This chapter examines modular systems for energy usage in vehicles. While major emphasis is placed on automobiles, the chapter also looks at in detail advanced modular power system management and distribution for affordable, supportable multi-vehicle space mission. In this regard, modular power generation and storage technologies such as solar array technology, fuel cell, and battery technologies are examined. The chapter also evaluates modular ship energy storage. For automobiles, the chapter examines modular fuel cell and fuel cell stack systems. Energy technology changes in modular automobiles are briefly assessed. The chapter also examines innovative modular integrated energy systems where power is exchanged between a house and automobile. In this regard, modular Verd2GO–EV connection is evaluated in detail. Finally, the chapter examines in detail the use of solar energy for modular, car, taxi, rapid transit systems, space vehicles, airplanes, ships, boats, and two wheelers. This usage is rapidly expanding all over the world.