Picture this. You have a motor turning an output generator, and the generator is producing enough energy to keep the motor running, as well as enough left over to power other things. (It's a little more complicated, but that is the general idea.)
And it's all built from off-the-shelf, readily-available components that are well-engineered for long duration running, and which have the needed certifications for power output suitable for home power.
This system generates power with NO fuel NO charging and little upkeep.
I know, it sounds crazy. But it works. Or at least that is the aim.