The 230 V power just is connected to the mains.

Up to 800 W rated inverter power you don’t need a permit under current german law.

If I do not use the power in my house it will just flow back into the electrical grid.

For EV charging this shed produces not enough power. Charging the Twizy would need 3 days with optimal sun. Charging the Tesla about four weeks.

But there is a separate 10500 Wp solar array on the house and an energy management system which controls everything charging. See OpenWB on how this can be done.

• Renault EV hacked with OVMS and mostly running on locally produced electricity. Runs 80 km/h, seats two and always finds a parking spot.
• Kon-Tiki Oven to produce bio charcoal which we use a lot to make our soil somewhat less compact.
• Small Solar Power Roofs to keep the rain or the sun away when sitting on the bench (one can be seen behind the car).
• Total of about 50 kWp Solar, which we enjoy a lot - produces reasonable energy even during the Winter. Unfortunately, when the grid goes down, our own solar will go down also. People often underestimate the effort and investment needed to make a large solar system workable off-grid.

• New facade with about 25 cm of insulation made from wood fibre. All materials locally sourced, mostly from our own grounds. Keeps the building cool in summer and warm in winter.
• OpenWB EV charging of EV only when we have excess solar production.
• Rain water is not sent into the city collection system but kept on the grounds and further down is collected in a little lake.
• Cheap Solar Lights with motion detectors. Help a lot to not tip over during the night - even works reasonable during winter when the days are very short.

• Home-grown power management system: In winter we use excess energy to heat up the workshop ensuring it does not freeze during the night (if that’s not enough, and it cools down below 1 C we automatically use grid power to keep it from freezing.
• The fridge for the drinks is only run on excess power.
• Well insulated workshop build beside the house, providing additional insulation to the living quarters.

• Reactivated the old well, added a manual frost resistant water pump
• We are looking into using solar power to fill the reservoir from the well on demand. But this will need some trench digging.
• AirPods Pro or any other good noise-cancelling equipment to avoid getting def and dumb by roaring farm machinery.
• We have a shepherd’s wagon without any electricity. Basic services like warmth, light, coffee and pizza can be provided by fossil means.
• We have something like a tiny house completely running on off-grid on solar: electric stove, baking oven, warm water, floor heating, etc. Works very well for 10 years now.