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What is likely to happen, if anything, if I try and export to the grid and import from the grid simultaneously?

Andrew J

I have this scenario:  I want to export from a house battery to the grid during the period 23:30 to 01:00 at 3.6kW (until battery is empty.)  At the same time, I have my car plugged in charging at 7kW.  Would that have the net effect of pulling 3.4kW from the grid?  Is anything likely to fail?

As a basic summary, I can charge my house battery up at 7p from 23:30 to 05:30 and discharge it to the house during the rest of the day, thus I pay only 7p for electricity used.  I don't fully discharge the battery during this period so I can sell the remaining charge back to the grid at 15p before fully charging up again ready for the day.  However, I also need to charge my car up which I also do 23:30 to 05:30 - Note because of the tariff I am on I have NO control over when the charging actually occurs so I cannot configure it to avoid the time period where the house battery is discharging.  Re-configuring the battery to not discharge when I plug the car in is a laborious process which I want to avoid.  I only actually charge the car once or twice a week.

Parents

  •   While this sounds like a great plan, the payback won't be worth the effort.  I believe the car charging is separate from the battery storage.  You have a 6 hour window to charge your battery storage system.  How much capacity do you have?  Subtract the energy that you will use to defer buying electricity at the higher (15p) rate during the day.  The remainder is what you have the potential to make 8p per kWh.  If you have 2 kWh per day excess, you make 16p per day, less then 60£ in a year.

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  •   While this sounds like a great plan, the payback won't be worth the effort.  I believe the car charging is separate from the battery storage.  You have a 6 hour window to charge your battery storage system.  How much capacity do you have?  Subtract the energy that you will use to defer buying electricity at the higher (15p) rate during the day.  The remainder is what you have the potential to make 8p per kWh.  If you have 2 kWh per day excess, you make 16p per day, less then 60£ in a year.

Children