kind of variable heat load to heat a pool of water.

Any suggestions for a setup?

I live in Sweden and I've been granted a subsidy for a PV system. It must be grid tied, but it need not actually supply any energy to the external AC grid. I will get no compensation for energy fed to the external grid.


  • solar_davesolar_dave Solar Expert Posts: 2,380 ✭✭✭✭
    Re: Grid tied system that wont feed surplus energy to grid?

    This is a control problem, You need to be able to measure the amount you back feed and then just figure the amount of time near the end of the month to fire up the heater to burn off the amount you back fed the grid.

    You could probably do this manually but an automated system would be preferred I assume.
  • BB.BB. Super Moderators, Administrators Posts: 31,471 admin
    Re: Grid tied system that wont feed surplus energy to grid?

    Can you legally connect to the Grid with a GT inverter? Will they allow your meter to turn backwards but will not credit any power for you at the end of the month? In the US, there are some utility meters configured so they only turn forward... And if you feed power to the grid they actually charge you retail power rates as if you where using the power instead of generating it.

    Is this for heating a swimming pool? Generally, using solar thermal panels (and electric pumps) would be a more efficient way to heat a swimming pool.

    I am not sure if there is a system that can do this or not. Normally, Grid Tied is designed to output 100% of available power to the grid.

    The Xantrex/Schneider XW Hybrid Inverter System MAY be able to do what you ask--But it is a very expensive solution for just this function (it is capable of full GT, Off-Grid inverter with battery bank and backup generator support). It does give you emergency power if the utility power fails.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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