How to organize power from multiple power sources?

Question

Batteries

Need a power supply circuit from multiple sources.
Example:
there is a solar panel->battery->inverter 220, this is the first source of
normal mains power, this is the second source.
The controller should take the maximum from the first source, and if it is depleted or not enough voltage, then the missing is taken from the second source.

Answer 1

What does "missing" mean? In nature, there are probably devices for switching the load to a backup source in the event of a power failure from the main one.

Answer 2

From all of the above, it follows: It is
necessary to divide the energy "by time" - the energy is taken from the solar battery and the battery charged from the battery. The battery is discharged to 50% - the relay stupidly switches the power at home to a stationary power grid. The battery is charged by a solar battery. The battery was charged up to 90% - switching back to "solar" energy.
Good relays switch quickly, such as seamless power supply due to the short switching time.
I really don't see the point of all this confusion. Have you calculated the economy? How much does equipment + consumables cost - regular replacement of batteries, and how much - saved electricity?