Many days with rain and overcast weather one needs a back up power source. The mind jumps to a generator and its cost. I have had this trouble and then there is the associated noise.
The answer is the car yes the one you drive every day connect to the battery bank and now you can push into the batteries 78 amps of power and the noise is minimal. Different cars have different alternators and power outputs. Just not enough to run the dishwasher but it will run the fridge and the air conditioner which is reverse cycle.