The supply of electrical power from the socket is not guaranteed everywhere and at all times. This is especially true in remote locations and for mobile applications. But the seamless availability of charging points is also lacking in e-mobility.
Most of the time, we are dependent on energy storage devices, which supposedly are charged with CO2 cheaply using regenerative sources (solar, wind). However, it happens that these become empty. However, an oversized design of the regenerative sources is not sustainable, due to the associated costs and the CO2 footprint absorbed during production.
In e-mobility, too, attempts are being made to counteract the lack of range with ever larger battery packs. Although a reasonable concept of suitable engine power, well-dimensioned battery size in combination with an affordable hybrid system would achieve the lowest CO2 footprint.
MOTTO: "Give somthing back!"
An application-specific solution, taking into account the local boundary conditions, has to be optimally designed.