beep boop

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Joined 1 year ago
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Cake day: July 1st, 2023

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  • For a house of 6 people we installed 5kWh which is basically perfect for them, but they are also very resourceful with their electricity usage, running washing, cleaning and cooking during the day as to not drain the battery at night.

    But yeah if you dont get enough sun in your area its just a waste of money. My parents system will be payed off after 11 years if the sun stays at the level it has been at for the past 2 years.

    Predicting how import vs export costs might develop is also a big factor


  • I edited my comment and added a screenshot from my grafana dashboard to show the trend over the year and some other numbers. Batteries are expensive but they are worth imo. ~75% of the electricity usage of this house with 6 people comes from its own solar production. There is however a cut off for how much battery capacity makes sense. To get the last 20% of self sufficiency you would need a disproportionally larger battery to make up for long periods of low sun. so 80% is as good as its gonna get while staying cost effective.


  • There are web calculators where you put in your latitude, angle of the panels and total kWp of your installation. It then spits out a kWh prediction for the year. Might still be shitty to find a good one tho. I can tell you that the system i installed at my parents house with 10 kWp has produced 8.4MWh of AC output this year. I live in southern Germany which is around 48° latitude and it was pretty gray and rainy this summer so could be much better.

    This is daily total generation in kWh split up by how much went into the battery vs directly into live usage in the house vs exported to the grid.

    This shows the sources of all the electricity that the house used over the year on any given day. Red being imported electricity.